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Flashcards in Telencephalon Deck (507)
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1
Q

Number of Brodman areas

A

47

2
Q

6 layers of cerebral cortex

A

Molecular

External granular

External pyramidal

Internal granular

Internal pyramidal

Multiform

3
Q

Agranular cortex

A

Frontal lobe

Dominated by pyramidal rather than granular layers

4
Q

Granular cortex

A

Parietal sensory cortex

5
Q

Functions of non dominant hemisphere

A

Visual and spatial perception

Visual (non-language dependent) memory

6
Q

Functions of dominant hemisphere

A

Language

Language dependent hemisphere

7
Q

Wada test

A

Can be used to demonstrate hemispheric dominance.

Injection of sodium amytal into the ICA.

On the dominant side this will cause an arrest of speech for up to 30 seconds.

May be useful prior to temporal lobectomy when there is doubt over hemispheric dominance

8
Q

Key gyri on the lateral surface of the frontal lobe

A

Superior frontal gyrus

Middle frontal gyrus

Inferior frontal gyrus (pars triangularis, pars orbitalis, pars opercularis)

Precentral gyrus

9
Q

Key sulci on lateral surface of frontal lobe

A

Superior frontal sulcus

Inferior frontal sulcus

Pre-central sulcus

10
Q

Key gyri on superior view of frontal cortex

A

Superior frontal gyrus

Middle frontal gyrus

Inferior frontal gyrus

Precentral gyrus

11
Q

Key sulci on superior view of frontal lobe

A

Superior frontal sulcus

Inferior frontal sulcus

Precentral sulcus

12
Q

Key gyri on medial view of frontal lobe

A

Superior frontal gyrus

Paracentral lobule

Cingulate gyrus

13
Q

Key sulci on medial surface of frontal lobe

A

Cingulate sulcus

14
Q

Key gyri on orbital view of frontal lobe

A

Gyrus rectus

Medial orbital gyrus

Anterior orbital gyrus

Posterior orbital gyrus

Lateral orbital gyrus

15
Q

Key sulci on orbital surface of frontal lobe

A

Olfactory sulcus

Orbital sulcus

16
Q

Function of precentral gyrus

A

Motor cortex.

Contralateral movement of face, arm, leg, trunk

17
Q

Lesion to this area would result in?

A

This is the precentral gyrus

Monoplegia or hemiplegia depending on extent of damage

18
Q

Function of Broca’s area (dominant hemisphere)

A

Expressive centre for speech

19
Q

Lesions to this area would result in?

A

Dominant hemisphere:

Broca’s dysphasia (motor or expressive)

20
Q

Function of SMA

A

Motor planning

21
Q

Consequences of lesions affecting this area

A

SMA

Paralysis of head and eye movements to the opposite side.

Head turns and looks towards the diseased hemisphere and eyes look in the same direction

Hypokinetic mutism

22
Q

What makes up the prefrontal areas?

A

Vast parts of the frontal lobes anterior to the motor cortex as well as orbital part of frontal lobes

23
Q

Causes of prefrontal damage?

A

Often bilateral e.g. infarction, following haemorrhage from ACommA, neoplasm, trauma or frontal dementia resulting in a change of personality with antisocial behaviour/loss of inhibitions

24
Q

What are the three prefrontal syndromes?

A

Orbitofrontal syndrome

Frontal convexity syndrome

Medial frontal syndrome

25
Q

Feeatures of orbitofrontal syndrome

A

Disinhibition

Poor judgement

Emotional lability

26
Q

Features of frontal convexity syndrome

A

Apathy

Poor abstract thought

27
Q

Features of medial frontal syndrome

A

Akinetic

Incontinent

Sparse verbal output

28
Q

Additional associations of prefrontal lesions

A

Primitive reflexes e.g. grasp, pout

Disturbance of gait

Resistance to passive movement of limbs- paratonia

29
Q

Function of paracentral lobule

A

Cortical inhibition of bladder and bowel voiding

30
Q

The consequence of a lesion to this area

A

Loss of cortical inhibition of

Incontinence of urine and faeces

Particularly likely with hydrocephalus and is an important symptom in NPH

If involving motor/sensory leg may also have monoparesis and sensory disturbance in the contralateral lower limb.

31
Q

Key structures of parietal lobe

A

Post central gyrus

Superior parietal lobule

Inferior parietal lobule (angular gyrus and supramarginal gyrus)

32
Q

Key sulci of parietal lobe

A

Post-central sulcus

Intraparietal suclus

Parieto-occpital sulcus

33
Q

Function of post-central gyrus

A

Sensory cortex receives afferent pathways for appreciation of posture touch and passive movement

34
Q

Function of supramarginal and angular gyri (dominant hemisphere)?

A

Constitue Wernicke’s language area

This is the receptive area where auditory and visual aspects of comprehension are integrated

35
Q

Function of non-dominant parietal lobe

A

Important in concept of body image and awareness of external environment

The ability to construct shapes etc. results from such visual or proprioceptive skills

36
Q

Optic radiation and parietal lobe

A

Fibres of lower visual field pass through the parietal lobe

37
Q

Function of dominant parietal lobe

A

Implicated in the skills of handling numbers/caclulation

38
Q

Consequence of lesions to postcentral gyrus

A

Will result in cortical disturbance of sensation:

Postural

Passive movement

Accurate localisation of light touch

Two-point discrimination

Astereogenesis

Perceptual rivalry (sensory inattention)

39
Q

Astereognosis

A

Difficulty appreciating tactile size, shape, texture and weight of objects

40
Q

Consequence of lesions to supramarginal and angular gyri

A

Wernicke’s dysphasia

41
Q

Pathology in which lobes is commonly associated with seizures?

A

Frontal and temporal

42
Q

Name structures on the left side of the image

A
43
Q
A
44
Q

What are the five segments of the internal capsule?

A

Anterior limb

Genu

Posterior limb

Sublenticular segment

Retrolenticular segment

45
Q

Components of the anterior limb of the internal capsule

A

Frontopontine

Thalamocortical

Corticothalamic

Caudatoputamenal

46
Q

Components of the genu of the internal capsule

A

Corticobulbar fibres

Corticoreticulobulbar fibres

47
Q

Components of the posterior limb of the internal capsule

A

Corticospinal

Corticorubral

Corticothalamic

Thalamocortical

48
Q

Components of the sublenticular segment of the internal capsule

A

Auditory radiations

Optic radiations

Corticopontine fibres

49
Q

Components of the retrolenticular portion of the internal capsule

A

Optic radiations

Corticotectal fibres

Corticonigral fibres

Corticotegmental fibres

50
Q

Consequence of dominant hemispheric parietal lesion?

A

Confusion of right and left limbs,

Difficulty in distinguishing fingers on hand (finger agnosia)

Disturbance of calculation (acalculia)

Disturbance of writing (agraphia)

Constitutes Gerstmann’s syndrome

51
Q

Gerstmann’s syndrome

A

Finger agnosia

Agraphia

Acalculia

Left-right disorientation

52
Q

Gerstmann’s syndrome, which part of the brain

A

Dominant parietal lobe

53
Q

Consequence of damage to parietal optic radiation?

A

Inferior homonymous quadrantopia

54
Q

Key gyri on the lateral view of temporal lobe?

A

Superior

Middle

Inferior temporal gyrus

55
Q
A
56
Q

Key gyri on inferior view of temporal lobe?

A

Inferior temporal gyrus

Fusiform (temporo-occipital gyrus)

Parahippocampal gyrus

Lingual

Uncus

57
Q

The function of temporal lobe

A

Auditory cortex:

Dominant hemisphere- hearing of language

Non-dominant hemisphere- hearing of sounds/music

Middle and inferior temporal gyri are involved in learning and memory

Limbic lobe: inferior and medial portions of the temporal lobe including the hippocampus and parahippocampal gyrus

Visual pathways pass deep in the temporal lobe around the posterior horn of the lateral ventricle

58
Q

Location of the auditory cortex

A

Lies on the upper surface of the superior temporal gyrus, buried in the lateral sulcus (Heschl’s gyrus)

Brodmann 41, 42

59
Q

Where do the olfactory nerve fibres terminate?

A

Uncus

60
Q

Impairment of temporal lobe function:

Auditory cortex

A

Cortical deafness- rare as requires bilateral lesions but the patient may develop complete deafness and be unaware

Lesions which involve the surrounding association areas may result in difficulty in hearing spoken words or appreciating rhythm or music (Amusia)

Auditory hallucinations may occur in temporal lobe disease

61
Q

Impairment of temporal lobe function

Middle and inferior temporal gyrus

A

Disturbance of memory and learning

Complex partial seizures

62
Q

Impairment of temporal lobe function:

Limbic lobe

A

Complex partial seizures

Aggressive or antisocial behaviours

Inability to establish new memories

63
Q

Damage to temporal part of optic radiation

A

Upper homonymous quadranatopia

64
Q

Dominant hemisphere temporal lobe lesion

Speech disturbance

A

Wernicke’s dysphasia

65
Q

Location of the visual cortex?

A

Lies along the banks of the calcarine sulcus, this area is referred to as the striate cortex

Above and below this lies the parastriate cortex

Brodman area 17

66
Q

Striate cortex=

Parastriate cortex function

A

Primary visual cortex

When stimulated relays information to the parastriate cortex which is the association visual cortex.

67
Q

Consequence of cortical lesion affecting occipital lobe

A

Homonymous hemianopia with or without the involvement of the macula depending on the posterior extent of the lesion.

When only the occipital pole is affected, a central hemianopia field defect involving the macula occurs with a normal peripheral field of vision.

68
Q

Cortical blindness

A

Extensive bilateral cortical lesions of the straite cortex will result in cortical blindness.

In this, the pupillary light reflex is normal despite the conscious perception of the presence of illumination

69
Q

Anton’s syndrome

A

Cortical lesion affecting both striate and parastriate regions affects the interpretation of vision.

The patient is unaware of his visual loss and denies its presence. This denial in the presence of obvious blindness is Anton’s syndrome

70
Q

Causes of cortical blindness

A

May occur in vascular disease (PCA infarct) but also follows hypoxia and hypertensive encephalopathy or after surviving tentorial herniation

71
Q

Balint’s syndrome

A

Triad:

Simultagnosia- can see trees but not forest can test with Ishihara colour plates- will see colour but not the number

Optic ataxia- mislocalisation in space, hold a pen out they will miss but they can touch their own finger

Oculomotor apraxia- difficulty with visual pursuit, difficulty initiating

The inability to direct voluntary gaze associated with visual agnosia (loss of visual recognition) due to bilateral parieto-occipital lesions.

https://www.youtube.com/watch?v=A8BD5liH7ug

72
Q
A

Posterior ramus of lateral sulcus

73
Q
A

Post-central sulcus

74
Q
A

Ascending ramus of lateral cerebral sulcus

75
Q
A

Pars triangularis

76
Q
A

Parieto-occipital sulcus

77
Q

Cause of prosopagnosia

A

Patient unable to identify familiar face

Usually causd by bilateral lesions at occipito-temporal junction

78
Q

Name structures 1-10

A
  1. Longitudinal fissure of cerebrum.
  2. Superior margin of cerebrum.
  3. Frontal pole.
  4. Superior frontal sulcus.
  5. Inferior frontal sulcus.
  6. Precentral sulcus.
  7. Central sulcus.
  8. Postcentral sulcus.
  9. Intraparietal sulcus.
  10. Parieto-occipital sulcus.
79
Q

Name structures 11-20

A
  1. Transverse occipital sulcus.
  2. Occipital pole.
  3. Superior parietal lobule.
  4. Inferior parietal lobule.
  5. Postcentral gyrus.
  6. Paracentral lobule.
  7. Precentral gyrus.
  8. Inferior frontal gyrus.
  9. Middle frontal gyrus.
  10. Superior frontal gyrus
80
Q

Name structures 1-10

A
  1. Central sulcus.
  2. Precentral gyrus.
  3. Precentral sulcus.
  4. Superior frontal gyrus.
  5. Superior frontal sulcus.
  6. Middle frontal gyrus.
  7. Middle frontal sulcus.
  8. Frontal pole.
  9. Orbital gyri.
  10. Olfactory bulb.
81
Q

Name structures 11-20

A
  1. Olfactory tract.

12–14. Lateral sulcus.

  1. Anterior ramus.
  2. Ascending ramus.
  3. Posterior ramus.
  4. Frontal operculum.
  5. Frontoparietal operculum.
  6. Superior temporal gyrus.
  7. Middle temporal gyrus.
  8. Superior temporal sulcus.
  9. Inferior temporal sulcus.
82
Q

Name structures 21-30

A
  1. Inferior temporal gyrus.
  2. Preoccipital notch.
  3. Occipital pole
  4. Transverse occipital sulcus.
  5. Inferior parietal lobule.
  6. Intraparietal sulcus.
  7. Superior parietal lobule.
  8. Postcentral sulcus.
  9. Postcentral gyrus.
  10. Supramarginal gyrus.
83
Q

Name structures 31-36

A
  1. Angular gyrus.
  2. Pons.
  3. Pyramid (medulla oblongata).
  4. Olive.
  5. Flocculus.
  6. Cerebellar hemisphere.
84
Q

Name structures 1-10

A
  1. Longitudinal fissure of cerebrum,
  2. Cingulate sulcus.
  3. Cingulate gyrus.
  4. Sulcus of corpus callosum.
  5. Corpus callosum.
  6. Lateral sulcus.
  7. Claustrum.

8–9. Corpus striatum.

  1. Caudate nucleus.
  2. Putamen.

9–10. Lentiform nucleus.

  1. Globus pallidus.
85
Q

Name structures 11-19

A
  1. Thalamus.
  2. Subthalamic nucleus.
  3. Mamillary body.
  4. Amygdala.
  5. Optic tract.
  6. Third ventricle and choroid plexus.
  7. Body of fornix.
  8. Lateral ventricle and choroid plexus.
  9. Cortex of insula.
86
Q

Name structures 1-10

A
  1. Frontal pole of frontal lobe.
  2. Medial frontal gyrus.
  3. Cingulate sulcus.
  4. Sulcus of corpus callosum.
  5. Cingulate gyrus.
  6. Paracentral lobule.
  7. Precuneus.
  8. Subparietal sulcus.
  9. Parieto-occipital sulcus.
  10. Cuneus.
87
Q

Name structures 11-20

A
  1. Calcarine fissure.
  2. Occipital pole of occipital lobe.

13–16. Corpus callosum (cut surface).

  1. Rostrum.
  2. Genu.
  3. Body.
  4. Splenium.
  5. Lamina terminalis (cut surface).
  6. Anterior commissure (cut surface).
  7. Septum pellucidum.
  8. Fornix.
88
Q

Name structures 21-30

A
  1. Tela choroidea of third ventricle.
  2. Choroid plexus of third ventricle (cut edge).
  3. Transverse cerebral fissure.
  4. Thalamus.
  5. Interthalamic adhesion (cut surface).
  6. Interventricular foramen of Monro.
  7. Hypothalamus.
  8. Suprapineal recess and pineal body (cut surface).
  9. Vermis of cerebellum (cut surface).
  10. Cerebellar hemisphere.
89
Q

Name structures 31-40

A
  1. Choroid plexus of fourth ventricle.
  2. Medulla oblongata (cut surface).
  3. Fourth ventricle.
  4. Pons (cut surface).
  5. Tectal lamina (cut surface) and mesencephalic aqueduct of Sylvius.
  6. Mamillary body.
  7. Oculomotor nerve.
  8. Infundibular recess.
  9. Temporal lobe lateral occipitotemporal gyrus (fusiform gyrus)
  10. Rhinal fissure.
90
Q

Name structures 41-44

A
  1. Hypophysis (cut surface) with adenohypophysis (anterior lobe) and neurohypophysis (posterior lobe) of the pituitary gland.
  2. Optic chiasm (cut surface).
  3. Optic nerve.
  4. Olfactory bulb and tract.
91
Q

Name structures on the right side of the image

A
92
Q

Age of cells in more superficial layers of cerebral cortex

A

Younger, they pass superficially and form connections with the cells they pass.

93
Q

Neuronal cell morphology

A

Stellate, fusiform, pyramidal

94
Q

Allocortex

A

Three layers, located in the olfactory cortex, hippocampus and dentate gyrus

95
Q

External pyramidal layer projections

A

Commissural and ipsilateral cortico-cortical association fibres

96
Q

Internal pyramidal layer projections

A

Main efferents to the brainstem and spinal cord

97
Q

Broadman area

123

Location

A

Post-central gyrus

98
Q

Broadman area

123

Functional area

A

1o somatosensory cortex

99
Q

Broadman area

123

Function

A

Touch

100
Q

Brodman area

4

Location

A

Precentral gyrus

101
Q

Brodman area

4

Functional area

A

1o motor cortex

102
Q

Brodman area

4

Function

A

Voluntary motor control

103
Q

Brodman area

5

Location

A

Superior parietal lobule

104
Q

Brodman area

5

Functional area

A

3o somatosensory cortex

Posterior parietal association

105
Q

Brodman area

5

Function

A

Stereognosis

106
Q

Brodman area

6

Location

A

Precentral gyrus and rostral adjacent cortex- SMA and premotor area.

107
Q

Brodman area

6

Functional area

A

Supplementatry motor control

Supplemental eye field

Premotor adjacent cortex

Supplementary eye field adjacent cortex

108
Q

Brodman area

6

Function

A

Limb and eye movement planning

109
Q

Brodman area

7

Location

A

Superior parietal lobule

110
Q

Brodman area

7

Functional area

A

Posterior parietal association

111
Q

Brodman area

7

Function

A

Visuomotor control

Perception

112
Q

Brodman area

8

Location

A

Superior, middle, frontal gyri

Medial frontal lobe

113
Q

Brodman area

8

Functional area

A

FEF

114
Q

Brodman area

8

Function

A

Saccadic eye movements

115
Q

Brodman area

9, 10, 11, 12

Location

A

Superior, middle frontal gyri

Medial frontal lobe

116
Q

Brodman area

9, 10, 11, 12

Functional area

A

Prefrontal association cortex

Frontal eye fields

117
Q

Brodman area

9, 10, 11, 12

Function

A

Thought

Cognition

Movement planning

118
Q

Brodman area

13, 14, 15, 16

Location

A

Insular cortex

119
Q

Brodman area

17

Location

A

Banks of calcarine sulcus

120
Q

Brodman area

17

Functional area

A

Primary visual cortex

121
Q

Brodman area

17

Function

A

Vision

122
Q

Brodman area

18

Location

A

Medial and lateral occipital gyri

123
Q

Brodman area 18

Functional area

A

Secondary visual cortex

124
Q

Brodman area 18

Function

A

Vision, depth

125
Q

Brodman area 19

Location

A

Medial and lateral occipital gyri

126
Q

Brodman area 19

Functional area

A

Tertiary visual cortex

Middle temporal visual area

127
Q

Brodman area 19

Function

A

Vision, colour, motion, depth

128
Q

Brodman area 20

Location

A

Inferior temporal gyrus

129
Q

Brodman area 20

Functional area

A

Visual inferotemporal area

130
Q

Brodman area 20

Function

A

Form vision

131
Q

Brodman area 21

Location

A

Middle temporal gyrus

132
Q

Brodman area 21

Functional area

A

Visual inferotemporal area

133
Q

Brodman area 21

Function

A

Form vision

134
Q

Brodman area 22

Location

A

Superior temporal gyrus

135
Q

Brodman area 22

Functional area

A

Higher order auditory cortex

136
Q

Brodman area 22

Function

A

Hearing speech

137
Q

Brodman area

23, 24, 25, 26, 27

Location

A

Cingulate gyrus

Subcallosal area

Retrosplenial area

Parahippocampal gyrus

138
Q

Brodman area

23, 24, 25, 26, 27

Functional area

A

Limbic association cortex

139
Q

Brodman area

23, 24, 25, 26, 27

Function

A

Emotions

140
Q

Brodman area

28

Location

A

Parahippocampal gyrus

141
Q

Brodman area

28

Functional area

A

Primary olfactory cortex

Limbic association cortex

142
Q

Brodman area 28

Function

A

Smell, emotion

143
Q

Brodman area

29, 30, 31, 32, 33

Location

A

Cingulate gyrus and limbic association cortex

144
Q

Brodman area

29, 30, 31, 32, 33

Functional area

A

Limbic association cortex

145
Q

Brodman area

29, 30, 31, 32, 33

Function

A

Emotions

146
Q

Brodman area

34, 35, 36

Location

A

Parahippocampal gyrus

147
Q

Brodman area

34, 35, 36

Functional area

A

Primary olfactory cortex

Limbic association cortex

148
Q

Brodman area

34, 35, 36

Function

A

Smell, emotion

149
Q

Brodman area

37

Location

A

Middle and inferior temporal gyri at temporo-occipital junction

150
Q

Brodman area 37

Functional area

A

Parietal-temporal-occipital association cortex

Middle temporal visual area

151
Q

Brodman area 37

Function

A

Perception, vision, reading, speech

152
Q

Brodman area

38

Location

A

Temporal pole

153
Q

Brodman area

38

Functional area

A

Primary olfactory cortex, limbic association cortex

154
Q

Brodman area

38

Function

A

Smell, emotions

155
Q

Brodman area

39

Location

A

Inferior parietal lobule (angular gyrus)

156
Q

Brodman area

39

Functional area

A

Parietal-temporal-occipital association cortex

157
Q

Brodman area

39

Function

A

Perception, vision, reading, speech

158
Q

Brodman area

40

Location

A

Inferior parietal lobule (supramarginal gyrus)

159
Q

Brodman area 40

Functional area

A

Parietal-temporal-occipital association cortex

160
Q

Brodman area

40

Function

A

Perception, vision, reading, speech

161
Q

Brodman area

41

Location

A

Heschl’s gyri and superior temporal gyrus

162
Q

Brodman area

41

Functional area

A

Primary auditory cortex

163
Q

Brodman area

41

Function

A

Hearing

164
Q

Brodman area 42

Location

A

Heschl’s gyrus and superior temporal gyrus

165
Q

Brodman area 42

Functional area

A

Secondary auditory cortex

166
Q

Brodman area 42

Function

A

Hearing

167
Q

Brodman area 43

Location

A

Insular cortex

Frontoparietal operculum

168
Q

Brodman area 43

Functional area

A

Gustatory cortex

169
Q

Brodman area 43

Function

A

Taste

170
Q

Brodman area 44

Location

A

Inferior frontal gyrus (frontal operculum)

171
Q

Brodman area 44

Functional area

A

Broca’s area

Lateral premotor cortex

172
Q

Brodman area 44

Function

A

Speech, movement planning

173
Q

Brodman area 45

Location

A

Inferior frontal gyrus (frontal operculum)

174
Q

Brodman area 45

Functional area

A

Prefrontal association cortex

175
Q

Brodman area 45

Function

A

Thought, cognition, planing behaviour

176
Q

Brodman area 46

Location

A

Middle frontal gyrus

177
Q

Brodman area 46

Functional area

A

Prefrontal association cortex (dorsolateral prefrontal cortex)

178
Q

Brodman area 46

Function

A

Thought, cognition, planning behaviour, eye movement

179
Q

Brodman area 47

Location

A

Inferior frontal gyrus (frontal operculum)

180
Q

Brodman area 47

Functional area

A

Prefrontal association cortex

181
Q

Brodman area 47

Function

A

Thought, cognition, planning, behaviour

182
Q

What are the main sensory cortices

A

Somatosensory (1, 2, 3)

Visual (17)

Auditory (41, 42)

Gustatory (43)

Olfactory (not distinctly localised) 34

183
Q

How did Brodman map the brain?

A

Topographical analysis of cortical cytoarchitecture

184
Q

Location of primary somatosensory area

A

Post-central gyrus (3, 1, 2)

185
Q

Inputs to the primary somatosensory area

A

VPL and VPM thalamic nuclei (medial lemniscus, spinothalamic and trigeminothalamic tracts)

Input for 1: muscle spindles and skin

Input for 2: Deep (joint) receptors

Input for area 3a: Muscle spindles

186
Q

Course of fibres to primary somatosensory area

A

ML/STT-> VPLc/VPM- > S1

187
Q

Draw the sensory homunculus

What to note

A

Face and tongue have bilateral representation

188
Q

Location of secondary somatosensory area

A

Located on the superior bank of the lateral sulcus

189
Q

Input to secondary somatosensory area

A

Ipsilateral VPLc and VPM thalamic nuclei

Bilateral S1

190
Q

Output secondary somatosensory area

A

Ipsilateral S1 and motor cortex

191
Q

Difference between primary and secondary somatosensory areas

A

The secondary somatosensory area receives bilateral fibres from the entire body, most of its fibres come from the primary somatosensory area

Body is bilaterally represented in the 2o with the leg most posterior and the face anterior which is the reverse of the primary somatosensory cortex

192
Q

Location of the somatosensory association area

A

Superior parietal lobule (5, 7)

193
Q

Function of somatosensory association areas

A

Integrates sensory data

Lesion causes tactile agnosias or astereognosis

194
Q

Location of 1o visual cortex

A

Located in the walls and floors of the calcarine sulcus, extends around the occipital pole (17)

195
Q

1o visual cortex

Input and output

A

Input-LGN with geniculocalcarine passing in the outer wall of the lateral ventricle to the calcarine sulcus (external sagittal stratum)

Output- Internal sagittal stratum-> cortifcofugal fibres-> superior colliculus and LGB

196
Q

Visual vertical meridian cortical region

A

Has commissural fibres for bilateral representation

197
Q

Ganglion cell receptive field

A

A region of the retina that affects the firing of one retinal ganglion cell

It is either on centre and off surround or on surround and off centre

198
Q

Band of Baillarger

A

In striate cortex- stripe of Gennari which are collaterals of the primary visual cortical axons in layer IVb

199
Q

Input on 2o visual cortex

A

LGB and pulvinar

200
Q

Lesion of 2o visual cortex

A

Causes visual agnosia

201
Q

Location of the transverse gyri of Heschl

A

Superior temporal gyrus, buried in the temporal operculum of the Sylvian fissure

202
Q

1o auditory cortex

Input-output

A

MGB fibres passing through the sublenticular internal capsule

Each cochlea projects bilaterally but more to the contralateral side.

The trapezoid body is the only auditory commissure needed for sound localisation

203
Q

Input on gustatory area

A

Ipsilateral nucleus solitarius-> VPMpc-> area 43

204
Q

Location of the vestibular cortex

A

Inferior parietal cortex

Bilaterally represented

205
Q

What are the main motor areas of cortex

A

1o motor area

Premotor area

SMA

FEF

206
Q

Draw the motor homunculus

A
207
Q

Location of 1o motor cortex

A

Precentral gyrus, involved in voluntary motor control

208
Q

Cellular make up of the 1o motor cortex

A

Pyramidal cells of Betz make up 3% of the corticospinal fibres

Columns may be present

Not somatotopic

Unilateral projection except bilateral to eye, face, tongue

209
Q

Neurotransmitters in 1o motor cortex

A

Glutamate and aspartate

210
Q

Premotor cortex location

A

Lateral aspect of the cortex, anterior to area 4

211
Q

Function of premotor cortex

A

Voluntary motor control for responses dependent on sensory input

212
Q

Input on premotor cortex

A

Cortical, VL and VA thalamic nuclei

213
Q

Unilateral lesion of premotor cortex

A

No deficit

214
Q

Location of the SMA

A

Medial aspect of the hemisphere, anterior to area 4, medial superior frontal gyrus

215
Q

Function of SMA

A

Programming, planning and initiating of motor movements

Neurones are somatotopically organised

216
Q

Input and output of SMA

A

Input bilateral

Output: ipsilateral areas 4, 6, 5 and 7

Contralateral M2, bilateral SC, caudate, putamen and thalamus

217
Q

SMA lesion

A

Hemiparesis/plegia

Diminished spontaneous speech

May have volitional movement with effort

218
Q

Location of FEF

A

Area 8

Rostral to the premotor area (caudal middle frontal gyrus)

219
Q

Function of FEF

A

Initiates saccades

Stimulation causes contralateral eye deviation

220
Q

Which Brodmann area controls ipsilateral pursuit?

A

Occipital eye centre (17)

221
Q

Projections of FEF

A

riMLF

Interstitial nucleus of Cajal

PPRF

SC

222
Q

Input to motor area

A

Ipsilateral VL and VLo -> M1

Contralateral cerebellum-> M1

Medial GP-> ipsilateral thalamic Va, VLo, CM-> M2 and premotor cortex

S1-> all of M1

M2-> M1 and premotor cortex

Motor cortex has reciprocal fibres with the thalamus

223
Q

Surface marking of the Sylvian fissure

A

Point 3/4 of the way on a line over the SSS from the nasion to the inion

Mark the frontozygomatic point: 2.5cm along the orbital rim above the zygomatic arch

Sylvian fissure extends along the line connecting these two points

224
Q

Angiographic localisation of the Sylvian point

A

Most posterior branch of the MA

Should be 5cm from the midline on an AP film and corresponds to the top of the insula

225
Q

Surface marking of the Rolandic fissure

A

Mark the upper Rolandic point: 2cm posterior to the halfway point along the midline nasion/inion line (also measured as 2.5cm behind the pterion along the Sylvian line)

Mark the lower Rolandic point: junction between the line from the upper rolandic point to the mid-zygomatic arch and the Sylvian fissure line

Motor strip is usually 4-5cm behind the coronal suture

226
Q

Wernicke’s area

A

Brodmann 22

227
Q

Broca’s area

A

44, 45

228
Q

Primary motor cortex

A

4

229
Q

Primary somatosensory cortex

A

1, 2, 3

230
Q

FEF

A

8

231
Q

Primary auditory cortex

A

41, 42

232
Q

Gustatory cortex

A

43

233
Q

Primary visual cortex

A

17

234
Q

Primary olfactory cortex

A

34

235
Q

Components of the limbic system

A

Limbic lobe

Hippocampal formation

Amygdaloid nucleus

Hypothalamus

Anterior nucleus of the thalamus

236
Q

Components of the limbic lobe

A

Subcallosal

Cingulate

Hippocampal gyri

Collectively these gyri form a ring around the rostral portion of the brainstem

237
Q

Components of the hippocampal formation

A

Hippocampus

Dentate gyrus

Parahippocampal gyrus

238
Q

Parts of the hippocampus

A

Head

Body

Tail

239
Q

Overview of the structural arrangement of the hippocampus

A

Bilaminar archicortical structure consisting of Ammon’s horn (hippocampus proper) and dentate gyrus with one lamina rolled up in another

It is an intraventricular expansion of the temporal lobe cortex and forms the floor of the temporal horn of the lateral ventricle

Anteriorly it enlarges to form the pes hippocampus

Posteriorly it terminates beneath the splenium

240
Q
A
241
Q

Histological composition of hippocampus

A

Three-layered archicortex

Molecular layer

Pyramidal

Polymorphic

242
Q

Afferent connections of the hippocampus

A

Entorhinal area

Septal area

Anterior thalamic nucleus

Mamillary bodies

Noradrenergic fibres from locus coeruleus

Serotonergic fibres from raphe nuclei

Fornix carries commissural fibres that originate in the hippocampus on the opposite side

243
Q

Efferent connections of the hippocampus

A

Ventricular surface of hippocampus covered by alveus (WM) which contains fibres that originate in large pyramidal cells of the hippocampus, these converge on the medial border and continue posteriorly as the fimbria

Fimbria continues as crus of fornix which becomes crura to converge and form the body of the fornix

Forms two columns which terminate in the mamillary bodies

Also sends fibres to the anterior thalamic nucleus, midbrain reticular formation and contralateral hippocampus

244
Q

Intrahippocampal connection

A

Perforant pathway connects the entorhinal cortex to dentate gyrus

Mossy fibres connect dentate to CA3

Schaffer collaterals connect CA3 to CA1

Fibres emerge from alveus to form fimbria and ultimately emerge posteriorly as the fornix

245
Q

Dentate gyrus

A

A narrow band of cortex with a notched appearance

Located between the fimbriae of the hippocampus and parahippocampal gyrus

Continuous with uncus anteriorly and posteriorly with the indusium griseum

Archicortex histologically with a granule cell layer rather than pyramidal

All dentate gyrus efferents are confined to the hippocampal formation.

246
Q

Parahippocampal gyrus

A

Located between hippocampal fissure and collateral sulcus

Continuous with hippocampal formation along the medial border of the temporal lobe

Neocortex though in the subiculum there is a transition between neocortex and archicortex

247
Q
A

Parahippocampal gyrus

248
Q

Amygdaloid nucleus

A

Large gray mass covered by rudimentary cortex

Located in the anterior pole of the temporal lobe, in front of and above the tip of the inferior horn of the lateral ventricle and just below the uncus of the parahippocampal gyrus

249
Q
A

Amygdala

250
Q

Nuclear groups of the amygdala

A

Corticomedial, just below the pyriform area of the temporal lobe and receives fibres from olfactory bulb and cortex

Basolateral- reciprocal connections with the visual, auditory, somatosensory cortices as well as the thalamus and brainstem reticular formation

251
Q

Efferent output of the amygdaloid nucleus

A

Reciprocal fibres to sources of input

Stria terminalis to the hypothalamic nuclei, the fibres of which accompany the C-shaped caudate nucleus as it loops around the thalamus

252
Q

Papez

A

American neurologist who described circuit in 1937 thought to be involved in emotion

253
Q

Describe Papez circuit

A

Association areas of the prefrontal, parietal, temporal and occipital cortices send fibres to the cingulate gyrus

Cingulate gyrus to the parahyippocampal gyrus

Hippocampus

Information is then relayed via fornix to the mamillary bodies

Projected from mamillary bodies via mamillothalamic tract to the anterior nucleus of the thalamus

From thalamus to cingulate gyrus

254
Q

What white matter bundle carries efferents from cingulate and parahippocampal gyri to the hippocampus as part of Papez circuit?

A

Cingulum

255
Q

What is “a”

A

Cingulum bundle

256
Q

Role of the hippocampus in memory

A

Recent memory- ability to learn and retrieve material after intervals of minutes, hours or days

The Hippocampus, mamillary bodies and dorsomedial nucleus of the thalamus are involved in this.

These structures appear to store and retrieve memories from the cerebral cortex

Lesions to these areas are marked by recent memory loss with preservation of immediate and remote memory

e.g. Korsakoff’s and surgical destruction of hippocampi (previously performed on patients with medically refractory epilepsy

257
Q

Which structures are involved in Korsakoff’s

A

Bilateral destruction of mamillary bodies and dorsomedial nuclei

258
Q

Function of amygdaloid nucleus

A

Concerned with emotions and autonomic consequences.

Receives afferents from areas of the cortex representing all sensory modalities

Effects mediated by the hypothalamus which receives amygdaloid efferents via stria terminalis

259
Q

The patient noted rising epigastric sensation with a fleeting inexplicable sense of fear

Then observed to stare blankly into space and not responding to conversation

Then fumbled with her dress in a purposeless and uncoordinated manner, pale and sweaty with irregular breathing pattern.

Becomes responsive after 3 minutes and stops stereotyped fumbling

Amnestic for episode

Remains slightly confused for hours after the event.

A

Temporal lobe seizure

Clinically manifested by sensory, motor, psychic and autonomic manifestations.

The psychic and autonomic symptoms appear to arise as a result of abnormal discharge in amygdaloid nucelus

260
Q

Henry Molaison

A

An American man who underwent bilateral medial temporal lobectomy in an attempt to cure epilepsy.

Consequently, he suffered from both anterograde and retrograde amnesia.

Retrograde amnesia improved but he was unable to form new memories or learn new information.

Resided in a care home from 1957 until his death.

261
Q

What separates the cingulate gyrus from the corpus callosum

A

The callosal sulcus and indusium griseum

262
Q

What are the only interneurones in the cerebral cortex that use glutamate?

A

Stellate cells.

All the other interneurones use GABA

263
Q

Cells of Martinotti

A

Present at many levels of cortex, send axons that end in the most superficial layers of the cortex

264
Q

Which areas of cortex do not receive commissural fibres from contralateral hemisphere

A

Hand and foot areas of somatosensory cortex

Primary visual cortex

265
Q

Hippocampal commissure

A

Traverse midline inferior to the splenium of corpus callosum containing fibres that connect the posterior columns of the fornix

266
Q
A

Frontal aslan tract

Connects posterior portion of the IFG to the SMA and pre-SMA

Impaired verbal fluency but preserved semantic processing (uncinate)

Identified in DTI studies in primary progressive aphasia which has both nonfluent and semantic variants.

267
Q

Afferent connections of 1o motor cortex

A

Premotor area

Somatosensory cortex

VL nucleus of thalamus

268
Q

Cortical representation SMA

A

Bilateral body representation

Face rostral, leg caudal

269
Q

Features of SMA syndrome

A

Akinetic mutism with contralateral paresis

Not able to initiate voluntary movement but when passively initiated movement and strength are within normal limits.

The patient may localise with the affected arm

Can be differentiated from a CST lesion through preservation of tone in the affected arm (CST lesion would result in flaccid paralysis).

270
Q

Premotor cortex and lesion

A

Concerned with planning and programming of movements.

Helps to store programs of motor activity that have been developed as a result of past experiences.

Lesions here may result in apraxia.

271
Q

Def: apraxia

A

Impairment of movement execution in absence of paralysis

272
Q

Location of secondary somatosensory cortex

A

Superior lip of posterior limb of lateral fissure

273
Q

Representation of secondary somatosensory areas

A

Bilatearl cortical representation

274
Q

Tonotopic organisation of 1o auditory cortex

A

Impulses related to low frequencies are located in anterolateral portion of cortex

Impulses related to high frequencies are located in the posteromedial cortex

275
Q

Lesions involving primary auditory cortex

A

Bilateral projection of auditory tracts so lesions of auditory cortex result in a decrease in the perception of sound only

276
Q

Right hemisphere syndromes

A

Constructional apraxia

Dressing apraxia

Neglect and Denial

Colour blindness

277
Q

Constructional apraxia

A

Right hemisphere syndrome

Inability to draw or costruct 2 or 3 dimensional objects as a result of a disorder in learned movements.

Right parietal lesion

278
Q

Localisation:

Constructional apraxia

A

Right parietal lesions (non-dominant)

279
Q

Dressing apraxia

A

Unable to properly clothe self.

May involving leaving the left side partly undressed

Right parietal lesion (non-dominant)

280
Q

Localisation;

Dressing apraxia

A

Right parietal (non-dominant)

281
Q

Neglect and denial

A

Patient with neglect tends to neglect half the space contralateral to the lesion e.g. clock with numbers crowded onto the side of the lesion or only shave half of the face.

Denial disorder- can result in anosognosia

Non-dominant hemisphere lesions

282
Q

Colour blindness

A

Achromatopsia

Cannot sort colours according to hue

Can be a result of the bilateral or non-dominant inferior occipitotemporal lesion

Different from colour agnosia

Lesion spares primary visual cortex.

Non-dominant occipital lobe

283
Q

Colour agnosia

A

Inability to name or point to colours without ability to sort colours according to hue (which would be colour blindness)

Dominant hemisphere

284
Q

Localisation: Colour blindness

A

Non-dominant occipital lobe

285
Q

Dominant hemisphere syndromes

A

Dysphasia

Apraxias:
Ideational
Ideomotor

Agnosia:
Visual
Colour

Alexia without agraphia

Gerstmann’s:
Left right disorientation
Finger anomia
Dyscalculia
Agraphia

286
Q

Ideomotor apraxia

A

Inability to perform previously learned motor acts that cannot be explained by disturbances in sensation, strength or comprehension

Involves Wernicke’s area conveyed via arcuate fasciculus to the premotor cortex in frontal lobe either right or left (bilateral representation)

Dominant hemisphere

Ideomotor- inability to perform single task e.g. can’t comb hair with comb
Ideational- inability to perform correct sequences of task e.g. to brush teeth.

287
Q

Best way to test for ideomotor apraxia

A

Ask the patient to brush hair or clean teeth

Typically demonstrate errors such as gripping toothbrush inaccurately or failing to open mouth etc.

288
Q

Visual agnosia

A

Inability to recognise objects visually in absence of disturbance of visual acuity or general intellectual function

Can either be as a result of a defect in visual perception (unable to name objects pointed to or nameed)- bilateral visual association area or visual association (unable to name objects but may be able to point at them or draw them)- bilateral inferior occipitotemporal lobes or dominant occipital lobe and crorpus callosum

Most patients who have visual agnosia are alexic

289
Q

Alexia without agraphia

A

Affected individual is unable to read but can write

Dominant occipital cortex and posterior corpus callosum

Alexia is due to the disconnection of the dominant inferior parietal lobule which is responsible for processing auditory and visual information necessary for reading and writing is disconnected.

The patient is able to write as the inferior parietal lobule itself is preserved.

290
Q

Localisation:

Alexia without agraphia

A

Dominant occipital lobe and posterior corpus callosum

291
Q

Gerstmann’s syndrome

A

Dyscalculia

Finger agnosia

Left-right disorientation

Agrapiha

Dominant parietal lesion

292
Q

Bihemsipheric syndromes

A

Ideational apraxia

Anton’s syndrome

293
Q

Ideational apraxia

A

Defect in motor planning of a higher order than that associated with ideomotor apraxia

Patients are able to perform individual motor acts but are unable to coordinate the complex sequences of acts that constitute everyday motor tasks.

e.g. may be able to light a match or put cigarette in mouth but unable to perform the full sequence from taking cigarette from packet to lighting it

294
Q

Key to localisation of weakness to the cortex

A

“Cortical findings” i.e. aphasia, astereognosis, anosognosia, homonymous VF defects

295
Q

How to discriminate between cortical and subcortical CTS disruption

A

Absence of cortical findings

296
Q

LMN syndrome with the absence of sensory involvement localises to

A

Anterior horn cell or anterior spinal root prior to the exit of the spinal canal or purely motor peripheral nerve

297
Q

Ideational apraxia

A

Failure to conceive and act, either when commanded or sponatneously

298
Q

Ideomotor apraxia

A

Ability to conceive of motor action to be executed but inability to act

299
Q

How to differentiate between ideational and ideomotor apraxia

A

Patient may be observed performing simple tasks e.g. dressing/washing/shaving- inability to perform these would be manifestation of ideomotor apraxia

Inability to perform complex learned tasks e.g. hammering nail or opening door would be considered ideational apraxia

300
Q

Stages of central herniation

Cheyne-Stokes Respiratory

Small pupils

Intact VOR

Appropriate motor response

A

Dicencephalic stage

301
Q

Stages of central herniation

Sustained regular hyperventilation

Midposition irregular pupils or unilateral blown

Dyconjugate gaze with impaired VOR

Decerebrate posturing

A

Midbrain-upper pons

302
Q

Stages of central herniation

Ataxic or eupnic breathing

Midposition or fixed pupils

Absent VOR

No motor response

B/L upgoing plantars

A

Lower-pons/medullary stage

303
Q

Stages of central herniation

Apnoeic episodes

Irregular pulse

Hypotension

No motor response

A

Medullary stage

304
Q

Pattern of sensory deficit cortical vs subcortical

A

Cortical sensory deficits tend to produce relatively mild hemisyndromes primarily affecting arm and face or leg (MCA vs ACA)

Because motor and sensory fibres converge as they pass through deep subcortical structures, subcortical injuries tend to produce dense hemisyndromes affecting face, arm, leg.

305
Q

How to test simultagnosia

A

Can interpret individual components of image but not wider picture.

i.e. can see trees but not forest

Can test with Ishihara colour plates- will see colour but not number

Part of Balint’s syndrome

https://www.youtube.com/watch?v=A8BD5liH7ug

306
Q

How to test optic ataxia

A

Mislocalisation in space, hold a pen out they will miss but they can touch their own finger i.e. not cerebellar

Part of Balint’s

https://www.youtube.com/watch?v=A8BD5liH7ug

307
Q

Hodotopic frame concept

A

Catani et al concept

Includes both topological (i.e. cortical functional epicentres) and hodological (connectivity between areas) views for understandng brain function

i.e. Cortex and white matter as a network

308
Q

Extent of lesion in Broca’s dysphasia

A

Injury to the cortical area may not cause Broca’s dysphasia but a transient speech disorder

Broca’s dysphasia occurs with injury to Broca’s, middle inferior PreCG and WM underneath

309
Q

Two major streams in the hodological model of language

A

Dorsal stream

Ventral steam

310
Q

Function of dorsal stream

A

Phonological processing

311
Q

Components of dorsal stream

A

Two layers:

Superficial

SLF: II- III and temporoparietal

Deep:

Arcuate fasciculus

312
Q

Function of ventral stream

A

Semantic processing

313
Q

Components of the ventral stream

A

Intra-temporal network:

MLF

ILF

IFOF

314
Q

Role of frontal-aslan tract in the dual-stream model of language

A

Driving of speech

Initiation and speech spontaneity

315
Q

Structures connected by IFOF

A

Two layers

Superficial: superior parietal lobule, Wernicke’s occipital association area and fusiform area at the occipitotemporal gyrus to IFG

Deep:

Originates in similar areas and terminates in multiple areas including orbitofrontal, MFG and dorsolateral PFC.

316
Q
A

Rhinal sulcus

317
Q
A

Medial temporal lobe

Semilunar gyrus

318
Q
A

Semi-annular sulcus

319
Q
A

Ambient gyrus

320
Q
A

Uncinate gyrus

321
Q
A

Infolded head of hippocampus

322
Q
A

Anterior part of parahippocampal gyrus

323
Q
A

Intralimbic gyrus- part of dentate gyrus

324
Q
A

Band of Giocamini

Tail of dentate gyrus

325
Q
A

View from medial→ lateral into temporal horn of lateral ventricle, green= uncal sulcus between hippocampus (yellow) and amygdala

326
Q

Parahippocampal surfaces

A

Rhoton describes three surfaces of the parahippocampal- lower against tent/middle fossa, rounded medial surface, upper surface medial to the dentate gyrus. The PCA can run on the upper surface of the parahippocampal gyrus

With a subtemporal approach to reach the upper surface of parahippocampal gyrus is likely to require significant traction on temporal lobe

327
Q

Ventricular relation to cerebral convexity:

Frontal horn

A

Inferior frontal gyrus

328
Q

Ventricular relation to cerebral convexity:

Atrium

A

Supramarginal gyrus

329
Q

Ventricular relation to cerebral convexity:

Temporal horn

A

Medial temporal gyrus

330
Q

Cranial location of the foramen of Monro

A

Deep to a point 2cm above pterion, behind the lower third of the coronal suture

331
Q

Ventricular relation to cerebral convexity:

Foramen of Monro

A

Deep to central part of pars opercularis of IFG

332
Q

Cerebral hemisphere:

3 surfaces

A

Lateral

Medial

Basal

333
Q

Cerebral hemisphere:

3 margins

A

Superior

Inferior

Medial

334
Q

Cerebral hemisphere:

3 poles

A

Frontal

Temporal

Occipital

335
Q

Cerebral hemisphere:

3 types of WM

A

Projection

Commissural

Association

336
Q

Cerebral hemisphere:

5 lobes

A

Frontal

Parietal

Temporal

Occipital

Insular

337
Q

What is useful for identifying the precentral gyrus during Sylvian split?

A

Pars opercularis which is located just anterior to the precentral gyrus and gyral bridge (red arrow) which commonly prevents the central sulcus from opening directly onto the Sylvian fissure

338
Q

What is useful for identifying the post-central gyrus

A

The anterior bank of the supramarginal gyrus is just behind the post-central sulcus

The supramarginal gyrus is where the Sylvian fissure terminates

339
Q

Limen insulae

A

Trans: Threshold to insula

Forms the junction point between anterior and posterior stem of the lateral sulcus.

Lateral limit of anterior perforated substance

Point at which the insular cortex is continuous with cortex over the amygdala and superior temporal gyrus.

340
Q

Sulci of insular

A

Circular sulcus defines the limit

Central sulcus separates short from long gyri

341
Q

Short insular gyri

A

Deep to pars triangularis and opercularis

342
Q

Cortical landmark for foramen of Monro

A

Deep to a point on pars opercularis

1cm above Sylvian fissure

Deep to the midlevel of the short gyri of the insular

343
Q

What separates cuneus and lingula?

A

Calcarine sulcus

344
Q

Calcar avis

A

Prominence in the lower part of medial atrial wall overlying calcarine sulcus

345
Q

Inferior choroidal point

A

The inferior extent of the choroidal fissure (cleft between thalamus and fornix)

Located just behind the head of hippocampus›

346
Q

Opening the choroidal fissure between pulvinar and crus of fornix exposes

A

Quadrigeminal cistern

347
Q

Opening choroidal fissure between lower surface of thalamus and fimbria of fornix exposes

A

Ambient cistern

348
Q

Opening choroidal fissure adjacent to body of fornix exposes

A

Third ventricle

349
Q

What marks the lower edge of velum interpositum in the third ventricle?

A

Striae medullaris thalami

350
Q

The posterior border of the parietal lobe on the lateral surface

A

Upper half of a line from impression of upper end of parieto-occipital sulcus to the pre-occipital notch

351
Q

Surfaces of frontal lobe

A

4

Lateral

Medial

Basal

Sylvian

352
Q

Inferior gyri of the temporal lobe from medial to lateral

A

Parahippocampal

(collateral and rhinal sulcus)

Occipitotemporal (fusiform gyrus)

(occipitotemporal sulcus)

Inferior temporal

353
Q

Isthmus of cingulate gyrus

A

Narrow strip of cortex at posterior end of parahippocampal gyrus

Wraps round splenium and connects the posterior end of parahippocampal gyri with cingulate gyrus

354
Q

What sulcus separates precuneus and cingulate gyrus?

A

Subparietal sulcus

355
Q

Gyri of the inferior surface of the occipital lobe

A

Lower part of lingula

Inferior occipital gyrus

Posterior part of occipitotemporal gyrus

356
Q

Groups of cerebral sulci

A

Classified by Ono et al into three groups:

Those that are commonly continuous or uniterrupted

Low interruption rates

Regularly interrupted

357
Q

Uniformly continuous sulci

A

Sylvian Fissure

Callosal

Parieto-occipital sulci

358
Q

Highly continuous sulci

A

Central

Collateral

Calcarine sulci

359
Q

Parts of Sylvian fissure

A

Superficial

Deep

360
Q

Organisation of superficial Sylvian fissure

A

Stem and 3 rami

Stem begins medially at ACP. and extends laterally along the sphenoid ridge to the pterion where it divides into anterior horizontal, anterior ascending and posterior rami

361
Q

Organisation of deep Sylvian fissure

A

AKA Sylvian cistern

Sphenoidal compartment

Operculoinsular compartment

362
Q

Extent of sphenoidal compartment of Sylivan fissure

A

Extneds laterally from cistern around the ICA between frontal and temporal lobes

363
Q

Roof of sphenoidal compartment of Sylvian

A

Posterior part of the orbital surface of the frontal lobe and anterior perforated surface

Caudate, lentiform and anterior limb of internal capsule are located above roof

364
Q

Floor of the sphenoidal compartment of Sylvian fissure

A

Anterior part of planum polare, area free of gyri on upper temporal pole

Uncus located at medial part of floor

365
Q

What underlies the limen insulae

A

The cingulum

366
Q

How does the sphenoidal compartment communicate medially?

A

Through the Sylvian vallecula, tubular opening between the medial end of the temporal and frontal lips of the fissure to communicate with the opticocarotid cisterns

367
Q

Etymology: Vallecula

A

Valley

368
Q

https://link.springer.com/chapter/10.1007/978-3-030-54879-7_26

A
369
Q

Borders of anterior perforated substance

A

Anterior: olfactory striae

Posterior: optic tract and stem of temporal lobe

Medial: interhemispheric fissure

Laterally: limen insula

370
Q

Anterior segment of uncus faces

A

Anterior perforated substance

371
Q

Posterior segment of uncus faces

A

Cerebral peduncle

372
Q

Location of posterior perforated substance

A

Between the cerebral peduncles

373
Q

Planum temporale

A

Posterior part of the upper surface of the temporal lobe

Made up of the transverse temporal gyri

374
Q

Planum polare

A

The anterior part of the upper surface of the temporal lobe

Free of gyri and has a shallow trough to accommodate the MCA.

375
Q

Stem of temporal lobe

A

Thin layer of gray and white matter that connects the temporal lobe to the lower insula

Position above the lateral and anterior edge of the temporal horn

376
Q

Passage of optic radiations from LGB in temporal lobe

A

Pass laterally from LGB and course in roof of temporal horn along temporal stem and lateral to atrium to reach the calcarine surface

377
Q

Portions of operculoinsular compartment of sylvian fissure

A

Two narrow clefts, opercular and insular

378
Q

Opercular cleft

A

Portion of operculoinsular compartment of Sylvian fissure

Situated where the sylvian surfaces of the frontal lobe and parietal lobe face the sylvian surface of temporal lobe below

379
Q

Insular cleft

A

Part of operculoinsular cleft of Sylvian fissure

Has a superior limb- located between the insula and opercula of the frontal and parietal lobes

Inferior limb located between insula and temporal operculum.

380
Q

What structures form the upper lip of opercular cleft

A

Frontal gyri:

Pars orbitalis, triangularis, opercularis, precentral

Parietal gyri:

Post-central and supramarginal gyrus

381
Q

What structures form the lower lip of the opercular cleft

A

Planum temporale

Planum polare

382
Q

Sylvian point

A

Medially directed arterial apex

Formed by the most posterior MCA branch turning sharply away from the insula pointing towards the atrium

383
Q

When is the insula visualised during sylvian dissection

A

Only when the lips of the fissure are widely separated, except in the area below the inferior angle of the pars triagnularis which can be attracted to expose a small area of the insular surface

384
Q

Where is it safest to begin opening fissure

A

The natural upward retraction of pars triangularis creates the largest opening in the superficial compartment of the Sylvian fissure and provides an area where the fissure is widest

385
Q

What is the floor of the anterior half of the basal ganglia

A

The anterior perforated substance

386
Q

What sulcus demarcates the insula

A

Circular sulcus

387
Q

Location of limen insula

A

Slightly raised area overlying uncinate fasciculus

Lateral border of the anterior perforated substance

Located at the junction of the sphenoidal and operculoinsular compartments

388
Q

Insular apex

A

Anteroinferior angle of the insula

Located below the apex of the pars triangularis

389
Q

Anterosuperior angle of insula points to

A

Sylvian point

390
Q

Divisions of insula

A

Separated into an anterior and posterior part by the central sulcus of insula

Anterior:

3-5 short gyri

Posterior:

anterior and posterior long gyri

391
Q

Superior temporal sulcus corresponds to which portion of the insula

A

Lower border

392
Q

What is deep to the lower border of the insula

A

Optic tract coursing in the roof of the ambient cistern near the midline

393
Q

Divisions of the central sulcus

A

Superior curve

Inferior curve

Together they form an inverted letter S

394
Q

Inferior frontal convolution

A

Portion of frontal lobe that constitues pars orbitalis, triangularis and opercularis

395
Q

Relationship of precentral gyrus to ventricle

A

Located lateral to the posterior part of the body of the ventricle

396
Q

Relationship of postcentral gyrus to ventricle

A

Lateral to anterior part of atrium

397
Q

What separates the middle frontal gyrus and cingulate gyrus?

A

The deep white matter forming the centrum semiovale

398
Q

Relation of inferior frontal sulcus to corpus callosum

A

Located at the level of the upper margin of the anterior part of corpus callosum

399
Q

Extended Sylvian

A

Demarcates lower border of the parietal lobe, extending posteriorly along axis of sylvian fissure

400
Q

Depth of intraparietal surface is directed towards what strutcture

A

Roof of the atrium and occipital horn

401
Q

Constituents of the inferior parietal lobule

A

Anterior supramarginal gyrus

Posterior angular gyrus

402
Q

Which bit of cortex is lateral to the atrium of the lateral ventricle

A

Supramarginal gyrus

403
Q

Lamboid sutures approiximate which cortical portion

A

Parieto-occipital junction

404
Q

Approximate lateral cortical landmark of the calcarine sulcus

A

Level of a line extending posteriorly along the long axis of the superior temporal sulcus

405
Q

Which structures are deep to the middle temporal gyrus

A

Temporal horn, ambient and crural cisterns

406
Q

Location of ascending ramus of the cingulate sulcus

A

Between the paracentral lobule and precuneus

407
Q

Location of precuneus

A

Between the paracentral lobule and parieto-occipital sulcus

408
Q

Etymology: cuneus

A

Wedge

409
Q

Location of cuneus

A

Between parieto-occipital sulcus and calcarine sulcus

410
Q

Location of lingual gyrus

A

Below the calcarine sulcus

411
Q

Location of paraterminal/paraolfactory gyrus

A

Below rostrum of corpus callosum

412
Q

Relationship of corpus callosum to ventricular system

A

Genu wraps around frontal horn

Body form roof of body of lateral ventricle

Splenium adjacent to atrium

413
Q

Bulb of corpus callosum

A

Prominence in the medial wall of atrium formed by the forceps major passing posteriorly from the splenium of corpus.

414
Q

Stria terminalis

A

Courses between the caudate and thalamus

415
Q

What separates the sublenticular optic and auditory radiations from the temporal horn?

A

Tapetum

416
Q

What separates cingulate gyrus from precuneus and parietal lobe?

A

Subparietal sulcus

417
Q

Subparietal sulcus

A

Posterior continuation of cingulate sulcus behind marginal ramus

418
Q

Paracentral ramus of cingulate sulcus

A

Ascends at the midportion of corpus callosum to separate SFG from paracentral lobule

419
Q

Marginal ramus of cingulate sulcus

A

Ascends at the level of the posterior 1/3rd of corpus callosum and separates the paracentral lobule from the precuneus

420
Q

Paraterminal gyrus

A

Narrow triangle of gray matter in front of the lateral edge of lamina terminalis that is continuous with indusium griseum

421
Q

What separates the paraterminal gyrus from the paraolfactory gyrus?

A

By the shallow posterior paraolfactory sulcus

422
Q

What structures does the anterior paraolfactory sulcus separate

A

The paraolfactory gyrus from anterior part of frontal pole

423
Q

Borders of precuneus

A

Anterior- marginal sulcus

Posteriorly- parieto-occipital suclus

Inferiorly- subparietal sulcus

424
Q

Cortical landmark of subparietal sulcus

A

Located approximately at the level of the intraparietal sulcus

425
Q

Location of striate cortex on calacarine sulcus

A

Part posterior to the junction with parieto-occipital sulcus has striate cortex on upper and lower lips

Anterior to the junction it is on the lower lip only

426
Q

Fasciolar gyrus

A

Dentate gyrus blends posteriorly behind the splenium and becomes continuous with indusium griseum

427
Q

Parts of uncus

A

Two segments:

Anterior

Posterior:

Upper and lower

428
Q

Relationship of the optic tract to uncus

A

Passes above the medial edge of the posterior segment in the crural cistern

429
Q

Location of the nucleus basalis

A

Orbital surface of the frontal lobe below the anterior commissure

430
Q

Location of nucleus accumbens

A

Anterior to the basalis

431
Q

Into what does the upper margin of the amygdala blend

A

Into the globus pallidus

432
Q

Inferior choroidal point

A

Lower end of choroidal fissure and attachment of choroid plexus in temporal horn

Lies just behind the head of the hippocampus

The point at which the anterior choroidal artery enters the lateral ventricle

433
Q

Location of crural cistern

A

Between uncus segment and cerebral peduncle

434
Q

What divides the posterior uncus into upper and lower parts

A

Uncal notch

435
Q

What forms the upper part of the posterior uncus

A

Upper part is predominantly formed by the hippocampal head

436
Q

What forms the lower part of the posterior uncus

A

Parahippocampal gyrus

437
Q

Relation of optic tract to amygdala

A

Medial to junction of the amygdala with the globus pallidus

438
Q

What are the prominences that correspond to the collateral sulcus

A

The collateral eminence in the floor of the temporal horn

Collateral trigone in the floor of the atrium

439
Q

What lies medial to the apex of the uncus?

A

CN3

440
Q

With what is the rhinal sulcus continuous?

A

Collateral sulcus

441
Q

Distance of temporal horn from temporal pole

A

Approximately 2.5cm

442
Q

What is the rough basicortical extent of frontal horn

A

Extend as far as the horizontal H of the orbital suclus anteriorly

443
Q

Which vessels enter/exit the temporal horn at the inferior choroidal point?

A

Inferior ventricular vein exits

Anterior choroidal artery enters

444
Q

What connects the central core to the remainder of the hemisphere and where is this found?

A

The cerebral isthmus

Located deep to circular sulcus of insular

445
Q

Issues with opening isthmus at the lower edge of circular sulcus

A

Will give entry into the temporal horn but at the mid-point of the circular sulcus the incision will cross sub lenticular fibres containing the optic and auditory radiations where they leave LGB/MGB

446
Q

Arrangement of central core gray matter at the level of anterior perforated substance

A

Caudate and lenticular nucleus are in continuity

Amygdala is in continuity with lenticular nucleus

These also blend into the nucleus basalis and accumbens

447
Q

Which portion of the isthmus is safe

A

Opening anterior part of isthmus carries less risk

Yasargil and Wieser reach the amygdala for amygdalohippocampectomy using 1-2cm incision through circular sulcus and lower isthmus just behind limen insula

448
Q

Location of stria terminalis

A

Arises in the amygdala and courses along the border between caudate nucleus and thalamus in wall of lateral ventricle deep to the thalamostriate vein

449
Q

Location of uncinate fasciculus

A

Curves around stem of Sylvian fissure and connects the frontal and temporal lobes

Located at lateral edge of anterior perforated substance, bordering anteroinferior part of insula

450
Q

Parts of uncinate fasciculus

A

Upper:

Unites gyri on the superolateral part of frontal lobe with lateral temporal gyri

Lower:

Unites gyri on orbital surface of frontal lobe with parahippocampal and other medial temporal gyri

451
Q

Location of cingulum

A

Courses along medial aspect of cerebral hemisphere forming most of the WM of the cingulate gyri

Connects subcallosal, paraolfactory areas with cingulate gyrus, parahippocampal gyri

452
Q

Location of SLF

A

Along upper and lateral border of lentiform nucleus and insula

Arches backward from frontal lobe lateral to internal capsule, through parietal + occipital lobe arch downward to reach temporal lobe

453
Q

Relationship of the internal capsule to the lateral ventricle

A

Anterior limb is separated from frontal horn by the caudate

Posterior limb separated from the body by the thalamus

Genu reaches the ventricle at the level of the foramen of Monro

454
Q

Location of subthalamic nucleus

A

Situated in interval between cerebral peduncle and midbrain

455
Q

Relationship of SLF to optic radiations

A

The optic radiations are deep to the SLF

456
Q

Relationship of SLF to extreme and external capsules

A

SLF is deep to the extreme and external capsules

457
Q

Relationship of caudate to thalamus

A

Tail of caudate extends along the lateral edge of the thalamus

458
Q

Why is the anterior limb of the internal capsule darker than posterior

A

There are bridges of transcapsular gray matter extending across the anterior limb of IC between caudate and lentiform nuclei

459
Q

How do fibres from LGB reach the superior bank of calcarine fissure?

A

Leave upper part of LGB and course almost directly posterior around lateral aspect of the atrium to reach the visual cortex

460
Q

How do fibres from LGB reach inferior bank of calcarine fissure

A

Pass from lower part of LGB looping forward and downwards into the temporal lobe, forming Meyer’s loop before turning back

461
Q

Divisions of the optic radiation

A

Divided into anterior, middle and posterior groups

462
Q

Anterior group of optic radiation

A

Meyer’s loop

Subserve upper half of visual field

Pass anteriorly along the roof of the temporal horn as far as tip and then loop along the lateral and inferior aspects of the atrium and occipital horn

463
Q

Middle group of optic radiation

A

Subserve macula and course laterally above roof of temporal horn, turning posteriorly along the lateral wall of atrium and occipital horn

464
Q

Posterior group of optic radiation

A

Pass directly backwards along lateral wall of atrium and occipital horn to end in the upper lip of calcarine fissure

465
Q

Relation of SLF to insula

A

SLF courses in deep WM around outer edges of insula and lentiform nucleus

466
Q

Which WM bundle lies deep to limen insula?

A

Uncinate faiculus

467
Q

What is causing the white matter prominence marked by the red arrows?

A

The intersection of fibres of the corpus callosum and corona radiata

468
Q

What is exposed through the window in the ventricular wall marked by the yellow arrow?

A

Window through calcar avis is exposing gray matter of calcarine suclus below

469
Q

Relationship of the fornix to the foramen of Monro

A

Columns of fornix pass superior and anteriorly

470
Q

Cortical landmark of anterior corpus callosum

A

In the midline, deep to the upper part of the inferior frontal gyrus

471
Q

Cortical landmark of splenium of corpus callosum

A

Deep to supramarginal gyrus and lower third of a pre and post-central gyri

472
Q

Parts of corpus callosum

A

Rostrum

Genu

Body

Splenium

Tapetum

473
Q

What commissural fibres arise from the genu of the corpus callosum?

A

Forceps minor which forms the anterior wall of the frontal horn and interconnects frontal lobe

474
Q

Which tracts arise from splenium of corpus callosum

A

Forceps major

Tapetum which sweeps inferolaterally to form the roof and lateral wall of atrium, temporal and occipital horns.

475
Q

What structures are connected by the anterior commissure

A

Interconnects the olfactory structures and temporal gyri on both sides

476
Q

Parts of the fornix

A

Fimbria

Crus

Body

Columns

477
Q

What separates the fimbria from dentate gyrus?

A

Fimbriodentate sulcus

478
Q

What separates the fimbria from the LGN and and optic/auditory radiations

A

Choroidal fissure

479
Q

Where do the crurara of the fornix meet to form the body of the fornix?

A

At the junction between the atrium and body of lateral ventricle

Passes above thalamus and below septum pellicdum in lower part of medial wall of body of lateral ventricel

480
Q

Where does the body of the fornix separate into the two columns

A

At the anterior margni of the foraemn of Monro

481
Q

Where is the hippocampal commissure?

A

In the area below the splenium, interconnectinhte medial edges of the crura of the fornix

482
Q

Relation of central sulcus to coronal suture

A

Normally 3.5-4.5cm behind

483
Q

Parts of the choroidal fissure

A

Body part- between body of fornix and thalamus

Atrial part- between crus and pulvinar

Temporal part- between fimbria and stria terminais

484
Q

Importance of choroid fissure

A

Allows access to third ventricle

In termporal region demarcates those structures located laterally that can be removed from those medially that should be preserved

485
Q

Structure of the septum pellucidum

A

Streatches between the anterior corpus callosum and body of fornix

Paired laminae separating frontal horns and bodies of lateral ventricles in midline

486
Q

Attachment of septum pellucidum in the frontal horn

A

Attached to the rostrum of corpus callosum below and genu above

487
Q

Posteiror margin of septum pellicdum

A

Where the body of fornix meets splenium

488
Q

Basis of cavum septum

A

Cavity in midline between the two laminae of septum

489
Q

Location of kyehole

A

3cm anterior to pterion

Above the lateral end of superior orbital rim and under the most anterior point of attachment of the temporalis muscle and fascia to the temporal line.

490
Q

What forms the posterior edge of the foramen on Monro?

A

The anterior thalamic tubercle which is the prominence overlying the anterior thalamic nucleus

491
Q

What forms the lateral half o f the anterior wall of the atrium?

A

Pulvinar

492
Q

What forms the anterior wall of the quadrigeminal cistern?

A

Pulvinar

493
Q

Why is the central sulcus nearer to the coronal suture at its lower end than at its higher?

A

As it ascends it is directed more posteriorly

494
Q

Cortical landmark of pineal gland

A

At the level of the posterior part of the middle temporal gyrus

495
Q

Best transcortical approaches to cerebrum

A

Frontal lobe:

Middle or superior frontal gyri

Parietal loebe:

Superior parietal lobule

Intraparietal sulcus

Temporal:

Lower part of lateral or basal surface

496
Q

Sulci suitable for apporaching deep lesions

A

Superior frontal

Inferior temporal

Occipitotemporal

Collateral

Intaraparietal sulci

497
Q

Structures accessible via trans-sylvian dissection

A

Insula

Basal ganglia

Uncus

Orbit

Anterior cranial fossa

Olfactory

Optic

Oculomotor

Chiasmatic/interpeduncular/carotiod/lamina terminalis/crural cisterns

ICA, ​MCA and proximal ACA, basilar tip

498
Q

Why does the posterior part of the interhemispheric cistern provide an excellent route to the quadrigeminal cistern

A

There are no bridging veins between posterior part of SSS and the occipital lobe

499
Q

Structures accessible via subfrontal approach

A

Cribiform plate

Orbital roof

Optic nerves

Chiasmatic, lamina terminalis cisterns

Medial part of Sylvian fissure

500
Q

Structures accessible via anterior subtemporal approach

A

Lesions along whole lateral margin of incisura back to the junction of ambient and quadrigeminal cisterns

Less risk with retraction as the basal bridging veins tend to be more posteriorly located

501
Q

What are the three principle steps in temporal lobectomy

A

Lateral temporal exposure and removal

Medial disconnection of hippocampus

Anterior disconnection of hippocampus

Posterior disoconnection

Removal of remaining amygdala in front of uncal rescess

502
Q
A
503
Q

Etymology corpus callosum

A

Corpus meaning body

Callosum meaning tough

504
Q

Etymology of fornix

A

Arch or vault

505
Q

Etymology of sulcus

A

Furrow made with plow in Latin

506
Q

Etymology parietal

A

From latin paries “wall”

507
Q
A