Forebrain Dz

Question 1

what is the forebrain? what is it formed of?

Answer 1

area of brain rostral to the tentorium cerebelli (divides cerebellum and forebrain)
- formed of telencephalon (cerebrum) and thalamus (part of diencephalon)

Question 2

Know where different regionsof the cortex lie

Answer 2

• olfactory bulbs and tracts
• forntal lobes
• parietal lobes
• temporal lobes
• occipital lobes q

Question 3

Which cranial nerves do not exit the brainstem?

Answer 3

1 + 2

- all others exit the brainstem

Question 4

Where do the olfactory bulbs and tracts lead to and what are they responsible for?

Answer 4

• perception of smell
• cell bodies in nasal epithelium
• cribiform plate
• limbic system
• cribiform lobe
• rhinencephalon

Question 5

what is specieal about CN1 and 2?

Answer 5

not really nerves
- olfactory tracts are collections of lots of small fibres
-

Question 6

temporal lobe responsible for..

Answer 6

• adutiroy area
• vestibular concious perception
• pyriform lobe olfactory and limbic system (emotion)

Question 7

frontal lobes responsible for..

Answer 7

• mainly motor area

- corticospinal and corticonuclear tracts of CONTRALATERAL body

Question 8

parietal lobes repsonsible for..

Answer 8

sensory mainly, some motor areas (or to motor areas? hard to tell from notes..)

Question 9

occipital lobes responsible for..

Answer 9

visual concious perception

Question 10

Outline the visual pathway

Answer 10

• Retina
• optic nerve [retinal ganglion cells, glial cells and meninges, myelinated extension of the brain]
• optic chiasm (lateral retina remains ipsilateral, medial retina decussates)
• optic tract
• lateral geniculate nucleus
• optic radiation
• occipital lobe

Question 11

What is papilloedema?

Answer 11

• bulging of the optic nerve into the vitreous d/t optic neuritis

Question 12

Outline the path of the menace response

Answer 12

• visual pathway
• occipital lobe association fibres to motor cortex
• projection fibres to PONTINE nucleus in pons (brainstem)
• transverse fibres to contralateral cerebellar cortex
• efferent cerebellar fibres to facial nuclei
• facial nerve to obicularis oculi m.
• blink

Question 13

When may the menace be absent for reasons other than tract problems?

Answer 13

• first 10-12 weeks (learned response)
• stressed
• lethargic
• disorientated patients

Question 14

CLinical signs of forebrain dysfunction

Answer 14

> mental status
- altered (depression/delerium/confusion/stupor/coma)
- behavioural changes ( thalamic) eg. hemi-neglect syndrome where one visual FIELD is lost [eg. will only eat half of dinner etc.]
seizures
- always indicate forebrain involvement by definition
gait
- normal OR
- head pressing
- body turn [pleurothotonus], head turn or circling towards side of lesion
postural reaction deficits
- loss of concious postural reactions (eg. paw placement) on contralateral limb to lesion
decreased facial sensation
- contralateral to lesion
- trigem branches all 3 have sensory component (+ mandibular has motor)
- pathway to parietal and frontal lobes
NORMAL spinal reflexes
- (unless multifocal dz causing them elsewhere)

Question 15

Which side of the brain do visual deficits in hemi-neglect syndrome indicate the lesion is on?

Answer 15

opposite side to visual defect side

Question 16

Which side is the lesion with a left head turn?

Answer 16

Left

Question 17

What type of ataxia does forebrain involvmenet cause?

Answer 17

proprioceptive

Question 18

What are the 3 branches of trigem? Which are sensory and which are motor?

Answer 18

opthalmic
maxillary
mandibular
- all sensory 
- mandibular only = motor to mm. of mastication

Question 19

Which parasite can cause ^Intracranial pressure in the cat?

Answer 19

• Taenia parasitic cysts
• ^ ICP squashes cerebellum
• > transtentorial herniation and herniation of cerebellum through foramen magnum

Question 20

slides of tx of cases supposed to be put on learn???

Answer 20

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