nervous system chapter 13

Question 1

55 y/o male to A&E with weakness in right arm and leg. Reduced tactile sensation on his right arm and leg.

Which side of the brain affected and why?

Answer 1

• left side of brain
• contralateral hemisphere supplies motor sensation
• due to decussation

Question 2

2 most common causes that would lead to weakness in both legs and reduced tactile sensation in both legs

Answer 2

1. thromboembolic stroke

2. haemorrhagic stroke

Question 3

nerve roots when testing biceps

Answer 3

C5, C6

Question 4

nerve roots when testing ankle jerk

Answer 4

S1

Question 5

nerve roots when testing patellar reflex

Answer 5

L3, L4

Question 6

Where is CSF produced and reabsorbed?

Answer 6

1. choroid plexus via ultrafiltration in ventricles
2. travels via intraventricular foramen on Monroe from lateral to third ventricles
3. through cerebral aqueduct into fourth ventricle
4. via foramina of Magendie and Luschka into subarachnoid space
5. reabsorbed via arachnoid granulations in the superior saggital sinus

Question 7

Long term alcohol abuse can result in:

Answer 7

• degeneration of neutrons in cerebellar cortex via nutritional deficiency

Question 8

describe break down of alcohol

Answer 8

• alcohol oxidised to acetaldehyde via alcohol dehydrogenase
• acetaldehyde oxidised to acetate via aldehyde dehydrogenase

Question 9

classic triad of cerebellar disease

Answer 9

1. dysdiadochokinesia
2. dysmetria (lack of coordination of movement)
3. ataxia

Question 10

outline mechanisms for repair when a peripheral nerve is damaged?

Answer 10

• Wallerian degeneration of distal axon begins
• macrophages, phagocytes and Schwann cells migrate and clear necrotic debris
• axonal sprouting then occurs at proximal stump
• grows until they enter distal stump

Question 11

which part of the brain is commonly affected in Parkinsons?

Answer 11

• basal ganglia

Question 12

functions of basal ganglia

Answer 12

• control of voluntary motor activity
• control of reflex muscular activity
• control of muscle tone

Question 13

What three signs characterise Parkinsons disease?

Answer 13

1. tremor at rest
2. rigidity
3. bradykinesia

Question 14

some ocular signs that may be present with an expanding brain haematoma?

Answer 14

• papilloedema
• esotropia (Esotropia is a form of strabismus in which one or both eyes turns inward.)
• mydriasis (dilation of pupil of eye)
• ptosis

Question 15

extradural haemorrhage

Answer 15

• between skull and periosteal dura

- due to meningeal artery rupture

Question 16

subarachnoid haemorrhage

Answer 16

• between arachnoid and Pia mater

- contains CSF

Question 17

subdural haemorrhage

Answer 17

• potential space between dura and arachnoid

- due to rupture of bridging veins

Question 18

28 y/o female presents to A&E with head trauma. patient has blood stained watery fluid leaking out of ear (cerebrospinal fluid ottorhea) .

what bone has been fractured?

what two cranial nerves should be tested?

Answer 18

• temporal bone

1. facial nerve
2. vestibulocochlear

Question 19

tract for crude touch

Answer 19

anterior spinothalamic

Question 20

tract for pain and temperature

Answer 20

• spinal cord lateral spinothalamic

Question 21

where does lateral corticospinal tract decussate

Answer 21

• medulla

- thus would correspond to ipsilateral side

Question 22

what type of Motor neurone disease would cause fasciculations?

suggest some other neurological findings

Answer 22

• lower motor neurone
• flaccid paralysis
• hyporeflexia
• atrophy of muscles

Question 23

what info does the dorsal column deliver?

Answer 23

• fine touch
• proprioception
• vibration

Question 24

spinothalamic tract delivers

Answer 24

pain and temperature

Question 25

spinocerebellar tract transmits

Answer 25

- proprioception | - to cerebellum

Question 26

corticospinal tract

Answer 26

- descending | - conscious control of skeletal muscle

Question 27

man presents to hospital after having fainted earlier today. he experienced slurred speech shortly but seems to have recovered. insists he is fine. indicative of:

Answer 27

- transient ishcaemic attack - duration < 24 hours - as a result of atherothromboembolism from carotid

Question 28

a patient who can understand what I being said but found it difficult to express himself. what type of aphasia is this?

Answer 28

- Broca's aphasia

Question 29

where in the brain is the cortex for Broca's aphasia found?

Answer 29

- inferior frontal gyrus | - middle cerebral artery

Question 30

frontal lobe atrophy may result in

Answer 30

- loss of attention - loss of abstract thought - preservation - innappropriate behaviour

Question 31

a patient who presents with tremors, rigidity and myoclonic jerks most likely has damage too

Answer 31

basal ganglia

Question 32

describe normal pressure hydrocephalus

Answer 32

- abnormal CSF accumulation in ventricular system - brain increases with increased ventricle size - hence no increase in pressure

Question 33

classic triad of normal pressure hydrocephalus

Answer 33

- gait disturbances - sphincter disturbance - dementia

Question 34

cresent shaped haematoma suggestive of:

Answer 34

- subdural haemorrhage

Question 35

between what two layers is a subdural haematoma found?

Answer 35

- between dura mater | - and arachnoid mater meningeal layers

Question 36

describe what is coning / tonsillar herniation

Answer 36

- cerebellar tonsils forced through foramen magnum - due to increased intracranial pressure - eventual compression of brainstem - dysfunction to centres of brain responsible for controlling cardiac and respiratory function

Question 37

syringomyelia

Answer 37

- fluid filled cyst exists within spinal cord - can expand and enrage into grey and white matter - thus compressing tissue of corticospinal and spinothalamic tracts and anterior horn cells - causes dissociated sensory loss

Question 38

ipsilateral blinders suggest lesion in the

Answer 38

optic nerve

Question 39

bitemporal hemianopia

Answer 39

lesion in optic chiasm

Question 40

homonymous hemianopia

Answer 40

lesion in optic tract

Question 41

left / right superior quadrantanopia suggests a

Answer 41

temporal lobe lesion

Question 42

corneal reflex

Answer 42

- ophthalmic branch of trigeminal nerve | - temporal and zygomatic branch of facial nerve

Question 43

lateral rectus innervated by

Answer 43

abducens nerve