nervous system chapter 13 Flashcards
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?
- left side of brain
- contralateral hemisphere supplies motor sensation
- due to decussation
2 most common causes that would lead to weakness in both legs and reduced tactile sensation in both legs
- thromboembolic stroke
2. haemorrhagic stroke
nerve roots when testing biceps
C5, C6
nerve roots when testing ankle jerk
S1
nerve roots when testing patellar reflex
L3, L4
Where is CSF produced and reabsorbed?
- choroid plexus via ultrafiltration in ventricles
- travels via intraventricular foramen on Monroe from lateral to third ventricles
- through cerebral aqueduct into fourth ventricle
- via foramina of Magendie and Luschka into subarachnoid space
- reabsorbed via arachnoid granulations in the superior saggital sinus
Long term alcohol abuse can result in:
- degeneration of neutrons in cerebellar cortex via nutritional deficiency
describe break down of alcohol
- alcohol oxidised to acetaldehyde via alcohol dehydrogenase
- acetaldehyde oxidised to acetate via aldehyde dehydrogenase
classic triad of cerebellar disease
- dysdiadochokinesia
- dysmetria (lack of coordination of movement)
- ataxia
outline mechanisms for repair when a peripheral nerve is damaged?
- 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
which part of the brain is commonly affected in Parkinsons?
- basal ganglia
functions of basal ganglia
- control of voluntary motor activity
- control of reflex muscular activity
- control of muscle tone
What three signs characterise Parkinsons disease?
- tremor at rest
- rigidity
- bradykinesia
some ocular signs that may be present with an expanding brain haematoma?
- papilloedema
- esotropia (Esotropia is a form of strabismus in which one or both eyes turns inward.)
- mydriasis (dilation of pupil of eye)
- ptosis
extradural haemorrhage
- between skull and periosteal dura
- due to meningeal artery rupture
subarachnoid haemorrhage
- between arachnoid and Pia mater
- contains CSF
subdural haemorrhage
- potential space between dura and arachnoid
- due to rupture of bridging veins
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?
- temporal bone
- facial nerve
- vestibulocochlear
tract for crude touch
anterior spinothalamic
tract for pain and temperature
- spinal cord lateral spinothalamic
where does lateral corticospinal tract decussate
- medulla
- thus would correspond to ipsilateral side
what type of Motor neurone disease would cause fasciculations?
suggest some other neurological findings
- lower motor neurone
- flaccid paralysis
- hyporeflexia
- atrophy of muscles
what info does the dorsal column deliver?
- fine touch
- proprioception
- vibration
spinothalamic tract delivers
pain and temperature
spinocerebellar tract transmits
- proprioception
- to cerebellum
corticospinal tract
- descending
- conscious control of skeletal muscle
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:
- transient ishcaemic attack
- duration < 24 hours
- as a result of atherothromboembolism from carotid
a patient who can understand what I being said but found it difficult to express himself. what type of aphasia is this?
- Broca’s aphasia
where in the brain is the cortex for Broca’s aphasia found?
- inferior frontal gyrus
- middle cerebral artery
frontal lobe atrophy may result in
- loss of attention
- loss of abstract thought
- preservation
- innappropriate behaviour
a patient who presents with tremors, rigidity and myoclonic jerks most likely has damage too
basal ganglia
describe normal pressure hydrocephalus
- abnormal CSF accumulation in ventricular system
- brain increases with increased ventricle size
- hence no increase in pressure
classic triad of normal pressure hydrocephalus
- gait disturbances
- sphincter disturbance
- dementia
cresent shaped haematoma suggestive of:
- subdural haemorrhage
between what two layers is a subdural haematoma found?
- between dura mater
- and arachnoid mater meningeal layers
describe what is coning / tonsillar herniation
- 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
syringomyelia
- 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
ipsilateral blinders suggest lesion in the
optic nerve
bitemporal hemianopia
lesion in optic chiasm
homonymous hemianopia
lesion in optic tract
left / right superior quadrantanopia suggests a
temporal lobe lesion
corneal reflex
- ophthalmic branch of trigeminal nerve
- temporal and zygomatic branch of facial nerve
lateral rectus innervated by
abducens nerve
