Y4 Neurology Flashcards
describe the transmission of an AP to create muscle contraction?
- Presynaptic voltage-gated Ca2+ channels open → Ca2+ influx
- ACh vesicles released from presynaptic terminal
- ACh diffuses across cleft
- ACh binds to nicotinic receptors on post-synaptic
terminal - → Na+ influx → depolarisation → Ca2+ release from SR
→ muscle contraction - ACh is degraded by acetylcholinesterase and choline is
taken up into presynaptic terminal.
what receptor does ACh bind to at the post synaptic terminal of the NMJ?
nicotinic
what blocks ACh vesicle fusion at the NMJ?
botulinum, LEMS
what blocks nicotinic ACh receptors at the NMJ?
Non-depolarising: atracurium, vecuronium
Depolarising: suxamethonium
what three conditions are associated with dopamine pathways?
schizoaffective disorder
parkinsons
hyperprolactinaemia
what dopamine pathways in the brain are associated with schizoaffective disorder?
Mesocorticolimbic: SCZ
what dopamine pathways in the brain are associated with parkinsons ?
Nigrostriatal: Parkinsonism
what dopamine pathways in the brain are associated with hyperprolactinaemia ?
Tuberoinfundibular: Hyperprolactinaemia
what symptoms would you expect from a cortical lesion?
Hyperreflexia proximally in arm or leg
Unexpected patterns
what symptoms would you expect from a cord lesion ?`
Quadriparesis / paraparesis
Motor and reflex level: LMN signs at level of lesion and UMN signs below
what symptoms would you expect from a internal capsule lesion?
Contralateral hemiparesis ̄c pyramidal distribution.
where is the lesion with fasciculations?
LMN
where is the lesion for brown sequard syndrome?
hemi spinal cord
what are the symptoms of brown sequard syndrome ?
Ipsilateral loss of proprioception / vibration and UMN weakness with contralateral loss of pain
what symptoms are seen in cerebellar syndrome?
Dysdiadochokinesia
Dysmetria: past-pointing
Ataxia: limb / trunkal
Nystagmus: horizontal = ipsilateral hemisphere
Intention tremor
Speech: slurred, staccato, scanning dysarthria
Hypotonia
what are some common causes of cerebellar syndrome ?
Paraneoplastic: e.g. from bronchial Ca Alcohol: thiamine and B12 deficiency Sclerosis Tumor: e.g. CPA lesion Rare: MSA, Friedrich’s, Ataxia Telangiectasia Iatrogenic: phenytoin Endo: hypothyroidism Stroke: vertebrobasilar
what visual disturbance is seen with posterior cerebral artery occlusion?
Contralateral homonymous hemianopia ̄c macula sparing.
what is the vascular cause of lateral medullary syndrome?
occlusion of one of the PICA arteries
what is ataxia?
The term ataxia refers to a lack of fine control of voluntary movements.
what does lateral medullarly syndrome result in?
Dysphagia Ataxia (ipsilateral) Nystagmus (ipsilateral) Vertigo Anaesthesia - Ipsilat facial numbness + absent corneal reflex - Contralateral pain loss Horner’s syndrome (ipsilateral)
what symptoms does Millard-Gubler Syndrome have ?
Effects: 6th and 7th CN palsy + contralateral hemiplegia
what causes Millard-Gubler Syndrome?
Pontine lesions
what are the effects of an anterior spinal artery occlusion? (Becks syndrome)
Para- / quadri-paresis
Impaired pain and temperature sensation
Preserved touch and proprioception
what does LEMS stand for?
Lambert-Eaton myasthenic syndrome
where does LEMS affect?
the NMJ
what can cause peripheral neuropathy?
DM, EtOH, uraemia
what can cause damage to the dorsal columns?
B12 deficiency
what is lost when the dorsal columns are damaged ?
proprioception
