Neuro Notes Flashcards
what is the mechanism of action of anticonvulsants
they inhibit calcium channels
name an excitatory/depolarising synapse
glutamate
which synapse is anion selective (-ive charge)
GABA
what is the mechanism of action of Benzos
increase Cl- entry to enhance initiation of inhibitory synapses
enhance the effect of GABA
which clinical syndrome is seen with ‘same side paralysis, opposite side pain’
brown sequard syndrome
where is the somatosensory cortex located
the post central gyrus
what do gamma motor neurones innervate and what is the reflex called
the muscle spindle fibres
the myotactic reflex
what do alpha motor neurones innervate
innervate a bulk of muscle fibres within a muscle
define a motor unit
consists of an alpha motor neurone and all the skeletal muscle fibres it innervates
within the ventral horn, where do flexor LMNs sit in relation to the extensor LMNs
Flexor LMNs sit Far away - flexor LMNs sit Dorsal to the extensor LMNs in the ventral horn
what is the myotactic reflex mediated by
the release of glutamate
what are the 3 main pathologies seen in Alzheimer’s disease
- neurofibrillary tangles (intracellular TAU PROTEIN)
- senile plaques (extracellular)
- loss of cortical neurones
which area of the brain is affected 1st in Alzheimer’s dementia
nucleus basalis of meynart
the main site of cholinergic initiation in the brain
what are the senile plaques in Alzheimer’s disease made of
amyloid B protein
which congenital disorder sees Alzheimer’s onset in 2rd/4th decade
Downs syndrome
where do most berry aneurysms occur
arterial bifurcations (esp the internal carotid artery)
what is the strongest risk factor for vascular dementia
hypertension
what are lewy bodies made of
alpha synuclein
What are the 3 most common causes of bacterial meningitis in neonates
- listeria
- Group B strep
- E.Coli
What are the 3 most common causes of bacterial meningitis in immunocompromised
- strep pneumoniae
- Neisseria meningitidis
- listeria
What is the most common cause of bacterial meningitis in children <4y/o
haemophilus influenza B
What are the 2 most common causes of bacterial meningitis in >21y/o
1st = Strep pneumonia 2nd = neisseria meningitidis
why is levodopa not used in <70y/o
can build up tolerance
high risk of dyskinesia
what is the most common cause of degenerative Parkinson’s
multi system atrophy
in a pyramidal lesion, are arm and leg flexors or extensors weakened
arm extensors are weakened
leg flexors are weakened
which lobe is commonly involved in progressive supranuclear palsy and what clinical picture does this cause
frontal lobe
causes apathy, disinhibition and impaired reasoning
if listeria is suspected in bacterial meningitis, what else is added to the IV ceftriexone
IV amoxicillin
what is an extra dural haematoma caused by
middle meningeal artery rupture
which brain injury can present with a lucid interval
extra dural haematoma
which haematoma is most likely to affect bridging veins
subdural haematoma
when is carbamazepine used as epilepsy treatment
in focal seizures
which 2 contraceptive drugs lose their efficacy when carbamazapine is used
POP and progesterone implant
which type of epilepsy seizure is ethusixamide used in
absence seizures
which antiepileptic drug can make absence seizures worse
carbamazepine
what does the ‘HEAD’ acronym stand in relation to signs of an epileptic seizure in temporal lobe
Hallucinations
Epigastric rising motion
Automatisms (lip smacking, grabbing, plucking)
De ja vu, postical dysphasia
what signs would suggest a seizure has occurred in the parietal lobe
sensory parasthesia (tingling/numbness)
postical weakness is suggestive of a seizure in which area
frontal lobe
motor signs are usually seen if there is a seizure in this area
which are the only 2 cranial nerves that don’t receive bilateral innervation from the corticobulbar nerve
7 and 11
total anterior circulation infarct presents with how Many of the criteria for stroke
all 3!
treatment for a tension headache
amitryptiline
saccular berry aneurysms cause what ?
subarachnoid haemorrhage
what’s the most common cause of meningitis in ages 10-21
neisseria meningitidis
