Neurology Flashcards
Locus ceruleus significance
Found in pons, source of Norepinephrine
Raphe nuclei significance
Found in pons, medulla, midbrain. Source of serotonin
Striatum & lentiform defined
Striatum: Putamen (motor) + caudate (cognitive)
Lentiform: Putamen + globus pallidus
Two important causes of locked-in syndrome
1) Central pontine myelinolysis (rapidly corrected hyponatremia)
2) Basilar artery stroke (think of the paramedian reticular formation)
Brain area most vulnerable to ischemia
Hippocampus (neocortex, cerebellum, watershed areas as well)
Clasp-knife spasticity, and fasciculations. Signs of what?
Clasp-knife - upper motor neuron sign (increased tone and resistance to movement that suddenly releases)
Fasciulations - lower motor neuron sign
Superoxide dismutase 1 significance?
Defect in SD1 can be associated with ALS
Side note: ALS can be treated with Riluzole (Glutamate antag)
Patient presents with isolated inability to look upward. Lesion and cause?
Parinaud syndrome from lesion in superior colliculus. Can be caused by tumor in the pineal gland, just superior to superior colliculus (caudal to cerebellum, on posterior surface of midbrain). Remember inferior colliculus is for hearing
Foramen spinosum
Skull base entry point for the middle meningeal artery
Stapedius muscle in inner ear. Innervation?
CN VII. Thus branchial arch 2 derivative
Cholesteatomas composed of what
Keratin overgrowth within middle ear space
CN IV lesion
Trochlear palsy, patient has difficulty with depression of eye when looking medially (superior oblique). Hypertropy that’s worse when looking medially
MOA of sumatriptan
5-HT agonist specifically in CNS vasculature. This causes vasoconstriction of these arteries and decreases the inflammation thought to be responsible for cluster headaches and migraines
Neurofibromatosis type 1 genetics
NF-1 mutation on chromosome 17. NF-1 usually inhibits Ras pathways.
Skin neurofibromas usually derived from neural crest cells
MOA of opioid analgesics
Agonist of opioid receptors, results in decreased synaptic transmission by opening K channels and closing Ca channels necessary for release of neurotransmitters.
Two epilepsy drugs associated with Stevens-Johnson syndrome
Lamotrigine (when titrated too quickly) and Ethosuximide (for absence seizures). Also, phenytoin, carbamazepine (just btw)
Ethosuximide MOA
Blocks T-type Ca channels in the thalamus. Indicated for absence seizures
Benzos with shortest half-lives?
ATOM: alprazolam, triazolam, oxazepam, midazolam. Highest abuse potential
3 main embryonic structures that give rise to CNS?
Prosencephalon: forebrain
Mesencephalon: midbrain
Rhombencephalon: hindbrain (i.e. cerebellum)
Memantadine MOA
NMDA receptor antag used in treatment of Alzheimers. NTBCw/ Amantadine a stimulator of dopamine release and inhibitor of dopamine reputake (Parkinsons)
Pramipexole, ropinirole MOA?
Non-ergot direct dopamine agonists used in treatment of Parkinson’s disease
Selegiline MOA
Inhibition of central MAO-B which degrades dopamine to 3-MT
Anterior choroidal artery. Origin and structures it supplies
Branch of the internal carotid just before it gives off ACA and MCA. Supplies posterior limb of internal capsule, LGN, choroid plexus (hence the name), hippocampus, amygdala, uncus
Weber test for hearing loss
Conductive hearing loss: localizes to the affected ear
Sensorineural hearing loss: localizes to unaffected (contralateral) ear
