Brain and Behavior, Week 4 Flashcards
Useful dermatomal landmarks:
C5 = shoulder T4 = nipple line T10 = umbilicus L1 = groin
Most common causes of locked-in syndrome:
Most common: Pontine stroke
2nd most common: osmotic demyelination syndrome
Hallmark signs of encephalitis:
HA, fever, mental status changes
Acute disseminated encephalomyelitis (ADEM):
Post-infectious auto-immune response to infection resulting in enchephalitis
Diagnostic criteria for pseudotumor cerebri:
- Papilledema
- Normal neuro exam except for CN abnormalities
- Normal imaging
- Normal CSF
- High ICP
What event can provoke an absence seizure in susceptible individuals?
Hyperventilation
What is the EEG finding in a person having an absence seizure?
3 HZ spike and wave
Diagnostic criteria for MS:
- At least 1 lesion in 2 of 4 spaces
- New T2 or Gad enhancing lesion relative to baseline
- Must meet criteria for both TIME and SPACE
- 1st episode called “clinically isolated syndrome”
- NOT a radiographic diagnosis
What’s the main advantage of disease modifying therapies for MS?
- Reduction of relapse rates
- PROBABLY slows progression to disability
Some drugs for treating focal seizures:
Phenytoin, Carbamazepine
Side effects of phenytoin:
Ataxia, nystagmus, gingival hyperplasia, osteomalacia, long term cerebellar toxicity
What is ethosuxamine useful for?
Absence seizures
Depakote is highly protein bound. What’s the consequence of this with regard to its use with phenytoin?
They’re both protein bound, so using Depakote with phenytoin will decrease the fraction of phenytoin that’s protein bound, and therefore increase its serum concentration.
Major drug interaction with lamotrigine:
Valproic acid. Valproic acid can increase the concentration of lamotrigine by as much as 200%
Which anti-seizure drug in contraindicated in patients with a sulfa allergy?
Zonisamide
Upper boundary of the spinal cord:
Medial lemniscus
Where do motor neurons cross from one side of the nervous system to the other?
Medulla
What is the function of the medial lemniscus?
- Area where somatosensory fibers traveling up the posterior columns decussate
- Part of the posterior-column/medial lemniscus pathway
- Made up of internal arcuate fibers, which are composed of nucleus gracilis and nucleus cuneatus axons
- 1-ary axons synapse at nucleus gracilis/cuneatus, then 2-ary neurons decussate and travel contralaterally up to thalamus
Upper motor neuron diseases:
- MS
- ALS
- Cerebral palsy
Lower motor neuron diseases:
- Muscular dystrophy
- Myasthenia gravis
- ALS
- Guillain Barre
- Floppy baby
MOA for phenytoin:
Uses:
- Sodium channel antagonist
- Partial, general
Indications for phenobarbitol:
CI:
- Partial, general
- Liver or kidney dz, airway obstruction, porphyria
MOA for carbamazepine:
Uses:
- Sodium channel antagonist
- Partial, general
MOA for Depakote:
- Sodium/Ca channel antagonist, GABA agonist
- Partial, general, absence, infantile spasms, myoclonic/tonic
MOA for benzodiazapenes:
Uses:
- GABA potentiator, chloride channel enhancer
- Partial, general, myoclonic
MOA for ethosuxamide:
Uses:
- Ca channel antagonist
- Absence
MOA for felbamate:
Uses:
- GABA agonist, NMDA antagonist
- All seizures
MOA for Lamictal:
Uses:
- Sodium channel antagonist, glutamate inhibitor
- All seizures
MOA for topiramate:
Uses:
- Sodium channel antagonist, GABA agonist, NMDA antagonist
- Partial, general, absence, atonic, Lennox-Gastaut
Indications for gabapentin:
CI:
- Partial, general
- None (adjust for renal dosing)
Indications for pregabalin:
CI:
- Adjunctive
- None
GABA-acting drugs:
Phenobarbitol, primidone, valproate, benzos, felbamate, tiagabine, gabapentin, pregabalin, topiramate, zonisamide, vigabatrin
NMDA antagonists:
Felbamate, topiramate, pregabalin
Sodium channel antagonists:
Phenytoin, phenobarbitol, primidone, valproate, carbamazepine, lamotrigine, topiramate, zonisamide
Calcium channel antagonists:
Ethosuxamide, phenobarbitol, valproate, zonisamide
Shy-Drager syndrome (Multi Systems Atrophy):
- Severe autonomic dysfunction
- Vocal cord problems: stridor
- MRI shows cerebellar and pontine atrophy
- Treat Sx (orthostasis, anhidrosis, incontinence, etc) and sleep (CPAP) problems
- Levodopa for Parkinsonism
