Epilepsy/Seizures Flashcards
Most common diagnostic test to diagnose epilepsy
Electroencephalogram (EEG)
Records electrical activity in the brain
CT and MRI can identify some conditions that can provoke seizures, including brain tumors and damage from a stroke
Three main types of seizures
Focal seizures - one side of the brain, can spread to the other side
Generalized seizures - start on both sides
Unknown onset seizures - location unknown, occurred unwitnessed or occurs during the night
Two different types of focal seizures
Focal aware seizures = no loss of consciousness (formerly known as simple partial seizure)
Focal seizure with impaired awareness = loss of consciousness (formerly known as complex partial seizure)
Define absence seizure
Seizure with non-motor symptoms
Presents as staring spells
Define status epilepticus (SE)
seizure lasting beyond 5 minutes
When can long term damage occur with an untreated seizure?
After 30 minutes
However treatment should begin after 5 minutes
Non-IV options for initial management of seizure?
Initial management = benzos
Can give IM midazolam
Diazepam rectal gel (Diastat, or Diastat AcuDial for patients who are at risk for long-lasting seizures)
Intranasal or buccal midazolam
Status epilepticus treatment algorithm (table p 963)
0-5 minutes: Stabilization phase (start EEG, check BG, treat with D25/D50 or raisins (jk), check AED levels, check elecrolytes, may need O2)
5-20 minutes: Initial treatment phase [if seizure continues past 5 mins: give BZD (IV midazolam Versed, IV lorazepam Ativan, rectal diazepam Diastat)]
20-40 minutes: Second treatment phase (Give regular AED option; IV fosphenytoin, valproic acid, levetiracetam. Can consider phenobarbital if other options unavailable]
Drugs that can lower the seizure threshold (there’s a lot)
Antipsychotics Antivirals Bupropion Carbapenems (especially imipenem with higher doses/renal impairment) Cephalosporins Lithium Lindane Mefloquine Meperidine (chronic dosing, poor renal fx) Metoclopramide PCNs Quinolones Alcohol withdrawal Infection and fever (esp in children) Theophylline Tramadol Varenicline
Non-drug treatment of refractory seizures
Ketogenic diet
High fat, low protein, low carb
Class effect of anti-epileptic drugs
CNS depression
(Dizziness, confusion, sedation, ataxia, coordination difficulties)
Can also cause bone loss and increase fracture risk (after 2 yrs), so supplement with calcium and vitamin D
Drugs that can cause hypohidrosis in children
Hypohidrosis = lack of sweating
Topiramate and zonisamide
Limit sun exposure
AED that can cause drug induced rash in children
Lamotrigine
Rash can be fatal
Enzyme inducing AEDs
Cabamazepine Oxcarbamazepine Phenytoin Fosphenytoin Phenobartbital Primidone Topiramate Valproic acid can also inc lamotrigine levels (inc risk of fatal rash)
AED use in pregnancy (long ass card im sorry)
Older AEDs (clonazepam, phenobarbital, primidone, phenytoin, fosphenytoin, carbamazepine, and valproic acid) have known teratogenic risk Valproic acid has the highest risk Newer agents risk profile not well defined but most have some degree of risk
Women of childbearing age on AEDs should get folate supplementation
Note AEDs can reduce efficacy of oral contraceptives!
Drug levels should be monitored more closely because they may need increased doses as AED levels can decrease during pregnancy however drug levels can INCREASE postpartum requiring lower doses
Required AED monitoring for all AED’s, and which ones require blood monitoring?
Seizure frequency (to ensure efficacy) Mental status (to minimize adverse effects)
Blood levels: phenytoin (trough 10-20 mcg/mL, free 1-2.5 mcg/mL), valproic acid (50-100 mcg/mL total), carbamazepine (4-12 mcg/mL), phenobarbital (20-40 mcg/mL, 15-40 mcg/mL for children)
Phenytoin kinetics
Michaelis-Mentin, or saturable kinetics
Can saturate enzymes so small increases in dose can cause large increases in drug level
Corrected phenytoin - when do we use it and whats the formula?
Low albumin (< 3.5 g/dL) and CrCL > 10 mL/min
Correction = total/[(0.2 x albumin) + 0.1]
FREE LEVELS do NOT require any correction