Exam 1: Seizure & Epilepsy Flashcards
ILAE classification of common seizures
- how do they begin (focal/general)
- Is the person aware or impaired?
- Other features/ behavioral symptoms
Simple partial seizure
conscious of seizure occurring
motor, sensory, somatosensory, autonomic, behavioral manifestations
Complex partial seizure
impaired consciousness - remains after seizure
behavioral manifestations, hallucinations, same behavior every time
Secondary generalized
starts with partial onset but evolves into tonic clinic
often due to tumor, or other anatomical reason
Generalized Absence
petit mal
last seconds, generally in childhood
alteration of consciousness
General myoclonic
bilateral, involuntary rhythmic jerking of muscles
General Clonic
sustained muscle contractions
altering with relaxation
General Tonic
Sustained muscle contractions
with stiffening
General tonic-clonic “grand mal”
sudden loss of conciousness
rigid, falls to ground, lasts for 1 minute
can evolve to status epilepticus
General atonic
Drop attack, mainly in children
sudden loss of postural tone and falls to the ground
Pathophysiology of seizures
Abnormal firing of neurons due to ion channels
not enough inhibitory activity of GABA
too much excitatory activity of NMDA
How AED drugs work
Increase the inhibitory effects of GABA
Decrease the excitatory effects of NMDA (Na, Ca)
Causes of seizures
inherited
acquired
congenital
drug withdrawal
drug induced
Acquired seizures
head trauma, brain surgery, Cerebrovascular disease
infections, meningitis, flu, toxoplasmosis, Measles, mumps, syphillis
Metabolic disorders
Drugs withdrawal cause seizure
alcohol
benzodiazepines
barbituates
antiepileptics
Drugs that induce seizures
certain abx
antidiabetic drugs
anesthetics
antimalarials
antispastics
antidepressants
antipsychotics
Risk factors of breakthrough seizures; or if many at once, for any person
- sleep deprivation
- many missed AED dose
- alcohol withdrawal/rec drug misuse
- exhaustion
- strobe lights
- intercurrent infections
- metabolic disturbances
- uncommon: loud noise, hot bath
Rational polypharmacy
Risks:
1. DDI (carbamazepine + VPA = epoxide tox)
2. Drug burden (toxicity)
Rational
1. multiple MOA = synergy (lamotrigine + topiramate)
AED to use in pregnancy
Phenobarbital
lamotrigine
ethosuximide
topiramate
Oxcarbamazepine
AED to AVOID in pregnancy
phenytoin
valproic acid
Levetiracetam MOA
AMPA glutamate receptor non-competitive antagonist
Levetiracetam ADR
weight gain
Levetiracetam DDI
enhances CNS depressants
Levetiracetam disadvantages
Renal - dose adjust
Lamotrigine MOA
Na block to inhibit stimulatory AA (glutamate/aspartate)
Lamotrigine ADR
SJS/TEN
Influenza-like syndrome
Somnolense, blurry vision, ataxia, HA, aggression
Must titrate AED
Lamotrigine
Topiramate
Gabapentin MOA
GABA analog
inhibit reuptake
Gabapentin ADR
somnolense
Blurry vision, ataxia
Fatigue, nystagmus
Topiramate MOA
NA block potentiates GABA
Topiramate ADR
Expressive aphasia
Psych/cognitive dysfunction
Weight loss
Urolithiasis
BILATERAL paresthesias (not stroke)
sedation, dizziness, fatigue
Vigabatrin MOA
inhibits GABA metabolizing enzyme like valproic acid
Vigabatrin ADR
Visual field defects
psychosis and depression
VERY LIMITED USE - infantile spasms
Zonisamide MOA
Prolongs Na channel Inactivation
Zonisamide ADR
Loss of appetite, nausea, vomiting
but well absorbed GI
Tigabine MOA
Inhibits GABA reuptake and increases its level
Tigabine ADR
Mild memory impariment
Asthenia
Abdominal pain
sedation, dizziness,
Valproic acid MOA
increases GABA by inhibiting degrading enzymes
Valproic acid ADR
GI intolerance d/t poor solubility
weight gain (increased appetite)
hepatotoxicity
transient hair loss
NEURAL TUBE DEFECT
Valproic acid DDI
inhibits metabolism of
CTPP
Carbamazepine
Topiramate
Phenytoin
Phenobarbital
VPA also used for
GENERAL seizures
MANIA
Migraine Prophy
Mood
Phenytoin MOA
Na, Ca, influx block
inhibits excitatory aminoacids
Phenytoin ADR
GINGIVAL HYPERPASIA
hirsutism
HYDRANTOIN SYNDROME (fetal cleft)
megaloblastic anemia
OSTEOMALACIA
[GI upset]
[CNS: sedation, HA, vertigo, nystagmus]
[vein thrombosis]
Phenytoin also used for
partial, tonic clonic, NOT ABSENCE
V FIB
Carbamazepine MOA
similar to phenytoin
Na, Ca block
Carbamazepine ADR
HYPONATREMIA/water intoxication
Congenital malformations
RASH
BLOOD dyscrasias
SELF. INDUCER
Drugs with enzyme activity
Sodium valproate
Phenytoin
Carbamazepine
Levetiracetam (?)
Tigabine
AED with GI upset
VPA
Pheny
carba
zonisamide
tigabine
Seizure is Medical Emergency If
- Longer than 10 minutes or a 2nd one starts (status epilepticus risk)
- Difficultly in rousing at 20 min interval
- Compliants of vision change
- Vomitting
- Persistent HA after rest period
- Unconscious with failure to respond
- Pupils unequal or excessively dilated
FIRST AID for Generalized Tonic-Clonic Seizures
- Record the time of seizure onset
- Stay with the patient until the seizure ends
- Have someone call 911
- Prevent person from hurting himself or herself. Place something soft under the head, loosen tight clothing, and clear area of sharp or hard objects.
- DO NOT
- Force any objects into patient’s mouth
- Restrain patient’s movements.
- Pour liquids into patient’s mouth or offer any food, drink or medication until fully awake
- Turn patient on his or her side to allow saliva to drain from mouth
- Give artificial respiration if patient does not resume breathing after seizure.
- Provide area for patient to rest until fully awakened, accompanied by responsible adult.
