Week 6: Seizures, Epilepsy and Status Epilepticus Flashcards
Define epilepsy and seizures.
- Epilepsy: recurrent unprovoked seizures
- Seizures: abnormal excitation of cortical neurons, spreading to adjacent neurons and brain structures
What are the causes of epilepsy?
- 70% idiopathic
- vascular, developmental, trauma, neoplasm, infection, degeneration
List the classifications of epilepsy.
- partial: onset localizes to one area in cortex
- primary generalized: onset is bilateral synchronous, though to arise from thalamic triggers
A. symptomatic: can be related to a prior insult or injury
B. Idiopathic: unknown cause/inherited
What are the characteristics of a tonic/clonic primary generalized epilepsy?
- eyes roll up or to side
- head may turn
- limb rigidity followed by limb jerking
- fall, cry
- may turn blue due to diaphragmatic tightening
- may have tongue biting, urinary incontinence
- post ictal confusion
What are the characteristics of an absence primary generalized epilepsy?
- rapid onset (staring spell), rapid offset
- brief stare for 10-20 sec, eye fluttering
- no post octal confusion, but has amnesia for event
- age: 3-11 yo
- EEG findings: 3/sec generalized spike wave
- autosomal dominant with variable penetrance
Describe juvenile myoclonic epilepsy (a primary generalized seizure)?
- peak age: 12-22 yo
- myoclonic jerks plus: tonic clonic seizures, clonic-tonic-clonic, absence
- frequently occur upon awakening
- good prognosis on anti epileptic drugs, frequency recurrence off AEDs
- triggers: sleep deprivation, stress, EtOH/drug use “college”
- autosomal dominant with variable penetrance
- EEG pattern: 4-6 per second polyspike-waves
How are partial seizures classified?
Based on level of consciousness
- simple partial: normal consciousness
- complex partial: impaired consciousness
Where are partial seizures most common in the brain?
temporal lobe
What are the characteristics of temporal lobe seizures (partial)?
- aura: deja vu, abdominal rising, fear
- followed by: staring, behavior arrest
- lip smacking, automatisms
- post ictal confusion
- duration: 20 secs to 2 mins
What are the signs of extra-temporal onsets by lobes?
- Frontal lobe: brief, early motor activity, seizures cluster frequently. Fencer posturing, head turning early, gesturing
- parietal lobe: sensory phenomena, speech changes
- occipital lobe: visual aura
Compare and contrast complex partial and absence seizures.
Complex partial -2-5 minutes duration -aura -motionless stare -automatisms: lip smacking -confusions 5-20 mins post ictally Absence -brief 10-20 secs -no aura -motionless stare common -eye fluttering, rare jerks -no post ictal confusion
Compare primary and secondary generalized seizures.
PRIMARY -abrupt onset -no aura -tonic-clonic, tonic, clonic -genetic component common -early onset in life SECONDARY -follows partial seizure -can have abrupt onset -tonic-clonic -subjective aspects of partial seizure: visual, tactile, auditory symptoms -later life onset
What are the characteristics of febrile seizures?
- 90% in 6mos-3 years
- occur in up to 5% of children
- during rising phase of fever
- inherited
- simple vs complex
What is the difference between simple and complex febrile seizures?
Simple
- solitary events, 15 mins
- focal features
- family history of epilepsy
- abnormal neuro exam
- multiple seizures in 24 hours
Define status epilepticus.
Continuous seizure lasting 30 minutes or more, or multiple seizures within 30 minutes without recovery of consciousness between seizures
What are the causes of status epilepticus?
- febrile illness in patients with epilepsy
- anti epileptic drug withdrawal
- anoxia
- stroke
- trauma
- CNS infection
When is treatment initiated for seizures?
- risk of recurrence after first seizure is 35%
- risk of recurrence after subsequent seizure is 90%
- risk is increased with abnormal MRI, CT, EEG, neuro exam, family hx,
