Seizures, epilepsy, and status epilepticus

Question 1

Epilepsy and seizures

Answer 1

• Epilepsy: recurrent unprovoked seizures
• Seizures: abnormal excitation of cortical neurons spreading to adjacent neurons/brain structures
• Abnormal excitation due to: excessive synaptic excitation (stimulation of glutamate receptors AMPA and NMDA), blockage of inhibitory synapses (GABA), changes in extracellular fluid (increased K or decreased Ca), glial cell glutamate release

Question 2

Epilepsy epidemiology

Answer 2

• Prevalence: 2.5 million in US

- Incidence (lifetime): 1.3-3.1%

Question 3

Etiology of epilepsy

Answer 3

• 70% idiopathic
• Symptomatic (related to prior insult): vascular, developmental, trauma, neoplasm, infection, degenerative
• Partial epilepsy: onset localizes to one area of cortex
• Primary generalized: onset is bilateral synchronous, arises from thalamus

Question 4

Primary generalized epilepsies

Answer 4

• Absence
• Tonic (tense)/clonic (convulse) or clonic/tonic/clonic
• Can be only tonic or only clonic
• Myoclonic
• Atonic (drop attacks)

Question 5

Generalized tonic/clonic seizures

Answer 5

• Eyes roll up or deviate
• Head may turn
• Limb rigidity
• Fall or cry
• May turn blue (diaphragmatic tightening)
• Tongue biting, incontinence
• Post-event confusion

Question 6

Absence seizures

Answer 6

• Rapid onset (staring spell) followed by rapid offset
• Brief (10-20 sec) stare and eye flutters
• No post-ictal (event) confusion
• Amnesia for event
• Age of onset: 3-11 yo
• EEG findings: 3hz generalized spike-wave (may cause cognitive impairment)
• Autosomal dominant w/ variable penetrance
• Hyperventilation assists in eliciting the EEG pattern

Question 7

Juvenile myoclonic epilepsy

Answer 7

• Peak age: 12-22 yo
• Absence, myoclonus, tonic/clonic seizures
• Good prognosis on AEDs (anti-epileptic drugs), bad w/o
• Triggers: sleep deprivation, stress, EtOH/drugs
• Autosomal dominant w/ variable penetrance
• EEG patterns: 4-6 hz polyspike wave
• Frequently occur upon awakening
• Precipitated by college phenomena (etoh, stress, sleep deprivation)

Question 8

Partial seizures

Answer 8

• Simple partial: normal consciousness
• Complex partial: impaired consciousness
• All can become generalized
• Must have neuroimaging to ensure no surgical intervention necessary
• Most common: temporal lobe (80%), but can be in any lobe
• Temporal lobe seizures: aura (deja vu, fear, ect) followed by staring/behavioral arrest, lip-smacking, automatisms, post-ictal confusion
• Duration: 20 sec- 2 min

Question 9

Partial seizures: extra-temporal

Answer 9

• Frontal lobe: brief, early motor activity, seizures cluster frequently, fencer posturing
• Parietal lobe: sensory phenomena, speech changes
• Occipital lobe: visual aura

Question 10

Complex partial vs absence

Answer 10

• Complex partial: 2-5 min duration, aura, motionless stare, automatisms (lip smacking, hand wringing), confusion 5-30 min post-ictally
• Absence: brief event (10-20 sec), no aura, motionless stare, eye flutters, rare jerks, no post-ictal confusion

Question 11

Primary generalized seizures vs secondary generalized seizures

Answer 11

• Primary: abrupt onset, no aura, tonic/clonic or clonic or tonic, genetic component common, onset early in life
• Secondary: follows partial seizure, can be abrupt onset, tonic/clonic, subjective aspects of partial seizure (visual/auditory), later life onset

Question 12

Febrile seizures

Answer 12

• Most in young children: 6 mo- 3 yrs
• Occur during rising phase of fever, inherited
• Can be simple (solitary events 15 min duration, focal features, family history, multiple seizures in 24 hrs, abnormal neuro exam
• Rx: prevent fever (bath + antipyretics), rectal diazepam

Question 13

Status epilepticus

Answer 13

• Continuous seizure lasting 30 min or more, or multiple seizures for at least 30 min w/o recovery of consciousness
• Causes: febrile illness in pts w/ epilepsy, AED withdrawal
• Anoxia, stroke, trauma, CNS infection
• Causes brain injury and if >1hr has 50% mortality

Question 14

Evaluating a single seizure

Answer 14

• History of event (aura, description of event, post-ictal events)
• Medical history (LOC, precipitating factors, ect)
• Family/social Hx
• PE, neuro exam
• Lab studies: EEG, MRI, blood work

Question 15

Administering Rx

Answer 15

• Initiate Rx (AEDs) on first seizure
• First seizure: risk of recurrence is 35%
• Subsequent seizure risk: >90%
• Report alteration of mental status to public health, must document pt was instructed not to drive
• Epilepsy first aid: airway, breathing, circulation (ABCs)
• Get them on ground and left side (if vomiting)
• Time the event (>3 min call 911(, be prepared for post-ictal behavior