Seizures

=I. Case Histories= =II. Background=

D. Classification of Seizure Disorders
=III. The Patient With Seizures= =IV. Management of Seizures=

E. Surgical Options
==F. Education =V. Special Problems=

C. Refractory Seizures
=VI. Discussion of Case Histories=

Seizures are 'stereotyped' ask, 'are they exactly the same each time?'

greek epilamvanein, or 'to be seized'

seizure: an episode of altered behavior or sensrorium caused by excessive and hypersynchronous discharge of neurons epilepsy: condition of recurrent, unprovoked seizures a single seizure does not epilepsy make needs be more than one seizure

aura: abnormality experienced with some pt at beginning of seizures, not associated w/ clinical signs automatism...coordinated, sterotyped seizures lip smacking, chewing verbalizaation of short, stereotyped phrases

partial vs generalized partal: dichotomy refers to how seizure starts partial: **initial activation** of a system of neurons limited to a single **part of one cerebral hemisphere** simple partial:: consciousness not impaired complex partial: consciousness imparied Generalized seizure:: **initial involvement of both hemispheres** based off clinical and EEG changes

simple partial siezures can spread to limbic or subcortial regions and become coplex partial seizures either simple or complex partial seizures can spread and become secondarily generalized...partial seizures with secondary generalization

focal start implies partial seizure

Mnaifestations Motor autonomic Sensory Somatosensory Special sensory... depending on start


 * generalized seizures: **

absensed (petit mal) myoclonic clonic tonic tonic-clonic > starts stiffening, then progresses to jerking atonic

dichotomies

Idiopathic vs SYmptomatic
 * Idiopathic** cause unto itself....distinctive, well-defined syndrome with known or likely genetic cause
 * symptomatic** means symptom of known or suspected CNS abnormality

generalized vvs localization-related(focal) if mostly partial seizures, then localization-related epilepsy

Childhood Absensce Epilepsy Onset between ages 4 and 8 spells begin suddenly: blank stare, interuption of ongoing activity may be provoked by hyperventilation Characteristic EEG: 3 Hz spike, wave complexes

Rx: Ethosuximide, Valproic acid, lamotrigine, zonisamide (*may be exacerbated by carbamazepine, gabapentin, tiagabine) Ethosuximide is treatment of choice for this form of epilepsy more than 2/3 cases resolve by teen eyars
 * need to memorize childhood absence epilepsy treated with ethosuximide**

Juvenile myoclonic epilepsy Onset between 12, 18 generalized tonic-clonic Szs myoclonic jerks may begin a year or more before.... usually shortly after awakening EEG: 4-6 Hz polyspike and wave

Benign Rolandic EPilepsy

Rx: Any AED except Ethosuximide Prognosis: resolves by teen years

Most comon symptomatic Often Hx febrile dzs, then long interval sz-free simple partial or ocmplex partial szs EEG: Mesial temporal abnormalities MRI: Mesial temporal sclerosis Prognosis: may respond to meds, may need surgery (anterior temporal resection)
 * Mesial Temporal Sclerosis**

Abnormality of medial hippocampal lobe often give words during sz tell something can thent est them afterwards ("Green elephant")

pathophysiology: disinhibition refractory period keeps from having circular activity

contributeing procecesses: 1. activity of voltage-gated ion channels 2) distribution and activity of inhibitory synapsses...GABA-ergic distribution, acti vity of excitatory synapses...esp glutaminergic

In mesial temporal sclerosis... mossy fibers of hippocampus sprout collateral fibers could serve as a substrate for recurrent excitatory circuits may relate to role of hippocampus in plasticity and memory... sizures themselves may induce collateral sprouting.

Pathology: anything goes...anything can predispose to abnormal circuits

Myoclonic activity, seizures considered different

even more steroetyped than movement disorders, TIAs migrains, sleep disorders, syncope may need description from observers

diff diag: syncopY; usually warning of lightheadedness, often after emotion, standing up movement disorders: usually ongoing, or if episodic, variable in duration Sleep disorders: occur in specific phase of sleep TIAs: usually negative symptoms migrains: longer duration, often with headache

sometimes people have spells...and we don't know wwhat they are.

non-epileptic spells pseudo-seizures often less sterotyped, more variable than seizures usually not voluntary may be same process as conversion disorder

suggestive characteristics: bilateral limb movements with preserved consciousness pelvic thrusting vigorous side-to-side head turning unresponsiveness, forced eye closure

to be absolutely sure, need EEG

EEG is helpful test...

frontal lobes are hardest...tend to be more coordinated....
 * AEDs, surgery, and VNS**

lookfor cause provoked? on crack? head CT electrolytes, BUN, creatinine, glucose, Ca++, Mg++, LFTs, CBC< urinaysis, toxicology screen LP unless meningeal process very unlikely if cause found, treat it otherwise....recommend AED only 50% of pts have recurrence...unclease why Either way: No Driving
 * diagnosis**

Phenytoin: Dilantin Seizure types: partial generalized easy to load once a day dosing low cost in use since 1938 disadvanates: complex kinetics, many drug interactions quirks: gingival hyperpalsia, histutism, osteoporosis, rash, cerebellar damage nonlinear pharmacokinetics
 * Advantages

Sieuzre types: parital Advanatges: sustained release in use since 1974 auto-induction of hepatic metabolism Drug interactions : note: Erythromycin reduces clearance: potential toxicicty neutropenia, rash,
 * CArbamazapine**

Valporate/Eepakote Seizure types: partial generalized Advanages: broad spectrum IV form available

Disadvantages: Hepatic ehnzym inhibitor drug intaractions Weight gain tremor alopecia thrombocytopenia pancreatitis hyperamonemia

drug of second choice for absence

valporic acid seems to have 2x higher risk, at least
 * all antiepileptic drugs have some risk of fetal malformations**

Gabapentin/neurontin

Advantages: No drug interactions non-hepatic metabolism easyto leoad orally very safe, well tolearted

Disadvantages: saturable absorption short half-life may be less effective than other AEDs expense

QUirks: Weight gain Peripheral edema

Pregabalin.... same advantages, same quirks.... still being sorted out

lamotrigine... eizure types: partial, generalized broad spectrum seems very potent less sedating than other AEDs very few studies done slow to load....esp in pts on valproate expensive
 * rash**


 * Topiramate**

seizure types; partial generalized

Advanatages: broad spectrum doesn't alter other AEDs causes weight loss

disadvantages; slow to load expensive metabolic acidosis...carbonic anhyrase inhibitor rarely, glaucoma
 * kidney stones
 * cognitive slowing/word finding difficulty

Levetiracetam Seizure tyeps: partial, generalized Broad pectrum no drug-drug interactions relatively rapid titration disadvantages: expensive quirks: ehavioral problems rare psychosis

DON'T stop just because serum drug level is high--normal ranges are population averages, don't nececessarily apply to invidicuals if seizure control achieved,start ot taper the first AED..... if pt still having seizures: taper one two AEDs, start a 3rd
 * rules**
 * Increase does until no seizures
 * If seizures not controlled on max tolerated dose, ad 2nd AED

no success with several drugs, consider... should admit for EEG monitoring?
 * reassess diagnosis...really seizures?
 * consider surgical management


 * spells must be epileptic
 * seizures myst be partial
 * all seizures myst have same focus
 * focus must be in region of brain that can be safely removed

about 50% of those with partial seizures that dont respond to AEDs are eligible for surgery

about 70% sz free aftewards Other intervention...... VaGUS NERVE STIMULATION.... ABOUT EQUAL TO aed EFFICACY NO SIDE EFFECTS MECHANISM UNKNOWN PROVIDES INTERMITTENT STIMULATION...30S ON, 5 MIN OFF OR CAN HAVE HAND Held magnet to activate

if select pt right, resection surgery very effective

ketogenic diet.... almost no carbhydrate increases ketones, acids mechanism unknown compliance very difficult 'religion' about it...

Status epilepticus most seizures resolve in 45-90 seconds
 * need to read about**

Pregnancy: use AED, butt ry to use only one; keep constant low dose; avoid valproate