Clinical Epilepsy

Dr. A Jayam-Trouth

· Definition: (There is no one clear definition).

§ There are areas in which there is a problem with increased excitation decreased inhibition, will end up with a seizure. Some of these areas are controlled by genes that have been identified in some areas like juvenile myoclonic epilepsy. In some areas they are still searching for answers.

§ The bottom line is that you are not going to find one area but you are going to see multiple areas of membrane disturbance, which contributes to hyperirritability or partial depolarization.

§ Then, with certain clinical factors, there is a spread of activity from this group of abnormal neurons to adjacent normal neurons and that is when you have the clinical manifestations of seizure.

· Definition:

¨ Episode or paroxysmal involuntary alteration in consciousness, motor activity, behavior, sensory perception, visual function or autonomic function.

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· Etiology and Pathogenicity

§ Neuronal irritation and spread of activity to adjacent or deeper neurons.

§ Known cause for neuronal dysfunction: (Secondary seizures or symptomatic)

· Most common:

¨ Adult: ETOH

¨ Children: Febrile

§ Unknown Cause: Idiopathic seizures

· Symptomatic

§ Secondary to trauma, infection, tumor, intoxication, metabolic defects, congenital anomalies, vascular malformations or degenerative disease.

· Recurrent Primary Seizures = Epilepsy

§ Etiology of neuronal hyperirritability is unknown.

· Increased excitability agents or decreased inhibitory agents or membrane receptor dysfunction.

¨ Receptors that might be involved:

Ø AMPA

Ø NMDA

¨ Neurotransmitters

Ø Glutamate – excitatory

Ø GABA – inhibitory

¨ Channel Problems

Ø Na

Ø Ca

¨ Genetic Factors

§ Triggering Factors (especially in children)

· Emotion Upset

· Fatigue

· Fever

· Medication:

¨ Amphetamines

¨ Phenothiazines

¨ Some anti-histamines

· Sleep Deprivation

· ETOH

· Can only trigger a seizure if you have underlying abnormal neurons

□ Classification

· Generalized

· Partial or Focal

· Partial with secondary Generalization

□ Generalized Seizures

· EEG

§ Single most important test

§ Bi-hemispheric spread of activity on the EEG – sensoriam alteration

· Ictus = seizure

· Types

§ Generalized Tonic Clonic

§ Absence

§ Myoclonic- atonic

· Generalized Tonic Clonic (Grand Mal)

§ Aura vague

§ Generalized tonicity of muscles

§ Epileptic cry

§ Tongue biting

§ Urinary Incontinence

§ Apnea

§ Cyanosis

§ Intermittent clonicity- muscle jerking

§ Post ictal

· Total neuronal inhibition

· Sleep

· Confusion

· Agitation

· Disorientation

· Medications:

§ Phenytoins- Dilantins

§ Carbamazepine- Tegretol/Carbatrol

§ Valproic Acid- Depakene/Depakote

§ Lamotrigine – Lamictal

§ Barbiturates – Phenobarbitol; Mysoline

§ Benzodiazepine – Lorazepam – Ativan; Diazepam- Valium

§ Clonazepam – Klonopin

□ Absence Seizures (Petit Mal)

· Children 5-12 years

· Brief episodes of loss of consciousness; vacant staring; occasional automatisms

· No aura

· No post-ictal phases

· Precipitated by hyperventilation

· EEG Characteristics

§ 3 second spikes and waves

§ Bilateral to synchronous

· Medications:

§ Ethosuximide – Zarontin (less problematic)

§ Valproic Acid – Depakote

□ Myoclonic/Atonic Seizures (Lennox-Gastaut; West Syndrome)

· EEG Characteristics

§ Hyperarrhythmic EEG

· Medications:

§ Valproic Acid

§ Topiramate-Topomax

· Usually associated with damaged brain

· Difficult to control

· West’s Syndrome

§ In Infant 3-8mos

§ Infantile myoclonic seizures

§ Salon spasms

§ Total body myoclonus

§ High association with mental retardation

§ Medications:

· Lamotrigine- Lamictal

· Benzodiazepine- Clonazepam; Klonopin

· ACTH (Steroids)

¨ Will produce immunosuppression

· Ketogenic Diet

¨ Induce ketosis; control seizures; have to monitor

□ Focal/Partial Seizures

· Elementary motor (Todd’s Paralysis)

§ Sensory

§ Visual

§ Autonomic

· Partial Complex Seizures

§ Psychomotor/Temporal Lobe

· Aura

¨ Special sensory hallucinations

¨ Olfactory

¨ Auditory

¨ Visual

¨ Gustatory

¨ Behavioral abnormalities

· Cognitive problems: memory

¨ Ne jamais pas

¨ Deja vous

· Autonomic problems (spread may be in the hypothalamus)

¨ Sweating

¨ Tearing

· Automatisms- may appear weird and “kooky”

· EEG characteristics

¨ Focal Spikes/slow waves

¨ Fronto/temporal regions

¨ May see metafocus on other lobe

· Medications:

¨ Carbamazepine-Tegretol

¨ Oxcarbazepine- soon to be released

¨ Valproic Acid- Depakote

¨ Topirmate- Topomax

¨ Lamotrigine-Lamictal

¨ Phenytoin-Dilantin

¨ Other medications for partial seizures:

Ø Tiagabine - Gabatril

Ø Vigabatrin-Not available in the USA

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Ø Additional Readings

Ø EPILEPSY

Ø Epilepsy Foundation

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