Electrical status epilepticus in sleep

Wafaa AL Shehhi

R3 Pediatric Neurology Resident

January 2013

Roadmap

Definitions.

Etiology.

Pathophysiology.

CSWS.

LKS.

Electrophysiology and imaging.

Differential Diagnosis.

Treatment.

Prognosis.

Definitions

Electrical status epilepticus in sleep (ESES): an electroencephalographic pattern showing significant activation of epileptiform discharges in sleep.

Continuous spike wave in slow-wave sleep (CSWS) and Landau-Kleffner syndrome (LKS) describe the clinical epileptic syndromes seen with ESES.

Definitions

In Party’s original article, “continuous” was used only if the EEG showed a spike wave index of 85% to 100% and if these abnormalities persisted on 3 or more records over a 1- month period of time.

The spike wave index defined as: total number of minutes of all spike and slow-wave abnormalities multiplied by 100 and devided by the total nonrapid eye movement sleep minutes.

Etiology

Underlying structural abnormalities.

CNS infection.

Underlying immune disorder.

Idiopathic.

Pathophysiology

ESES: Activation of the reticulo-thalamic-cortical system with seconday bilateral synchronization through the corpus callosum.

CSWS

• Children with CSWS often presented with:

global regression.

Loss of language expressive aphasia.

Loss of temporospatial skills.

Hyperactivity.

Short-term memory deficits.

Aggressiveness.

Motor deficits ataxia, dystonia, dyspraxia.

CSWS

Epilepsy:

Seizures are the presenting symptom in 80% of children with CSWS.

The most common seizure types including GTC, typical absence and simple acnd complex partial seizures.

CSWS

Age of onset:

Ranging from 1-14 years.

A mean between 4-8 years.

Outcome: poorer in children with earlier age at onset.

LKS

The primary clinical manifestation : language regression.

An acquired auditory agnosia.

Other clinical symptoms:

Irritability.

Hyperkinesia.

Attention-deficit disorder.

Autistic- like behavior.

LKS

Epilepsy:

Seizures present in 70-80% and are typically infrequent and easily treated.

Age of onset:

3-8 years.

A peak at 4-5 years.

Electrophysiology and imaging

EEG:

In CSWS: EEG during wakefulness typically shows epileptiform discharges that are focal, multifocal, or diffuse, often with frontotemporal or frontocentral predominance.

During sleep, there is dramatic activation of diffuse epileptiform discharges.

Electrophysiology and imaging

In LKS: the awake EEG is variable; it may contain focal, multifocal or generalized epileptic abnormalities, or it may be normal.

The focal epileptiform activity is often posterotemporal.

During sleep marked activation.

Electrophysiology and imaging

Magnetoencephalography:

Determination of electrical currents in the brain by measuring their associated magnetic field.

Structural neuroimaging:

In children with LKS usually normal.

In CSWS: cortical dysplasia, congenital stroke, diffuse atrophy, white matter changes, abnormal or delayed myelination, tubers and chiri II malformation.

Differential Diagnosis

BCECTS (benign childhood epilepsy with centrotemporal spikes).

Lennox Gastaut Syndrome.

Pervasive Developmental Disorders.

Developmental Language Disorders.

Treatment

Antiepileptic agents:

Valproic acid, ethosuximide ,benzodiazepines and keppra.

Contraindicated: phenytoin, carbamazepine and barbiturates.

High –Dose Benzodiazepines (1mg/kg).

Treatment

Steroids and Adrenocorticotropic Hormone:

Prednisolone (2-5 mg/kg/d).

Methylprednisolone (20mg/kg/d x 3 days).

ACTH (80 IU/d with a 3 months taper).

Intravenous Gamma-Globulin:

IVIG (2 g/kg over 4 days).

Treatment

Multiple Subpial Transections.

Other therapies:

Ketogenic diet.

Vagal nerve stimulation.

Treatment of attention deficit in ESES:

Methylphenidate.

Prognosis

Seizures:

Seizures ultimately resolve or markedly decrease in frequency by puberty.

Electroencephalographic discharge:

Improvement occures progressively over time, with initial reduction in frequency and spread of discharge in sleepfollowed by normalization of the awake recording and normalization of the sleep recording.

Prognosis

Neuropsychological outcome:

10-44% normal language and intelligence.

One of the most predictive factors for poor long-term neuropsychological outcome is the duration of ESES.

Summary

CSWS and LKS are uncommon but probably underrecognized epileptic syndromes that are associated with ESES.

If clinically suspected, an adequate sleep EEG with recording of slow- wave sleepmust be obtained to confirm this diagnosis.

Early treatment with effective therapy to ameliorate the ESES pattern is essential for improvement in neuropsychological outcome.

References