Educationals

Lennox - Gastaut Syndrome

Incidence- 3% of childhood seizures.

Etiology : Many causes. 25% are Cryptogenic.

Cardinal features :

• Neurologically abnormal children
• Atypical absences
• Axial tonic seizures
• With sudden falls (atonic/myoclonic)
• Progressive mental deterioration

Age 2-8 years (3-5 years), seen more in males with no family history
EEG: shows diffuse slow spike and wave (1-2.5 Hz), multifocal
abnormalities during inter ictal period and abnormal background activity.

Seizures :

• Tonic seizures are a necessary component.
• Atypical absences commonly seen.
• Massive myoclonic jerks, myoclonic atonic seizures.
• Episodes of status epilepticus lasting for days.
• Recurrent loss of tone and falls forward with facial injuries.
• Myoclonic twitches of eyelid and mouth observed.

Resistant to treatment; the following treatment has been tried :
Sodium valproate, nitrazepam, clonazpam, vigabatrin, felbamate.
ACTH, IV gammaglobulin, TRH
Ketogenic diet
Corpus callosotomy.
Prognosis: For seizure control and mental development is poor.

Myoclonic Astatic
Incidence -1-2% of all epilepsies.
Age 2-5 years
Characterised by high genetic predisposition

Normal development and no neurological deficits before onset.

Seizure type	- Primarily generalised myoclonic, myoclonic astatic. Short absences with myoclonic jerks. Generalised tonic clonic seizures in 75%. History of febrile seizures in 28%
EEG	- Irregular spike and wave activity in sleep. Bilateral synchronous irregular spike and wave activity. Paroxysms of irregular spike, wave and polyspikes. Photosensitivity. No multifocal abnormality

Prognosis related to seizure frequency. Spontaneous remission occasionally occurs 50% continue to have seizures.

Later childhood (5-10 years)

Typical absence epilepsy
Benign partial epilepsy with rolandic (centro-temporal) spikes
Benign partial epilepsy with occipital spikes/ paroxysms
Landau - Kleffner syndrome

Childhood Absence (Petit mal)

Onset : Before puberty (5-10years)

Previously normal children, more often in females.

Type of seizure : Absences are the initial presenting seizures which are short in duration with abrupt onset and termination and high frequency of seizures per day. There is impairment of consciousness with total amnesia of the event. This can be easily done at the bedside by asking the patient to hyperventilate for 2- 3 minutes and precipitate a seizure.

EEG : shows a bilateral, symmetrical, synchronous discharges of spike and wave at 3c/second, with a normal background activity and precipitated by hyperventilation, with an abrupt onset and termination on spike and wave complexes.

Simple absences seen in 10%

Complex with mild motor component seen in 45%. There may be increased postural tone, decreased postural tone or if prolonged then associated with automatisms.

Prognosis : There are no recognisable focal deficits and seizures do not persist beyond adolescence. Later may develop generalised tonic clonic seizures in 40%.

The response to ethosuximide, valproate or clonazepam is complete.

Benign Partial Epilepsy with Centrotemporal Spikes (BECT-Rolandic)

Age of occurrence : 3-10 years

History of previous febrile seizures seen in 7-9%

Family history of epilepsy or abnormal EEG in 40%

Neurologically : Normal children

Seizures: are many, brief, in clusters, mainly focal and involving face and oropharynx with clonic jerking of face and mouth with speech arrest, guttural sounds and drooling, somatosensory or may progress to generalised tonic clonic seizures. Two thirds occur in sleep.

EEG : Large, diphasic, high voltage centrotemporal spikes, followed by slow waves, seen in clusters. Unilateral in 60% and bilateral in 40% more prominent in sleep with a normal background activity.

Prognosis is excellent and recovery is the rule without recurrence after discontinuation of medication.