Clinical features:
(1) The condition usually develops in a pediatric patient (typically a child < 4 years of age) associated with an acute febrile illness.
(2) The patient develops prolonged clonic seizures which may progress to status epilepticus. The jerks are usually unilateral but may be generalized or may start on one side and shift to the other side.
(3) The patient often becomes comatose.
(4) Later the patient develops hemiplegia involving the side showing the clonic activity. If the clonic activity shifts sides, then the side involved last is involved. Rare patients may become quadriplegic.
(5) The hemiplegia is initially flaccid and then becomes spastic. In patients with reversal of the paralysis persistent neurologic finding may be present (increased deep tendon reflexes, pyramidal tract signs, weakness, spasticity).
(6) Mental retardation and/or aphasia may develop.
(7) Later the patient develops epilepsy, usually starting in the hemisphere contralateral to the hemiplegia. This may be simple partial, complex partial, or generalized seizures. Occasionally patients may develop recurrent status epilepticus.
Imaging studies:
(1) During the acute phase there is edema of one hemisphere.
(2) Weeks later the affected hemisphere shows global cerebral hemiatrophy.
(3) Cerebral angiography shows normal vasculature.
The incidence is low in countries using modern therapy for prolonged seizures and status epilepticus, such as intravenous diazepam. It is now more commonly seen in developing countries with limited medical resources.
