HHHH Syndrome

At a glance

HHHH is an acronym that stands for Hereditary Hemihypotrophy, Hemiparesis, and Hemiathetosis. It is characterized by congenital unilateral (left or right) hemiparesis with subsequent development of hemihypoplasia and athetoid posturing of the left hand. Other clinical features include hemiatrophy, involuntary movements, and seizures. It has been suggested that either an autosomal dominant or X-linked inheritance is likely.

Incidence and genetic inheritance

Very rare disease. X-linked or autosomal dominant (variable expression in heterozygous females); autosomal recessive inheritance also has been evocated.

Clinical aspects

Congenital unilateral (left or right) progressive hemiparesis followed by hemihypotrophy with particular athetoid posturing of the hand. Seizures are frequent.

Anesthetic considerations

Evaluate neurologic function (clinical, history, CT, EEG). Careful intraoperative positioning is needed. Consider interaction between antiepileptic treatment and anesthetic drugs.

References