A RARE CASE OF HYDRANENCEPHALY

Abstract

Hydranencephaly is a rare congenital abnormality characterized by replacement of the cerebral hemispheres by a large cerebrospinal fluid pool. It is thought to be caused by occlusion of bilateral internal carotid arteries in the fetal life mainly during the second trimester due to a variety of causes. It is one of the recognized forms of brain malformations which is usually associated with intrauterine fetal demise and is therefore rarely seen in postnatal life.It is a rare entity with a reported incidence of less than 1 per 10,000 live births.Hyderanencephaly is an isolated abnormality with a severe prognosis, affecting the cerebral mantle. Midbrain is usually not involved.Differential diagnosis is mainly relevant when considering severe hydrocephalus,poroencephalic cystand alobar holoprosencephaly. Clinical features include intact brainstem reflexes without evidence of higher cortical activity. Infants with this condition are normal at birth however, after a few weeks, they usually become irritable and have increased muscle tone and, after a few months of life, seizures and hydrocephalus (excessive accumulation of CSF in the brain) may develop. Other symp-toms are growth retardation, impaired vision, deafness and spastic paralysis. Due to the late onset of most symptoms and signs, the diagnosis may be delayed.