Hydranencephaly

Hydranencephaly is a rare condition in which the brain's cerebral hemispheres are absent and replaced by sacs filled with cerebrospinal fluid.

An infant with hydranencephaly may appear normal at birth. The infant's head size and spontaneous reflexes such as sucking, swallowing, crying, and moving the arms and legs may all seem normal. However, after a few weeks the infant usually becomes irritable and has increased muscle tone. After a few months of life, seizures and hydrocephalus (excessive accumulation of cerebrospinal fluid in the brain) may develop.

Other symptoms may include visual impairment, lack of growth, deafness, blindness, spastic quadriparesis (paralysis), and intellectual deficits.

Hydranencephaly is considered to be an extreme form of porencephaly (a rare disorder characterized by a cyst or cavity in the cerebral hemispheres) and may be caused by vascular infections or traumatic disorders after the 12th week of pregnancy. Diagnosis may be delayed for several months because early behavior appears to be relatively normal. Some infants may have additional abnormalities at birth including seizures, myoclonus (spasm or twitching of a muscle or group of muscles), and respiratory problems.

There is no definitive treatment for hydranencephaly. Treatment is symptomatic and supportive. Hydrocephalus may be treated with a shunt (a surgically implanted tube that diverts fluid from one pathway to another).

The outlook for children with hydranencephaly is poor. Death generally occurs before age 1.

Information provided by the
National Institute of Neurological Disorders and Stroke,
National Institutes of Health

Each year, Medical College of Wisconsin physicians care for more than 180,000 patients, representing nearly 500,000 patient visits. Medical College physicians practice at Children's Hospital of Wisconsin, Froedtert Memorial Lutheran Hospital, the Milwaukee VA Medical Center, and many other hospitals and clinics in Milwaukee and southeastern Wisconsin.