Detailed Information on Megalencephaly

Megalencephaly is marked by an abnormally large, heavy, usually malfunctioning brain. The head may be enlarged at birth or become abnormally big in the early years. The brain weight is greater than standard for the age and sex of the baby or child. This results in a large, often asymmetrical head. Head enlargement may be evident at birth or the head may become abnormally large in the early years of life. Symptoms of megalencephaly may include delayed development, convulsive disorders, corticospinal (brain cortex and spinal cord) dysfunction, and seizures.

Megalencephaly may be caused by a disturbance in the process that controls the way nerve cells separate to form new cells (called nerve cell proliferation). The condition also may be caused by factors connected to abnormal brain growth or from chromosomal abnormalities. Megalencephaly affects males more frequently than females. Unilateral megalencephaly or hemimegalencephaly is a rare condition that is characterized by the enlargement of one side of the brain. The prognosis for child’s and children with megalencephaly depends upon the underlying reason and the linked neurological disorders.

The prognosis for children with hemimegalencephaly is worse. There is no standard treatment for megalencephaly. Treatment is symptomatic and supportive. For patients with neurological and/or physical problems, management may include anti-epileptic drugs for seizures, treatment of medical complications related to the underlying syndrome, and rehabilitation for neurological problems such as speech delay, poor muscle tone, and poor coordination. Placement in a residential care facility may be necessary for those a case in which megalencephaly is accompanied by severe mental retardation or uncontrollable.