Articles » NINDS Megalencephaly Information Page: NINDS

NINDS Megalencephaly Information Page: NINDS

Article title: NINDS Megalencephaly Information Page: NINDS

Main condition: Megalencephaly

Conditions: Megalencephaly

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What is Megalencephaly?
Megalencephaly, also called macrencephaly, is a condition in which there is an abnormally large, heavy, and usually malfunctioning brain. By definition, the brain weight is greater than average for the age and gender of the individual. Head enlargement may be evident at birth or the head may become abnormally large in the early years of life. Megalencephaly is thought to be related to a disturbance in the regulation of cell reproduction or proliferation. In normal development, neuron proliferation - the process in which nerve cells divide to form new generations of cells - is regulated so that the correct number of cells is formed in the proper place at the appropriate time. Symptoms of megalencephaly may include delayed development, convulsive disorders, corticospinal (brain cortex and spinal cord) dysfunction, and seizures. Megalencephaly affects males more often than females. Unilateral megalencephaly or hemimegalencephaly is a rare condition and is characterized by the enlargement of one-half of the brain. Children with this disorder may have a large, sometimes asymmetrical head. Often they suffer from intractable seizures and mental retardation.

Is there any treatment?
There is no definitive treatment for megalencephaly. Treatment is symptomatic and supportive.

What is the prognosis?
The prognosis for individuals with megalencephaly largely depends on the underlying cause and the associated neurological disorders. The prognosis for those with hemimegalencephaly is poor.

What research is being done?
The NINDS supports and conducts neurogenetic research which focuses on identifying and studying the genes involved in normal brain development. The knowledge gained from these fundamental studies provides the foundation for understanding how this process can go awry and, thus, may eventually give clues to understanding disorders such as megalencephaly.

Selected references

Bradley, W, et al (eds).
Neurology in Clinical Practice: The Neurological Disorders. vol. II, 2nd edition, Butterworth-Heinemann, Boston, p. 1480 (1996).

Rowland, L (ed).
Merritt's Textbook of Neurology. 9th edition, Williams & Wilkins, Baltimore, pp. 519-520 (1995).

Asbury, A, et. al. (eds).
Diseases of the Nervous System: Clinical Neurobiology. vol. I, 2nd edition, W.B. Saunders Co., Philadelphia, pp. 616-617 (1992).

Gooskens, R, et. al.
Megalencephaly: Definition and Classification. Brain & Development, 10:1; 1-7 (1988).

DeMyer, W.
Megalencephaly: Types, Clinical Syndromes, and Management. Pediatric Neurology, 2:6; 321-328 (1986).

 Organizations

March of Dimes Birth Defects Foundation
1275 Mamaroneck Avenue
White Plains, NY 10605
resourcecenter@modimes.org
http://www.modimes.org/
Tel: 914-428-7100 888-MODIMES (663-4637)
Fax: 914-428-8203

National Organization for Rare Disorders (NORD)
P.O. Box 8923
(100 Route 37)
New Fairfield, CT 06812-8923
orphan@rarediseases.org
http://www.rarediseases.org/
Tel: 203-746-6518 800-999-NORD (6673)
Fax: 203-746-6481

National Institute of Child Health and Human Development (NICHD)
National Institutes of Health
Bldg. 31, Rm. 2A32
Bethesda, MD 20892-2425
NICHDClearinghouse@mail.nih.gov
http://www.nichd.nih.gov/
Tel: 301-496-5133 800-370-2943

This fact sheet is in the public domain. You may copy it.Provided by:
The National Institute of Neurological Disorders and Stroke
National Institutes of Health
Bethesda, MD 20892



 » Next page: NINDS Melkersson-Rosenthal Syndrome Information Page: NINDS

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