Main Page | See live article | Alphabetical index Macrencephaly (from Greek "makros" - big, large and "enkephalos" - brain) is a condition present at or soon after birth in which the brain is abnormally large. Generally this is the case when it's measures are statistically more than 98% of the population. The brain can become larger due to certain diseases like Alexander disease, later phases of the Tay-Sachs disease, and spongy degeneration of infancy. The large growth of the brain is usually not caused by the formation of tumors. Macrencephaly is also known as macrencephalia and macroencephaly. See also cephalic disorders. This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.