Batten disease is a fatal, inherited disorder of the nervous system that begins in childhood. In some cases, the early signs are subtle, taking the form of personality and behavior changes, slow learning, clumsiness, or stumbling. Symptoms of Batten disease are linked to a buildup of substances called lipopigments in the body's tissues. Lipopigments are made up of fats and proteins. Because vision loss is often an early sign, Batten disease may be first suspected during an eye exam. Often, an eye specialist or other physician may refer the child to a neurologist. Diagnostic tests for Batten disease include blood or urine tests, skin or tissue sampling, an electroencephalogram (EEG), electrical studies of the eyes, and brain scans.