All of the causes of<unk>  are still unknown. Sometimes<unk>  surfaces abruptly within days or weeks, while in other cases it develops over a longer period of time. A Mayo Clinic report indicates: "Comprehensive medical and neurological examinations in children diagnosed with<unk>  seldom uncover an underlying medical or neurological cause. Although the occurrence of epilepsy is higher in children with<unk> , experts don't know whether epilepsy plays a role in causing the disorder."<unk> , especially in cases of later age of onset, has also been associated with certain other conditions, particularly the following: * Lipid storage diseases: In this condition, a toxic buildup of excess fats (lipids) takes place in the brain and nervous system. * Subacute sclerosing panencephalitis: Chronic infection of the brain by a form of the measles virus causes subacute sclerosing panencephalitis. This condition leads to brain inflammation and the death of nerve cells. * Tuberous sclerosis (TSC): TSC is a genetic disorder. In this disorder, tumors may grow in the brain and other vital organs like kidneys, heart, eyes, lungs, and skin. In this condition, noncancerous (benign) tumors, hamartomas, grow in the brain. * Leukodystrophy: In this condition, the myelin sheath does not develop in a normal way causing white matter in the brain to eventually fail and disintegrate.
Childhood disintegrative disorder
Epilepsy
Childhood schizophrenia
HIV/AIDS
Conduct disorder
Brain tumor
Personality development disorder
Rett syndrome