[Hypothalamic hamartoma: detailed presentation of a case].

We describe a seven year old child with a hypothalamic hamartoma. Classical symptoms of hypothalamic hamartoma include gelastic epileptic laughter, precocious puberty, aggressiveness, and progressively worsening epilepsy. After a normal first few years of life, this case presents all these symptoms except the precocious puberty. He has a markedly morbid personality disorder: he assaults strangers and relatives, bites people, spits in their faces unpredictably, is coprolalic and coprophagic, has gelastic laughter, puts pencils, erasers, and other non-comestible objects in his mouth, chews and ingests them, has tics (plays noisily with his saliva, empty chewing, compulsive spitting) and is self-injurious. None of the medications attempted to date have been of any help. Medical prognosis is somber, and this case is difficult to institutionalize, the more "congenial" institutions being insufficiently equipped to protect him and the beneficiaries and staff from his aggressive behavior. MRI showed the typical profile of hypothalamic hamartoma, and the diagnosis was confirmed with partial resection. This case illustrates that a tiny lesion, the size of a small cherry, can have extremely morbid psychological consequences. Detailed neuropsychological evaluation, certain unusual electroencephalographic traits and neurosurgical issues are discussed.