Infantile and juvenile presentations of Alexander's disease: a report of two cases

We describe 2 new cases of Alexander's disease, the first to be reported in Belgium. The first patient, a 4-year-old girl, presented with progressive megalencephaly, mental retardation, spastic tetraparesis, ataxia and epilep sy; post-mortem examination showed widespread myelin loss with Rosenthal fi bers (RFs) accumulation throughout the neuraxis. She was the third of heter ozygotic twins, the 2 others having developed normally and being alive at a ge 5 years. The second patient developed at age 10 years and over a decade spastic paraparesis, palatal myoclonus, nystagmus, thoracic hyperkyphosis a nd thoraco-lumbar scoliosis with radiological findings of bilateral anterio r leukoencephalopathy. Brain stereotactic biopsy at age 16 years demonstrat ed numerous RFs. With these 2 cases, we review the literature on the variou s clinico-pathological conditions reported as Alexander's disease. We discu ss the nosology of this entity and the pathogeny of RFs formation and dysmy elination. Clues to the diagnosis of this encephalopathy in the living pati ent are briefly described.