Two cases of the juvenile form of amaurotic family idiocy were described in the present communication.
1) Case 1 was a 11-year-10-month boy. His family history had consanguinities. He was slightly deteriorated before the onset of the disease. At the age of 5 years, the ataxia of gait was initially manifested. Later there developed the progressive mental deterioration and the “Blitz-Nick- Salaam Krämpfe”. On neurological examinations the marked cerebellar syndroms (ataxia, intention-tremor and hypotonia), the involuntary movements and the narrowing of the ocular vessels could be recognised.
Case 2 was 10-year-7-month girl. Her two brothers died of amaurotic family idiocy. She had been healthy until she complained of the myoclonic contractions of the tips of the fingers. The mental deterioration, the convulsive seizures and the visual disturbances were gradually appeared. The neurological examinations showed the involuntary movements, the hypotonia, the optic atrophies and the retinal degeneration. Both patients died six years after the onset of the disease.
2) The autopsy findings of the brains in both cases revealed macroscopically the generalised atrophy and the increased consistency. Microscopically the essential changes were observed in the neuronal swelling and the lipidosis. These changes were distributed ubiquitously throughout the central nerves system and were most markedly in the cerebral cortexes, decreasing by degrees caudally. Furthermore in the case 1, the severest damage was seen in the cerebellar cortex. In the cerebellum of case 1, the entire nerve cell elements except Golgi's cells and the nerve fivers were almost completely obliterated. The swelling of axons in the the cerebral cortexes was recognised in both cases. too.
3) The findings of the organs such as liver, spleen and others in case 2 revealed no lipid accumuration as seen in Niemann-Pick's disease. There were observed the degeneration of the retinal outer layer which was characteristic of the juvenile form of the disease.
4) From the results of the histochemical observations in both cases it was concluded that the intraneuronal substances consisted of the mixture of the sphingomyelin and PAS-positive substances that might be the glycolipid. A part of them and the substances in the fat granulle cells were assumed to be combined with the protein.
5) Above mentioned results, the clinical, the histological and the histochemical findings in both cases indicated the jnvenile form of the disease. In case 1 there would be the developmental anomaly of the brain beside the essential chages of amaurotic family idiocy.