[Presenting psychiatric and cognitive disorders in adult neurolipidoses]

Neurolipidoses may present as psychiatric illness or dementia which may be isolated for a long time without neurological manifestations. Thus the relation with a metabolic disease may be difficult to establish. In this survey, we wish to present our clinical and biological experience in relation with lysosomal or peroxisomal disorders giving rise to neurolipidoses, a review of the literature, as well as the elements which allow to present a diagnostic strategy. We report mainly on metachromatic leukodystrophy, GM2 gangliosidosis, Fabry's disease, Niemann-Pick type C, Kufs disease, adrenoleukodystrophy, cerebro-tendinous xanthomatosis. Psychiatric symptoms may overshadow subtle signs of cognitive and motor dysfunction. Careful and persistent neurodiagnostic evaluation must be performed even in cases when CT and MRI scans are considered normal. Resistance to psychotropic drugs may be an element of orientation. The biological diagnosis is mainly biochemical. Although most of the genes involved have been cloned, many of the mutations are private, except for metachromatic leukodystrophy for which specific mutations may be related to adult cases and either with predominantly motor or predominantly cognitive and psychiatric manifestations. This review discusses also other metabolic diseases which may present as isolated or predominant cognitive and psychiatric manifestations.