THE NOSOLOGY OF HALLERVORDEN-SPATZ DISEASE

The development of magnetic resonance imaging has increased the number of clinical and pathological reports of Hallervorden-Spatz disease an d Hallervorden-Spatz syndrome. The case-to-case variability is conside rable. However, if gene loci and basic pathogenetic mechanisms are to be appreciated, it is imperative that like cases be compared and studi ed. The designation Hallervorden-Spatz disease should be reserved for the pediatric neurodegenerative disorder, recognizing that it occurs e ither as a familial or a sporadic disorder. The diagnosis of Hallervor den-Spatz syndrome is non-specific and encompasses a number of distinc tive disorders, each having the pallidal triad of iron deposition, axo nal spheroids, and gliosis. Clinically or pathologically distinct grou ps include (a) female patients with dementia, quadriparesis, and neuro fibrillary tangles; (b) cases with Lewy bodies; and (c) cases with or without lipid abnormalities which have acanthocytosis and pigmentary r etinal degeneration. Adult-onset cases are quite variable, both clinic ally and pathologically. Iron deposition in the globus pallidus separa tes these disorders from others in which axonal spheroids occur. Undou btedly, the pallidal changes are related, some being primary and other possibly epiphenomena. Pathogenetic insights can only be achieved by investigating and comparing like cases.