The in vivo diagnosis of Hallervorden-Spatz disease is discussed in relation to the clinical manifestations and MRI findings in two children examined at the Department of Paediatrics, University Hospital of Aarhus, Denmark. Characteristic clinical findings of the late infantile type are a gradual onset with gait disturbance, corticospinal tract signs, rigidity and dystonia, especially oromandibular involvement, and mental deterioration. MRI may be normal at first and will later show hypo-intensity in the globus pallidus in T2-weighted images and an area of hyperintensity in the anteromedial portion, corresponding to the ‘eye-of-the-tiger’ sign. In some cases, both globus pallidus and substantia nigra are involved, showing hypo-intensities consistent with iron deposition. The diagnostic findings in five additional cases reported in the literature are also tabulated. Age at onset ranged from 1 to 4 years. MRIs were positive when examined at 7 to 12 years. 
COMMENT. Hallervorden-Spatz disease occurs as 1) a classic post-infantile type, with onset between 7 and 15 years; 2) late infantile type, with onset before 6 years of age and leading to death within 10 years; and 3) an adult form, onset between 20 and 60 years, and fatal within 10 years. In addition to the clinical and MRI findings, the diagnosis of Hallervorden-Spatz disease is made by exclusion of other neurodegenerative disorders, some having identical MRI changes, including the ‘eye-of-the-tiger’ sign. The rare association of Hallervorden-Spatz disease and acanthocytosis has been described by Swisher CN et al , and HARP syndrome, characterized by hypoprebetalipoproteinemia, acanthocytosis, retinitis pigmentosa, and pallidal degeneration, may include the ‘eye-of-the-tiger’ sign in the MRI. Reports of HARP syndrome and commentaries are included in Progress in Pediatric Neurology II, PNB Publishers, 1994, p477; and Ped Neur Briefs April 1995;9:26-27).