Familial pediatric rapidly progressive extrapyramidal syndrome: is it Hallervorden-Spatz disease?

The clinical features of two children of a family with rapidly progressive extrapyramidal-pyramidal-dementia complex have been described. Inheritance seems most likely to be autosomal recessive. Magnetic resonance imaging results of brain were negative. Even so, the authors argued in favor of a diagnosis of Hallervorden-Spatz disease because the cases fulfilled the clinical criteria for diagnosis of this disease. Apart from the negative magnetic resonance findings, the other unusual feature was the early development of levodopa-induced dyskinesia. Few conditions need to be considered in the differential diagnosis of a childhood-onset rapidly progressive extrapyramidal syndrome. Such conditions include Wilson's disease, Hallervorden-Spatz disease (HSD), juvenile form of Huntington's disease, juvenile neuronal ceroid lipofuscinosis, early-onset Machado-Joseph disease neuroacanthocytosis, storage disorders, and variant form of dopa-response dystonias (DRD). Rarer conditions are Leigh's disease, Lafora body disease, and dentato-rubro-pallido-luysian atrophy. HSD is a rare disorder characterized by progressive extrapyramidal dysfunction and dementia. Onset is most commonly in late childhood or early adolescence. The disease can be familial or sporadic. When familial, it is inherited recessively and has been linked to chromosome 20. Recently, a mutation in the pantothenate kinase (PANK2) gene on band 20pl3 has been described in patients with typical HSD. HSD produces typical magnetic resonance imaging (MRI) changes in brain, aiding in antemortem diagnosis. The typical finding is of bilaterally symmetrical hyperintense signal changes in the external segment of globus pallidus, with surrounding hypointensity on T(2)-weighted image. These imaging features are fairly diagnostic and have been termed the "eye-of-the tiger sign". The hyperintensity represents pathologic changes, including gliosis, demyelination, neuronal loss, and axonal swelling, and the surrounding hypointensity is caused by loss of signal secondary to iron deposition. Described herein are the clinical aspects of a family with autosomal recessive inheritance with rapidly progressive extrapyramidal-pyramidal-dementia complex but with negative brain MRI results. The diagnosis should be considered a variant form of HSD.