Levodopa-responsive parkinsonism in hereditary spastic paraplegia with thin corpus callosum.

Hereditary spastic paraplegia with thin corpus callosum is a rare degenerative disease, which is characterized by a progressive weakness of the lower limbs with a hypoplastic corpus callosum, and is often associated with other symptoms such as mental impairment, amyotrophy, sensory disturbances, dysuria, nystagmus and cataract. We describe two siblings (brother and sister) who showed a thin corpus callosum on MRI, one of whom showed the pure form of progressive spastic paraplegia, while the other showed predominant levodopa-responsive parkinsonism. The present cases are illustrative of a phenotypic heterogeneity in the same family of spastic paraplegia with a thin corpus callosum, despite the identical neuroimaging findings, and also presented another form of autosomal recessive juvenile levodopa-responsive parkinsonism.