Neurological and neuroradiological progression in hereditary spastic paraplegia with a thin corpus callosum

We followed-up a Japanese man suffering from hereditary spastic paraplegia with a thin corpus callosum (HSP-TCC) by single photon emission computed tomography (SPECT) using I-123 N-isopropyl-p-iodoamphetamine (I-123-IMP) over 4 years (25 to 29 years old). Besides the initial symptoms of lower limb spasticity, mental deterioration slightly progressed and upper limb spasticity and slight cerebellar ataxia were developed, during the period. Cranial magnetic resonance imaging (MRI) revealed an extremely thin corpus callosum and medial frontal atrophy, which remained essentially unchanged during the period. I-123-IMP SPECT demonstrated that cerebral blood flow was decreased in the thalamus and the medial frontal, temporal and parietal cortices at the first examination, and that the thalamus showed further reduction but the other involved regions presented essentially no progression during the follow-up period. This is the first report referring to the longitudinal clinical and neuroradiological changes in HSP-TCC.