Diffusion tensor imaging in familial spastic paraplegia with mental impairment and thin corpus callosum.

We investigated 2 Japanese siblings with a complicated form of familial spastic paraplegia. Cranial magnetic resonance (MR) imaging revealed marked thinning of the corpus callosum. Diffusion tensor imaging (DTI) showed microstructural changes in the thalamus, basal ganglia, and cerebral white matter, and single photon emission computed tomography (SPECT) using 99mTc-ethylcysteinate dimer showed very similar findings. DTI and SPECT effectively revealed global changes not revealed by conventional MR imaging.