Hereditary spastic paraplegia with frontal lobe dysfunction: a clinicopathologic study.

The authors report an unusual family with hereditary spastic paraplegia (HSP) with frontal lobe dysfunction having the onset in the sixth decade. All the patients showed hypoperfusion in the frontal lobes and thalami on SPECT. Neuropathologic findings revealed thin corpus callosum and degeneration in the thalamic dorsomedial nuclei as well as degeneration of the corticospinal tracts. This family was likely affected by a novel form of HSP characterized by frontal lobe dysfunction caused by thalamic degeneration.