Progressive supranuclear palsy and corticobasal ganglionic degeneration: differentiation by clinical features and neuroimaging techniques.

To assess the extent of overlap between clinically diagnosed patients with progressive supranuclear palsy (PSP) and corticobasal ganglionic degeneration (CBGD) we compared clinical scores for rigidity, bradykinesia, supranuclear gaze abnormalities, hemineglect and limb apraxia, postural instability, neck rigidity, and limb dystonia in 15 patients with a degenerative rigid-akinetic syndrome at presentation and at follow-up 3 to 120 months later. Only the presence of hemineglect, usually in combination with limb apraxia, was a reliable and early clinical factor for discriminating between these two conditions. These symptoms were present at admission in all 4 CBGD patients but not in any of the 11 PSP patients either at presentation or later during serial examinations. Though supranuclear ophthalmoplegia, neck rigidity, and postural instability were already observed in most CBGD patients at presentation, their scores remained low compared to those for PSP patients over the longterm. CT-scans and MRI were helpful in supporting clinically-based diagnoses made at presentation in that the vast majority of the PSP patients exhibited various degrees of midbrain atrophy and 50 percent of the CBGD patients exhibited asymmetric pericentral cortical atrophy.