Neuropsychological functioning in cortical-basal ganglionic degeneration

Reports of neuropsychological functioning in patients with cortical-basal ganglionic degeneration (CBGD) are sparse. Sawle et al. ^[1] stated that one of their six CBGD patients exhibited ``dysphasia,'' four showed ``memory impairment,'' and that the patients displayed some deficits on tasks ``thought to reflect frontal lobe or other cerebral dysfunction.'' Blin et al. <sup>[2]</sup> found that their five CBGD patients had a mean Wechsler Adult Intelligence Scale Verbal IQ of 89, mean Raven's IQ of 95, mean Wechsler Memory Scale MQ of 88, and deficient generation of animal names and words beginning with ``m.'' Rinne et al. ^[3] reported that on initial examination, seven of 36 patients showed ``slight generalized cognitive impairment,'' often suggesting more severe involvement of one of the hemispheres, but these authors did not provide the specific neuropsychological tests employed. At follow-up, nine of 30 patients displayed evidence of ``generalized higher mental function involvement,'' but some additional patients showed visuospatial and ``frontal'' deficits. Most recently, Pillon and colleagues *RF 3a* found that their 15 CBGD patients exhibited executive function and motor deficits similar to those shown by patients with supranuclear palsy (PSP); memory abilities superior to Alzheimer's disease (AD) patients; and asymmetric praxis disorders not shown by either PSP or AD patients.

In the current study, we conducted a neuropsychological investigation of a relatively large sample of CBGD patients (N equals 21) to delineate more precisely the pattern of neuropsychological strengths and weaknesses associated with CBGD. In addition, we sought to determine whether CBGD patients could be differentiated from patients with another neurodegenerative disorder, AD, who exhibit a different pattern of cortical (e.g., medial temporal lobe) and subcortical (e.g., basal forebrain) involvement. We compared CBGD patients with AD patients who did not display extrapyramidal symptoms and with AD patients who did display such symptoms (AD plus EPS), since …