WHICH CLINICAL-FEATURES DIFFERENTIATE PROGRESSIVE SUPRANUCLEAR PALSY (STEELE-RICHARDSON-OLSZEWSKI SYNDROME) FROM RELATED DISORDERS - A CLINICOPATHOLOGICAL STUDY

The difficulty in differentiating progressive supranuclear palsy (PSP, also called Steele-Richardson-Olszewski syndrome) from other related disorders was the incentive for a study to determine the clinical feat ures that best distinguish PSP Logistic regression and classification and regression tree analysis (CART) were used to analyse data obtained at the first visit from a sample of 83 patients with a clinical histo ry of parkinsonism or dementia confirmed neuropathologically: includin g PSP (n = 24), corticobasal degeneration (n = II), Parkinson's diseas e (PD, n = II), diffuse Lewy body disease (n = 14), Pick's disease (n = 8) and multiple system atrophy (MSA, n = 15). Supranuclear vertical gaze palsy, moderate or severe postural instability and falls during t he first year after onset of symptoms classified the sample with 9% er ror using logistic regression analysis. The CART identified similar fe atures and was also helpful in identifying particular attributes that separate PSP from each of the other disorders. Unstable gait, absence of tremor-dominant disease and absence of a response to levodopa diffe rentiated PSP from PD. Supranuclear vertical gaze palsy, gait instabil ity and the absence of delusions distinguished PSP from diffuse Lewy b ody disease. Supranuclear vertical gaze palsy and increased age at sym ptom-onset distinguished PSP front MSA. Gait abnormality, severe upwar d gaze palsy, bilateral bradykinesia and absence of alien limb syndrom e separated PSP from corticobasal degeneration. Postural instability s uccessfully classified PSP from Pick's disease. The present study may help to minimize the difficulties neurologists experience when attempt ing to classify these disorders at early stages.