STRIATED ANAL-SPHINCTER DENERVATION IN PATIENTS WITH PROGRESSIVE SUPRANUCLEAR PALSY

Anal sphincter electromyography may contribute to the differential dia gnosis between Parkinson's disease (PD) and other parkinsonisms featur ing autonomic dysfunction, such as multiple system atrophy (MSA). Alth ough patients with progressive supranuclear palsy (PSP) do not normall y exhibit clinical signs of autonomic dysfunction, a few may be first seen with urinary and fecal incontinence. We performed an electromyogr aphic study of the anal sphincter in 12 patients with clinical criteri a of probable or definite PSP, two of them with clinical manifestation s of vesical and anal sphincter dysfunction, The results have been com pared with those obtained from six patients with PD and six patients w ith MSA. An abnormal anal sphincter examination was present in five of 12 PSP patients (41.6%). The abnormal motor units of these patients w ere indistinguishable from those observed in patients with MSA, Patien ts with MSA had the largest, and patients with PD had the lowest, prop ortion of abnormal motor units, We conclude that some patients with PS P may have electromyographic signs of denervation in the anal sphincte r, which make them indistinguishable by using this test alone from pat ients with MSA.