The Effects of Pallidotomy Surgery on Sentence Rate Measures
across Three Tasks in Parkinson’s Patients

G Schulz, M Greer, W Friedman

Experimental and clinical evidence suggest that limb motor symptoms of human Parkinson’s disease (PD) can be surgically ameliorated by pallidotomy. However, the reuslts of this surgery on speech motor symptoms has been equivocal. Acoustic analysis of sentence rate measures taken from reading, picture description and conversation were conducted on 25 patients with idiopathic PD prior to and three months following unilateral pallidotomy surgery. Results are similar to other reoprts in that PD patients with mild hypokinetic dysarthria prior to surgery demonstrated greater positive changes in sentence rate measures (speaking rate, pause duration, pause frequency) following surgery than those with moderate or severe hypokinetic dysarthria. The task differences observed in the present study support the need to evaluate treatment outcomes across tasks to accurately determine efficacy.