Photoglottographic measures in Parkinson's disease

This study examines the usefulness of photoglottographic measures in reflec ting the phonatory effect of Parkinson's disease. In the first experiment, data obtained by photoglottography were compared between 15 male patients w ith Parkinson's disease and 15 normal male speakers of similar age. Six pho toglottographic parameters, mean open quotient (OQ), mean speed quotient (S Q), perturbation of open quotient (POQ), perturbation of speed quotient (PS Q), frequency perturbation ratio (FPR), and amplitude perturbation ratio (A PR), in sustained vowel phonation were investigated. Increased SQ (t = -2.7 31, df = 28, P = 0.011) and POQ (t = -2.584, df = 28, P = 0.015) were signi ficantly associated with data from patients in comparison to normal speaker s. The FPR, APR, and OQ were not significantly different between normal sub jects and patients. A follow-up experiment, including 12 female and 19 male patients with Parkinson's disease, was designed to evaluate the sensitivit y of SQ and POQ in detecting vocal dysfunction. The sensitivity of SQ was f ound to be relatively high (93.5%), while that of POQ was :low (45.2%). Met hodological issues regarding the effects of gender, age, stage of the disea se, and treatment on photoglottographic measures in Parkinson's disease wer e discussed.