Effect of bilateral stimulation of the subthalamic nucleus on parkinsonian voice

The purpose of this study was to assess several acoustic features of the voices of 26 parkinsonian patients under two conditions, with and without bilateral chronic stimulation of the subthalamic nucleus (STN) to estimate the effectiveness of this procedure on parkinsonian speech. When compared to unstimulated patients, stimulated patients showed longer duration of sustained vowels, shorter duration of sentences, nonsense words, and pauses, more variable fundamental frequency (f0) in sentences, and more stable f0 during sustained vowels. Relative intensity was unchanged in both conditions. Further acoustic analyses are warranted to clarify the role of STN stimulation on parkinsonian speech.     

Aphemia after a penetrating brain wound: A case study

The speech of a patient with aphemia (pure anarthria) resulting from a penetrating brain wound was studied using linguistic and acoustic observations as well as electromyographic recordings from four labial muscles. The results are discussed in relation to phonetic disintegration's syndrome and apraxia of speech which, respectively, enhance linguistic disorders and motor programming disturbance.     

Effect of bilateral stimulation of the subthalamic nucleus on parkinsonian dysarthria

Never was the effect of bilateral stimulation of the subthalamic nucleus (STN) evaluated quantitatively on all the components of speech production, that is articulation, respiration and phonation, at the same time. It is the purpose of this study which uses force measurements of the articulatory organs and acoustic analysis in 16 parkinsonian patients. With STN stimulation, reaction and movement time of the articulatory organs decreased and their maximal strength, as well as their precision increased. We also noted a large beneficial effect on voice with a significant improvement in respiratory and phonatory functions.