Effects of medication and subthalamic nucleus deep brain stimulation on tongue movements in speakers with Parkinson's disease using electropalatography: A pilot study

Abstract

Parkinson's disease (PD) affects speech in the majority of patients. Subthalamic nucleus deep brain stimulation (STN-DBS) is particularly effective in reducing tremor and rigidity. However, its effect on speech is variable. The aim of this pilot study was to quantify the effects of bilateral STN-DBS and medication on articulation, using electropalatography (EPG). Two patients, PT1 and PT2, were studied under four conditions: on and off medication and ON and OFF stimulation. The EPG protocol consisted of a number of target words with alveolar and velar stops, repeated 10 times in random order. The motor part III of the Unified Parkinson Disease Rating Scale (UPDRS) indicated significantly improved motor scores in the ON stimulation condition in both patients. However, PT1's articulation patterns deteriorated with stimulation whereas PT2 showed improving articulatory accuracy in the same condition. The results revealed different effects of stimulation and medication on articulation particularly with regard to timing. The study quantified less articulatory undershoot for velar stops in comparison to alveolars. Furthermore, the findings provided preliminary evidence that stimulation with medication has a more detrimental effect on articulation than stimulation without medication.

Disruption of programmed masticatory movements in unilateral MPTP-treated monkeys as a model of jaw movement abnormality in Parkinson’s disease

“…These abnormalities could reflect regional manifestations of generalized hypokinesia, rigidity and other axial motor symptoms, or more specific effects on mechanisms regulating particular orofacial movements. Both patients with Parkinson's disease and animal models evidence deficits in orofacial movements, such as precise control of the tongue; in the early, often hemi-Parkinsonian stage of the disease, impairment in functions such as speech increases with the progression of the disease (Connor and Abbs 1991;Kane et al 2011;Hartinger et al 2010;Bakke et al 2011). The difficulties of swallowing observed in advanced Parkinson's disease patients, i.e.…”

Measures to evaluate the effects of DBS on speech production

“…There are several studies in which EPG pattern differences have been reported between speakers with dysarthria and control groups, or between specific patients and one or two control speakers (see McAuliffe & Ward, 2006), but group effects are not consistent across studies. A recent study by Hartinger, Tripoliti, Hardcastle, and Limousin (2011) reported EPG changes for two patients with Parkinson disease pre- and post-DBS stimulation, in which tongue-to-palate contact patterns for stop consonants were better for one patient, but worse for the other following stimulation. Although Hartinger et al (2011) interpreted the EPG data in terms of articulatory speeds, the specific relationship between variations in speech movements and specific EPG patterns is unknown, largely because the proper studies have not been done.…”

“…A recent study by Hartinger, Tripoliti, Hardcastle, and Limousin (2011) reported EPG changes for two patients with Parkinson disease pre- and post-DBS stimulation, in which tongue-to-palate contact patterns for stop consonants were better for one patient, but worse for the other following stimulation. Although Hartinger et al (2011) interpreted the EPG data in terms of articulatory speeds, the specific relationship between variations in speech movements and specific EPG patterns is unknown, largely because the proper studies have not been done. To date, then, the EPG literature does not seem consistent with the third criterion of providing insight to the underlying speech movement disorder and its potential modification by a treatment such as DBS.…”

Treatment of dysarthria following subthalamic nucleus deep brain stimulation for Parkinson's disease

“…The severity, nature and perceptual characteristics of such speech difficulties can be variable and so far difficult to predict 2 . Some reports showed increase in loudness of speech following surgery with concomitant reduced intelligibility 2,9,10 . Speech problems can often limit the overall benefits of the procedure.…”