Strength, Endurance, and Stability of the Tongue and Hand in Parkinson Disease

Abstract

Weakness and fatigue in the orofacial system often are presumed to contribute to the dysarthria associated with neuromotor disorders, although previous research findings are equivocal. In this study, tongue strength, endurance, and stability during a sustained submaximal effort were assessed in 16 persons with mild to severe Parkinson disease (PD) and a perceptible speech disorder. The same measures were taken from one hand for comparison. Only tongue endurance was found to be significantly lower in these participants than in neurologically normal control participants matched for sex, age, weight, and height. Analyses of data from a larger sample comprising the present and retrospective data revealed lower-than-normal tongue strength and endurance in participants with PD. No significant correlations were found between tongue strength and endurance, interpause speech rate, articulatory precision, and overall speech defectiveness for the present and previously studied participants with PD, bringing into question the influence of modest degrees of tongue weakness and fatigue on perceptible speech deficits.

Perceptions of effort during handgrip and tongue elevation in Parkinson's disease

“…A retrospective analysis of data from both studies revealed lower than normal tongue strength and endurance but no differences between PD and normal control subjects for handgrip performance [10]. These findings support the expected decrements in maximal performance, but only for the axial structure tested.…”

“…right hand, left hand) within each item (e.g. finger taps) [10]; scores were recalculated according to common practice, based on a total of 108, weighting each subitem equally.…”

“…Subjects scored 'highly probable normal' for dementia [27]. These persons participated in a larger investigation, and were described in more detail previously [10]. Subjects provided written informed consent, as approved by the Institutional Review Board of the University of Iowa.…”

“…During data collection for the same 16 pairs of subjects reported previously [10], the study included additional tasks to quantify effort using three techniques. These tasks are of interest physiologically and clinically because they may provide quantitative indicators of fatigue without depending on maximal performance.…”

“…Previously, Solomon and colleagues [9,10] tested strength and endurance (at 50% of maximum strength) of handgrip and tongue elevation in a total of 36 patients with PD and 36 matched normal control subjects. A retrospective analysis of data from both studies revealed lower than normal tongue strength and endurance but no differences between PD and normal control subjects for handgrip performance [10].…”