Lung Function Testing On and Off Dopaminergic Medication in Parkinson's Disease Patients With and Without Dysphagia

Abstract

Background: Swallowing function in individuals with Parkinson's disease (PD) can be negatively affected by dopaminergic medication with associated inhibition of brainstem reflexes. Three different "swallowing-safety" profiles of PD patients were previously observed, classified according to swallowing safety on and off levodopa. Methods: Here, we investigated the effects of L-dopa on pulmonary function tests (PFTs) on 26 individuals with PD from the three different swallowing-safety profiles. PFTs results were compared to predicted values and direct comparisons between the groups with or without dysphagia were performed with nonparametric statistical tests (i.e., Kruskal-Wallis). Results: A short (12-hour) withdrawal from L-dopa did not result in any significant changes in PFTs, and no differences on PFTs results were observed between the different dysphagic groups the on and off L-dopa state. No correlation was observed between the PFTs results with swallowing safety profiles of PD patients. Conclusions: Although deglutition seems to be at least partially affected by dopaminergic repletion, dopaminergic mechanisms do not seem to be responsible for PD patients' performance in PFTs.Parkinson's disease (PD) is the most common neurodegenerative disorder after Alzheimer's disease and its prevalence increases with age.

Speech and Voice Response to a Levodopa Challenge in Late-Stage Parkinson’s Disease

“…Finally, motor speech production also depends on the appropriate function of peripheral nervous system ( 7 ). Dysfunction of speech articulation may also be partly attributed to muscular denervation and atrophy, resulting in respiratory muscles impairment whose function does not improve with l -dopa as recently shown in a sample of PD patients in HY 2–4 ( 38 ). Such muscle impairment is presumably even more severe among older PD patients who have a worse motor status as our sample.…”

Dysregulation of Respiratory Center Drive (P0.1) and Muscle Strength in Patients With Early Stage Idiopathic Parkinson's Disease

“…Furthermore, all these parameters of respiratory muscle performance tended to increase in the “on” period rather than the “off” period, although this increase did not reach statistical significance (22). This was due to poor posture restricting chest and abdominal movements, rigidity resulting in poor chest wall compliance and disrupted respiratory muscle coordination (23). Consistent with previous studies, our findings that the values of PImax and PEmax in early-stage IPD were significantly lower than the healthy controls suggest that inspiratory muscle strength appears to be impaired in IPD patients at very early stage (24).…”