Levodopa-responsive breathing discomfort in Parkinson’s disease patients

Abstract

In Parkinson's disease (PD), respiratory disturbances have been reported and the effect of levodopa on respiratory function remains controversial. The objective of this study was to evaluate pulmonary function utilizing spirometric and subjective evaluations in mild to moderated PD. Thirty-four consecutive sporadic PD patients (Hoehn and Yahr scale: 1-3) were prospectively evaluated using clinimetric scales, spirometry and modified Borg scale, all in off- and on-conditions. To check the respiratory function, a follow-up was performed at 4 years in a subgroup of these patients. Spirometric results were normal for all patients in both the on- and off-conditions at baseline. After levodopa administration, in addition to a significant improvement in subjective state of breathing discomfort, the mean forced expiratory volume in 1 s (FEV1), vital capacity (VC), forced vital capacity (FVC) values and their mean percentages predicted values (FEV1%, VC%, FVC%) were significantly increased (p < 0.05). Moreover, residual volume, total lung capacity, and the FEV1/FVC ratio were not significantly different for the ON and OFF conditions. At 4-year follow-up no resulting variations in the baseline values for FEV1%, FVC% or VC% were revealed. The results from this prospective study suggest that PD patients report frequently pulmonary discomfort. Levodopa improves respiratory symptoms. Pulmonary restrictive and obstructive dysfunctions, when not present at baseline, might not be present at 4-year follow-up.

Respiratory Dysfunctions in Parkinson’s Disease Patients

“…Levodopa treatment is able to moderately enhance the quality of breathing by ameliorating the obstructive and restrictive pulmonary impairments, but without impact or even a negative consequence for ventilatory capacity due to generating diaphragmatic dyskinesias. Tambasco et al demonstrated that levodopa treatment enhanced the respiratory function of patients and, subsequently, respiratory discomfort was decreased [ 65 ]. There were no associations between levodopa and respiratory improvements found in the primary stages of the disease, but in the evolutive stages, medication could account for sustaining the maximum inspiratory oral pressure and sniff nasal inspiratory pressure [ 66 ] and could have a beneficial effect on the restrictive pattern of the respiratory impairments by aiding the coordination rather than improving the strength [ 66 ].…”

Brainstem Ventilatory Dysfunction: A Plausible Mechanism for Dyspnea in Parkinson's Disease?

“…Although there have been numerous studies of pulmonary function in PD, few have investigated the contributions of central and peripheral respiratory mechanisms using functional respiratory testing in patients with dyspnea. Table summarizes the key studies addressing pulmonary dysfunction in PD and shows the frequency of restrictive and obstructive patterns . Review of these studies shows a lack of consistent findings, which is likely due to the fact that they included diverse cohorts of patients at different stages of disease and used variable outcome measures.…”

“…Table 1 summarizes the key studies addressing pulmonary dysfunction in PD and shows the frequency of restrictive and obstructive patterns. 4,17,[22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37] Review of these studies shows a lack of consistent findings, which is likely due to the fact that they included diverse cohorts of patients at different stages of disease and used variable outcome measures. However, a restrictive pattern of pulmonary dysfunction has been a consistent finding, reported in up to 94% of cases in different studies.…”

Ventilatory Impairments Associated with Parkinson’s Disease: A Systematic Review and Meta-Analysis

“…Four studies evaluated FVC% and FEV 1 % in PD patients during ON and OFF treatment states [18, 19, 21, 22]. The majority of them concluded that PD ON groups obtained significantly higher values compared to PD OFF groups, but the study of Hampson et al [19] shows contrary results.…”