Early occurrence of inspiratory muscle weakness in Parkinson’s disease

<div><p>Introduction</p><p>In Parkinson’s disease (PD), respiratory insufficiency (including functional and muscle disorders) can impact dysarthria and swallowing. Most studies of this topic have been performed retrospectively in populations of patients with advanced PD. The objective of the present study was to characterize lung function (under off-drug conditions) in early-stage PD patients at baseline and then again two years later.</p><p>Methods</p><p>Forty-one early-stage PD patients (mean ± SD age: 61.7 ± 7.7; mean ± SD disease duration: 1.9 ± 1.7 years) were prospectively enrolled and compared with 36 age-matched healthy controls. Neurological evaluations and pulmonary function testing were performed in the off-drug condition at the inclusion visit and then two years later.</p><p>Results</p><p>Pulmonary function testing did not reveal any restrictive or obstructive disorders; at baseline, inspiratory muscle weakness was the only abnormality observed in the PD group (in 53.7% of the patients, vs. 25% in controls; p = 0.0105). The PD patients had a lower mean maximal inspiratory mouth pressure than controls and a lower sniff nasal inspiratory pressure. Two years after the initiation of chronic treatment with antiparkinsonian medications, the maximal inspiratory mouth pressure and the sniff nasal inspiratory pressure tended to be higher. Lastly, overall motor outcomes were not significantly worse in patients with inspiratory muscle weakness than in patients without inspiratory muscle weakness.</p><p>Conclusion</p><p>Inspiratory muscle weakness seems to be common in patients with early-stage PD, and was seen to be stable over a two-year period. Additional long-term follow-up studies are required to specify the impact of this new feature of PD.</p></div

Changes over time in clinical and PFT parameters between V1 and V2.

<p>Changes over time in clinical and PFT parameters between V1 and V2.</p

A comparison between PD patients and healthy subjects.

<p>A comparison between PD patients and healthy subjects.</p

Individual values of inspiratory resistances before and after autogenic drainage in 30 CF patients.

<p>A, Rrs_5; B, Rrs_11; C, Rrs_19; D, Rrs₅–Rrs₁₉.</p

Comparison (in an analysis of covariance) of clinical changes between V1 and V2 in PD patients with and without inspiratory muscle weakness.

<p>Comparison (in an analysis of covariance) of clinical changes between V1 and V2 in PD patients with and without inspiratory muscle weakness.</p

Characteristics of the cystic fibrosis patients.

<p>Characteristics of the cystic fibrosis patients.</p

Results of covariance analyses on the decrease of water phosphorus concentrations based on the trophic state.

<p>For each trophic state, n = 39. The first letter of the acronym corresponds to the water (A for <i>Alsatian</i> and V for <i>Vosgian</i> water), the second letter corresponds to the subpopulation (A for <i>Alsatian</i> and V for <i>Vosgian</i> subpopulation) e.g. AV: <i>Vosgian E</i>. <i>nuttallii</i> in <i>Alsatian</i> water. The results of the multiple comparisons among slopes are given by an exponent letter: values that do not differ at the 0.05 level are noted with a same letter (a < b < c).</p><p>Results of covariance analyses on the decrease of water phosphorus concentrations based on the trophic state.</p

Results of covariance analyses on the decrease of water phosphorus concentrations based on the rearing treatment (subpopulation and water).

<p>For each treatment, n = 39. The first letter of the acronym corresponds to the water (A for <i>Alsatian</i> and V for <i>Vosgian</i> water), the second letter corresponds to the subpopulation (A for <i>Alsatian</i> and V for <i>Vosgian</i> subpopulation) e.g. AV: <i>Vosgian E</i>. <i>nuttallii</i> in <i>Alsatian</i> water. The results of the multiple comparisons among slopes are given by an exponent letter: values that do not differ at the 0.05 level are noted with a same letter (a < b < c).</p><p>Results of covariance analyses on the decrease of water phosphorus concentrations based on the rearing treatment (subpopulation and water).</p

Results of covariance analyses on the decrease of water phosphorus concentrations based on the season.

<p>For each season, n = 39. The first letter of the acronym corresponds to the water (A for <i>Alsatian</i> and V for <i>Vosgian</i> water), the second letter corresponds to the subpopulation (A for <i>Alsatian</i> and V for <i>Vosgian</i> subpopulation) e.g. AV: <i>Vosgian E</i>. <i>nuttallii</i> in <i>Alsatian</i> water. The results of the multiple comparisons among slopes are given by an exponent letter: values that do not differ at the 0.05 level are noted with a same letter (a < b < c).</p><p>Results of covariance analyses on the decrease of water phosphorus concentrations based on the season.</p

Dynamics of water phosphorus in summer.

<p>Dynamics of water phosphorus (in μg.l⁻¹.g⁻¹ of plant initial dry mass) and results of a linear model regression analyses under eutrophic and hypertrophic conditions, for all the possible combinations of water and subpopulation, during the summer experiment. In the legend, AA, AV, VA, VV include the information on the treatment, the first letter refers to the type of water and the second one to the subpopulation (e.g. AV means <i>Alsatian</i> water and <i>Vosgian</i> subpopulation).</p