Parkinson's disease (PD) is a neurodegenerative disorder resulting from the death of motor neurons in the substantia nigra and is associated with reduced lung volumes.

To analyze the compartmental distribution of thoracoabdominal volumes in PD patients evaluated by optoelectronic plethysmography (OEP) and describe the respiratory function of the sample.

This is a cross-sectional study in which 16 patients (12 men and 4 women), between 50 and 75 years old, classified in stages 2 to 3 of the Hoehn and Yahr Scale, were evaluated by OEP and spirometry. Data collection was performed at the Cardiopulmonary Physical Therapy Laboratory (LACAP) of UFPE.

In the analysis of the distribution of thoracoabdominal volumes, there was a predominance of abdominal tidal volume compared to the other compartments (VCab% = 0.34 > VCrcp% 0.13 > VCrca% 0.09, with p <0.001). Patients maintained tidal volume (Vt), minute ventilation (Ve), and respiratory rate (RR) within the normal range (Vt 0.54 ± 0.22 L; Ve 9.198 ± 3.40 L/min; RR 18.25 ± 5.73), and forced spirometry yielded an FEV1 (% predicted) of 0.71 ± 0.17 L and FVC (% predicted) of 0.69 ± 0.58 L.

The results suggest that in the distribution of thoracoabdominal volumes, there was an abdominal predominance compared to the others. In the respiratory pattern and spirometric variables, patients presented normal ventilation with a predominance of abdominal breathing pattern, despite the presence of longer inspiratory time. Despite the condition of Parkinson's disease, patients without medication therapy and normal respiratory function showed greater ventilation in the abdominal compartment compared to the thoracic compartments.

Despite normal respiratory function, future studies should elucidate the reasons for the disadvantage of thoracic impairments compared to abdominal impairments in the breathing pattern of these patients. An alternative would be to compare this assessment of the respiratory pattern in patients with medication use.