Respiratory Evaluation in Spinocerebellar ataxia Type 2.

Spinocerebellar ataxia type 2 (SCA2) is a progressive cerebellar syndrome that may lead to respiratory impairments. However, our understanding of the degree and characteristics of the respiratory involvement in SCA2 individuals remains limited. This study evaluates respiratory in SCA2 patients. This cross-sectional study included a group of controls and patients with SCA2. Participants underwent assessments including spirometry, maximal inspiratory (MIP) and expiratory (MEP) pressures, sniff nasal inspiratory pressure (SNIP), cough flow peak (CFPs), neurophysiological right phrenic and accessory nerves conduction studies and evaluations with the SARA and ICARS ataxia severity scales. A total of 16 adults with SCA2, and 20 healthy controls were included. Patients with SCA2 exhibited significantly reduced respiratory parameters compared to healthy controls. Key findings included lower forced vital capacity (FVC), forced expiratory volume in 1 s (FEV₁), and peak expiratory flow (PEF), with reductions observed in both absolute values and percentages (p < 0.01). They also showed decreased maximal inspiratory (MIP) and expiratory pressures (MEP), sniff nasal inspiratory pressure (SNIP), cough flow peak (CFP) values and oxygen saturation (SpO₂), reduced amplitude of motor potentials of the right phrenic nerve and increased end-tidal CO₂ (ETCO₂). The combined involvement of respiratory and neurophysiological parameters reflects impairment of both pulmonary capacity and respiratory muscle strength. Patients with SCA2 have significant impairment in respiratory parameters, including reduced pulmonary capacity and respiratory muscle strength, compared to healthy subjects. These findings highlight the relevance of including respiratory assessment and target interventions as part of the clinical management of patients with SCA2.