The severity of respiratory disorders in different forms of amyotrophic lateral sclerosis

Abstract

Sleep-disordered breathing (SDB) substantially impairs quality of life in a patient with amyotrophic lateral sclerosis (ALS) and promote the addition of serious respiratory and cardiovascular complications. Objective: to identify the early signs of SDB in patients with various onset ALS using a comprehensive sleep assessment. Patients and methods. A questionnaire survey using a comprehensive test for sleep disorders was conducted in 65 patients: 39 of them had ALS (male:female ratio, 25:14; age, 59 [51; 66] years) and 26 patients made up a control group (male:female ratio, 13:13; age, 54 [43; 59] years). The questionnaire consists of 50 questions; the results were expressed as scores. Screening portable polysomnographic study was conducted in patients with newly diagnosed ALS at the relatively early stages of the disease. A total of 61 patients (32 women and 29 men; median (Me and the 25th and 75th percentile) age was 62 [55; 67] years) were examined. The disease duration was 12 [8.9, 27.1] months after the onset of the first symptoms. The body mass index was 25.7 [23.3, 28.7] kg/m2 . In the study group, ALSFRSR [9] scores at study inclusion were 34.32 [32; 38]. Cervicothoracic onset ALS was present in 23 patients; 26 and 12 patients had bulbar and lumbosacral onsets, respectively. Screening diagnosis of sleep was carried out using a Polymate YH-1000C portable polysomnograph (BMC, China) that registered nasopharyngeal flow (airflow through the nasal and oral cavities); thoracoabdominal movements (movements of the thoracic and abdominal walls); hemoglobin oxygen saturation of arterial blood ( SpO2); a snore sound through the microphone; and sleeping position (actography). Results. The comprehensive screening study of breathing during sleep shows the underestimation of the complaints and symptoms of subclinical respiratory disorders in patients with ALS. Portable pulse oximetry at the early stages of the disease revealed changes in the nocturnal respiratory parameters that indicated a predisposition to the development of hypoventilation syndrome. Bulbar-onset ALS patients who had significantly higher apnea/hypopnea index (AHI) and oxygen desaturation (ODI) and lower mean SpO2 with the development of hypoventilation syndrome and, to a lesser extent, obstructive sleep apnea syndrome were most vulnerable to the development of SDB. A correlation analysis revealed the impact of minimal SpO2, ODI, and apnea duration on cardiorespiratory parameters in ALS patients and the possibility of their use as markers to analyze of SDB and cardiac arrhythmias during screening studies in these patients. Conclusion. The early detection and correction of respiratory failure symptoms can prolong patients' life and improve its quality. The screening study of nocturnal sleep and SDB in patients with ALS is a simple and informative method to evaluate a range of respiratory disorders, especially at the early stages of the disease.