Diaphragmatic motor cortex hyperexcitability in patients with chronic obstructive pulmonary disease.

BACKGROUND AND OBJECTIVES: Respiratory muscles dysfunction has been reported in COPD. Transcranial magnetic stimulation (TMS) has been used for assessing the respiratory corticospinal pathways particularly of diaphragm. We aimed to study the cortico-diaphragmatic motor system changes in COPD using TMS and to correlate the findings with the pulmonary function. METHODS: A case control study recruited 30 stable COPD from the out-patient respiratory clinic of Main Alexandria University hospital- Egypt and 17 healthy control subjects who were subjected to spirometry. Cortical conduction of the diaphragm was performed by TMS to all participants followed by cervical magnetic stimulation of the phrenic nerve roots. Diaphragmatic resting motor threshold (DRMT), cortical motor evoked potential latency (CMEPL), CMEP amplitude (CMEPA), peripheral motor evoked potential latency (PMEPL), PMEP amplitude (PMEPA) and central motor conduction time (CMCT) were measured. RESULTS: 66.7% of COPD patients had severe and very severe COPD with median age of 59 (55-63) years. There was statistically significant bilateral decrease in DRMT, CMEPA and PMEPA in COPD group versus healthy subjects and significant increase in CMEPL and PMEPL (p <0.01). Left CMCT was significantly prolonged in COPD group versus healthy subjects (p <0.0001) but not right CMCT. Further, there was significant increase in CMEPL and CMCT of left versus right diaphragm in COPD group (p = 0.003 and 0.001 respectively) that inversely correlated with FEV1% and FVC% predicted. Right and left DRMT were insignificantly different in COPD group (p >0.05) but positively correlated with FEV1/FVC, FEV1% and FVC% predicted. CONCLUSION: Central cortico-diaphragmatic motor system is affected in COPD patients with heterogeneity of both sides that is correlated with pulmonary function. SIGNIFICANCE: Coticospinal pathway affection could be a factor for development of diaphragmatic dysfunction in COPD patients accordingly its evaluation could help in personalization of COPD management especially pulmonary rehabilitation programs.

Comorbidities associated with obstructive sleep apnea: a retrospective Egyptian study on 244 patients.

PURPOSE: The aim of the present study was to assess prevalence of associated comorbidities in a group of patients diagnosed with obstructive sleep apnea syndrome (OSAS). METHODS: This retrospective study enrolled 244 consecutive patients diagnosed by polysomnogram with OSAS between October 2010 and January 2015 after being referred to our Sleep-Related Breathing Disorders Unit, Chest Diseases Department, in the Alexandria Main University Hospital. RESULTS: Of 244 patients, 47% were men, mean age was 56.9 years, and mean apnea-hypopnea index was 43.6 events per hour. Patients were categorized into two groups: group 1 (38%), mild and moderate OSAS, and group 2 (62%), severe, very severe, and extreme OSAS. Comorbidities were present in 91% of patients. The most common comorbidities were obesity, hypertension (HTN), and diabetes mellitus (DM). Prevalence of obesity, HTN, DM, congestive heart failure, deep vein thrombosis, pulmonary embolism (PE), and hypothyroidism was significantly higher in severity group 2. PE, bronchial asthma, and chronic obstructive pulmonary disease were significantly higher among men, whereas hypothyroidism was significantly higher among women. During this period of over 4 years, mortality rate was 8%. The majority of deaths occurred at night. Most of the studied patients (60%) either received no treatment or were not adherent to positive airway pressure (PAP) therapy. None of the patients received surgicaltreatment. The majority (50%) gained access to PAP therapy through donations. Associated hypoventilation was the only significant predictor of PAP adherence. Quality of life was significantly better among PAP adherent patients. CONCLUSIONS: Patients suffering from OSAS have very high prevalence of comorbidities indicating a great burden on the healthcare system. Despite this fact, over 50% of the patients studied did not receive any treatment. Charities were the main portal fortreatment.