title: Brain Damage and Motor Cortex Impairment in Chronic Obstructive Pulmonary Disease: Implication of Nonrapid Eye Movement Sleep Desaturation.
abstract: OBJECTIVE
  Nonrapid eye movement (NREM) sleep desaturation may cause neuronal damage due to the withdrawal of cerebrovascular reactivity. The current study (1) assessed the prevalence of NREM sleep desaturation in nonhypoxemic patients with chronic obstructive pulmonary disease (COPD) and (2) compared a biological marker of cerebral lesion and neuromuscular function in patients with and without NREM sleep desaturation.
  
  
  METHODS
  One hundred fifteen patients with COPD (Global Initiative for Chronic Obstructive Lung Disease [GOLD] grades 2 and 3), resting PaO2 of 60-80 mmHg, aged between 40 and 80 y, and without sleep apnea (apnea-hypopnea index < 15) had polysomnographic sleep recordings. In addition, twenty-nine patients (substudy) were assessed i) for brain impairment by serum S100B (biological marker of cerebral lesion), and ii) for neuromuscular function via motor cortex activation and excitability and maximal voluntary quadriceps strength measurement.
  
  
  RESULTS
  A total of 51.3% patients (n = 59) had NREM sleep desaturation (NREMDes). Serum S100B was higher in the NREMDes patients of the substudy (n = 14): 45.1 [Q1: 37.7, Q3: 62.8] versus 32.9 [Q1: 25.7, Q3: 39.5] pg.ml(-1) (P = 0.028). Motor cortex activation and excitability were lower in NREMDes patients (both P = 0.03), but muscle strength was comparable between groups (P = 0.58).
  
  
  CONCLUSIONS
  Over half the nonhypoxemic COPD patients exhibited NREM sleep desaturation associated with higher values of the cerebral lesion biomarker and lower neural drive reaching the quadriceps during maximal voluntary contraction. The lack of muscle strength differences between groups suggests a compensatory mechanism(s). Altogether, the results are consistent with an involvement of NREM sleep desaturation in COPD brain impairment.
  
  
  BACKGROUND
  The study was registered at www.clinicaltrials.gov as NCT01679782.
authors.affiliation: Movement To Health Laboratory, Euromov, University of Montpellier, Montpellier, France.|Clinique du Souffle La Vallonie, Fontalvie, Lodève, France.
authors.forename: Francois
authors.initials: F
authors.lastname: Alexandre
authors.affiliation: Clinique du Souffle La Vallonie, Fontalvie, Lodève, France.|Clinique du Souffle Les Clarines, Fontalvie, Riom-es-Montagnes, France.
authors.forename: Nelly
authors.initials: N
authors.lastname: Heraud
authors.affiliation: UMR866 Dynamique Musculaire et Métabolisme, INRA, University of Montpellier, Montpellier, France.|Laboratoire Performance Santé Altitude, EA 4604, University of Perpignan Via Domitia, Font-Romeu, France.
authors.forename: Anthony M J
authors.initials: AM
authors.lastname: Sanchez
authors.affiliation: Clinique du Souffle La Vallonie, Fontalvie, Lodève, France.|Clinique du Souffle Les Clarines, Fontalvie, Riom-es-Montagnes, France.
authors.forename: Emilie
authors.initials: E
authors.lastname: Tremey
authors.affiliation: Clinique du Souffle La Vallonie, Fontalvie, Lodève, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Oliver
authors.affiliation: Clinique du Souffle Les Clarines, Fontalvie, Riom-es-Montagnes, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Guerin
authors.affiliation: Movement To Health Laboratory, Euromov, University of Montpellier, Montpellier, France.
authors.forename: Alain
authors.initials: A
authors.lastname: Varray
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D001930:Brain Injuries / Q000097:blood / Q000150:complications* / Q000473:pathology / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000503:physiopathology*; D009119:Muscle Contraction / Q000502:physiology; D053580:Muscle Strength / Q000502:physiology; D010100:Oxygen / Q000378:metabolism*; D017286:Polysomnography; D015995:Prevalence; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications* / Q000378:metabolism / Q000503:physiopathology*; D052097:Quadriceps Muscle / Q000294:innervation / Q000502:physiology; D064568:S100 Calcium Binding Protein beta Subunit / Q000097:blood; D012890:Sleep / Q000502:physiology*
chemical_list: D015415:Biomarkers; D064568:S100 Calcium Binding Protein beta Subunit; C579160:S100B protein, human; D010100:Oxygen
keywords: central nervous system; cerebral cortex; electromyography; muscle weakness; voluntary activation