Respiratory motor function in individuals with centronuclear myopathies.
I NTRODUCTION: Individuals with X-linked myotubular myopathy (XLMTM) and other centronuclear myopathies (CNMs) frequently have profound respiratory insufficiency that requires support early in life. Still, few quantitative data exist to characterize respiratory motor function in CNM.



We evaluated the reliance upon mechanical ventilation (MV), ventilatory kinematics, unassisted tidal volumes, and maximal respiratory pressures in 14 individuals with CNMs, including 10 boys with XLMTM.



Thirteen participants required full-time, invasive MV. Maximal inspiratory pressures were higher in subjects who breathed unsupported at least 1 hour/day as compared with 24-hour MV users [33.7 (11.9-42.3) vs. 8.4 (6.0-10.9) cm H(2)O, P < 0.05]. Years of MV dependence correlated significantly with MEP (r = -0.715, P < 0.01).



Respiratory function in CNMs may be related to deconditioning from prolonged MV and/or differences in residual respiratory muscle strength. Results from this study may assist in evaluating severe respiratory insufficiency in neuromuscular clinical care and research.
Department of Physical Therapy, University of Florida, P.O. Box 100154, Gainesville, Florida, 32610-0154, USA.
Barbara K
BK
Smith
Department of Pediatrics, Vanderbilt University, Nashville, Tennessee, USA.
Markus S
MS
Renno
College of Medicine, University of Kentucky, Lexington, Kentucky, USA.
Meghan M
MM
Green
Department of Pediatrics, University of Florida, Gainesville, Florida, USA.
Terry M
TM
Sexton
Department of Pediatrics, University of Florida, Gainesville, Florida, USA.
Lee Ann
LA
Lawson
Department of Physical Therapy, University of Florida, P.O. Box 100154, Gainesville, Florida, 32610-0154, USA.
Anatole D
AD
Martin
Department of Pediatrics, University of Florida, Gainesville, Florida, USA.
Manuela
M
Corti
Department of Pediatrics, University of Florida, Gainesville, Florida, USA.
Barry J
BJ
Byrne
D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D020914:Myopathies, Structural, Congenital / Q000150:complications* / Q000628:therapy; D011312:Pressure; D012120:Respiration Disorders / Q000175:diagnosis* / Q000209:etiology*; D012121:Respiration, Artificial / Q000379:methods; D012129:Respiratory Function Tests / Q000379:methods*; D012132:Respiratory Muscles / Q000503:physiopathology; D055815:Young Adult
centronuclear myopathy; clinical trial design; mechanical ventilation; myotubular myopathy; respiratory function