Functional recovery of diaphragm paralysis: a long-term follow-up study.
BACKGROUND
Long-term functional outcome of diaphragm paralysis is largely unknown.


METHODS
A retrospective study was conducted in 23 consecutive patients (21 males, 56+/-9 years) with uni- or bilateral diaphragm paralysis to examine whether functional respiratory recovery can be predicted from the compound motor action potential (CMAP) of the diaphragm at the time of diagnosis. Pulmonary function and CMAP were evaluated at baseline and at follow-up. CMAP amplitude and latency were recorded by surface electromyography with percutaneous electrical stimulation of the phrenic nerve. Patients were followed for (median) 15 months up to 131 months (range 5-131). Functional respiratory recovery was defined as an increase in forced vital capacity > 400 ml.


RESULTS
Functional recovery occurred in 43% of the patients after 12 months (10 out of 23) and in 52% after 24 months (12 out of 23). Type and etiology of paralysis did not influence recovery. CMAP, anthropometric characteristics and baseline pulmonary function did not predict functional respiratory recovery. Whether respiratory muscle training improved pulmonary function is uncertain. Moreover, it did not result in a greater percentage functional respiratory recovery. Relapse after an initial improvement was observed in 26% of the patients.


CONCLUSIONS
The present study indicates that functional recovery of diaphragm paralysis is difficult to predict and may occur years after the onset of the paralysis.
Gayan-Ramirez
Ghislaine
G
Respiratory Muscle Research Unit, Laboratory of Pneumology and Respiratory Division, Katholieke Universiteit Leuven, Onderwijs en Navorsing 1 bus 706, Herestraat 49, B-3000 Leuven, Belgium. ghislaine.gayan-ramirez@med.kuleuven.be
Gosselin
Nadège
N
Troosters
Thierry
T
Bruyninckx
Frans
F
Gosselink
Rik
R
Decramer
Marc
M
D000200:Action Potentials; D000368:Aged; D003964:Diaphragm / Q000503:physiopathology*; D004558:Electric Stimulation; D004576:Electromyography; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D008168:Lung / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009046:Motor Neurons / Q000502:physiology; D009431:Neural Conduction; D010791:Phrenic Nerve / Q000503:physiopathology; D020127:Recovery of Function; D012129:Respiratory Function Tests; D012133:Respiratory Paralysis / Q000503:physiopathology*; D016896:Treatment Outcome