title: Changes of the phrenic nerve motor response in amyotrophic lateral sclerosis: longitudinal study.
abstract: OBJECTIVE
  Phrenic nerve motor amplitude (Diaphr Ampl) is predictive of hypoventilation in amyotrophic lateral sclerosis (ALS). We aimed to evaluate its change over disease course and to correlate it to other measurements.
  
  
  METHODS
  Forty-nine unselected patients (35 men, 13 bulbar-onset, 56.5+/-8.9 years) with definitive or probable ALS were included. They were evaluated at entry (time 0) and 4-6 months (5.2+/-1.0) later (time 1) with: functional ALS rating scale (ALS-FRS) and respiratory subscore (ALS-FRSr); forced vital capacity (FVC); maximal inspiratory pressure (MIP); mean O(2) saturation overnight (SpO(2)mean); sniff maximal inspiratory pressure (SNIP); Diaphr Ampl and mean amplitude of the ulnar nerve response (ADM Ampl).
  
  
  RESULTS
  ALS-FRS, ALS-FRSr, Diaphr Ampl, FVC, SNIP, ADM Ampl (p<0.01) and SpO(2)mean (p<0.05) declined significantly. MIP did not change significantly (p=0.203). Coefficient of variation was similar for FVC, Diaphr Ampl, ADM Ampl and ALS-FRS but higher for SNIP. The percentage of change for Diaphr Ampl was significantly correlated to FVC and SNIP, but not to ADM Ampl or ALS-FRS.
  
  
  CONCLUSIONS
  Diaphr Ampl decreased significantly in a short period of time and its change is correlated to other respiratory tests. This test can be useful in patients with marked facial weakness or uncooperative.
  
  
  CONCLUSIONS
  Diaphr Ampl is useful to monitor respiratory function in ALS patients and can be applied in clinical trials.
authors.affiliation: Neuromuscular Unit, Institute of Molecular Medicine - Faculty of Medicine, University of Lisbon, Lisbon, Portugal.
authors.forename: Susana
authors.initials: S
authors.lastname: Pinto
authors.affiliation: Department of Neurosciences, Hospital de Santa Maria, Lisbon, Portugal.
authors.forename: Ruth
authors.initials: R
authors.lastname: Geraldes
authors.affiliation: Neuromuscular Unit, Institute of Molecular Medicine - Faculty of Medicine, University of Lisbon, Lisbon, Portugal.
authors.forename: Nuno
authors.initials: N
authors.lastname: Vaz
authors.affiliation: Neuromuscular Unit, Institute of Molecular Medicine - Faculty of Medicine, University of Lisbon, Lisbon, Portugal; Department of Physical Medicine and Rehabilitation, Hospital de Santa Maria, Lisbon, Portugal.
authors.forename: Anabela
authors.initials: A
authors.lastname: Pinto
authors.affiliation: Neuromuscular Unit, Institute of Molecular Medicine - Faculty of Medicine, University of Lisbon, Lisbon, Portugal; Department of Neurosciences, Hospital de Santa Maria, Lisbon, Portugal. Electronic address: mamedemg@mail.telepac.pt.
authors.forename: Mamede
authors.initials: M
authors.lastname: de Carvalho
mesh_terms: D000328:Adult; D000368:Aged; D000690:Amyotrophic Lateral Sclerosis / Q000175:diagnosis / Q000503:physiopathology*; D003964:Diaphragm / Q000294:innervation / Q000502:physiology; D018450:Disease Progression; D005500:Follow-Up Studies; D006801:Humans; D007040:Hypoventilation / Q000175:diagnosis / Q000503:physiopathology; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength / Q000502:physiology; D010791:Phrenic Nerve / Q000502:physiology*; D011446:Prospective Studies; D012129:Respiratory Function Tests / Q000379:methods