title: Peroneal F-wave characteristics under submaximal stimulation.
abstract: OBJECTIVE
  F-wave studies are valuable tools in clinical neurophysiology. F-wave parameter estimation must be based on multiple F-wave traces due to their inherent variability. Repetitive supramaximal stimulation is uncomfortable for many patients. This study tested the hypothesis that submaximally stimulated nerves yield F-wave parameters equivalent to those obtained with supramaximal stimulation.
  
  
  METHODS
  Thirty-five peroneal nerves from 27 subjects were stimulated both supramaximally and submaximally. CMAP and F-wave responses from the extensor digitorum brevis muscle were recorded and analyzed offline. Automated algorithms were used to determine F-wave parameters.
  
  
  RESULTS
  Mean, minimum, maximum F-wave latencies, F-wave duration, and chronodispersion showed no statistically significant difference under the two stimulation conditions. F-wave persistence, amplitude, and subject's discomfort level, were lower with statistical significance. The correlation coefficient of submaximal and supramaximal mean F-wave latencies was 0.977 and their intraclass correlation coefficient was 0.976. The bias of the mean latencies was 0.21 ms and the 95% limits of agreement were less than 5% of the mean F-wave latency.
  
  
  CONCLUSIONS
  F-waves acquired with submaximal stimulation possess characteristics statistically equivalent to those obtained under supramaximal stimulation, as measured by the latency and duration parameters. Persistence and amplitude were lower. Reduction in discomfort level was also achieved.
authors.affiliation: NeuroMetrix Inc, Waltham, MA 02451, USA. xuan_kong@neurometrix.com
authors.forename: X
authors.initials: X
authors.lastname: Kong
authors.forename: P
authors.initials: P
authors.lastname: Bansal
authors.forename: J T
authors.initials: JT
authors.lastname: Megerian
authors.forename: S N
authors.initials: SN
authors.lastname: Gozani
mesh_terms: D000328:Adult; D000344:Afferent Pathways / Q000502:physiology; D000368:Aged; D004558:Electric Stimulation / Q000009:adverse effects / Q000379:methods; D004568:Electrodiagnosis / Q000379:methods* / Q000592:standards; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009046:Motor Neurons / Q000502:physiology; D018482:Muscle, Skeletal / Q000294:innervation / Q000502:physiology; D009422:Nervous System Diseases / Q000175:diagnosis*; D009431:Neural Conduction / Q000502:physiology*; D017060:Patient Satisfaction; D010543:Peroneal Nerve / Q000502:physiology*; D011237:Predictive Value of Tests; D011930:Reaction Time / Q000502:physiology; D012018:Reflex / Q000502:physiology; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted; D013997:Time Factors