F-wave acquisition using low-current stimulation.
The purpose of this study was to assess the feasibility of utilizing low-current stimulation for F-wave generation, thereby avoiding the discomfort of repetitive supramaximal stimulation. We employed the same technique as is used for generating F waves in the conventional way, except for using a stimulating current that was just strong enough to evoke a motor response on the oscilloscope. This usually required a stimulus of about 10-15 mA at 0.2-ms duration. Both median nerves of 30 subjects were evaluated with this technique and with F waves generated by the conventional technique in the same subjects. Amplitudes were larger when using supramaximal current stimulation. However, there was no statistical difference between F-wave latencies, chronodispersion, and persistence (penetrance) elicited with maximal and low-current stimulation. This procedure should represent a significant improvement for patient comfort during electrodiagnostic procedures involving F-wave studies.
DiBenedetto
Margarete
M
Department of Physical Medicine and Rehabilitation, University of Virginia, 545 Ray C Hunt Drive, Suite 240, PO Box 801004, Charlottesville, Virginia 22908-1004, USA. md3q@virginia.edu
Gale
Shawn D
SD
Adarmes
Demitri
D
Schabacker
Michael
M
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004558:Electric Stimulation / Q000009:adverse effects; D004568:Electrodiagnosis / Q000009:adverse effects / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008475:Median Nerve / Q000502:physiology; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000294:innervation / Q000502:physiology*; D009431:Neural Conduction / Q000502:physiology*; D010146:Pain / Q000503:physiopathology; D010865:Pilot Projects; D011446:Prospective Studies