Boekestein et al. insisted that muscle twitching in the tongue observed with ultrasonography in our study indicated fibrillations rather than fasciculations. We disagree. The muscle movement was highly irregular and involved muscle bundles over 3 mm in diameter that could not be caused by contraction of single muscle fibers. [1] These features are very consistent with fasciculations.
Boekestein et al. also stated that fasciculations in the tongue have different properties from those in other muscles: " highly predictable and regular, and more continuous. " We think that they are not true fasciculations but contraction fasciculation, non-spontaneous ongoing motor unit activity. [2] As shown in the supplemental video, patterns and rhythm of fasciculations are almost identical in the tongue and biceps brachii muscle, and entirely different from those of fibrillations on muscle ultrasound previously reported [3].
A prospective evaluation of ultrasound, high-density surface EMG, concentric needle EMG, and visual inspection is required and would verify our findings.
1. Kimura J, Electrodiagnosis in diseases of nerve and muscle. Philadelphia: F. A. Davis Company;1983.
2. Denny-Brown D, Pennybacher JB. Fibrillation and fasciculation in voluntary muscle. Brain 1938;1: 311-312.
3. Pillen S, Nienhuis M, van Dijk JP, Arts IM, van Alfen N, Zwarts MJ. Muscles alive: ultrasound detects fibrillations. Clin Neurophysiol 2009;120:932-936.
Boekestein et al. insisted that muscle twitching in the tongue observed with ultrasonography in our study indicated fibrillations rather than fasciculations. We disagree. The muscle movement was highly irregular and involved muscle bundles over 3 mm in diameter that could not be caused by contraction of single muscle fibers. [1] These features are very consistent with fasciculations.
Boekestein et al. also stated that fasciculations in the tongue have different properties from those in other muscles: " highly predictable and regular, and more continuous. " We think that they are not true fasciculations but contraction fasciculation, non-spontaneous ongoing motor unit activity. [2] As shown in the supplemental video, patterns and rhythm of fasciculations are almost identical in the tongue and biceps brachii muscle, and entirely different from those of fibrillations on muscle ultrasound previously reported [3].
A prospective evaluation of ultrasound, high-density surface EMG, concentric needle EMG, and visual inspection is required and would verify our findings.
1. Kimura J, Electrodiagnosis in diseases of nerve and muscle. Philadelphia: F. A. Davis Company;1983.
2. Denny-Brown D, Pennybacher JB. Fibrillation and fasciculation in voluntary muscle. Brain 1938;1: 311-312.
3. Pillen S, Nienhuis M, van Dijk JP, Arts IM, van Alfen N, Zwarts MJ. Muscles alive: ultrasound detects fibrillations. Clin Neurophysiol 2009;120:932-936.
For disclosures, see original article.