Single motor unit H reflexes recorded in thenar muscles at rest

✍ Scribed by François-Charles Wang; Paul J. Delwaide

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 238 KB
• Volume: 22
• Category: Article
• ISSN: 0148-639X
• DOI: 10.1002/(sici)1097-4598(199902)22:2<291::aid-mus28>3.0.co;2-n

✦ Synopsis

The report by Dillingham et al. 1 questions the general electromyographic (EMG) wisdom that fibrillation potentials develop and resolve earliest in proximal muscles in a damaged root distribution. The data presented do not allow the authors to make such a judgment. Apparently, patients were selected for entry into the study based on EMG features of cervical radiculopathy requiring denervation in at least two muscles in the diagnosed root distribution, but we are not informed of the criteria by which specific root level diagnoses were made. 2 A number of patients were entered into the study based on the presence of paraspinal fibrillation only (''indeterminate levels''). Some patients demonstrated multilevel paraspinal fibrillation potentials and evidence of bilateral cervical radiculopathies (''multiple radiculopathies''), further confusing the issue of the timing of the onset of the radiculopathy, and the segmental source of the fibrillation potentials. Five of the patients included in the analysis were said to have fibrillation potentials in a cervical root distribution 5 years after onset of the symptoms, adding doubt to the cause of the paraspinal fibrillation and the timing of onset. Clinical criteria used for the inclusion of patients with cervical radiculopathy were not reviewed in the methods section and there was no information about the underlying structural causes of the radiculopathies or their anatomic correlation with the root levels diagnosed by EMG. 2 Regardless of the quality of the statistical analysis, the lack of precision in the data on which the statistics were based prevents any conclusions from being drawn.