In addition, there are sampling errors. My own practice is to obtain an MRI when clinically indicated, with a view to epidural blocks, surgery or the like, and perform an EMG, if further confirmation is needed. It has even been suggested in the literature that examining only the paraspinous muscles for the changes mentioned above is sufficient to confirm that the suspected nerve root compression is recent, ongoing, or recovering. The EMG is helpful all right, but not the gold standard. A careful clinical examination by an experienced forensic chiropractic medical examiner is the gold standard.
Gallstones are always abnormal, and they're taken out.
We're not dealing with gallstones. The term also encompasses somatosensory, motor and other evoked potential. However, in the majority of electrodiagnostic medicine laboratories, the scope is more limited, consisting of the two basic studies and possibly some special studies. Most of the special studies are variations of the nerve conduction studies and have relatively limited application. In forensic practice, electrodiagnostic studies serve as an extension of the clinical exam.