"Slow" myotonic discharges.
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Action Potentials↗
Biomedical subjects
Paul E Barkhaus
Publications and source records attributed to Paul E Barkhaus.
Electrodiagnostic testing in neuromuscular disorders.
For the past approximately six decades, electrodiagnostic testing orelectrodiagnosis (EDX) has played an increasingly important role in the clinical evaluation of patients who have neuromuscular disorders. This in part is because of a greater understanding of the pathophysiology of these disorders. Also of importance is the development of the techniques themselves, beginning with basic needle electromyography (EMG) and electroneurography (or nerve conduction studies) (NCS) in the 1940s. Today the clinician has a larger menu of testing options, including somatosensory evoked potentials,quantitative EMG, single fiber EMG, and autonomic testing. The advent of computers has added speed and accuracy to testing
Electrodiagnosis↗
Motor unit number index (MUNIX).
The surface-recorded compound muscle action potential (CMAP) and electromyographic (EMG) interference pattern is used to compute the motor unit number index (MUNIX). The MUNIX demonstrated all known changes in the number of motor units in normal subjects, and in patients with amyotrophic lateral sclerosis (ALS). In normal subjects MUNIX decreased slightly with age and showed excellent reproducibility. In many ALS patients MUNIX was reduced even when the CMAP was normal. Lower MUNIX values were seen in weaker muscles. This is a noninvasive method that requires minimal electrical stimulation. It is performed in less than 5 min. This makes it suitable for serial EMG investigations.
Action Potentials↗