EMG Findings

While this chapter and even this book are not intended to be a textbook in electrodiagnosis, we have chosen video samples of typical abnormal discharges that neuromuscular specialists often face, such as myopathic units, myotonic discharges, myokymia, fibrillations, and neurogenic firing. Other EMG clips are embedded in other chapters. It is not unusual for referred neuromuscular patients to carry an erroneous clinical diagnosis based on incidental EMG discharges such as myotonic discharges. On the other hand, voluntary activity may be reported as abnormal discharges and a diagnosis of denervation is erroneously given. Knowledge of anatomy, physiology, and clinical neuromuscular medicine are important for an EMG to be useful in the diagnosis.