An Examination of the Importance of Electromyography (EMG) and Nerve Conduction Studies (NCS) Studies in the Evaluation of Persistent Paresthesia of the Hand Through Two Clinical Cases

Background: Provocative clinical tests are often performed during the physical exam when patients present with paresthesia of one or both hands. Although Tinel's test is commonly done at the wrist and elbow for suspected neuropathy, studies have shown that this test does not have a high sensitivity or specificity. Electrodiagnostic testing can be used to accurately determine the cause of suspected neuropathy and provide useful information not provided by provocative testing. Case Information: The first patient was a 90-year-old male who presented with a six month history of progressively worsening numbness and tingling in the right fourth and fifth digits. The second patient was a 52-year-old male who presented with persistent numbness and tingling in the fourth and fifth digits of the hands bilaterally. On physical exam, Tinel's test was performed at the wrists and elbows with both patients testing negative bilaterally for both. Nerve conduction studies revealed that the 90 year-old patient had a significant drop in conduction velocity across the elbow for the right ulnar nerve. For the 52 year-old male, nerve conduction studies showed prolonged latency and diminished amplitude of the left ulnar sensory nerve across the wrist. Conclusions: Despite both patients having similar presentations, electrodiagnostic testing showed that the cause of their symptoms was different. Consistent with the recent literature, our negative Tinel's test and positive NCS findings in two cases of patients with ulnar neuropathy further support that physicians cannot rely on special tests alone to pinpoint the location or clarify the cause of symptoms consistent with neuropathy. Additional testing is needed, particularly in the form of EMG and NCS studies, to further elucidate the cause of the pathology to better direct care and find the patient proper treatment to restore function.