One Challenging Case, Many Perspectives: Clinical Collaboration on AANEM Connect

A challenging clinical case recently sparked a robust discussion on AANEM Connect, demonstrating the value of bringing neuromuscular and electrodiagnostic medicine professionals together to share their expertise, experience, and different approaches to complex patient presentations.

The discussion began when a physician who recently completed fellowship asked colleagues for help evaluating a patient whose clinical examination, electrodiagnostic testing, and imaging raised an important localization question: Were the patient's findings best explained by bilateral ulnar neuropathies, cervical radiculopathy, or potentially more than one coexisting lesion?

AANEM Connect members quickly joined the discussion, examining not only what the studies showed, but also how much weight should be given to each finding.

Several participants emphasized the importance of correlating cervical imaging with the clinical and electrodiagnostic findings rather than assuming that an abnormal MRI identified the source of the patient's symptoms.

Lawrence Robinson, MD, noted that several findings favored ulnar neuropathy, including absent ulnar sensory responses, temporal dispersion in ulnar motor responses, needle EMG abnormalities limited to ulnar-innervated muscles, and imaging demonstrating structural changes involving the ulnar nerve. Other participants similarly cautioned that cervical MRI abnormalities are common with increasing age and may not necessarily explain a patient's clinical presentation.

The conversation also explored the controversial concept of "double crush syndrome." Daniel Dumitru, MD, PhD, distinguished between the theory that one neural lesion predisposes another portion of the nerve to injury and the possibility that a patient can have two separate disorders involving related neural structures.

As the discussion continued, members suggested additional ways to distinguish an ulnar nerve lesion from C8 root or lower trunk pathology.

The dorsal ulnar cutaneous sensory response also generated considerable discussion. Because its anatomy can provide additional localization information in some patients, participants considered how it might contribute to distinguishing an ulnar lesion at the elbow from more distal or proximal pathology.

Other suggestions included high-resolution neuromuscular ultrasound to evaluate the ulnar nerve along its course, cervical paraspinal examination, and, when appropriate and technically feasible, evaluation of other muscles and sensory nerves that may help distinguish root, plexus, and peripheral nerve involvement.

Just as importantly, the discussion demonstrated that electrodiagnostic localization is not always reducible to a single finding. Participants explored anatomical variation, patterns of axonal loss and demyelination, the significance of temporal dispersion, and why particular muscles may be spared even in patients with substantial ulnar neuropathy.

The original poster returned throughout the discussion with additional clinical and electrodiagnostic information, allowing participants to continue refining their thinking. But the learning did not stop with the original case.

After Daniel Dumitru, MD, PhD, mentioned his preference for an orthodromic dorsal ulnar cutaneous (DUC) nerve study, another member asked him to explain his technique. Dr. Dumitru returned to the discussion with a detailed response, including example waveforms and references, explaining his preference for the orthodromic approach and raising questions about the physiologic origin of the routinely recorded antidromic response.

His observations raised a broader technical question about the routinely performed antidromic DUC study: To what extent might the recorded waveform include both near-field and far-field components, and what implications could that have for its diagnostic use? Rather than presenting his observations as definitive, Dr. Dumitru invited other members to consider the findings and contribute their perspectives.

That exchange captures one of the benefits of AANEM Connect. A question about one challenging patient developed into a broader conversation about anatomy, electrodiagnostic localization and technique—and then generated a new discussion about the interpretation and physiology underlying a commonly performed nerve conduction technique.

As one participant with more than three decades in neuromuscular neurophysiology observed during the discussion, learning remains a continuous process, and challenging cases provide opportunities for clinicians at every career stage to learn from one another.

Continue the Discussion on AANEM Connect

The summary above captures only part of the conversation. Read the original AANEM Connect thread to see the complete case, the different diagnostic approaches suggested by members, and Dr. Dumitru's follow-up discussion of the DUC study, including example waveforms and references.