Ulnar Neuropathy Differential Diagnoses

Updated: Aug 31, 2022
  • Author: Elanagan Nagarajan, MD, MS; Chief Editor: Nicholas Lorenzo, MD, CPE, MHCM, FAAPL  more...
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DDx

Diagnostic Considerations

When diagnostic problems occur, they are often related to the clinician’s failure to realize that the diagnosis of ulnar neuropathy is complex and requires great care. This condition is notably harder to diagnose or localize than the more common carpal tunnel syndrome. The precise localization of an ulnar neuropathy cannot be achieved, and the clinician should acknowledge when the data are insufficient to determine where the ulnar lesion is located. Problems can occur at virtually every step.

Failure to perform a thorough history and examination (see Presentation) is probably the most crucial cause of mistakes in diagnosis. Conversely, a comprehensive history and physical examination can usually tell the clinician the most critical fact—whether an ulnar neuropathy is likely to be present—even if precise lesion localization is not always possible.

Another possible cause of misdiagnosis is failure to search for Martin-Gruber anastomosis during neurophysiologic testing (see Workup). As a consequence, the physician may inaccurately diagnose conduction block.

Similarly, failure to increase testing sensitivity by assessing nerve conduction to the first dorsal interosseous muscle and the abductor digiti minimi may cause the examiner to miss an existing ulnar neuropathy. [109]

Another standard error is testing only one nerve in the limb, thereby missing other potential conditions, such as polyneuropathy.

Finally, the clinician may perform the electrodiagnostic tests at suboptimal limb temperatures (< 30°C), leading to falsely prolonged latencies and increased amplitudes. [110]

In addition to the conditions listed in the differential diagnosis, other problems to be considered include the following:

  • Alcoholism

  • Burns and heterotopic bone

  • Diabetes mellitus

  • Elbow injuries and deformities

  • Hypothyroidism

  • Infections

  • Malnutrition

  • Renal disease

  • Perineural adhesions

  • Rheumatoid disease

  • Space-occupying lesions (including tumors)

  • Syringomyelia

  • Ulnar artery aneurysms or thrombosis at the wrist

  • Valgus ligament instability

  • Wrist fractures

Differentials

Alcohol (Ethanol) Related Neuropathy

Amyotrophic Lateral Sclerosis

Brachial Plexus Abnormalities

Cervical Disc Disease

Cervical Spondylosis

Epicondylitis

Pancoast Tumor

Thoracic Outlet Syndrome

Traumatic Peripheral Nerve Lesions

Differential Diagnoses