Ulnar Neuropathy Differential Diagnoses

Updated: May 23, 2017
  • Author: Charles F Guardia, III, MD; Chief Editor: Nicholas Lorenzo, MD, MHA, CPE  more...
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DDx

Diagnostic Considerations

When diagnostic problems occur, they are often related to the clinician’s failure to realize that diagnosis of ulnar neuropathy is difficult and requires great care. This condition is notably harder to diagnose or localize than the more common carpal tunnel syndrome is. Not uncommonly, precise localization of an ulnar neuropathy cannot be achieved, and the clinician should acknowledge when the data are insufficient to permit a reliable determination of 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 important cause of mistakes in diagnosis. A thorough history and physical examination can usually tell the clinician the most important fact—that is, whether an ulnar neuropathy is likely to be present at all—even if precise localization of the lesion is not always possible.

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

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

Another common 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