Ulnar Neuropathy at the Wrist

Abstract

A case of ulnar nerve compression at the wrist within Guyon's canal is reported. The clinical presentation initially appeared consistent with an ulnar nerve entrapment at the elbow. The true diagnosis of an ulnar sensorimotor nerve lesion occurring within the canal of Guyon was made electrophysiologically. Magnetic resonance imaging demonstrated compression of the nerve within the canal by a ganglionic cyst, which was confirmed by surgical intervention. Ulnar nerve entrapment at the wrist is uncommon and difficult to diagnose; therefore, it is important to understand the nerve's anatomical course and distribution to allow for accurate diagnosis by clinical and electrodiagnostic evaluations. Electrodiagnosis is an important tool in identifying ulnar nerve lesions at the wrist while excluding other disorders in the differential and recognizing coexisting pathology.

Identification of Double Compression Lesion of Ulnar Nerve after Cubital Tunnel Release

“…In our case, we experienced the double compression syndrome of the ulnar nerve, which was diagnosed late after the surgical decompression of the cubital tunnel. Pearce et al 7 emphasized the importance of electrodiagnosis and stated that the electrodiagnostic study was sensitive in the detection of compression of the ulnar nerve at Guyon's canal. However, Osterman 8 reported that similar motor latencies were demonstrated between an isolated carpal tunnel syndrome and double compression syndrome and it seemed difficult to classify a single nerve lesion as the double crush syndrome by an electrodiagnostic study.…”

Lesão aguda do ramo motor do nervo ulnar no punho após treinamento com cabo de guerra

“…The ulnar nerve is the second most severely impaired nerve in compression syndromes of the upper limb, and proximal involvement in the elbow is much more common (2,4,5) .…”

“…The clinical presentation of ulnar nerve lesions shows variation due to the complex anatomical course of the nerve at its most distal sites, which hinders semiological and electrophysiological interpretation, resulting in diagnostic challenge (4,5) . In Guyon's canal, the ulnar nerve can be compressed along its course, producing sensory, motor or mixed deficits.…”

Role of Skeletal Muscle MRI inPeripheral Nerve Disorders

“…The hypothenar muscle may be spared in a distal lesion of the deep motor branch. A MRI may help exclude the presence of a mass lesion (Pearce et al, 2009) and an axial MRI at the level of the metacarpal bones is useful for detecting denervation of the intrinsic hand muscles (Andreisek et al, 2006).…”