Ganglion cyst of Guyon’s canal as a rare cause of compression neuropathy of the ulnar nerve (literature review and case report)

The study objectiveis to analyze the existing research literature devoted to this problem and to assess clinical characteristics and specific features of the diagnosis and rational neurosurgical treatment for ganglion cyst of Guyon’s canal (GCGC) that caused compression neuropathy of the ulnar nerve.Materials and methods.Since 1955, researchers reported only 19 cases of ganglion cysts located in the wrist area and associated with tunnel neuropathy of the ulnar nerve. Since this condition is extremely rare, we present our own clinical observations.Results.Using the literature data, we described various types of ulnar nerve compression according to individual nerve characteristics determining clinical manifestations of GCGC. We analyzed the prevalence of GCGC among patients of various age and gender, disease pathogenesis, and main diagnostic methods. A patient with GCGC-associated compression ischemic neuropathy of the ulnar nerve was treated in the neurological clinic of the I. M. Sechenov First Moscow State Medical University in 2016. Using visualization tools, we found a ganglion cyst located on the palmar surface at the level of the hook-shaped bone. The cyst caused medial displacement of the ulnar nerve and ulnar artery. We performed microsurgical decompression of the right ulnar nerve at the level of Guyon’s canal and removed the articular ganglion cyst using a standard procedure. In the postoperative period, we observed partial regression of neurological disorders.Conclusion.To identify the cause of ulnar nerve neuropathy in Guyon’s canal, a physician should consider both clinical and electrophysiological data and the results of ultrasound examination and/or magnetic resonance imaging. A detailed examination of these patients allows clarifying morphological characteristics of the lesion and identifying such a rare lesion as ganglion cyst.