Isolated Compression of Deep Palmar Branch of Ulnar Nerve by a Midpalmar Ganglion: A Rare Case Report

Introduction UN lesions in the wrist and hand can cause a variety of different clinical findings, depending on precise location. Findings might range from a pure sensory deficit to pure motor syndromes with weakness that may or may not involve the hypothenar muscles. This depends on whether the lesion involves the main trunk, the sensory branch only, or the deep palmar branch at different sites from just at the hypothenar muscles to the lateral palm. UN compression at the wrist can be caused by a variety of intrinsic and extrinsic factors [1]. Isolated compression of only the deep branch of UN by a ganglion is very rare [1,2]. We describe the clinical, neurophysiological and MRI findings in a patient with a clinical diagnosis of deep palmar branch lesion of UN. The purpose of this case report is to describe the MR imaging characteristics, presenting symptoms and electrophysiological findings with emphasis on the MR imaging anatomy of UN at wrist and palm.