Compression of the deep branch of the ulnar nerve in Guyon's canal by a ganglion: two cases

Introduction Ulnar nerve compression at the wrist can be caused by a variety of intrinsic and extrinsic factors. Isolated compression of only the deep branch of ulnar nerve by a ganglion is very uncommon. Ultrasound examination can clearly show the cystic lesion compressing the nerves. Materials and methods We present two cases of compression of deep branch of ulnar nerve by a ganglion in the Guyon's canal. Two male patients presented with history of progressive weakness and paraesthesia in the medial 11/2 digits of the non-dominant hand. Interestingly, both the patients noticed sudden onset and rapid progress of the symptoms and signs. Clinical examination revealed typical symptoms of ulnar nerve (deep branch) palsy. Nerve conduction studies showed severe denervation of the deep branch of the ulnar nerves in both the patients and ultrasound confirmed the diagnosis. Surgical decompression led to complete recovery. Results and discussion Whilst compression by a ganglion in the Guyon's canal is rare but well recognized, a feature of both of our cases was the rapid progression and severe nature of the compressive symptoms and signs. This is in contrast to the more typical features of compressive neuropathy and should alert the clinician to the possible underlying cause of compression. Early decompression has the potential to promote a complete recovery.