A rare case of a punched nerve syndrome of the deep motor branch of the ulnar nerve

Uncommon Anatomical Causes of Ulnar Compression: A Narrative Review

OBJECTIVES

Some patients develop ulnar nerve compression due to rare anatomical variations or malformations. The aims of this review are to provide a comprehensive overview of anatomical structures and variations that can cause ulnar nerve compression and to evaluate treatment options.

METHODS

Case reports and case series about rare cases of unusual ulnar nerve compression published from January 2000 until April 2022 were obtained from databases Embase, MEDLINE, and Web of Science. A total of 48 studies describing 64 patients were included in our study.

RESULTS

The following structures have proven to cause ulnar nerve compression: anconeus epitrochlearis, accessory abductor digiti minimi, vascular anomalies, palmaris longus, fibrous bands, and flexor carpi ulnaris. All cases except one have had a surgical release of the ulnar nerve resulting in diminished symptoms or complete recovery at follow-up.

CONCLUSIONS

In addition to considering common compression points, it is important to be aware that proximal compression symptoms, such as pain and a positive Tinel sign at the medial elbow, may be attributed to a hypertrophic AE or vascular anomaly. Distal compression symptoms encompass swelling, along with pain and a positive Tinel sign at the distal forearm. Various structures contributing to distal compression include an accessory abductor digiti minimi muscle, an accessory or anomalous palmaris longus muscle, or an accessory or hypertrophic flexor carpi ulnaris muscle. The occurrence of fibrous bands exhibits variability, manifesting in diverse locations across the arm.Level of Evidence: IV.

Vascular entrapment neuropathy of the tibial nerve within the gastrocnemius muscle

Background:

Vascular compression is an extremely rare cause of mononeuropathy and compression of selective tibial nerve branches is an additionally a rare finding and makes diagnosis difficult.

Case Description:

Here within, we describe the case of a 41-year-old male who presented with isolated mononeuropathy of the medial gastrocnemius (MG) branch of the tibial nerve presented as persistent fasciculations and atrophy. After electromyography and clinical evaluation, surgical exploration was recommended. A vascular bundle was found to be compressing the MG branch of the tibial nerve and thus was ligated to decompress the nerve. Postoperatively, all fasciculations improved and muscle atrophied improved.

Conclusion:

Vascular compression resulting in mononeuropathy of the peripheral nerves is a rare clinical entity. Clinicians should include these etiologies on their differential when considering surgical exploration of mononeuropathies.

Ultrasonography of the Peripheral Nerves of the Forearm, Wrist and Hand: Definition of Landmarks, Anatomical Correlation and Clinical Implications

BACKGROUND

 Peripheral nerve pathologies of the upper extremity are increasingly assessed by high-resolution ultrasonography (HRUS), yet rapid identification of nerve segments can be difficult due to small nerve diameters and complex regional anatomy. We propose a landmark-based approach to speed up and facilitate evaluation and intervention in this region.

METHOD

 Relevant landmarks and section planes for eleven nerve segments of the forearm, wrist and hand were defined by ultrasonography in cadaver arms before cryosection and topographical neurovascular preparation. Information on all nerve segments and a pictorial guide including anatomical cross-sections, topographical preparations and HRUS images are provided. The identification rates of these nerve segments were then assessed in 20 healthy volunteers.

RESULTS AND CONCLUSION

 Sonographic landmarks and guidelines for the rapid identification and assessment of nerves of the forearm, wrist and hand are presented in pictorial and tabular form, including discussion of normal variants. Utilizing this overview should facilitate training, diagnostic examinations and intervention for nerves of the upper extremity.

KEY POINTS

  · High-resolution ultrasound enables assessment of peripheral nerves of the forearm, wrist and hand.. · A landmark-based approach can facilitate and speed up nerve evaluation in these regions.. · High detection rates could be reproduced using the proposed landmark-based approach..

CITATION FORMAT

· Gruber L, Loizides A, Peer S et al. Ultrasonography of the Peripheral Nerves of the Forearm, Wrist and Hand: Definition of Landmarks, Anatomical Correlation and Clinical Implications. Fortschr Röntgenstr 2020; 192: 1060 - 1072.

Isolated Compression of the Ulnar Nerve Motor Branch: A Case Series With 3 Unique Etiologies

BACKGROUND

Although ulnar neuropathies are commonly encountered, isolated involvement of the motor branch is exceedingly rare. Previous reports of this entity describe compression as the deep motor branch passes through the piso-hamate hiatus and the adductor pollicis hiatus. This case series described 3 cases of motor branch compression due to unique etiologies which resolved after surgery.

METHODS

A retrospective chart review identified patients with compression of the ulnar nerve motor branch. From these patients, 3 were selected with a unique etiology for compression. Patient demographics, objective and subjective findings, and pathology identified during surgery were recorded and analyzed.

RESULTS

Eight patients had compression of the ulnar nerve motor branch and 3 unique etiologies were selected; an intraneural ganglion, a constricting leash of vessels, and a series of compressing fibrous bands. All required surgery, and each patient had full resolution of symptoms by 1 year postoperatively.

DISCUSSION

Patients presenting with complaints of weakness with a positive Froment and Egawa signs but a negative Wartenberg sign and no sensory complaints can be a diagnostic dilemma. Compression of the ulnar nerve motor branch must be considered, and here we present 3 unique cases. Activity modification in those presenting early may be curative, although many ultimately require surgery. In the cases presented here, all patients experienced full resolution of their symptoms by 1 year after surgery.

[Cubital tunnel syndrome : Diagnostics and therapy]

Cubital tunnel syndrome is the second most common nerve compression syndrome observed in the upper extremity. Mechanical irritation of the ulnar nerve is also found in the upper and the lower arm even though cubital tunnel syndrome is documented most of the time. Apart from clinical examination electrophysiological testing is the most important contributor to the therapy decision. Depending on the clinical manifestation conservative treatment with elbow splinting may be appropriate. In the event of persistent or advanced nerve irritation surgical decompression may be the sensible intervention. Open or endoscopically assisted in situ decompression is currently recommended as the primary intervention while anterior transposition of the ulnar nerve is recommended for revision surgery.