The cubital tunnel syndrome caused by the intraneural or extraneural ganglion cysts: Case report and review of the literature. J Plast Reconstr Aesthet Surg. 2017;70:1404-1408. [PMID: 28803901 DOI: 10.1016/j.bjps.2017.05.006]

Cubital tunnel syndrome: anatomy, pathology, and imaging

Cubital tunnel syndrome (CuTS) is the second most common peripheral neuropathy in the upper limb. It occurs due to ulnar nerve compression within the fibro-osseous cubital tunnel at the elbow joint. Although CuTS is typically diagnosed clinically and with electrodiagnostic studies, the importance of imaging in evaluating the condition is growing. Knowing the typical imaging findings of ulnar nerve entrapment is necessary for precise diagnosis and proper treatment. In this article, we focus on the clinical features, workup and complex imaging of the "anatomic" cubital tunnel and relevant pathological entities.

Multimodality imaging review of ulnar nerve pathologies

The ulnar nerve is the second most commonly entrapped nerve after the median nerve. Although clinical evaluation and electrodiagnostic studies remain widely used for the evaluation of ulnar neuropathy, advancements in imaging have led to increased utilization of these newer / better imaging techniques in the overall management of ulnar neuropathy. Specifically, high-resolution ultrasonography of peripheral nerves as well as MRI has become quite useful in evaluating the ulnar nerve in order to better guide treatment. The caliber and fascicular pattern identified in the normal ulnar nerves are important distinguishing features from ulnar nerve pathology. The cubital tunnel within the elbow and Guyon's canal within the wrist are important sites to evaluate with respect to ulnar nerve compression. Both acute and chronic conditions resulting in deformity, trauma as well as inflammatory conditions may predispose certain patients to ulnar neuropathy. Granulomatous diseases as well as both neurogenic and non-neurogenic tumors can also potentially result in ulnar neuropathy. Tumors around the ulnar nerve can also lead to mass effect on the nerve, particularly in tight spaces like the aforementioned canals. Although high-resolution ultrasonography is a useful modality initially, particularly as it can be helpful for dynamic evaluation, MRI remains most reliable due to its higher resolution. Newer imaging techniques like sonoelastography and microneurography, as well as nerve-specific contrast agents, are currently being investigated for their usefulness and are not routinely being used currently.

Cubital tunnel syndrome of the ulnar nerve caused by an epineural ganglion cyst: a case report and review of the literature

BACKGROUND

The ulnar nerve has a long and complex anatomical course, originating from the brachial neural plexus in the neck with nerve trunk formation at the posterior neck triangle, and on to the axilla. This intricate anatomical pathway renders the nerve susceptible to compression, direct injury, and traction throughout its course. Compression of the ulnar nerve is the second most common compression neuropathy of the median nerve adjacent to the wrist joint, after carpal tunnel syndrome.

CASE PRESENTATION

A 45-year-old Sudanese housewife complained of progressive right forearm and hand muscle wasting, pain, and neuropathic symptoms. She was diagnosed with right-sided cubital tunnel syndrome. The diagnosis was derived intraoperatively from a nerve conduction study suggesting the level of conduction block and recommending decompression. Magnetic resonance imaging was not done preoperatively due to financial limitations. An epineural ganglion (15 × 20 mm²) compressing and flattening the ulnar nerve was diagnosed intraoperatively. Surgical decompression of the ulnar nerve and removal of the epineural ganglion achieved a remarkable postoperative result and pleasing outcome.

CONCLUSION

Surgical management is the cornerstone of treatment for compressive neuropathy and ranges from simple nerve decompression to complex neurolysis procedures and nerve transposition to adjust the anatomical course of the nerve.

Cubital Tunnel Syndrome Due to Multiple Intraneural Cysts at Elbow: A Case Report and Review of Literature

Cubital tunnel syndrome is a common disorder that affects the upper limb and involves compression of the ulnar nerve. However, this syndrome is rarely caused by multiple intraneural ganglion cysts. Of all intraneural ganglion cysts, only 9% affect the elbow. This study presents a case report of a 73-year-old female patient who manifested pain, numbness, tingling, and paralysis of the medial aspect of her left forearm, fourth, and fifth fingers of the left hand for six months. Intraoperative findings showed multiple intraneural cysts at the left elbow, which were confirmed via histopathology. The cysts were surgically excised, whereas the ulnar nerve was released into the cubital tunnel and anteriorly transposed. Complete sensory and motor recovery were achieved. Although similar cases of intraneural cysts were reported in the literature, this case has the uniqueness of the unusual number and site of intraneural cysts in the ulnar nerve on the background of osteoarthritic changes. Therefore, the aim of reporting this case is to increase awareness of the presence of these cysts when the symptoms are severe.

Preoperative Imaging of Intraneural Ganglion Cysts: A Critical Systematic Analysis of the World Literature

BACKGROUND

Advancements in imaging and an understanding of the pathomechanism for intraneural ganglion cyst formation have led to increased awareness and recognition of this lesion. However, the precise role of imaging has been advocated for but not formally evaluated.

METHODS

We performed a systematic review of the world literature to study the frequency of imaging used to diagnose intraneural ganglion cysts at different sites and compared trends in identifying joint connections.

RESULTS

We identified 941 cases of intraneural ganglion cysts, of which 673 had published imaging. Magnetic resonance imaging (MRI, n = 527) and ultrasonography (US, n = 123) were the most commonly reported. They occurred most frequently in the common peroneal nerve (n = 570), followed by the ulnar nerve at the elbow (n = 88), and the tibial nerve at the ankle (n = 58). A joint connection was identified in 375 cases (48%), with 62% of MRIs showing a joint connection, followed by 16% on US, and 6% on computed tomography (CT). MRI was statistically more likely to identify a joint connection than was US (P < 0.01). In the last decade, joint connections have been identified with increasing frequency using preoperative imaging, with up to 75% of cases reporting joint connections.

CONCLUSIONS

Preoperative imaging plays an important role in establishing the diagnosis of intraneural ganglion cyst as well as treatment planning. Imaging has proved superior to the sole reliance of operative exposure to identify a joint connection, which is necessary to treat the underlying disease. Failure to identify cyst connections on imaging can result in an inability to truly address the underlying pathoanatomy at the time of definitive surgery, leading to a risk for clinical recurrence. Therefore, management should be guided by an intersection between new knowledge presented in the literature, clinical expertise, and surgeon experience.

Intraneural or extraneural ganglion cysts as a cause of cubital tunnel syndrome: A retrospective observational study

Purpose

Cubital tunnel syndrome caused by ganglion cysts has rarely been reported. The purpose of this study was to evaluate the surgical treatment outcomes of a patient diagnosed with cubital tunnel syndrome caused by intraneural or extraneural cysts and to summarize our experience.

Method

In total, 34 patients were evaluated retrospectively from January 2011 to January 2020 with a follow-up of more than 24 months. Preoperative data, such as demographic data, clinical symptoms, physical examination findings, and laboratory tests, were all recorded and pre-operative and post-operative data were compared. The function was evaluated by the modified Bishop scoring system and the McGowan grade at the last follow-up.

Results

Improvement of interosseous muscle strength, the Visual Analog Scale (VAS), 2-point discrimination (2-PD), electromyogram (EMG) result, Wartenberg sign, claw hand, and weakness could be clearly observed in all patients. Extraneural cysts were completely removed and the pedicles of the cysts were ligated. Intraneural cysts were incised and drained, and part of their cyst walls were removed using a microsurgical technique. All patients underwent anterior subcutaneous transposition (AST). At the last follow-up, McGowan's (0-IIa) grade increased from seven patients (20.6%) preoperatively to 27 patients (79.4%); the excellent and good rate according to the modified Bishop scoring system was 82.4% (28 patients), and all patients had no symptoms of recurrence after surgery.

Conclusion

The treatment of cubital tunnel syndrome caused by intraneural or extraneural cysts achieved good long-term results through extraneural cyst resection or intraneural cyst incision and drainage combined with subcutaneous transposition. Early diagnosis and surgical treatment are essential for the patient's postoperative recovery.

A Comparative Study Using Electromyography to Assess Hand Exercises For Rehabilitation After Ulnar Nerve Decompression

Ulnar nerve (UN) entrapment is a common peripheral neuropathy and can lead to dysfunction of both sensory and motor function of the hand. Surgical release is the mainstay of treatment, but post-operative rehabilitation of UN innervated intrinsic muscles is lacking evidence. This cohort study utilized surface electromyography (EMG) and assessed the activation of UN innervated intrinsic and extrinsic hand muscles during four exercises in healthy participants. Exercises included rotating baoding balls, squeezing a stress ball or grip device every second, and repetitive finger abduction against a rubber band. Normalized percent activation of each muscle was calculated for each exercise. It was demonstrated that rubber band resistance (RBR) finger abduction showed significantly increased activation in both intrinsic muscles tested, while minimizing activation of the one tested UN innervated extrinsic muscle. Thus, to best target the intrinsic hand muscles without fatiguing extrinsic muscles, the inexpensive and practical RBR exercise is beneficial in post-UN release rehabilitation.

The Role of Imaging for Disorders of Peripheral Nerve

Peripheral nerve imaging is a helpful and sometimes essential adjunct to clinical history, physical examination, and electrodiagnostic studies. Advances in imaging technology have allowed the visualization of nerve structures and their surrounding tissues. The clinical applications of ultrasound and magnetic resonance imaging (MRI) in the evaluation of peripheral nerve disorders are growing exponentially. This article reviews basics of ultrasound and MRI as they relate to nerve imaging, reviews advantages and limitations of each imaging modality, reviews the applications of ultrasound and MRI in disorders of peripheral nerve, and discusses emerging advances in the field.

Peripheral nerve tumors of the hand: Clinical features, diagnosis, and treatment

The majority of the tumors arising from the peripheral nerves of the hand are relatively benign. However, a tumor diagnosed as malignant peripheral nerve sheath tumor (MPNST) has destructive consequences. Clinical signs and symptoms are usually caused by direct and indirect effects of the tumor, such as nerve invasion or compression and infiltration of surrounding tissues. Definitive diagnosis is made by tumor biopsy. Complete surgical removal with maximum reservation of residual neurologic function is the most appropriate intervention for most symptomatic benign peripheral nerve tumors (PNTs) of the hand; however, MPNSTs require surgical resection with a sufficiently wide margin or even amputation to improve prognosis. In this article, we review the clinical presentation and radiographic features, summarize the evidence for an accurate diagnosis, and discuss the available treatment options for PNTs of the hand.

Neuromuscular ultrasound in clinical practice: A review

Neuromuscular ultrasound (NMUS) is becoming a standard element in the evaluation of peripheral nerve and muscle disease. When obtained simultaneously to electrodiagnostic studies, it provides dynamic, structural information that can refine a diagnosis or identify a structural etiology. NMUS can improve patient care for those with mononeuropathies, polyneuropathy, motor neuron disease and muscle disorders. In this article, we present a practical guide to the basics of NMUS and its clinical application. Basic ultrasound physics, scanning techniques and clinical applications are reviewed, along with current challenges.

Ulnar intraneural cysts as a cause of cubital tunnel syndrome: presentation of a case and review of the literature

INTRODUCTION

Intraneural cysts usually involve the common peroneal nerve, and in many cases, they are causing symptoms due to neural compression. It is hypothesized that these cysts originate from the adjacent joints while articular pathology is a major contributing factor for the formation of these lesions. Although ulnar nerve is the second most commonly affected nerve, these lesions usually develop distally at the Guyon tunnel, so cubital tunnel syndrome due to epineural cysts is very rare. In such cases, elaborate preoperative work-up is mandatory and surgical treatment should follow certain well-defined principles.

CASE DESCRIPTION

A 60-year-old female patient presented with complaints of pain along the medial side of her elbow, forearm and hand and a tingling sensation in the same distribution for the past 2 months. The patient had sustained an injury 15 years ago, and a distal humerus fracture was diagnosed at that time. Radiological signs of posttraumatic elbow arthritis were evident at the initial evaluation. The patient was diagnosed with cubital tunnel syndrome which was further confirmed by nerve conduction studies, and she underwent surgical decompression of the nerve. During surgery, intraneural cysts were identified and addressed by excision, while dissection of the articular branch of the nerve was also performed. Pain and numbness subsided shortly after surgery, while the patient remained free of symptoms until the last follow-up.