Nerve Compression in the Upper Limb

The Peripheral Nerve Surgeon's Role in the Management of Neuropathic Pain

Neuropathic pain (NP) underlies significant morbidity and disability worldwide. Although pharmacologic and functional therapies attempt to address this issue, they remain incompletely effective for many patients. Peripheral nerve surgeons have a range of techniques for intervening on NP. The aim of this review is to enable practitioners to identify patients with NP who might benefit from surgical intervention. The workup for NP includes patient history and specific physical examination maneuvers, as well as imaging and diagnostic nerve blocks. Once diagnosed, there is a range of options surgeons can utilize based on specific causes of NP. These techniques include nerve decompression, nerve reconstruction, nerve ablative techniques, and implantable nerve-modulating devices. In addition, there is an emerging role for preoperative involvement of peripheral nerve surgeons for cases known to carry a high risk of inducing postoperative NP. Lastly, we describe the ongoing work that will enable surgeons to expand their armamentarium to better serve patients with NP.

Multihit Injury of the Radial Nerve in a 62-year-old Woman: A Case Report

We report the case of a 62-year-old female patient with a triple-crush radial nerve injury, diagnosed in subsequent order following a fracture of the left humerus. The patient developed flaccid paralysis of all muscles innervated by the left radial nerve except the triceps brachii and reported a sensory deficit corresponding to the innervation territories of the posterior nerve of the forearm as well as the superficial branch of the radial nerve. Following neurolysis of the radial nerve at the humerus level, wrist extension as well as sensory perception on the dorsal aspect of the forearm recovered, but finger extension and thumb abduction were still impossible. Following neurological evaluation and nerve ultrasound, supinator syndrome was diagnosed and the patient underwent decompression surgery. Following surgical decompression, motor recovery was observable but a sensory deficit remained in the area innervated by the superficial branch of the radial nerve. In consequence, the third crush injury of the left radial nerve, that is, Wartenberg syndrome or cheiralgia paraesthetica was diagnosed. Decompression surgery of the superficial branch of the radial nerve was performed and the patient reported profound amelioration of her sensory symptoms during a follow-up examination at our outpatient clinic 6 weeks postoperatively.

A Brief Review of In Vitro Models for Injury and Regeneration in the Peripheral Nervous System

Nerve axonal injury and associated cellular mechanisms leading to peripheral nerve damage are important topics of research necessary for reducing disability and enhancing quality of life. Model systems that mimic the biological changes that occur during human nerve injury are crucial for the identification of cellular responses, screening of novel therapeutic molecules, and design of neural regeneration strategies. In addition to in vivo and mathematical models, in vitro axonal injury models provide a simple, robust, and reductionist platform to partially understand nerve injury pathogenesis and regeneration. In recent years, there have been several advances related to in vitro techniques that focus on the utilization of custom-fabricated cell culture chambers, microfluidic chamber systems, and injury techniques such as laser ablation and axonal stretching. These developments seem to reflect a gradual and natural progression towards understanding molecular and signaling events at an individual axon and neuronal-soma level. In this review, we attempt to categorize and discuss various in vitro models of injury relevant to the peripheral nervous system and highlight their strengths, weaknesses, and opportunities. Such models will help to recreate the post-injury microenvironment and aid in the development of therapeutic strategies that can accelerate nerve repair.

Possible points of compression of the ulnar nerve: Tricks and traps that await clinicians from an anatomical point of view

The ulnar nerve can be subject to numerous types of compression. The most common are cubital tunnel and ulnar tunnel syndromes, but there are many others with more uncommon etiologies. The existence of additional communicating branches, median nerve involvement, various types of injuries, and unusual anatomical variations can be a challenge for both diagnosis and treatment. This review presents a comprehensive depiction of ulnar nerve entrapment syndromes with particular reference to their anatomical background, risk factors, and clinical evaluation. Even common disorders can result from atypical morphological changes. It is important to be familiar with them as it is a key ability in daily medical practice.

Median Nerve Mononeuropathy and Meralgia Paresthetica After Prone Positioning in a Patient with COVID-19 ARDS: A Case Report

CASE

Throughout the COVID-19 pandemic, prone positioning has decreased mortality in patients with severe acute respiratory distress syndrome. We present the unique case of a patient who developed left median nerve mononeuropathy and bilateral meralgia paresthetica after prone positioning while afflicted with COVID-19. These nerve injuries have been rarely reported in the literature and never before in the same patient.

CONCLUSION

Our case highlights the importance of increased care when positioning patients prone by padding bony prominences, evenly distributing pressure across known sites of peripheral nerve entrapment, and giving consideration to prone-positioning time intervals when caring for intubated patients.

Nerve wrapping for recurrent compression neuropathy: A systematic review

BACKGROUND

The recurrence of symptoms following primary nerve compression surgery can occur in up to 25% of cases. Nerve wrapping can be utilised for revision surgery. An ideal barrier should minimise the chance of fibrosis, scarring and allow for adequate nerve gliding. This review evaluates the use of autologous or commercially available allograft and xenograft options as barriers against nerve scarring following revision surgery.

METHODS

PubMed, Ovid Embase and Cochrane databases were searched using the All Fields Index. Nine hundred titles underwent title screening with 11 studies being included in the final analysis. The risk of bias was assessed using the Methodological Index for Non-Randomised Studies (MINORS) tool. PRISMA guidelines were followed at all stages and the review was registered with PROSPERO (CRD 42020182818).

RESULTS

The 11 studies comprised of all case series. In total, 114 patients were included, with ages ranging from 28 to 90. Previously, the number of revision surgeries ranged from 0 to 5. Autologous veins were used in 6 studies, collagen in 3 studies and human amniotic membrane in 2 studies. Improvements in subjective and objective outcomes were seen with all wrap types. Pain was the most common residual symptom (46% of patients). The most common complication was pain at the donor site following vein harvest (19% of patients).

CONCLUSION

This is the first systematic review to summarise the outcomes of nerve wraps for revision compression neuropathy. While improvements in outcomes were reported, further comparative studies are needed to determine the best nerve wrap.

Ultrasound-guided percutaneous electrical stimulation for a patient with cubital tunnel syndrome: a case report with a one-year follow-up

Objective: Patients with ulnar neuropathy usually experience sensory disturbances, weakness, and decreased function; however, optimal treatment approaches for this condition are not conclusive.Case Description: A 48-year-old male with cubital tunnel syndrome was previously managed with a multimodal approach including splinting, neural mobilizations, and exercises with no change in symptoms. Approximately 1 year after the initial onset, he received three sessions of ultrasound-guided percutaneous electrical stimulation (PENS) and self-neural glides as a home program.Outcomes: After PENS intervention, the patient experienced a dramatic improvement in function and symptoms as measured by the Disabilities of the Arm, Shoulder and Hand Outcome Measure (DASH) and self-reported version of the Leeds Assessment of Neuropathic Symptoms and Signs (S-LANSS) pain scale as outcomes. These improvements were maintained after 1, 3, 6, and 12 months. The patient also experienced self-perceived improvement in his condition as measured by the Global Rating of Change (GROC) at each follow-up.Conclusion: A patient with ulnar nerve entrapment at the elbow did not respond to a multimodal conservative care for the previous year. Once the patient was treated with ultrasound-guided PENS targeting the ulnar nerve, full functional recovery and resolution of symptoms were documented. Future clinical studies should examine the effects of PENS in managing neural entrapment syndromes on a statistically powered sample of patients.

[Surgical treatment of carpal tunnel syndrome: open release of the flexor retinaculum and hypothenar fat flap for revision surgery]

OBJECTIVE

Decompression of the median nerve by complete release of the flexor retinaculum and the distal antebrachial fascia. In the case of revision surgery providing of a scar-free covering of the median nerve, if necessary.

INDICATIONS

Carpal tunnel release is indicated for symptomatic patients with painful paraesthesia or neurological deficits after adequate diagnostic evaluation. The hypothenar fat flap is indicated in revision surgery if a sufficient nerve bed of the median nerve is needed and to restore nerve gliding.

CONTRAINDICATIONS

General operative limitations. The hypothenar fat flap is not indicated in revision surgery if median nerve irritation is not caused by surrounding scaring but other reasons like tendonitis.

SURGICAL TECHNIQUE

Proximal longitudinal incision of the palm. Subcutaneous dissection and incision of the palmar aponeurosis. Careful ulnar incision of the transverse carpal ligament. Considerate release of the distal and proximal parts of the retinaculum as well as the distal part of the antebrachial fascia. Exploration of the median nerve and palpation of the carpal tunnel and resection of compressive structures, if necessary. In case of revision surgery, if required, the hypothenar fat flap is raised. The fat flap is transposed without tension palmar to the median nerve and fixed to the radial side of the carpal tunnel.

POSTOPERATIVE MANAGEMENT

Early functional mobilization. Immobilization for a short period is optional. After revision surgery and hypothenar fat flap, splinting for one week is recommended.