Interpretation of Electrodiagnostic Studies: How to Apply It to the Practice of Orthopaedic Surgery

Peripheral Nervous System Complications after COVID-19 Vaccination

While vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains crucial, neurological complications have been detected following the coronavirus disease 2019 (COVID-19) vaccination. The neurological complications of COVID-19 vaccination can be seen in both the central nervous system (CNS) and the peripheral nervous system (PNS). In this study, we reviewed PNS complications after COVID-19 vaccination, their underlying mechanisms, diagnosis, and management. Inflammatory polyneuropathy, small fiber neuropathy, Parsonage-Turner syndrome (PTS), cranial mononeuropathies, and myasthenia gravis (MG) have been reported following COVID-19 vaccination. Inflammatory polyneuropathy following COVID-19 vaccination should be diagnosed early based on clinical presentation and treated with supportive care, and immunoglobulin or plasmapheresis to prevent respiratory distress if required. It is important to differentiate peripheral from central facial paralysis after COVID-19 vaccination to rule out upper motor neuron damage, including stroke. Diagnosis of small fiber neuropathy in the setting of COVID-19 vaccination should be suspected in patients with dysesthesia, dysautonomia, and lower extremity paresthesia. A skin biopsy of the proximal or distal lower limb should generally be considered for diagnosing small fiber neuropathy following COVID-19 vaccination. Even though pain at the injection site is one of the most common symptoms after COVID-19 vaccination, shoulder pain lasting more than 3 weeks should raise the suspicion of severe complications such as PTS. In addition to a proper physical examination as a reliable diagnosis tool, needle electromyography can be considered to help the diagnosis of PTS following COVID-19 vaccination. In our opinion, despite complications after COVID-19 vaccination, the benefit of vaccination immunity should not be forgotten.

Ultrasound as a Complementary Tool to Electrodiagnostics in the Evaluation of Compressive Neuropathy of the Common Fibular Nerve

Background

Compressive neuropathy of the common fibular nerve (CFN) is increasingly recognized as an etiology for foot drop and falls. Electrodiagnostic (EDX) studies are widely used to evaluate this condition, but such tests are invasive and costly. As with carpal and cubital tunnel syndromes, there may be patients with characteristic symptoms of CFN compressive neuropathy but normal EDX studies in which ultrasound may aid in decision-making.

Purpose

We sought to examine the association between ultrasound and nerve conduction studies (NCS) and electromyography (EMG) in the diagnosis of compressive neuropathy of the CFN.

Methods

We performed a retrospective review identifying 104 patients who underwent CFN decompression from January 1, 2015, to June 30, 2023. Patients were included if they had both ultrasound and NCS/EMG prior to CFN decompression for compressive neuropathy and if they were older than 18 years at time of surgery. Patients were excluded if they had entrapment secondary to trauma, iatrogenic injury, or if they had had superficial fibular decompression alone without CFN decompression. After applying exclusion criteria, 17 patients remained in the cohort.

Results

Mean ultrasound cross-sectional area and side-to-side (STS) ratios were significantly higher in those with abnormal compound muscle action potential (CMAP) amplitudes versus those with normal CMAP amplitudes. The probability of having an abnormal CMAP amplitude when STS ratio was abnormal was 18 times greater compared with those with normal STS ratio. With each unit increase in STS ratio, CMAP amplitude was reduced by 2.79 mV.

Conclusions

This retrospective review found that ultrasound may provide complementary diagnostic information to EMG/NCS for compressive neuropathy of the CFN. Further study is needed to examine the relationship between ultrasound findings for CFN compressive neuropathy and results of surgical decompression.

Advances in Imaging of Compressive Neuropathies

Ultrasound and magnetic resonance neurography are useful modalities to aid in the assessment of compressive neuropathies, although they are still limited in their resolution of nerve microstructure and their capacity to monitor postoperative nerve recovery. Optical coherence tomography, a preclinical imaging modality, is promising in its ability to better identify structural and potential physiologic changes to peripheral nerves, but requires additional testing and research prior to widespread clinical implementation. Further advances in nerve imaging may elucidate the ability to visualize the zone of nerve injury intraoperatively, monitor the progression of nerve regeneration, and localize problems during nerve recovery.

From Conservative Measures to Surgical Interventions, Treatment Approaches for Cubital Tunnel Syndrome: A Comprehensive Review

Cubital tunnel syndrome (CuTS) is a neuropathic condition characterized by the compression or irritation of the ulnar nerve at the elbow, resulting in a wide spectrum of symptoms ranging from pain and numbness to muscle weakness and impaired hand function. This comprehensive review delves into the diverse landscape of CuTS treatment approaches, emphasizing the importance of early intervention. The review explores how these strategies aim to alleviate symptoms and enhance patient well-being by beginning with conservative measures encompassing rest, splinting, medications, physical therapy, and lifestyle adjustments. Non-surgical medical interventions, including nerve gliding exercises, ultrasound-guided nerve injections, and orthotic devices, are considered alternative therapies for symptom relief. Surgical interventions, such as decompression procedures and emerging techniques, are discussed in detail, highlighting their indications and expected outcomes. Throughout this review, the critical role of patient-centered care is underscored, emphasizing the need for tailored treatment plans that respect individual preferences and goals. Recognizing the unique nature of each CuTS case, shared decision-making between patients and healthcare providers is advocated, ensuring that interventions align with specific patient needs. As research advances, promising developments in diagnosis, surgical techniques, and drug therapies offer hope for more effective management of CuTS, paving the way for improved symptom relief and enhanced nerve function.

Diagnostic Uncertainty in Cervical Radiculopathy

Cervical radiculopathy is defined as a pathological process affecting the cervical nerve root(s). While not an uncommon entity, this report describes a case of cervical radiculopathy in an active duty Marine with unique features to include the C5 nerve root as the primary point of injury with corresponding severe motor weakness that warranted expedited workup. This expedited workup included early referral to Neurology for nerve conduction and electromyography (EMG) studies that were ultimately diagnostic in the setting of equivocal Magnetic Resonance Imaging findings. This highlight of this case is the demonstration of the utility of EMG in cervical radiculopathy evaluation, which aided in an efficient and effective treatment course. We contend that in cases of cervical radiculopathy with a focal deficit of profound weakness with shoulder abduction and elbow flexion, obtaining nerve conduction studies and EMGs within the first 4 to 6 weeks of presentation should be viewed as essential for the long-term recovery and effective management of the injured service member, particularly when injury to the upper trunk of the brachial plexus can also account for these specific motor deficits. This report will cover a brief review of the pathophysiology, evaluation, and natural history of cervical radiculopathy with special attention paid to the timing and efficacy of EMG.

Electrodiagnostic Studies in Degenerative Cervical Myelopathy

The diagnosis of degenerative cervical myelopathy can generally be made with a thorough history, physical examination, and spinal imaging. Electrodiagnostic studies, consisting of nerve conduction studies and electromyography, are a useful adjunct when the clinical picture is inconsistent or there is concern for overlapping pathology. Electrodiagnostic studies may be particularly helpful in identifying cases of myeloradiculopathy, when there is combined nerve root and spinal cord injury, both with regards to prognosis and guiding surgical treatment. Electrodiagnostic studies are a useful adjunct for the spine surgeon and should be used when there are features atypical for degenerative cervical myelopathy or when there is suspicion for a concomitant disease process.

Traumatic brachial plexus injury: diagnosis and treatment

PURPOSE OF THE REVIEW

Traumatic brachial plexus injuries (BPI) are devastating life-altering events, with pervasive detrimental effects on a patient's physical, psychosocial, mental, and financial well-being. This review provides an understanding of the clinical evaluation, surgical indications, and available reconstructive options to allow for the best possible functional outcomes for patients with BPI.

RECENT FINDINGS

The successful management of patients with BPI requires a multidisciplinary team approach including peripheral nerve surgeons, neurology, hand therapy, physical therapy, pain management, social work, and mental health. The initial diagnosis includes a detailed history, comprehensive physical examination, and critical review of imaging and electrodiagnostic studies. Surgical reconstruction depends on the timing of presentation and specific injury pattern. A full spectrum of techniques including neurolysis, nerve grafting, nerve transfers, free functional muscle transfers, tendon transfers, and joint arthrodesis are utilized.

SUMMARY

Despite the devastating nature of BPI injuries, comprehensive care within a multidisciplinary team, open and practical discussions with patients about realistic expectations, and thoughtful reconstructive planning can provide patients with meaningful recovery.

Future Considerations in the Diagnosis and Treatment of Compressive Neuropathies of the Upper Extremity

Compressive neuropathies of the upper extremity are among the most common conditions seen by hand surgeons. The diagnoses of carpal tunnel syndrome and cubital tunnel syndrome have traditionally been made by a combination of history, physical examination, and electrodiagnostic testing. However, findings can be nonspecific and electrodiagnostic testing is invasive for the patient. The diagnosis of compressive neuropathies continues to evolve as technology advances, and newer diagnostic modalities predominantly focus on preoperative diagnostic imaging with ultrasound and magnetic resonance imaging/neurography. With the advent of cheaper, faster, and less invasive imaging, the future may bring a paradigm shift away from electrophysiology as the gold standard for the preoperative diagnosis of compressive neuropathies. Intraoperative imaging of nerve health is an emerging concept that warrants further investigation, whereas postoperative imaging of nerve recovery with ultrasound and magnetic resonance imaging currently has a limited role because of nonspecific findings and potential for misinterpretation. Advances in surgical treatment of compressive neuropathies appear to center around the use of imaging for less invasive neurolysis techniques and other adjunctive treatments with nerve decompression. The management of failed peripheral nerve decompressions and recurrent compressive neuropathies remains challenging.

Evaluation and Management of Adult Footdrop

Footdrop is a common musculoskeletal condition defined by weakness in ankle joint dorsiflexion. Although the etiology varies, footdrop is characterized by specific clinical and gait abnormalities used by the patient to overcome the loss of active ankle dorsiflexion. The condition is often associated with deformity because soft-tissue structures may become contracted if not addressed. Patients may require the use of special braces or need surgical treatment to address the notable level of physical dysfunction. Surgical treatment involving deformity correction to recreate a plantigrade foot along with tendon transfers has been used with notable success to restore a near-normal gait. However, limitations and postoperative dorsiflexion weakness have prompted investigation in nerve transfer as a possible alternative surgical treatment.

Surgical Treatment of Foot Drop: Patient Evaluation and Peripheral Nerve Treatment Options

Foot drop is a common clinical condition which may substantially impact physical function and health-related quality of life. The etiologies of foot drop are diverse and a detailed history and physical examination are essential in understanding the underlying pathophysiology and capacity for spontaneous recovery. Patients presenting with acute foot drop or those without significant spontaneous recovery of motor deficits may be candidates for surgical intervention. The timing, mechanism, and severity of neural injury resulting in foot drop influence the selection of the most appropriate peripheral nerve surgery, which may include direct nerve repair, neurolysis, nerve grafting, or nerve transfer.

Non-Invasive Muscular Atrophy Causes Evaluation for Limb Fracture Based on Flexible Surface Electromyography System

Muscular atrophy after limb fracture is a frequently occurring complication with multiple causes. Different treatments and targeted rehabilitation procedures should be carried out based on the causes. However, bedside evaluation methods are invasive in clinical practice nowadays, lacking reliable non-invasive methods. In this study, we propose a non-invasive flexible surface electromyography system with machine learning algorithms to distinguish nerve-injury and limb immobilization-related atrophy. First, a flexible surface electromyography sensor was designed and verified by in vitro tests for its robustness and flexibility. Then, in vivo tests on rats proved the reliability compared with the traditional invasive diagnosis method. Finally, this system was applied for the diagnosis of muscular atrophy in 10 patients. The flexible surface electromyography sensor can achieve a max strain of 12.0%, which ensures close contact with the skin. The in vivo tests on rats show great comparability with the traditional invasive diagnosis method. It can achieve a high specificity of 95.28% and sensitivity of 98.98%. Application on patients reaches a relatively high specificity of 89.44% and sensitivity of 91.94%. The proposed painless surface electromyography system can be an easy and accurate supplementary for bedside muscular atrophy causes evaluation, holding excellent contact with the body.

Evaluation of a Comprehensive Telemedicine Pathway for Carpal Tunnel Syndrome: A Comparison of Virtual and In-Person Assessments

PURPOSE

We evaluated a comprehensive telemedicine pathway for carpal tunnel syndrome (CTS). Our primary aim was to compare telemedicine and in-person administration of the six item CTS-6 instrument (CTS-6) in patients undergoing carpal tunnel release (CTR) and to determine whether surgical plans determined via telemedicine were altered by in-person assessments. We additionally aimed to assess agreement between telemedicine and in-person examinations.

METHODS

In this prospective investigation, patients referred to a hand surgeon for evaluation of CTS were offered a telemedicine pathway. A modified, virtual CTS-6 was administered during the telemedicine consultation and a virtual exam was performed. Patients indicated for CTR were evaluated in person on the day of surgery. Agreement between the telemedicine and in-person CTS-6 and exam findings was determined. Patients were evaluated via telemedicine postoperatively to determine satisfaction with the program and assess surgical complications.

RESULTS

A total of 32 cases were included. The mean CTS-6 score administered via telemedicine was 17.7, compared with 16.8 in person; this difference was not statistically significant. There were no cases indicated for CTR during the telemedicine visit that had a subsequent change in management based on the in-person evaluation. Agreement was lowest for the sensory assessment (63%). The Phalen and Durkan compression tests demonstrated high levels of agreement (97% and 94%, respectively). Satisfaction was high for patients in the telemedicine CTS pathway.

CONCLUSIONS

Overall agreement between telemedicine and in-person administration of the CTS-6 is high for patients with CTS. In patients indicated for CTR via telemedicine, an in-person examination does not appear to alter management. The telemedicine examination of hand sensation demonstrates lower levels of agreement with the in-person assessment. Telemedicine can serve as an alternative to conventional, in-person clinic visits for the diagnosis and postoperative management of uncomplicated, primary CTS.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic II.