Timing and appropriate use of electrodiagnostic studies

Unveiling the spiral groove: a journey through clinical anatomy, pathology, and imaging

AIM

To review the anatomy of the spiral groove, its clinical significance, and the imaging characteristics of common pathologies affecting this area, highlighting the strengths of different imaging modalities.

MATERIALS AND METHODS

A comprehensive review of the spiral groove anatomy and its clinical implications and an evaluation of various imaging techniques, including radiography, ultrasound, MRI, and CT, was conducted. The review covers pathologic conditions such as Saturday night palsy, humeral fractures, tumours, and infections, with an emphasis on their imaging findings and clinical implications.

RESULTS

The spiral groove provides a pathway for the radial nerve and the deep brachial artery, both crucial for upper limb function. Each imaging modality offers unique advantages: radiography is useful for initial assessment, ultrasound provides dynamic visualisation, MRI offers high-resolution soft tissue imaging, and CT is ideal for detailed bone anatomy. Understanding these imaging characteristics is essential for diagnosing fractures, assessing humeral alignment, and detecting nerve entrapment or injury.

CONCLUSION

Accurate imaging of the spiral groove is essential for diagnosing and treating pathologies related to this anatomical feature. The integrative approach of using appropriate imaging modalities enhances diagnostic precision and informs therapeutic strategies, ultimately improving patient outcomes.

State of the art review. Upper extremity revision nerve compression surgery

Although surgical release of upper extremity nerve compression syndromes is highly effective, persistence or recurrence of symptoms and signs may occur. Thorough investigation is necessary in this situation before treatment is recommended. If the symptoms cannot be explained by other pathology than compression of the affected nerve and if conservative management has not provided improvement, reoperation may be considered. This review provides an overview of the diagnostic and surgical considerations in the revision of carpal tunnel syndrome, cubital tunnel syndrome and thoracic outlet syndrome.Level of evidence: V.

Electrodiagnostic reporting preferences of referring physicians: An exploratory survey

INTRODUCTION/AIMS

Electrodiagnostic (EDX) studies play a crucial role in the evaluation of patients with peripheral nervous system disorders. Accurate and succinct communication of test results is critical to patient safety and clinical decision-making. The objective of this study was to explore EDX reporting preferences of referring physicians to improve quality of communication and patient care.

METHODS

An online survey was developed, and a purposive sampling strategy was used to recruit physicians in the authors' professional networks. Quantitative and qualitative survey data underwent frequency and thematic analyses, respectively.

RESULTS

There were 40 respondents, including: 21 non-surgical specialists, 12 surgical specialists, and 7 family physicians. Sections rated as most critical were diagnostic impression (97%) and summary/interpretation (72%). Only 18% reported numeric data as critical to their needs, preferring this data to be formatted as bullet points or tables without nerve conduction study waveforms. Regarding the format of the data summary and diagnostic impression sections, the majority of respondents preferred bullet points rather than paragraphs.

DISCUSSION

The results of this exploratory survey suggest that physicians who refer patients for EDX studies prefer reports that emphasize the interpretation of EDX data and a clear diagnostic impression, particularly in bullet point format. This project highlights important preferences and how they compare to recommended reporting guidelines, which may help improve communication and ultimately patient care. Future efforts should explore larger sample sizes with all key stakeholders in the EDX process to better understand reporting styles and preferences with greater nuance and context.

Classifying the Severity of Cubital Tunnel Syndrome: A Preoperative Grading System Incorporating Electrodiagnostic Parameters

BACKGROUND

Current classifications for cubital tunnel syndrome have not been shown to reliably predict postoperative outcomes. In this article, the authors introduce a new classification that incorporates clinical and electrodiagnostic parameters, including compound muscle action potential amplitude, to classify the preoperative severity of cubital tunnel syndrome. The authors compare this to established classifications and evaluate its association with patient-rated improvement.

METHODS

The authors reviewed 44 patients who were treated surgically for cubital tunnel syndrome. Patients were retrospectively classified using their proposed classification and the Akahori, McGowan-Goldberg, Dellon, and Gu classifications. Correlation of grades was assessed by Spearman coefficients and agreement was assessed by weighted kappa coefficients. Patient-reported impairment was assessed using the Disabilities of the Arm, Shoulder, and Hand questionnaire before and after surgery.

RESULTS

The classifications tended to grade patients in a similar way, with Spearman coefficients of 0.60 to 0.85 ( p < 0.0001) and weighted kappa coefficients of 0.46 to 0.71 ( p < 0.0001). Preoperative Disabilities of the Arm, Shoulder, and Hand scores increased with severity grade for most classifications. In multivariable analysis, the authors' classification predicted postoperative Disabilities of the Arm, Shoulder, and Hand score improvement, whereas established classifications did not.

CONCLUSIONS

Established classifications are imperfect indicators of preoperative severity. The authors introduce a preoperative classification for cubital tunnel syndrome that incorporates electrodiagnostic findings in addition to classic signs and symptoms.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Diagnostic, III.

Team Approach: Management of Brachial Plexus Injuries

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Traumatic brachial plexus injuries are relatively rare but potentially devastating injuries with substantial functional, psychological, and economic consequences.

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Prompt referral (ideally within 6 weeks of injury) to a center with a team of experts experienced in the diagnosis and management of these injuries is helpful to achieving optimal outcomes.

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Preoperative and intraoperative decision-making to diagnose and plan reconstructive procedures is complex and must take into account a number of factors, including the time from injury, concomitant injuries, preservation of cervical nerve roots, and the availability of intraplexal and extraplexal donor nerves for nerve transfer.

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A team approach is essential to ensure accurate localization of the pathology before surgery and to maximize rehabilitation after surgery, necessitating close contact between the surgical team, physiatrists, radiologists, and therapists.

Incidence, Risk Factors, Prevention, and Management of Peripheral Nerve Injuries Following Shoulder Arthroplasty

In this article, the authors review the incidence and causes of iatrogenic peripheral nerve injuries following shoulder arthroplasty and provide preventative measures to decrease nerve injury rate and management options. They describe common direct and indirect causes of injury such as laceration and retractor use versus arm positioning and lengthening, respectively. Preventative measures include an understanding of anatomy and high-risk locations in the shoulder, minimizing extreme ranges of arm motion and utilization of intraoperative nerve monitoring. Lastly, the authors review diagnosis and management of neurologic symptoms including how and when to use electrodiagnostic studies, nerve grafts, transfers, or muscle/tendon transfers.

Gunshot-related lower extremity nerve injuries

OBJECTIVE

The purpose of this study was to describe the frequency of nerve injury associated with lower extremity ballistic trauma, the associated skeletal and soft tissue injuries, and the rate of neurologic recovery.

DESIGN AND SETTING

A retrospective review of an institutional trauma database was completed at a single level 1 trauma academic medical center.

PATIENTS

This was an institutional review board approved retrospective cohort study of patients over 16 years of age presenting with ballistic-related traumatic injury to the lower extremities between May 2018 and May 2019. All patients identified with lower extremity ballistic trauma were included in this study. The rate of nerve palsy, associated skeletal injury, and operative fixation were recorded for each anatomic zone. Rates of associated concomitant vascular injury, fracture, and compartment syndrome were collected through a review of the electronic medical records. Chart review was performed to evaluate outcomes and nerve recovery.

RESULTS

Twenty-one patients (21 extremities, 21/148, 14%) were diagnosed by attending physicians, fellowship-trained in orthopedic trauma, as having ballistic-related nerve injuries. Seventy-three percent of patients with a documented neurologic injury (11/15) demonstrated complete nerve recovery as measured by the MRC and sensory scale assessment at most recent follow-up, while the rest demonstrated no improvement in their neurologic deficits from presentation. The rate of associated vascular injury in patients with lower extremity nerve palsies was 38% (8/21). While the rate of vascular injury in the absence of neurologic injury was 3% (4/127).

CONCLUSIONS

This series of lower extremity nerve injuries in a large sample of urban lower extremity ballistic trauma noted a high rate of concomitant nerve injuries. An associated diagnosis of a vascular injury appears to portend a higher risk of neurologic injury. Treating surgeons should have a high index of suspicion for associated vascular injury in patients presenting with a ballistic lower extremity nerve palsy.

Gunshot-Related Upper Extremity Nerve Injuries at a Level 1 Trauma Center

PURPOSE

Gunshot wounds can result in a spectrum of injuries to nerves, with little data to guide definitive treatment. We performed a retrospective evaluation of gunshot-related upper extremity injuries in an urban trauma center to analyze epidemiology, associated injuries, and short-term outcomes. We hypothesized that gunshot-related injuries would involve soft tissue cavitation, inducing axonotmesis and neuropraxia rather than neurotmesis injuries.

METHODS

All patients over the age of 16 with upper extremity gunshot trauma from May 2018 to May 2019 were identified through the University of Chicago orthopaedic and general surgery trauma databases. Initial nerve injuries were identified by physical examination. Patient demographic data, soft tissue and skeletal injury, treatment modality, and return of function were collected.

RESULTS

Ballistic injuries in 1302 patients were treated over 12 months. We identified 126 upper extremity gunshot injuries in 117 patients. Thirty-eight upper extremities (38 patients) had a documented nerve deficit (38/126, 30%) with a follow-up rate of 94% (34/36) at a mean of 351 days after injury (median, 202 days; range, 13-929 days). One patient had a subacute transradial amputation, and 1 patient was deceased at final follow-up. The presence of vascular injury and fracture increased the rate of neurologic injury after gunshot injuries. At the most recent follow-up, 68% (23/34) of patients with upper extremity injury had improvement in nerve function as measured by objective clinical assessment, with 24% (8/34) experiencing full recovery at an average of 368 days (median, 261 days; range, 41-929 days).

CONCLUSIONS

Nerve injury after ballistic trauma to the upper extremity is common. Vascular injury and fractures were associated with a higher risk of nerve injury. Short-term improvement in nerve function was seen in over half the cohort, suggesting a predominance of neuropraxic effects.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic IV.

Surgical Innovations to Restore Function in Pediatric Peripheral Nerve Conditions

Peripheral nerve injuries in children can result in devastating lifelong deficits. Because of the time-sensitive nature of muscle viability and the limited speed of nerve regeneration, early recognition and treatment of nerve injuries are essential to restore function. Innovative surgical techniques have been developed to combat the regenerative length and speed; these include nerve transfers. Nerve transfers involve transferring a healthy, expendable donor nerve to an injured nerve to restore movement and sensation. Nerve transfers are frequently used to treat children affected by conditions, including UE trauma, brachial plexus birth injury, and acute flaccid myelitis. Pediatricians play an important role in the outcomes of children with these conditions through early diagnosis and timely referrals. With this review, we aim to provide awareness of state-of-the-art surgical treatment options that significantly improve the function of children with traumatic nerve injuries, brachial plexus birth injury, and acute flaccid myelitis.

A prospective evaluation of phrenic nerve injury after lung transplantation: Incidence, risk factors, and analysis of the surgical procedure

BACKGROUND

Phrenic nerve injury (PNI) is a complication of lung transplantation related to the surgical procedure and associated with increased morbidity. However, the incidence and risk factors, specifically regarding surgical techniques, have not been adequately studied.

METHODS

We conducted a prospective single-center study over 4-years, in recipients of lung transplantation with a normal pretransplant phrenic nerve conduction study (PNCS). Diaphragm ultrasound and PNCS were performed in the first 21 postoperative days and PNI was defined when both tests were abnormal. Patients were followed up until hospital discharge. The association between transplant characteristics and PNI was analyzed by using logistic regression models.

RESULTS

Two hundred eleven lung grafts implanted in 127 patients were included in the study. After lung transplantation, PNI was diagnosed in 43.3% of the subjects and 29% of the operated hemithorax. Regression logistic model showed that the variables related to PNI were female gender (p = 0.02), bilateral lung transplantation (BLT) (p = 0.001), right lung graft (p = 0.003), clamshell incision (p = 0.01), mediastinal adhesions (p = 0.002), longer operative time (p = 0.003), intraoperative extracorporeal support (p = 0.02), and blood transfusion (p = 0.003). Conversely, age >61 years (p = 0.008) and higher thoracic diameter (p = 0.04) were protective factors. The use of electrocautery, cardiac mechanical retractors, and diaphragmatic traction was not associated with PNI. Morbidity was increased without any difference in mortality.

CONCLUSIONS

PNI is a frequent complication after lung transplantation, associated with higher morbidity. Mainly risk factors were age, BLT, female gender, and variables related to surgical difficulties. Lung graft in the right hemithorax and mediastinal adhesiolysis were the most relevant technical variables.

Prevention and Treatment of Nerve Injuries in Shoulder Arthroplasty

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Nerve injuries during shoulder arthroplasty have traditionally been considered rare events, but recent electrodiagnostic studies have shown that intraoperative nerve trauma is relatively common.

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The brachial plexus and axillary and suprascapular nerves are the most commonly injured neurologic structures, with the radial and musculocutaneous nerves being less common sites of injury.

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Specific measures taken during the surgical approach, component implantation, and revision surgery may help to prevent direct nerve injury. Intraoperative positioning maneuvers and arm lengthening warrant consideration to minimize indirect injuries.

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Suspected nerve injuries should be investigated with electromyography preferably at 6 weeks and no later than 3 months postoperatively, allowing for primary reconstruction within 3 to 6 months of injury when indicated. Primary reconstructive options include neurolysis, direct nerve repair, nerve grafting, and nerve transfers.

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Secondary reconstruction is preferred for injuries presenting >12 months after surgery. Secondary reconstructive options with favorable outcomes include tendon transfers and free functioning muscle transfers.

Nerve Ultrasound in Traumatic and Iatrogenic Peripheral Nerve Injury

Peripheral nerve injury is a potentially debilitating disorder that occurs in an estimated 2–3% of all patients with major trauma, in a similar percentage of medical procedures. The workup of these injuries has traditionally been clinical, combined with electrodiagnostic testing. However, this has limitations, especially in the acute phase of the trauma or lack of any recovery, when it is very important to determine nerve continuity and perform surgical exploration and repair in the case of the complete transection or intraneural fibrosis. Ultrasound can help in those situations. It is a versatile imaging technique with a high sensitivity of 93% for detecting focal nerve lesions. Ultrasound can assess the structural integrity of the nerve, neuroma formation and other surrounding abnormalities of bone or foreign bodies impeding the nerve. In addition, this can help to prevent iatrogenic nerve injury by marking the nerve before the procedure. This narrative review gives an overview of why and how nerve ultrasound can play a role in the detection, management and prevention of peripheral nerve injury.

Pseudoparalytic shoulder in a CoViD-19-positive patient treated with CPAP: A case report

The Authors report a case of a 46 years old man affected by severe acute respiratory syndrome caused by Novel Coronavirus 2019 and admitted to our hospital. The patient required continuous positive airway pressure therapy (CPAP) in the hospital ward and subsequently orotracheal intubation while in intensive care unit. The patient laid in lateral decubitus position for several hours every day while receiving CPAP therapy. During the hospitalization, he reported limitation of range of motion of the left upper limb, without any history of acute or previous trauma. The clinical appearance of the arm was suggestive of pseudoparalytic shoulder.

This case emphasizes the importance of proper body positioning during invasive and non-invasive mechanical ventilation in order to prevent peripheral nerve compression and further disability.

Pharmacological Attenuation of Electrical Effects in a Model of Compression Neuropathy

BACKGROUND

Peripheral nerve compression and entrapment can be debilitating. Using a validated animal model of peripheral nerve compression, we examined the utility of 2 drugs approved for other uses in humans, 4-aminopyridine (4-AP) and erythropoietin (EPO), as treatments for surgically induced ischemia and as adjuvants to surgical decompression.

METHODS

Peripheral nerve compression was induced in wild-type mice by placing an inert silicone sleeve around the sciatic nerve. Decompression surgery was performed at 6 weeks with mice receiving 4-AP, EPO, or saline solution either during and after compression or only after decompression. A nerve conduction study and morphometric analyses were performed to compare the extent of the injury and the efficacy of the therapies, and the findings were subjected to statistical analysis.

RESULTS

During peripheral nerve compression, there was a progressive decline in nerve conduction velocity compared with that in sham-treatment animals, in which nerve conduction velocity remained normal (∼55 m/s). Mice treated with 4-AP or EPO during the compression phase had significantly smaller declines in nerve conduction velocity and increased plateau nerve conduction velocities compared with untreated controls (animals that received saline solution). Histomorphometric analyses of newly decompressed nerves (i.e., nerves that underwent decompression on the day that the mouse was sacrificed) revealed that both treated groups had significantly greater proportions of large (>5-µm) axons than the untreated controls. Following surgical decompression, all animals recovered to a normal baseline nerve conduction velocity by day 15; however, treatment significantly accelerated improvement (in both the 4-AP and the EPO group), even when it was only started after decompression. Histomorphometric analyses at 7 and 15 days following surgical decompression revealed significantly increased myelin thickness and significantly greater proportions of large axons among the treated animals.

CONCLUSIONS

Both the 4-AP and the EPO-treated group demonstrated improvements in tissue architectural and electrodiagnostic measurements, both during and after peripheral nerve compression, compared with untreated mice.

CLINICAL RELEVANCE

Peripheral nerve decompression is one of the most commonly performed procedures in orthopaedic surgery. We believe that there is reason for some optimism about the translation of our findings to the clinical setting. Our findings in this murine model suggest that 4-AP and EPO may lessen the effects of nerve entrapment and that the use of these agents after decompression may speed and perhaps otherwise optimize recovery after surgery.

Combined Cubital and Carpal Tunnel Release Results in Symptom Resolution Outside of the Median or Ulnar Nerve Distributions

BACKGROUND

Resolution of symptoms including pain, numbness, and tingling outside of the median nerve distribution has been shown to occur following carpal tunnel release. We hypothesized that a similar effect would be found after combined release of the ulnar nerve at the elbow with simultaneous release of the median nerve at the carpal tunnel.

METHODS

20 patients with combined cubital and carpal tunnel syndrome were prospectively enrolled. The upper extremity was divided into six zones and the location of pain, numbness, tingling, or strange sensations was recorded pre-operatively. Two-point discrimination, Semmes-Weinstein monofilament testing, and validated questionnaires were collected pre-operatively and at six-week follow-up.

RESULTS

Probability of resolution was greater in the median nerve distribution than the ulnar nerve for numbness (71% vs. 43%), tingling (86% vs. 75%). Seventy percent of the cohort reported at least one extra-anatomic symptom pre-operatively, and greater than 80% of these resolved at early follow-up. There was a decrease in pain as measured by validated questionnaires.

CONCLUSION

This study documents resolution of symptoms in both extra-ulnar and extra-median distributions after combined cubital and carpal tunnel release. Pre-operative patient counseling may therefore include the likelihood of symptomatic improvement in a non-expected nerve distribution after this procedure, assuming no other concomitant pathology which may cause persistent symptoms. Future studies could be directed at correlating pre-operative disease severity with probability of symptom resolution using a larger population.

'Cuff Sign' a new maneuver for decision-making in patients with carpal tunnel syndrome

BACKGROUND

Carpal tunnel syndrome (CTS) is the most common entrapment neuropathy that results from compression of the median nerve within the carpal tunnel. In most patients, the diagnosis can be proposed based on patient history and clinical symptoms, with physical findings being attributed only in more severely affected patients. The purpose of this study is to introduce a reliable and accurate method for the proper selection of patients with mild carpal tunnel syndrome (CTS), for surgery.

MATERIALS AND METHODS

Electerodiagnostic studies are performed before and after placement of the cuff of the sphygmomanometer at the arm (Cuff sign), at a mean arterial pressure, for three minutes. Thirty symptomatic patients with mild findings on electrodiagnostic studies and 49 asymptomatic control hands have been included.

RESULTS

Fifteen patients reported good pain relief on the first postoperative day (50%), which increased to 21 on the fouteenth postoperative day (70%). The sensory latency changes were significantly higher in the pain relief group, both on the first and fourteenth postoperative days.

CONCLUSION

Considering the fact that cooperation of the patients is not necessary and the double effects of direct pressure and ischemia over the proximal parts of the median nerve leads to prolonged latencies, this test is a useful method for decision-making in patients with severe symptoms of CTS, despite the mild electrodiagnostic findings.