Clinical Neurophysiology in the Diagnosis of Peroneal Nerve Palsy

Fu's subcutaneous needling promotes axonal regeneration and remyelination by inhibiting inflammation and endoplasmic reticulum stress

Fu's subcutaneous needling (FSN) is a traditional Chinese acupuncture procedure used to treat pain-related neurological disorders. Moreover, the regulation of inflammatory cytokines may provide a favorable environment for peripheral nerve regeneration. In light of this, FSN may be an important novel therapeutic strategy to alleviate pain associated with peripheral neuropathy; however, the underlying molecular mechanisms remain unclear. This study revealed that patients who had osteoarthritis with peripheral neuropathic pain significantly recovered after 1 to 2 weeks of FSN treatment according to the visual analog scale, Western Ontario and McMaster Universities Osteoarthritis Index, Lequesne index, walking speed, and passive range of motion. Similarly, we demonstrated that FSN treatment in an animal model of chronic constriction injury (CCI) significantly improved sciatic nerve pain using paw withdrawal thresholds, sciatic functional index scores, and compound muscle action potential amplitude tests. In addition, transmission electron microscopy images of sciatic nerve tissue showed that FSN effectively reduced axonal swelling, abnormal myelin sheaths, and the number of organelle vacuoles in CCI-induced animals. Mechanistically, RNA sequencing and gene set enrichment analysis revealed significantly reduced inflammatory pathways, neurotransmitters, and endoplasmic reticulum stress pathways and increased nerve regeneration factors in the FSN+CCI group, compared with that in the CCI group. Finally, immunohistochemistry, immunoblotting and enzyme-linked immunosorbent assay showed similar results in the dorsal root ganglia and sciatic nerve. Our findings suggest that FSN can effectively ameliorate peripheral neuropathic pain by regulate inflammation and endoplasmic reticulum stress, thereby determine its beneficial application in patients with peripheral nerve injuries.

Foot drop in critically ill patients: a narrative review of an elusive complication with intricate implications for recovery and rehabilitation

Foot drop is a condition characterized by the inability to lift the foot upwards towards the shin bone. This condition may affect a proportion of critically ill patients, impacting on their recovery after the acute phase of the illness. The occurrence of foot drop in critical care patients may result from various underlying causes, including neurological injuries, muscular dysfunction, nerve compression, or vascular compromise. Understanding the etiology and assessing the severity of foot drop in these patients is essential for implementing appropriate management strategies and ensuring better patient outcomes. In this comprehensive review, we explore the complexities of foot drop in critically ill patients. We search for the potential risk factors that contribute to its development during critical illness, the impact it has on patients' functional abilities, and the various diagnostic techniques adopted to evaluate its severity. Additionally, we discuss current treatment approaches, rehabilitation strategies, and preventive measures to mitigate the adverse effects of foot drop in the critical care setting. Furthermore, we explore the roles of critical care physical therapists, neurologists, and other healthcare professionals in the comprehensive care of patients with foot drop syndrome and in such highlighting the importance of a multidisciplinary approach.

Neuropathy in multiple sclerosis patients treated with teriflunomide

OBJECTIVE

Teriflunomide is an oral medication approved for the treatment of patients with multiple sclerosis. The primary effect of teriflunomide is to reduce de novo pyrimidine synthesis by inhibiting mitochondrial dihydroorotate dehydrogenase, thereby causing cell-cycle arrest. We aimed to investigate the occurrence of peripheral neuropathy, a rare side effect of teriflunomide, in patients receiving teriflunomide.

METHODS

Multiple sclerosis patients receiving teriflunomide (n=42) or other disease modifying therapies (n=18) and healthy controls (n=25) were enrolled in this cross-sectional study between January 2020 and 2021. The mean duration of teriflunomide treatment was 26 months (ranging from 6 to 54 months). All participants underwent neurological examination and nerve conduction studies of tibial, peroneal, sural, superficial peroneal, median, and ulnar nerves by using surface recording bar and bipolar stimulating electrodes.

RESULTS

The mean superficial peroneal nerve distal latency and conduction velocity were significantly slower, and the mean superficial peroneal nerve action potential amplitude was lower in patients using teriflunomide (2.50 ms, p<0.001; 47.35 m/s, p=0.030; and 11.05 μV, p<0.001, respectively). The mean peroneal motor nerve distal latency was significantly longer and amplitude was lower in teriflunomide patients (3.68 ms, p<0.001, and 5.25 mV, p=0.009, respectively). During the study period, treatment switching to another disease-modifying therapy was planned in 10 patients, and all neuropathic complaints were reversed after switching.

CONCLUSION

Teriflunomide has the potential to cause peripheral neuropathy. The awareness of peripheral neuropathy, questioning the symptoms, and if suspected, evaluation with electromyography and switching the therapy in patients under teriflunomide treatment are crucial.

Recent advances in neuroanatomy: the myotome update

The myotome of a muscle is the basis for diagnosing spinal and peripheral nerve disorders. Despite its critical importance in clinical neurology, myotome charts presented in many textbooks, surprisingly, show non-negligible discordances with each other. Many authors do not even clearly state the bases of their charts. Studies that have presented with raw data regarding myotome identification are rather rare. A classic study in the 19th century that pursued the nerve course in cadavers still has a substantial influence on existing charts, despite its definite limitations. Other scarce studies in humans include identification by root stimulation during surgery, clinical observations in root avulsion or spinal cord injury and clinical and electromyographical investigations in patients with single radiculopathies or certain plexopathies. A few recent studies have proposed new theories regarding the myotomes of some muscles. T1 innervation of the median intrinsic hand muscles is a typical example. We have added a number of new findings, such as T1 innervation of the forearm flexor muscles innervated by the median nerve except the pronator teres and flexor carpi radialis, C5 innervation of the brachioradialis, and two C6 indicator muscles, pronator teres and extensor carpi radialis brevis. Increased accuracy of the myotome charts will improve the localisation in neurology.

Imaging of the Peripheral Nerves of the Lower Extremity

Continued advancements in magnetic resonance (MR) neurography and ultrasound have made both indispensable tools for the workup of peripheral neuropathy. Ultrasound provides high spatial resolution of superficial nerves, and techniques such as "sonopalpation" and dynamic maneuvers can improve accuracy. Superior soft tissue contrast, ability to evaluate both superficial and deep nerves with similar high resolution, and reliable characterization of denervation are strengths of MR neurography. Nevertheless, familiarity with normal anatomy, anatomic variants, and common sites of nerve entrapment is essential for radiologists to use both MR neurography and ultrasound effectively.

Neuropathic pain in peroneal nerve entrapment at the fibular head

BACKGROUND

Peroneal neuropathy at the fibular head (PNFH) is a mononeuropathy that typically presents with drop foot and sensory abnormalities over the skin area innervated by the peroneal nerve.

OBJECTIVE

The aim of the present study was to evaluate neuropathic pain in patients with PNFH.

METHODS

Patients with clinical and electrodiagnostic features consistent with PNFH associated with weight loss, leg postures, or prolonged sleep were included in the present retrospective cohort study. Nerve conduction studies were performed in the bilateral lower extremities of all patients. The Leeds assessment of neuropathic symptoms and signs scale (LANSS) was applied to all patients.

RESULTS

Thirty-two PNFH patients (78% males) were included in the study. The LANSS score in the majority of patients was lower than 12. There was 1 patient with a LANSS score of 12. The electrodiagnostic features of 16 patients were compatible with axonal degeneration. The mean LANSS scores of PNFH patients with and without axonal degeneration were 4.3 ± 3.7 and 5.2 ± 2.9, respectively (p = 0.255).

CONCLUSION

The present study showed that neuropathic pain is a rare symptom in patients with PNFH associated with weight loss, leg postures, or prolonged sleep.

Complete Foot Drop With Normal Electrodiagnostic Studies: Sunderland "Zero" Ischemic Conduction Block of the Common Peroneal Nerve

ABSTRACT

Common peroneal neuropathy is a peripheral neuropathy of multifactorial etiology often left undiagnosed until foot drop manifests and electrodiagnostic abnormalities are detected. However, reliance on such striking symptoms and electrodiagnostic findings for diagnosis stands in contrast to other commonly treated neuropathies, such as carpal tunnel and cubital tunnel syndrome. Poor recognition of common peroneal neuropathy without foot drop or the presence of foot drop with normal electrodiagnostic studies thus often results in delayed or no surgical treatment. Our cases document 2 patients presenting with complete foot drop who had immediate resolution after decompression. The first patient presented with normal electrodiagnostic studies representing an isolated Sunderland Zero nerve ischemia. The second patient presented with severe electrodiagnostic studies but also had an immediate improvement in their foot drop representing a Sunderland VI mixed nerve injury with a significant contribution from an ongoing Sunderland Zero ischemic conduction block. In support of recent case series, these patients demonstrate that common peroneal neuropathy can present across a broad diagnostic spectrum of sensory and motor symptoms, including with normal electrodiagnostic studies. Four clinical subtypes of common peroneal neuropathy are presented, and surgical decompression may thus be indicated for these patients that lack the more conventional symptoms of common peroneal neuropathy.

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.

Minimally Invasive Surgical Approach for Open Common Peroneal Nerve Neurolysis in the Setting of Previous Posterior Schwannoma Removal

The common peroneal nerve (CPN) runs laterally around the fibular neck and enters the peroneal tunnel, where it divides into the deep, superficial, and recurrent peroneal nerves. CPN entrapment is the most common neuropathy of the lower extremity and is vulnerable at the fibular neck because of its superficial location. Schwannomas are benign, encapsulated tumors of the nerve sheath that can occur sporadically or in cases of neurocutaneous conditions, such neurofibromatosis type 2. In cases with compressive neuropathy resulting in significant or progressive motor loss, decompression and neurolysis should be attempted. We present a technical note for the treatment of CPN compressive neuropathy in the setting of a previous ipsilateral schwannoma removal with a minimally invasive surgical approach and neurolysis of the CPN at the fibular neck.

Clinical Outcomes After Neurolysis for the Treatment of Peroneal Nerve Palsy: A Systematic Review and Meta-Analysis

BACKGROUND

Neurolysis techniques have been adapted for decompression of peripheral nerves in multiple locations, including the common peroneal nerve (CPN) at the fibular neck. The aim of this study was to conduct a systematic review and meta-analysis to summarize the clinical outcomes of neurolysis for the management of peroneal nerve palsy (PNP).

METHODS

Preferred Reporting Systems for Systematic Reviews and Meta-Analyses guidelines were followed for this meta-analysis. Four databases were queried, and randomized clinical trials, cohort studies, case-control studies, and case series with n > 10 published in English that evaluated clinical outcomes of neurolysis for the treatment of PNP and foot drop were included. Two reviewers completed screening and data extraction. Methodological quality was evaluated using the Newcastle-Ottawa Scale.

RESULTS

A total of 493 articles were identified through literature search. Title and abstract screening identified 39 studies for full-text screening. Ten articles met the inclusion criteria for qualitative analysis, and 8 had complete data for meta-analysis.Overall, there were 368 patients (370 nerves) who had neurolysis of the CPN for PNP, of which 59.2% (n = 218) were men and 40.8% (n = 150) were women. The mean age of the patients was 47.1 years (SD, 10.0 years), mean time to surgery was 9.65 months (SD, 6.3 months), and mean follow-up time was 28 months (SD, 14.0 months). The median preoperative Medical Research Council (MRC) score was 1 (IQR 0, 3), with 42.2% (n = 156) having MRC score of 0. The median postoperative MRC score was 5 (IQR 4, 5), with 53.9% (n = 199) having MRC score of 5. Complications of neurolysis of the peroneal nerve for treatment of PNP included postoperative infection (0.54%, n = 2), wound dehiscence (0.27%, n = 1), hematoma (0.54%, n = 2), bleeding (0.27%, n = 1), relapse of PNP (0.27%, n = 1), and 1 case of mortality due to sepsis.

CONCLUSIONS

Our meta-analysis shows that neurolysis of the CPN is safe and improves ankle dorsiflexion strength in patients with PNP. Future studies should use a standardized method of measuring sensory outcomes, and studies of higher levels of evidence are needed to better assess the clinical outcomes of neurolysis for treatment of PNP.

Prognostic indicators of surgical outcome in painful foot drop: a systematic review and meta-analysis

PURPOSE

Foot drop is a relatively uncommon presentation of lumbar degenerative disease and there is currently a paucity of evidence on management and outcomes which is reflective of the lack of standardised treatment provided to patients. The purpose of this systematic review and meta-analysis is to determine the effectiveness of surgical management and the factors that predict surgical outcome.

METHODS

A systematic database search of Cochrane Library, Ovid Medline, Pubmed, Embase and Google Scholar was undertaken from inception through August 2018. Only studies reporting on surgical outcome in adult patients who had a painful foot drop and underwent decompression were included. Case reports and studies with surgical fixation were excluded. Study quality was assessed using the Newcastle-Ottawa Scale. Data were pooled using a random-effects model.

RESULTS

797 studies were screened and 9 observational studies met the inclusion criteria. This resulted in a total of 431 patients who underwent decompression for foot drop. Pooled rates of outcome for improvement in foot drop MRC grade were 84.5% (range 67.9-96%). Sub-group meta-analyses of studies revealed a statistically significant association between duration of foot drop (pooled 4.95 [95% CI 1.13-21.74]), severity of preoperative weakness (pooled 0.38 [95% CI 0.15-0.93]) on post-operative outcome and age (pooled 6.28 [1.33-29.72]).

CONCLUSION

This is the first systematic review and meta-analysis to explore the outcome and prognostic indicators of lumbar decompression for foot drop. Findings indicate that age, duration of foot drop weakness and MRC grade of foot drop prior to intervention were strong predictors of surgical outcome.

Transfer of the Posterior Tibial Tendon for Chronic Peroneal Nerve Palsy

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The common peroneal nerve (CPN) is one of the most frequently injured nerves of the lower extremity.

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One-third of patients who develop CPN palsy proceed to chronic impairment without signs of recovery.

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Ankle-foot orthoses can provide improvement with respect to gait dysfunction and are useful as a nonsurgical treatment option.

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Severe cases of CPN palsy demonstrating no signs of recovery may require operative intervention with tendon transfer.

Common Peroneal Nerve Injury Related to Small Saphenous Vein Surgery: Report of 2 Cases and Review of the Literature

Although iatrogenic damage is less often involved, deep nerve injuries are reported especially as a result of small saphenous vein (SSV) dissection. Complete or partial division of the common peroneal nerve (CPN) during varicose vein operations causes substantial and serious disability. Most CPN injuries recover spontaneously; nonetheless, some require nerve surgery. Treatment depends on the nature of CPN injury. This report chronicles 2 instances of CPN injury after SSV surgery, addressing treatment strategies and therapeutic gains. The pertinent literature is also reviewed.

A Cadaveric Study of the Distal Biceps Femoris Muscle in relation to the Normal and Variant Course of the Common Peroneal Nerve: A Possible Cause of Common Peroneal Entrapment Neuropathy

The most frequent mononeuropathy in the lower extremity has been reported as the common peroneal nerve entrapment neuropathy (CPNe) around the head and neck of the fibula, although the mechanism of the neuropathy in this area cannot be fully explained. Therefore, the aim of this cadaveric study was to evaluate the relationship between morphologic variations of the distal biceps femoris muscle (BFM) and the course of the common peroneal nerve (CPN) and to investigate the incidence and morphological characteristics of anatomical variations in the BFM associated with CPNe. The popliteal region and the thigh were dissected in 115 formalin-fixed lower limbs. We evaluated consensus for (1) normal anatomy of the distal BFM, (2) anatomic variations of this muscle, and (3) the relationship of the muscle to the CPN. Measurements of the distal extents of the short and long heads of the BFM from insertion (fibular head) were performed. Two anatomic patterns were seen. First, in 93 knees (80.8%), the CPN ran obliquely along the lateral side of the BFM and then superficial to the lateral head of the gastrocnemius muscle. Second, in 22 cases (19.2%), the CPN coursed within a tunnel between the biceps femoris and lateral head of the gastrocnemius muscle (LGCM). There was a positive correlation between the distal extents of the short heads of the biceps femoris muscle (SHBFM) and the presence of the tunnel. The “popliteal intermuscular tunnel” in which the CPN travels can be produced between the more distal extension variant of the SHBFM and the LGCM. This anatomical variation of BFM may have a clinical significance as an entrapment area of the CPN in the patients in which the mechanism of CPNe around the fibula head and neck is not understood.

Peroneal neuropathy caused by an extraneural ganglion cyst in the supracondylar area of the femur: A case report

RATIONALE

Peroneal neuropathy is the most common type of peripheral neuropathy in the lower extremities. The peroneal nerve is usually compressed at the lateral aspect of the fibular head. Compression by ganglion cysts are one of the numerous underlying etiologies for peroneal nerve neuropathy and are most frequently located around the fibular neck and proximal tibiofibular joint. To the best of our knowledge, this is the first report of an extraneural ganglion cyst located at the level of the distal thigh that resulted in compressive peroneal neuropathy.

PATIENT CONCERNS

We report a case of a 56-year-old man with sudden onset of left foot drop and gait disturbance caused by an extraneural ganglion cyst located in the popliteal fossa.

DIAGNOSIS

Electrodiagnosis (EDX) suggested a peroneal nerve lesion. Subsequently, diagnostic ultrasonography (USG) revealed a cystic mass located within the left side of the supracondylar area of femur. Further magnetic resonance imaging confirmed that the mass was located at the proximal of popliteal fossa.

INTERVENTIONS

Surgical excision was performed using a direct posterior approach. The cystic mass was compressing the common peroneal nerve, and was carefully and completely removed ensuring that all nerve branches were protected.

OUTCOMES

A histopathologic evaluation confirmed the diagnosis of a ganglion cyst. There were no postoperative complications. Two months after the surgery, follow-up USG revealed no evidence of cyst recurrence or residual lesions. Six months after the surgery, the ankle dorsiflexor motor power improved and he experienced less pain and hypoesthesia.

LESSONS

Physicians should bear in mind that the peroneal neuropathy can occur because of the ganglion cyst in the distal thigh. The thorough evaluation of EDX and USG is crucial for the early diagnosis and surgical intervention, although there is no abnormal finding around the fibular neck.

The results of surgical decompression in the treatment of foot drop due to peroneal nerve entrapment after bariatric surgery

BACKGROUND

The loss of the fat pad surrounding the fibular head after rapid and excessive weight loss after bariatric surgery can lead to foot drop symptoms due to peroneal nerve entrapment (PNE). Conservative and surgical approaches have been described for the treatment of this condition, but there is some controversy over the effectiveness of the treatment modalities.

OBJECTIVE

We aimed to investigate the causes and frequency of foot drop due to PNE after bariatric surgery and to investigate the effects of peroneal nerve decompression (PND) as a surgical treatment for PNE.

SETTING

Single center, university surgical department.

METHODS

We retrospectively evaluated a series of 2607 patients in terms of neurologic complications after bariatric surgery. Patients' age, sex, co-morbid diseases, vitamin and electrolyte levels, body mass index and postoperative excess weight loss, affected limb, duration of symptoms, and muscle strength scores (according to the Medical Research Council scale) were recorded.

RESULTS

A total of 14 (.5%) patients had foot drop symptoms due to PNE. Of these patients, 9 underwent PND. The mean excess weight loss of PND patients at postoperative months 6 and 12 were 68.8 ± 13.5 and 100.9 ± 10.8, respectively. Foot drop symptoms became evident 5 to 11 months after bariatric surgery, affecting only a unilateral lower extremity in all patients. In laboratory analysis, there were no signs of nutritional and vitamin deficiency or insufficiency in any of the PND cases. Muscular strength was Medical Research Council grade 0 in all patients. The median duration of symptoms was 9 days, and the median complete recovery time was 40 days after PND. Patients who had a duration of symptoms for a maximum of 12 days were completely healed 30 days after PND.

CONCLUSION

PND should be the first-choice treatment procedure for acute foot drop due to PNE after bariatric surgery.

Ultrasound-guided treatment of common peroneal neuropathy caused by Baker's cyst: a clinical note - A case report

Background

Baker's cysts are usually located in the posteromedial side of the knee and seldom cause neuropathy.

Case

We describe the rare case of a 57-year-old woman with a popliteal cyst who presented with limping gait and pain in her lower leg. She was electronically diagnosed with common peroneal neuropathy and transferred to our pain clinic. On ultrasound examination, about 2.0 × 1.2 cm sized popliteal cyst was found to extend to the fibular head, compressing the common peroneal nerve. Therefore, ultrasound-guided aspiration of the cyst and a common peroneal nerve block were performed. Immediately after the procedure, the pain, dysesthesia, and limping gait were relieved. Although her pain and dysesthesia were relieved, she underwent the surgery because of limping gait.

Conclusions

In this case, we found the Baker's cyst, the cause of the common peroneal neuropathy, and treated it immediately by just simple ultrasound examination and aspiration.

Chronic Lower Leg Pain in Athletes: Overview of Presentation and Management

BACKGROUND

Athletes with chronic lower leg pain present a diagnostic challenge for clinicians due to the differential diagnoses that must be considered.

PURPOSE/QUESTIONS

We aimed to review the literature for studies on the diagnosis and management of chronic lower leg pain in athletes.

METHODS

A literature review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). The PubMed, Scopus, and Cochrane library databases were searched, and articles that examined chronic lower leg pain in athletes were considered for review. Two independent reviewers conducted the search utilizing pertinent Boolean operations.

RESULTS

Following two independent database searches, 275 articles were considered for initial review. After the inclusion and exclusion criteria were applied, 88 were included in the final review. These studies show that the most common causes of lower leg pain in athletes include medial tibial stress syndrome, chronic exertional compartment syndrome, tibial stress fractures, nerve entrapments, lower leg tendinopathies, and popliteal artery entrapment syndrome. Less frequently encountered causes include saphenous nerve entrapment and tendinopathy of the popliteus. Conservative management is the mainstay of care for the majority of cases of chronic lower leg pain; however, surgical intervention may be necessary.

CONCLUSIONS

Multiple conditions may result in lower leg pain in athletes. A focused clinical history and physical examination supplemented with appropriate imaging studies can guide clinicians in diagnosis and management. We provide a table to aid in the differential diagnosis of chronic leg pain in the athlete.

External neurolysis as a treatment for foot drop secondary to weight loss: a retrospective analysis of 200 cases

BACKGROUND

Peroneal nerve entrapment is the most common peripheral mononeuropathy of the lower limbs. Foot drop, a common presentation, leads to an impaired eversion and dorsiflexion of the foot. An intriguing observation is the occurrence of foot drop secondary to weight loss.

METHODS

A retrospective study of patients surgically treated for peroneal nerve entrapment was performed between January 1, 1995 and December 31, 2016, at the Department of Neurosurgery, Genk, Belgium. Out of a total of 421 patients, 200 patients with foot drop secondary to weight loss were included. For each subject, motor and sensory outcomes after external neurolysis were investigated. As a primary objective, we examined the postoperative outcomes of external neurolysis as a treatment for foot drop in patients with peroneal nerve entrapment at the fibular head secondary to weight loss. As a secondary objective, we analyzed the correlation between patient characteristics and the success rate of external neurolysis.

RESULTS

When defining success as a postoperative MRC score of 4 or 5, external neurolysis has a success rate of 85% in patients with foot drop secondary to weight loss. A significant difference (P = < 0.0001) between postoperative and preoperative MRC scores indicates that external neurolysis leads to significant improvement of motor function in patients with foot drop secondary to weight loss. A multiple logistic regression model showed that "preoperative MRC scores" and "duration of symptoms" were the only variables with an impact on postoperative MRC scores. Other variables such as "age," "gender," and "side of entrapment" had no significant impact on postoperative results.

CONCLUSIONS

Statistical analysis emphasizes the important role of external neurolysis in the treatment of peripheral peroneal nerve entrapment. Therefore, external neurolysis at the fibular head should be regarded as a very effective and safe procedure in patients with foot drop secondary to weight loss.

Unusual variant of distal biceps femoris muscle associated with common peroneal entrapment neuropathy: A cadaveric case report

RATIONALE

The anatomical variant of the distal biceps femoris muscle with regard to common peroneal nerve entrapment neuropathy (CPNe) was suggested through magnetic resonance images (MRI) study.

PATIENT CONCERNS

An unusual variant of distal biceps femoris muscle was observed in 78 years old male cadaver.

DIAGNOSES

The short head of biceps femoris muscle (SHBFM) was extended more distal and posteriorly.

INTERVENTION

The popliteal area was dissected at knee joint level in a cadaveric limb.

OUTCOMES

Common peroeal nerve (CPN) was situated within tunnel formed between the lateral head of the gastrocnemius muscle (LGCM) and the SHBFM. Also, the length of tunnel was 4.4 cm.

LESSONS

The case illustrated here, to the best of our knowledge, is the first one with cadaveric findings of variant of distal biceps femoris muscle associated with CPNe. The tunnel formed between the more posterior or distal extension of the SHBFM and the LGCM could be possible entrapment area of CPN, clinically.

Anatomical Variants of "Short Head of Biceps Femoris Muscle" Associated with Common Peroneal Neuropathy in Korean Populations : An MRI Based Study

Objective

In Asians, kneeling and squatting are the postures that are most often induce common peroneal neuropathy. However, we could not identify a compatible compression site of the common peroneal nerve (CPN) during hyper-flexion of knees. To evaluate the course of the CPN at the popliteal area related with compressive neuropathy using magnetic resonance imaging (MRI) scans of healthy Koreans.

Methods

1.5-Tesla knee MRI scans were obtained from enrolled patients and were retrospectively reviewed. The normal populations were divided into two groups according to the anatomical course of the CPN. Type I included subjects with the CPN situated superficial to the lateral gastocnemius muscle (LGCM). Type II included subjects with the CPN between the short head of biceps femoris muscle (SHBFM) and the LGCM. We calculated the thickness of the SHBFM and posterior elongation of this muscle, and the LGCM at the level of femoral condyles. In type II, the length of popliteal tunnel where the CPN passes was measured.

Results

The 93 normal subjects were included in this study. The CPN passed through the “popliteal tunnel” formed between the SHBFM and the LGCM in 36 subjects (38.7% type II). The thicknesses of SHBFM and posterior portions of this muscle were statistically significantly increased in type II subjects. The LGCM thickness was comparable in both groups. In 78.8% of the “popliteal tunnel”, a length of 21 mm to <40 mm was measured.

Conclusion

In Korean population, the course of the CPN through the “popliteal tunnel” was about 40%, which is higher than the Western results. This anatomical characteristic may be helpful for understanding the mechanism of the CPNe by posture.

Low Level Laser Therapy for Radial Nerve Palsy Patients : Our Experience

Background and Aims

Peripheral nerve injury is one of the frequent complaints which is seen in the outpatient clinic of our medical institute. In previous studies we have reported on the benefits of low level laser therapy (LLLT) for central nerve system disorders, namely cerebrovascular accidents and cerebral palsy. The present study is a report on our experience of the effects of LLLT for peripheral nerve palsy.

Materials and Methods

Over the past 5 years, 13 subjects visited the out-patient clinic with the chief complaint of radial nerve palsy caused by compression of the nerve through with abnormal positioning, and sleeping posture at night. The patients were treated with LLLT. A 1000 mW semi-conductor laser device was used, delivering 830 nm in continuous wave at a dose of 20.1 J/cm² /point, and five points were treated per session (i.e., 1 treatment) twice a week for 3 months (total 24 treatments). In 6 patients LLLT was combined with brace therapy.

Results

Modified Daniels' manual muscle testing was used to determine the effects of LLLT for the muscle power of the extensor carpi radialis, and on completing the treatment regimen excellent improvement was observed in 9 cases out of 13. Combination treatment (laser therapy with bracing) resulted in 4 excellent cases out of 6 cases. Discussions with the patients clarified that it was important for them to learn how to avoid the particular posture that could cause them radial nerve palsy in daily life in order to have continuous benefits from the treatment.

Conclusion

The present study demonstrated that LLLT was an effective form of treatment for radial nerve palsy. In addition, patients were advised to avoid any incorrect posture which might induce radial nerve palsy.

Peroneal Nerve Palsy Due to Subparaneurial Ganglion Cyst, a Rare Variant of Intraneural Ganglion Cyst

Intraneural ganglion cysts are rare mucinous cysts originating within the epineurium of peripheral nerves. Although ganglion cysts are the most frequent tumors of the upper and lower extremities, ganglion cysts rarely result in peripheral nerve compression. We report a case of a 30-year-old patient who presented with foot drop due to subparaneurial ganglion cyst, a variant of an intraneural ganglion cyst. Characteristic magnetic resonance imaging findings were essential in the preoperative diagnosis of intraneural ganglion cyst. The common peroneal nerve and its branches were recognized and traced to its bifurcation during the operation. The articular branches were addressed. The mucious content of the ganglion was typically found to be located within the subparaneurial compartment. Incision of the subparaneurial ganglion cyst was performed, and mucinous content was evacuated. At 2 months after the surgery, paralyzed peroneal nerve was recovered completely. Therefore, early diagnosis of intraneural ganglion, precise identification of the pathology, and proper treatment of the articular branch with atraumatic dissection of ganglion cyst are essential in the successful management of this rare lesion.

A mysterious case of complex regional pain syndrome in a 9-year-old girl

PURPOSE

To describe the clinical manifestation and the treatment of complex regional pain syndrome type II in childhood.

METHODS

Using information on the symptoms, diagnosis, rehabilitation and outcome of a young patient with complex regional pain syndrome type II.

RESULTS

A 9-year -old girl had severe pain in the region of the left foot, signs of a common fibular nerve entrapment, hyperalgesia not limited to the distribution of the injured nerve, weakness and temperature asymmetry unknown origin. She consulted few doctor's before she was given the right diagnosis of complex regional pain syndrome type II. Following the diagnosis the treatment started, it included intensive physiotherapy, electrical therapy and also supportive psychological therapy. Half a year later, the patient was free of the daily pain and returned to all physical activity without any restrictions.

CONCLUSIONS

The case report illustrates that peripheral nerve compression or injuries specifically, complex regional pain syndrome type II, should be taken into consideration when evaluating children with weakness and pain of the lower or upper limb. Implication of rehabilitation Raising the awareness of complex regional pain syndrome in the childhood is essential for an early diagnosis and appropriate treatment. The treatment options include early and adequate pain management inclusive electrical therapy and physiotherapy. Psychological therapy helps to avoid psychological stress reaction and the disease negative impact on the child's education and sports and the family social life.

Irreparable Radial Nerve Palsy Due to Delayed Diagnostic Management of a Giant Lipoma at the Proximal Forearm Resulting in a Triple Tendon Transfer Procedure: Case report and Brief Review of Literature

Background:

Non-traumatic radial nerve palsy (RNP) caused by local tumors is a rare and uncommon entity.

Methods:

A 62-year-old female presented with a left non-traumatic RNP, initially starting with weakness only. It was caused by a benign giant lipoma at the proximal forearm that was misdiagnosed over a period of 2 years. The slowly growth of the tumor led to an irreparable overstretching-related partial nerve disruption. For functional recovery of the patient, a triple tendon transfer procedure had to be performed.

Results:

Four months after surgery, the patient was completely able to perform her activities of daily living again. At the 10-months follow-up, strength of wrist extension, thumb's extension and abduction, and long fingers II-V extension had all improved to grade 4 in Medical Research Council scale (0-5). In order to restore motion, the patient reported that she would undergo the same triple tendon transfer procedure a second time where necessary. Due to the initially misdiagnosed tumor, there was an overall delayed duration of time for functional recovery of the patient.

Conclusion:

The triple tendon transfer procedure offers a useful and reliable method to restore functionality for patients sustaining irreparable RNP. However, it must be noted critically with our patient that this procedure probably would have been avoided. Initially, there was weakness only by entrapment of the radial nerve. RNP caused by local tumors are uncommon but known from the literature, and so it should be considered generally in differential diagnosis of non-traumatic RNP.

Postherpetic foot drop in an elderly case: undiagnosed diabetes mellitus?

Postherpetic neuralgia is the most commonly seen complication of herpes zoster, primarily in elderly and immunocompromised patients. However, motor involvement due to herpes zoster is very rare. A 65-year-old male patient presented with left leg pain, numbness and difficulty walking. He was diagnosed with having herpes zoster and treated with valacyclovir. Despite anti-convulsant and physical therapy, the patient developed foot drop and had an unexplained weight loss. Clinical and laboratory findings suggested previously undiagnosed diabetes mellitus. Three weeks after initiation of insulin treatment, he became normoglycemic, his pain was reduced, and foot drop disappeared almost completely. Postherpetic motor involvement as an unusual complication may signal an underlying systemic disease, particularly in elderly.

An evidence-based algorithm for the management of common peroneal nerve injury associated with traumatic knee dislocation

Traumatic knee dislocation is a complex ligamentous injury that may be associated with simultaneous vascular and neurological injury.Although orthopaedic surgeons may consider CPN exploration at the time of ligament reconstruction, there is no standardised approach to the management of this complex and debilitating complication.This review focusses on published evidence of the outcomes of common peroneal nerve (CPN) injuries associated with knee dislocation, and proposes an algorithm for the management. Cite this article: Deepak Samson, Chye Yew Ng, Dominic Power. An evidence-based algorithm for the management of common peroneal nerve injury associated with traumatic knee dislocation. EFORT Open Rev 2016;1:362-367. DOI: 10.1302/2058-5241.160012.

Diagnostic Cutoff Value for Ultrasonography of the Common Fibular Neuropathy at the Fibular Head

Objective

To establish the diagnostic cutoff value of ultrasonographic measurement for common fibular neuropathy (CFN) at the fibular head (FH).

Methods

Twenty patients with electrodiagnostically diagnosed CFN at the FH and 30 healthy controls were included in the study. The cross-sectional area (CSA) of sciatic nerve at mid-thigh level, common fibular nerve at popliteal fossa (PF), and common fibular (CF) nerve at FH were measured. Additionally, the difference of CF nerve CSA at the FH between symptomatic side and asymptomatic side (ΔSx–Asx), the ratio of CF nerve CSA at FH to at PF (FH/PF), and the ratio of CF nerve CSA at the FH symptomatic side to asymptomatic side (Ratio Sx–Asx) were calculated.

Results

CSA at the FH, FH/PF, ΔSx–Asx, and Ratio Sx–Asx showed significant differences between the patient and control groups. The cutoff value for diagnosing CFN at the FH was 11.7 mm² for the CSA at the FH (sensitivity 85.0%, specificity 90.0%), 1.70 mm² for the ΔSx–Asx (sensitivity 83.3%, specificity 97.0%), 1.11 for the FH/PF (sensitivity 47.1%, specificity 93.3%), and 1.24 for the Ratio Sx–Asx (sensitivity 72.2%, specificity 96.7%).

Conclusion

The ultrasonographic measurement and cutoff value could be a valuable reference in diagnosing CFN at the FH and improving diagnostic reliability and efficacy.

Progressive foot drop caused by below-knee compression stocking after spinal surgery

Foot drop is a debilitating condition, which may take many months to recover. The most common cause of foot drop is a neuropathy of the common peroneal nerve (CPN). However, similar symptoms can be caused by proximal lesions of the sciatic nerve, lumbar plexus or L5 nerve root. We present a rare and unusual case of a patient undergoing spinal surgery at the level of L5/S1 and presenting 4 weeks postoperatively with progressive foot drop. Although the initial concern was a postoperative lesion at L5, the cause for this delayed presentation was extrinsic compression of the CPN at the level of the fibular head by a tight-fitting below-knee thromboembolic deterrent stocking. Compression stockings are widely used in all branches of medicine and in the community. It is important to recognize this potential cause of progressive foot drop early as it is preventable by simple measures, which can significantly reduce morbidity.

Peroneal Nerve Palsy: Evaluation and Management

Peroneal nerve palsy is the most common entrapment neuropathy of the lower extremity. Numerous etiologies have been identified; however, compression remains the most common cause. Although injury to the nerve may occur anywhere along its course from the sciatic origin to the terminal branches in the foot and ankle, the most common site of compressive pathology is at the level of the fibular head. The most common presentation is acute complete or partial foot drop. Associated numbness in the foot or leg may be present, as well. Neurodiagnostic studies may be helpful for identifying the site of a lesion and determining the appropriate treatment and prognosis. Management varies based on the etiology or site of compression. Many patients benefit from nonsurgical measures, including activity modification, bracing, physical therapy, and medication. Surgical decompression should be considered for refractory cases and those with compressive masses, acute lacerations, or severe conduction changes. Results of surgical decompression are typically favorable. Tendon and nerve transfers can be used in the setting of failed decompression or for patients with a poor prognosis for nerve recovery.

Inhibition of soleus Hoffmann reflex by ankle-foot orthosis application in healthy volunteers

BACKGROUND

An ankle-foot orthosis is suggested to actively assist dorsiflexion of the foot by induction of a positive proprioceptive impact to ankle dorsiflexor muscles. However, an objective proof is missing.

OBJECTIVES

To assess the proprioceptive impact of an ankle-foot orthosis application by Hoffmann reflex recordings of the soleus muscle under static conditions. It was hypothesized that the use of an ankle-foot orthosis facilitated dorsiflexor motor function and thus a decreased the soleus Hoffmann reflex.

STUDY DESIGN

Experimental study in healthy volunteers, pre-post test design.

METHODS

In all, 20 healthy volunteers were enrolled in order to assess the proprioceptive impact of orthosis application. The Hoffmann reflex was recorded before, during, and after orthosis application.

RESULTS

Under orthosis application, the Hoffmann reflex significantly decreased as compared to before (p < 0.05) and after application (p < 0.05).

CONCLUSIONS

Findings indicate an inhibition of plantarflexors probably induced by facilitation of ankle dorsiflexors under static conditions. At first glance, it seems that foot orthoses primarily have a stabilizing effect on ankle joints in terms of simple mechanical bandages. However, the present results suggest an additional active impact on proprioceptive control.

CLINICAL RELEVANCE

The putative neuromodulatory effect on motor control may support the application of such ankle-foot orthoses in, for example, drop foot. Furthermore, the objective assessment of a neurophysiological mode of action of orthoses by Hoffmann reflex recordings might be an appropriate primary outcome parameter in clinical trials.

A Unique Case of Common Peroneal Nerve Entrapment

The authors present a case of a previously healthy 36-year-old man with a 3-day history of spontaneous complete right lower extremity foot drop. He noticed the symptoms immediately when he attempted to stand after waking from sleep. The patient had no history of similar symptoms, recent trauma, or peripheral nerve disease. Physical examination showed a slap foot gait, complete numbness of the lateral leg and dorsal foot, and 0/5 strength with ankle and great toe dorsiflexion and ankle eversion. Serum laboratory studies showed normal values. Nerve conduction studies confirmed increased latency and decreased amplitude of the right peroneal nerve at the knee, whereas electromyography showed denervation of the tibialis anterior and extensor digitorum brevis. Anteroposterior and lateral radiographs showed a normal right knee with the exception of a posterior fibular neck exostosis. Physical therapy, an ankle-foot orthosis, and a 5-day course of oral prednisone burst (50 mg) were prescribed. After 1 month of therapy without resolution, the patient underwent surgical release of the common peroneal nerve and excision of the bony prominence. Twelve days postoperatively, the patient had no sensory improvements but had improved findings on motor examination. Three months postoperatively, the patient had near-normal sensation to light touch in the superficial and deep peroneal nerves, with 5/5 strength and a normal gait. The patient returned to all activity without limitations. The authors present this unique case describing a fibro-osseous source of common peroneal compressive neuropathy and review the literature for spontaneous peroneal entrapment, highlighting the importance of prompt diagnosis and treatment.

The dangers of hemilithotomy positioning on traction tables: case report of a well-leg drop foot after contralateral femoral nailing

Background

Postoperative contralateral morbidities after fracture fixation surgery by hemilithotomy positioning on traction table is uncommon. We’d report a case of unexpected common peroneal nerve palsy developed on the contralateral side manifesting with drop foot after a common orthopedic femoral nailing.

Case report

A 28-year-old female sustained an unusual common peroneal nerve palsy manifesting contralateral drop foot after prolonged femoral nailing. Although the initial presentations were similar to the notorious well-leg compartment syndrome, a benign course with complete recovery in functions was observed 3 months later. After neurophysiologic exam and review of pertinent literature, this iatrogenic and transient dysfunction was delineated to be position-related neuropraxia.

Conclusion

Position adjustment at intervals or complete avoidance of prolonged knee hyperflexion is recommended to prevent contralateral common peroneal nerve morbidity.

Chiropractic care for foot drop due to peroneal nerve neuropathy

Peroneal nerve palsy is the most common entrapment neuropathy in the lower extremity, and the presentation of foot drop is a frequent initial manifestation of this disorder. This condition can have a marked influence on the patient's activities of daily living, and is classified as 'Impairment of Body Structure.' Current literature provides little direction to its evaluation and management, and the importance to differentially diagnose the causes of foot drop. Therefore, the purpose of this case report is to describe the application of chiropractic manipulative therapy, for a 14-year-old female with an insidious onset of foot drop.

[Peripheral nerve lesions of the lower leg due to tibiofibular ganglion]

Cystic formations around the knee are a common object of orthopedic treatment. When associated with neurological or vascular deficits further diagnostic imaging is required. This case study demonstrates the appearance of an intramuscular ganglion causing drop foot, arising from the tibio-fibular joint.

Manual therapy and neurodynamic mobilization in a patient with peroneal nerve paralysis: a case report

OBJECTIVE

The purpose of this case report is to describe a therapeutic intervention for peroneal nerve paralysis involving the sciatic nerve.

CLINICAL FEATURES

A 24-year-old man presented with peroneal nerve paralysis with decreased sensation, severe pain in the popliteal fossa, and steppage gait, which occurred 3 days prior to the consultation. Magnetic resonance imaging and electromyography confirmed lumbar disk herniation with sciatic common peroneal nerve entrapment in the popliteal fossa.

INTERVENTION AND OUTCOME

A combined treatment protocol of spinal and fibular head manipulation and neurodynamic mobilization including soft tissue work of the psoas and hamstring muscles was performed. Outcome measures were assessed at pretreatment, 1 week posttreatment, and 3-month follow-up and included numeric pain rating scale, range of motion, pressure pain threshold, and manual muscle testing. Treatment interventions were applied for 3 sessions over a period of 1 week. Results showed reduction of the patient's subjective pain and considerable improvement in range of motion, strength, and sensation in his left foot, which was restored to full function.

CONCLUSION

A combined program of spinal and fibular head manipulation and neurodynamic mobilization reduced pain, increased range of motion and strength, and restored full function to the left leg in this patient who had severe functional impairment related to a compressed left common peroneal nerve.

Foot drop caused by lumbar degenerative disease: clinical features, prognostic factors of surgical outcome and clinical stage

OBJECTIVE

The purpose of this study was to analyze the clinical features and prognostic factors of surgical outcome of foot drop caused by lumbar degenerative disease and put forward the clinical stage.

METHODS

We retrospectively reviewed 135 patients with foot drop due to lumbar degenerative disease. The clinical features and mechanism were analyzed. Age, sex, duration of palsy, preoperative muscle strength of tibialis anterior (TA), sensation defect of affected lower limb, affected foot, diagnosis and compressed nerve roots were recorded and compared with surgical outcome.

RESULTS

Foot drop was observed in 8.1% of all inpatients of lumbar degenerative disease. L5 nerve root compression was observed in 126 of all 135 patients (93.3%). Single, double and triple roots compression was observed respectively in 43, 83, and 9 patients (31.9%, 61.5%, and 6.6%). But there was no significant relationship between preoperative muscle strength of TA and the number of compressed roots. The muscle strength of TA was improved in 113 (83.7%) patients after surgery, but it reached to >=4 in only 21 (15.6%) patients. Improvement of the muscle strength of TA was almost stable at the 6-month follow-up. At the last follow-up, the muscle strength of TA was 1, 2, 3, 4, 5 respectively in 28, 24, 62, 13, 8 patients. Multivariate logistic regression showed duration of palsy (p=0.0360, OR=2.543), preoperative muscle strength of TA (p=0.0064, OR=5.528) and age (p=0.0309, OR=3.208) were factors that influenced recovery following an operation.

CONCLUSIONS

L5 nerve root was most frequently affected. The muscle strength of TA improved in most patients after surgery, but few patients can get a good recovery from foot drop. Patients of shorter duration of palsy, better preoperative muscle strength of TA and younger age showed a better surgical outcome.

Clinical characteristics of peroneal nerve palsy by posture

Objective

Posture induced common peroneal nerve (CPN) palsy is usually produced during the prolonged squatting or habitual leg crossing while seated, especially in Asian culture and is manifested by the onset of foot drop. Because of its similarity to discogenic foot drop, patients may be diagnosed with a lumbar disc disorder, and in some patients, surgeons may perform unnecessary examinations and even spine surgery. The purpose of our study is to establish the clinical characteristics and diagnostic assessment of posture induced CPN palsy.

Methods

From June 2008 to June 2012, a retrospective study was performed on 26 patients diagnosed with peroneal nerve palsy in neurophysiologic study among patients experiencing foot drop after maintaining a certain posture for a long time.

Results

The inducing postures were squatting (14 patients), sitting cross-legged (6 patients), lying down (4 patients), walking and driving. The mean prolonged neural injury time was 124.2 minutes. The most common clinical presentation was foot drop and the most affected sensory area was dorsum of the foot with tingling sensation (14 patients), numbness (8 patients), and burning sensation (4 patients). The clinical improvement began after a mean 6 weeks, which is not related to neural injury times. Electrophysiology evaluation was performed after 2 weeks later and showed delayed CPN nerve conduction study (NCS) in 24 patients and deep peroneal nerve in 2 patients.

Conclusion

We suggest that an awareness of these clinical characteristics and diagnostic assessment methods may help clinicians make a diagnosis of posture induced CPN palsy and preclude unnecessary studies or inappropriate treatment in foot drop patients.

Assessment of hip abductor power in patients with foot drop: a simple and useful test to differentiate lumbar radiculopathy and peroneal neuropathy

STUDY DESIGN

Prospective study on a diagnostic test.

OBJECTIVE

To determine the usefulness of hip abductor power assessment in the differential diagnosis of foot drop due to lumbar radiculopathy and peroneal neuropathy.

SUMMARY OF BACKGROUND DATA

Foot drop arises from various neuromuscular conditions. Differential diagnosis obvious in the typical case, however, is often inconclusive. There are few reports regarding the validity of hip abductor power in the differential diagnosis of foot drop.

METHODS

Sixty-one consecutive patients who presented with tibialis anterior weakness Medical Research Council grade of less than 3 were included and underwent neurological examination including the assessment of hip abductor power. Patient demographics, mechanism and pattern of foot drop, neurological findings, and the diagnoses were recorded. Final diagnoses were established on the basis of clinical information, imaging studies, and electrophysiological study in limited cases. Validity and reliability of the hip abductor power assessment in the differential diagnosis of foot drop due to lumbar radiculopathy and peroneal neuropathy were evaluated.

RESULTS

There were 44 men and 17 women, with a mean age of 46.8 years (19-77 yr). The final diagnosis was peroneal neuropathy in 28 patients, lumbosacral plexopathy in 9 patients, lumbar radiculopathy in 21 patients, and sciatic nerve disorder in 3 patients. Concomitant hip abductor weakness was found in 85.7% of lumbar radiculopathy and 3.6% of peroneal neuropathy. The sensitivity and specificity of hip abductor power in the differential diagnosis of foot drop due to the lumbar radiculopathy and peroneal neuropathy were 85.7% and 96.4%, respectively. The positive and negative predictive values were 94.7% and 90%, respectively.

CONCLUSION

Assessment of hip abductor strength is a simple and useful method in the differential diagnosis of foot drop due to lumbar radiculopathy and peroneal neuropathy.

Magnetic resonance neurography of common peroneal (fibular) neuropathy

OBJECTIVE

To examine diagnostic accuracy of semiquantitative and qualitative magnetic resonance neurography criteria in common peroneal nerve (CPN) neuropathy.

MATERIALS AND METHODS

Institutional review board approval was obtained with a waiver of informed consent for this Health Insurance Portability and Accountability Act-compliant retrospective study. A review of 28 knees in 28 subjects (12 males and 16 females; age range, 13-84 years; mean [SD] age, 42 [20] years) who had undergone magnetic resonance neurography of the knee was performed. Thirteen patients who had a final diagnosis of CPN were classified as cases, and 15 patients who lacked a final diagnosis of CPN neuropathy were classified as controls. Morphological characteristics of the CPN, including nerve T2 signal intensity, nerve size, nerve course, fascicles morphology, regional muscle edema, and fatty infiltration, and an overall assessment of the CPN as being normal or abnormal were evaluated by 2 independent radiologists blinded to the clinical history. Overall sensitivity, specificity, and accuracy compared against our reference standards were expressed as percentages. Interobserver agreements were assessed using linear weighted κ statistics.

RESULTS

Common peroneal nerve T2 signal abnormality had the highest sensitivity (77%) in identifying CPN neuropathy. Except for T2 signal abnormality, overall specificity for the nerve morphological parameters and muscle denervation change assessed was fairly high, ranging from 94% to 100%. The consensus accuracy ranged from 68% to 79% for the morphological characteristics assessed. The interobserver reproducibility was very good (k = 0.90 to 0.91) for assessment of regional muscle denervation changes and moderate (k = 0.46 to 0.59) for morphological CPN characteristics.

CONCLUSION

Magnetic resonance neurography is a useful modality in supplementing the diagnosis of CPN. Using predefined classification criteria helps standardize the morphological criteria of CPN neuropathy diagnosis.

Peroneal neuropathy after tibio-fibular fracture

Objective

To investigate the injury mechanism in patients who had peroneal neuropathy after a tibio-fibular fracture and the correlation between tibio-fibular fracture location and the severity of the peroneal neuropathy by using electrodiagnosis.

Method

Thirty-four patients with peroneal neuropathy after a tibio-fibular fracture were recruited for this study. Their medical records, radiologic and electrodiagnostic findings were investigated retrospectively. They were divided into 2 groups according to the existence of a fibular head fracture. The group of patients without the fibular head fracture was further classified according to the criteria of Orthopedic Trauma Association (OTA) classification. The differences between the two groups in the severity of the neuropathy and electrodiagnostic findings were evaluated.

Results

Nine cases (26.5%) had tibio-fibular fractures with a coexisting fibular-head fracture and 25 cases (73.5%) had tibio-fibular fractures without fractures in the fibular-head area. There was no statistical significance in the correlation between the existence of the fibular head fracture and the severity of the electrodiagnostic findings. Neither was there any statistically significant relationship between the site of the tibio-fibular fracture and the severity of the peroneal neuropathy (p>0.05).

Conclusion

This study showed there were numerous cases with common peroneal neuropathy after tibiofibular fracture without a coexisting fibular-head fracture, which shows the importance of indirect nerve injury mechanisms as well as that of direct nerve injury as a cause of peroneal neuropathy. In addition, this study showed that there was no statistically significant correlation between the site of tibio-fibular fracture and the severity of peroneal neuropathy.

Electrodiagnostic evaluation of lower extremity mononeuropathies

This article discusses the anatomy of lower limb mononeuropathies and reviews the general approach to evaluating patients in the electrodiagnostic laboratory with suspected mononeuropathies of the lower limb. Through illustrative cases of patients presenting with a floppy foot, buckling knee, or painful foot, the approaches using nerve conduction studies and needle electromyography are reviewed, and the pattern of findings of peroneal, tibial, sciatic, femoral, and obturator neuropathies is shown.