Peroneal neuropathy after weight loss

Anesthetic Considerations for Patients with Hereditary Neuropathy with Liability to Pressure Palsies: A Narrative Review

Hereditary neuropathy with liability to pressure palsies (HNPP) is an autosomal dominant demyelinating neuropathy characterized by an increased susceptibility to peripheral nerve injury from trauma, compression, or shear forces. Patients with this condition are unique, necessitating distinct considerations for anesthesia and surgical teams. This review describes the etiology, prevalence, clinical presentation, and management of HNPP and presents contemporary evidence and recommendations for optimal care for HNPP patients in the perioperative period. While the incidence of HNPP is reported at 7-16:100,000, this figure may be an underestimation due to underdiagnosis, further complicating medicolegal issues. With the subtle nature of symptoms associated with HNPP, patients with this condition may remain unrecognized during the perioperative period, posing significant risks. Several aspects of caring for this population, including anesthetic choices, intraoperative positioning, and monitoring strategy, may deviate from standard practices. As such, a tailored approach to caring for this unique population, coupled with meticulous preoperative planning, is crucial and requires a multidisciplinary approach.

Peroneal mononeuropathy and polyneuropathy in adolescents with Anorexia Nervosa: a case report and literature review

Peroneal neuropathy and polyneuropathy are displayed with a variable percentage in subjects affected by eating disorders and in particular by anorexia nervosa. Actually, little is known on features of these complications during the paediatric age. We describe the case of a female adolescent with right peroneal palsy and subclinical polyneuropathy associated with anorexia nervosa (AN). We review previous research about peroneal mononeuropathy and polyneuropathy associated with AN, and we develop a diagnostic and therapeutic protocol to help clinicians recognize and treat these disorders.

Fibular (peroneal) neuropathy

Fibular neuropathy has variable presenting features depending on the site of the lesion. Anatomical features make it susceptible to injury from extrinsic factors, particularly the superficial location of the nerve at the head of the fibula. There are many mechanisms of compression or other traumatic injury of the fibular nerve, as well as entrapment and intrinsic nerve lesions. Intraneural ganglion cysts are increasingly recognized when the mechanism of neuropathy is not clear from the medical history. Electrodiagnostic testing can contribute to the localization as well as the characterization of the pathologic process affecting the nerve. When the mechanism of injury is unclear from the analysis of the presentation, imaging with MRI and ultrasound may identify nerve lesions that warrant surgical intervention. The differential diagnosis of foot drop includes fibular neuropathy and other neurologic conditions, which can be distinguished through clinical and electrodiagnostic assessment. Rehabilitation measures, including ankle splinting, are important to improve function and safety when foot drop is present. Fibular neuropathy is less frequently painful than many other nerve lesions, but when it is painful, neuropathic medication may be required. Failure to spontaneously recover or the detection of a mass lesion may require surgical management.

Slimmer's Palsy Following Weight Loss Associated With Metastatic Breast Cancer: A Case Report

Common peroneal neuropathy (CPN), also known as Slimmer's Palsy, is an isolated peripheral neuropathy typically associated with rapid weight loss resulting in loss of adipose tissue and subsequent nerve compression at the fibular head and is up to three times more common in individuals with malignancy. In this case report, we describe the diagnosis of CPN in a 54-year-old female with a 2.5-month history of atraumatic left foot drop and left ankle paresthesias, preceded by a 35-40 pound weight loss over the prior 3.5 month period in the setting of metastatic breast cancer.

Sciatic and tibial neuropathies

The sciatic nerve is the body's largest peripheral nerve. Along with their two terminal divisions (tibial and fibular), their anatomic location makes them particularly vulnerable to trauma and iatrogenic injuries. A thorough understanding of the functional anatomy is required to adequately localize lesions in this lengthy neural pathway. Proximal disorders of the nerve can be challenging to precisely localize among a range of possibilities including lumbosacral pathology, radiculopathy, or piriformis syndrome. A correct diagnosis is based upon a thorough history and physical examination, which will then appropriately direct adjunctive investigations such as imaging and electrodiagnostic testing. Disorders of the sciatic nerve and its terminal branches are disabling for patients, and expert assessment by rehabilitation professionals is important in limiting their impact. Applying techniques established in the upper extremity, surgical reconstruction of lower extremity nerve dysfunction is rapidly improving and evolving. These new techniques, such as nerve transfers, require electrodiagnostic assessment of both the injured nerve(s) as well as healthy, potential donor nerves as part of a complete neurophysiological examination.

Neuropathy in paediatric type 1 diabetes mellitus - clinical characterization and analysis of risk factors in the diabetes prospective follow-up registry DPV (Diabetes-Patienten-Verlaufsdokumentation)-registry

OBJECTIVES

Data on the prevalence, clinical features and risk factors associated with paediatric diabetic neuropathy (DN) are scarce.

METHODS

We retrospectively analysed data from the DPV registry, including patients under 20 years of age, treated for type 1 diabetes mellitus (T1D) between 2005 and 2021. Patients with non-diabetic neuropathy were excluded. Data came from centres in Austria, Germany, Luxembourg and Switzerland.

RESULTS

1,121 of the 84,390 patients included had been diagnosed with DN. Univariate analysis showed patients with DN to be older and predominantly female, with a longer duration of T1D, higher insulin dosages per kg and day, lower rates of insulin pump therapy, higher postprandial glucose-, higher HbA_1c-and higher cholesterol levels, and higher diastolic and systolic blood pressure values. There was also a larger proportion of smokers and higher prevalence of diabetic retinopathy. Median duration of diabetes at diagnosis of DN was 8.3 years. Multivariable analysis, adjusted for demographics revealed an increased risk for DN among female patients and those who were older, underweight (BMI-SDS), smoked cigarettes or had a longer duration of T1D or higher levels of HbA_1c and postprandial blood glucose. The presence of retinopathy and higher cholesterol levels were also linked to increased risk while not-using insulin pump therapy was not.

CONCLUSIONS

DN can develop after just a short duration of T1D. Prevention may be achieved by a lowering of HbA_1c-and postprandial glucose levels through improved glycaemic control. This warrants further investigation. The slight female predominance suggests further hormonal and genetic etiological factors.

Conservative versus surgical treatment of foot drop in peroneal nerve entrapment: rationale and design of a prospective, multi-centre, randomized parallel-group controlled trial

BACKGROUND

High-quality evidence is lacking to support one treatment strategy over another in patients with foot drop due to peroneal nerve entrapment. This leads to strong variation in daily practice.

METHODS/DESIGN

The FOOTDROP (Follow-up and Outcome of Operative Treatment with Decompressive Release Of The Peroneal nerve) trial is a randomized, multi-centre study in which patients with peroneal nerve entrapment and persistent foot drop, despite initial conservative treatment, will be randomized 10 (± 4) weeks after onset between non-invasive treatment and surgical decompression. The primary endpoint is the difference in distance covered during the 6-min walk test between randomization and 9 months later. Time to recovery is the key secondary endpoint. Other secondary outcome measures encompass ankle dorsiflexion strength (MRC score and isometric dynamometry), gait assessment (10-m walk test, functional ambulation categories, Stanmore questionnaire), patient-reported outcome measures (EQ5D-5L), surgical complications, neurological deficits (sensory changes, motor scores for ankle eversion and hallux extension), health economic assessment (WPAI) and electrodiagnostic assessment.

DISCUSSION

The results of this randomized trial may elucidate the role of surgical decompression of the peroneal nerve and aid in clinical decision-making.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04695834. Registered on 4 January 2021.

Slimmer’s palsy following an intermittent fasting diet

Background

Isolated common peroneal neuropathy (CPN) is the most common lower extremity mononeuropathy and the third most common mononeuropathy overall in adults. It often associated with multiple aetiologies, such as trauma, hereditary neuropathies and iatrogenic causes. We report a rare case of acute bilateral foot drop in a late adolescent female following a rapid weight loss attributable to intermittent fasting diet.

Case presentation

A 19-year-old female presented with worsening bilateral foot drop following a rapid intentional weight loss by intermittent fasting diet. She lost 20% of her baseline bodyweight within a period of 4 months. Systemic disease and metabolic screenings for neuropathy differentials were unremarkable. Electrophysiological studies revealed severe entrapment neuropathy involving bilateral common peroneal nerves (CPN). Her confounding risk factors for CPN injury include contact sport activities and habitual leg crossing during sitting. Following a dietary modification and physical therapy she achieved complete recovery of weakness and function on follow-up.

Conclusions

In a patient with bilateral PN rapid weight loss, prognosis is good and complete neurologic recovery can be attained through combination of cessation of extreme diet and physical therapy.

Body Weight May Have a Role on Neuropathy and Mobility after Moderate to Severe COVID-19: An Exploratory Study

Background and Objectives: Among the extra-pulmonary manifestations of COVID-19, neuromuscular signs and symptoms are frequent. We aimed to assess the correlation between neuromuscular abnormalities (electrophysiological) and mobility measures (Berg Balance Scale and Timed-Up-and-Go test) twice, at least 6 weeks after hospital discharge and 6 months later, taking into account cognitive performance, nutrition, muscle strength, and submaximal exercise capacity. Materials and Methods: 43 patients (51.4 ± 9.3 years old) accepted to participate in the study; they had a dyspnea score ≤ 3 (Borg scale), and no history of neurology/neuromuscular/orthopedic disorders, but high frequency of overweight/obesity and weight loss during hospital stay. The two evaluations included physical examination, cognitive assessment, nutritional evaluation, muscle strength (hand-grip and quadriceps dynamometry), electromyography, Barthel Index, Six-Minute- Walk-Test (6MWT), Berg Balance Scale and Timed-Up-and-Go test. Bivariate and repeated measures covariance analyses were performed (significance level of 0.05). Results: Electrophysiological abnormalities were evident in 67% of the patients, which were associated with diminished performance on the 6MWT, the Berg Balance Scale and the Timed-Up-and-Go test. At each evaluation and between evaluations, scores on the Berg Balance Scale were related to the body mass index (BMI) at hospital admission and the 6MWT (MANCoVA R ≥ 0.62, p = 0.0001), while the time to perform the Timed-Up-and-Go test was related to the electrophysiological abnormalities, weight loss during hospital stay, sex, handgrip strength, and the 6MWT (MANCoVA, R ≥ 0.62, p < 0.0001). We concluded that, after hospital discharge, patients with moderate to severe COVID-19 may have neuromuscular abnormalities that can be related to BMI/weight loss, and contribute to mobility decrease. In patients with moderate to severe COVID-19 and high BMI/ large weight loss, neuromuscular and intended mobility assessments could be required to provide early rehabilitation. Apart from the 6MWT, handgrip dynamometry and the Timed-Up-and-Go test were useful tools to quickly assess fitness and mobility.

Surgical Treatment of Foot Drop: Pathophysiology and Tendon Transfers for Restoration of Motor Function

Foot drop is a common condition that may impact physical function and health-related quality of life. A detailed clinical history and physical examination are critical components of the initial evaluation of patients presenting with foot drop. Patients with refractory foot drop without spontaneous recovery of motor deficits, delayed presentation greater than 12 months from injury, or neural lesions that are not amenable to or have failed nerve reconstruction may be candidates for tendon transfers to restore active ankle dorsiflexion. The modified Bridle procedure is a dynamic tendon transfer that has demonstrated excellent functional outcomes in patients with refractory foot drop.

Childhood focal compressive mononeuropathies during the COVID-19 pandemic in Buenos Aires, Argentina

Introduction/Aims

Focal peripheral neuropathies are infrequently seen in pediatric patients. The COVID‐19 pandemic has disrupted normal life for many people, including complete lockdowns and school closing for long periods of time in many countries, which prompted children to stay at home. Our aim is to assess whether there has been an increased incidence of focal compressive peripheral neuropathies in the pediatric population during COVID‐19–associated lockdown.

Methods

Clinical, electrophysiological, and imaging characteristics were reviewed for patients referred to the electrodiagnostic (EDx) laboratory with suspicion of a focal neuropathy. The incidence of focal compressive peripheral neuropathies seen during the period of March to September 2020 was compared with the same time period in 2019.

Results

An increased incidence of focal neuropathies was seen in 2020 (31%) compared with 2019 (6.8%). During 2020, 7 fibular (peroneal) mononeuropathies and 2 ulnar neuropathies were diagnosed. Most patients with focal neuropathies were underweight and acknowledged prolonged screen time periods. Electrophysiological findings consisted of mostly demyelinating lesions with an overall good clinical outcome.

Discussion

In this study we raise awareness about a possible increased incidence of focal compressive peripheral neuropathies in children during COVID‐19–associated lockdown, which may be prevented with changing positions during sedentary activities.

A Novel Capsule Lumbar Interbody Fusion (CLIF) in Treating Foot Drop due to Lumbar Degenerative Diseases: a Prospective, Observational Study

Objective

This present study aimed to explore the clinical effects of a novel capsule lumbar interbody fusion (CLIF) on foot drop due to lumbar degenerative diseases.

Methods

Between June 2018 and January 2019, a total of 27 patients admitted to our department with lumbar degenerative diseases with associated foot drop were prospectively enrolled. Given the selection of surgical technique, patients were divided into traditional TLIF group and CLIF group. We assessed patients' neurological status using JOA and VAS score, tibialis anterior muscle strength using MMT score, diameter and hemodynamic parameters of the L5 nerve root using intraoperative ultrasonography (IoUS), and related radiological parameters of the lumbar spine. Operation time, blood loss, and surgery-associated complications were also recorded.

Results

The median duration of follow-up was 150 (6–1460) months. At the final follow-up, all patients acquired satisfactory improvement of neurological function. However, patients in the CLIF group showed better early recovery of foot drop three months after operation than those in the TLIF group, with 75% excellent rate. In addition, IoUS suggested that the diameter and hemodynamic parameters of the L5 nerve root were improved better in the CLIF group, which may suggest the correlation between the recovery of foot drop and the status of L5 nerve root. No severe complications were encountered with CLIF.

Conclusions

Our preliminary study revealed that the axial tension of L5 nerve root may be involved in the pathological mechanism of foot drop. The novel technique of CLIF can shorten the lumbar spine and can be effective and safe for the treatment of foot drop due to lumbar degeneration-related diseases.

An Update on Peroneal Nerve Entrapment and Neuropathy

Peroneal neuropathy is the most common compressive neuropathy of the lower extremity. It should be included in the differential diagnosis for patients presenting with foot drop, the pain of the lower extremity, or numbness of the lower extremity. Symptoms of peroneal neuropathy may occur due to compression of the common peroneal nerve (CPN), superficial peroneal nerve (SPN), or deep peroneal nerve (DPN), each with different clinical presentations. The CPN is most commonly compressed by the bony prominence of the fibula, the SPN most commonly entrapped as it exits the lateral compartment of the leg, and the DPN as it crosses underneath the extensor retinaculum. Accurate and timely diagnosis of any peroneal neuropathy is important to avoid progression of nerve injury and permanent nerve damage. The diagnosis is often made with physical exam findings of decreased strength, altered sensation, and gait abnormalities. Motor nerve conduction studies, electromyography studies, and diagnostic nerve blocks can also assist in diagnosis and prognosis. First-line treatments include removing anything that may be causing external compression, providing stability to unstable joints, and reducing inflammation. Although many peroneal nerve entrapments will resolve with observation and activity modification, surgical treatment is often required when entrapment is refractory to these conservative management strategies. Recently, additional options including microsurgical decompression and percutaneous peripheral nerve stimulation have been reported; however, large studies reporting outcomes are lacking.

Varied Presentation and Importance of MR Neurography of the Common Fibular Nerve in Slimmer's Paralysis

Slimmer's paralysis refers to a common fibular nerve palsy caused by significant and rapid weight loss. This condition usually results from entrapment of the common fibular nerve due to loss of the fat pad surrounding the fibular head. Several etiologies of common fibular nerve palsy have been proposed, including trauma, surgical complications, improperly fitted casts or braces, tumors and cysts, metabolic syndromes, and positional factors. We present 5 cases of slimmer's paralysis in patients who had lost 32–57 kg in approximately 1 year. In 2 cases, MR neurogram of the knee demonstrated abnormalities of the common fibular nerve at the fibular head. Two patients underwent a common fibular nerve decompression at the fibular head and attained improved gait and sensorimotor function. Weight loss, diabetes mellitus, and immobilization may have contributed to slimmer's paralysis in 1 case. Awareness of slimmer's paralysis in patients who have lost a significant amount of weight in a short period of time is imperative to detect and treat a fibular nerve neuropathy that may ensue.

Evidence in peroneal nerve entrapment: A scoping review

BACKGROUND AND PURPOSE

Daily management of patients with foot drop due to peroneal nerve entrapment varies between a purely conservative treatment and early surgery, with no high-quality evidence to guide current practice. Electrodiagnostic (EDX) prognostic features and the value of imaging in establishing and supplementing the diagnosis have not been clearly established.

METHODS

We performed a literature search in the online databases MEDLINE, Embase, and the Cochrane Library. Of the 42 unique articles meeting the eligibility criteria, 10 discussed diagnostic performance of imaging, 11 reported EDX limits for abnormal values and/or the value of EDX in prognostication, and 26 focused on treatment outcome.

RESULTS

Studies report high sensitivity and specificity of both ultrasound (varying respectively from 47.1% to 91% and from 53% to 100%) and magnetic resonance imaging (MRI; varying respectively from 31% to 100% and from 73% to 100%). One comparative trial favoured ultrasound over MRI. Variable criteria for a conduction block (>20%-≥50) were reported. A motor conduction block and any baseline compound motor action potential response were identified as predictors of good outcome. Based predominantly on case series, the percentage of patients with good outcome ranged 0%-100% after conservative treatment and 40%-100% after neurolysis. No study compared both treatments.

CONCLUSIONS

Ultrasound and MRI have good accuracy, and introducing imaging in the standard diagnostic workup should be considered. Further research should focus on the role of EDX in prognostication. No recommendation on the optimal treatment strategy of peroneal nerve entrapment can be made, warranting future randomized controlled trials.

Bilateral common peroneal neuropathy due to rapid and marked weight loss after biliary surgery: A case report

BACKGROUND

The causes of peroneal neuropathy are various, but are rarely due to weight loss. Bilateral peroneal neuropathy caused by weight loss after surgery has been reported only after bariatric surgery and there were no reports associated with other abdominal surgery. In this report, we describe a case of the bilateral peroneal neuropathy that occurred due to marked weight loss after biliary surgery.

CASE SUMMARY

A 58-year-old male did not receive adequate nutritional support after biliary surgery, and showed a massive weight loss over a short period of time (body mass index; 24.1 kg/m² to 20.5 kg/m² for 24 d). Then, foot drop occurred on both sides. Physical examination, electromyography (EMG) and magnetic resonance imaging studies were conducted and he was diagnosed as bilateral common peroneal neuropathy around the fibular head level. The patient was treated electrical stimulation therapy on both lower legs along with exercise therapy, and received sufficient oral nutritional support. The patient gradually recovered to his original weight, and the power of the dorsiflexor of bilateral ankles improved after conservative treatment. In addition, the follow-up EMG showed signs of improvement.

CONCLUSION

Any abdominal surgery that may have rapid and marked weight loss can lead to peroneal neuropathy as a complication.

New evidence for secondary axonal degeneration in demyelinating neuropathies

Development of peripheral nervous system (PNS) myelin involves a coordinated series of events between growing axons and the Schwann cell (SC) progenitors that will eventually ensheath them. Myelin sheaths have evolved out of necessity to maintain rapid impulse propagation while accounting for body space constraints. However, myelinating SCs perform additional critical functions that are required to preserve axonal integrity including mitigating energy consumption by establishing the nodal architecture, regulating axon caliber by organizing axonal cytoskeleton networks, providing trophic and potentially metabolic support, possibly supplying genetic translation materials and protecting axons from toxic insults. The intermediate steps between the loss of these functions and the initiation of axon degeneration are unknown but the importance of these processes provides insightful clues. Prevalent demyelinating diseases of the PNS include the inherited neuropathies Charcot-Marie-Tooth Disease, Type 1 (CMT1) and Hereditary Neuropathy with Liability to Pressure Palsies (HNPP) and the inflammatory diseases Acute Inflammatory Demyelinating Polyneuropathy (AIDP) and Chronic Inflammatory Demyelinating Polyneuropathy (CIDP). Secondary axon degeneration is a common feature of demyelinating neuropathies and this process is often correlated with clinical deficits and long-lasting disability in patients. There is abundant electrophysiological and histological evidence for secondary axon degeneration in patients and rodent models of PNS demyelinating diseases. Fully understanding the involvement of secondary axon degeneration in these diseases is essential for expanding our knowledge of disease pathogenesis and prognosis, which will be essential for developing novel therapeutic strategies.

A Rare Etiology of Bilateral Foot Drop: Weight Loss

Excessive weight loss especially when it occurs in a short period of time can lead to some neurological problems including peroneal nerve palsy. Foot drop is the most common presentation of peroneal neuropathies and they rarely occur bilaterally at the same time. Herein, we presented a 46-year-old male patient who developed bilateral foot drop after losing 25 kgs. in two months with an intensive weight reduction diet which was advised by a doctor as a therapeutic regimen. The electromyographic study confirmed the bilateral entrapment neuropathy of the peroneal nerves at the fibular necks and these findings could not be attributed to any other factor except the weight loss. After a balanced diet and a physiotherapy programme, he recovered completely. This case highlights an uncommon but a well documented etiology of peroneal neuropathies. Being aware of this complication and close follow-up are important for the prognosis of these patients. Keywords: foot deformities, peroneal neuropathies, weight loss

Drop Foot Secondary to a Peroneal Intraneural Ganglion Connected to the Superior Tibiofibular Joint: A Case Report

Peroneal neuropathy is the most frequent mononeuropathy of the lower extremity. Intraneural ganglion cysts (INGCs) are among rare causes of peroneal nerve palsy. According to the articular (synovial) theory, the articular branch plays the key role in the pathogenesis. Patients present with pain around the fibular head and neck, motor weakness resulting in foot drop and paresthesia in the anterolateral calf and foot. Ultrasonography (US) and MRI are both useful in the diagnosis, but MRI is the best imaging modality in the demonstration of the articular connection and the relation of the cyst with adjacent structures, even without special neurography sequences. We present a 32-year-old male patient referred to our neurosurgery clinic with suspicion of lumbar radiculopathy. He presented with right foot drop which began 3 weeks prior. On examination, there was 90% loss in the ankle dorsiflexion and finger extension. Ankle eversion was also weakened. There was no low back or posterolateral thigh pain to suggest L5 radiculopathy and sciatic neuropathy. Following negative lumbar spine MRI, peripheral neuropathy was concerned. Electrodiagnostic evaluations findings were consistent with acute/subacute common peroneal nerve (CPN) axonal neuropathy. Subsequent MRI of knee showed a homogeneous, thin-walled tubular cystic lesion, extending along the course of the CPN and its articular branch. Full recovery of the neuropathy was achieved with early diagnosis and decompression via microsurgical epineurotomy. The diagnosis of INGC was confirmed by histopathologic examination. INGCs, although rare, should also be considered in the differential diagnosis of peripheral mononeuropathies.

Lower extremity entrapment neuropathies

Entrapment neuropathies are frequently encountered by rheumatologists, not only because they are common but also because of their association with certain rheumatological and systemic disorders. Recognizing entrapment neuropathy early can help avoid progressive neurological deficits, as well as facilitate appropriate treatment measures, which can effectively minimize a patient's symptoms. Entrapment neuropathies may be distinguished from other musculoskeletal causes of lower extremity pain by identifying characteristic patterns of weakness and/or sensory loss, so a focused bedside neurological examination is key for diagnosis. In this chapter, we review the most common entrapment neuropathies that occur in the lower extremities, review the relevant neuroanatomy, outline a diagnostic approach to distinguish them from other mimics, and highlight appropriate management options.

Identifying Common Peroneal Neuropathy before Foot Drop

BACKGROUND

Common peroneal neuropathy shares the same pathophysiology as carpal tunnel syndrome. However, management is often delayed because of the traditional misconception of recognizing foot drop as the defining symptom for diagnosis. The authors believe recognizing common peroneal neuropathy before foot drop can relieve pain and help improve quality of life.

METHODS

One hundred eighty-five patients who underwent surgical common peroneal neuropathy decompression between 2011 and 2017 were included. The mean follow-up time was 249 ± 28 days. Patients were classified into two stages of severity based on clinical presentation: pre-foot drop and overt foot drop. Demographics, presenting symptoms, clinical signs, electrodiagnostic studies and response to surgery were compared between these two groups. Multivariate regression analysis was used to identify variables that predicted outcome following surgery.

RESULTS

Overt foot drop patients presented with significantly lower preoperative motor function (percentage of patients with Medical Research Council grade ≤ 1: overt foot drop, 90 percent; pre-foot drop, 0 percent; p < 0.001). Pre-foot drop patients presented with a significantly higher preoperative pain visual analogue scale score (pre-foot drop, 6.2 ± 0.2; overt foot drop, 4.6 ± 0.3; p < 0.001) and normal electrodiagnostic studies (pre-foot drop, 31.4 percent; overt foot drop, 0.1 percent). Postoperatively, both groups of patients showed significant improvement in quality-of-life score (pre-foot drop, 2.6 ± 0.3; overt foot drop, 2.7 ± 0.3). Patients with obesity or a traumatic cause for common peroneal neuropathy were less likely to have improvements in quality of life after surgical decompression.

CONCLUSION

Increased recognition of common peroneal neuropathy can aid early management, relieve pain, and improve quality of life.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, II.

Hereditary neuropathy with liability to pressure palsies

Hereditary neuropathy with liability to pressure palsies (HNPP) is characterized by recurrent sensory and motor neuropathy in individual nerves starting in adolescence or young adulthood, focal conduction abnormalities at entrapment sites on nerve conduction studies, and sausage-like swellings (tomacula) of the myelin sheaths by nerve biopsy. It is characterized genetically by the deletion of the chromosome 17p11.2-p12 region including the peripheral myelin protein-22 gene in the overwhelming majority of cases. HNPP may be frequently underdiagnosed or misdiagnosed owing to the heterogeneity of clinical and electrophysiological appearance. The main objective of this review is to describe clinical manifestations, paraclinical features such as electrodiagnostic, pathological, radiological and genetics findings, and possible treatments.

Entrapment Neuropathies of the Lower Extremity

Entrapment neuropathies in the lower limbs are a common neurologic problem and may present in any medical setting. Accurate identification and management of these nerve palsies can prevent pain, sensory loss, incoordination, and muscle weakness that may significantly affect a patient's functional mobility. In this article, the authors focus on the cause, signs and symptoms, diagnosis, and treatment of select entrapment neuropathies of the lower extremity, including palsies of the common peroneal, lateral femoral cutaneous, femoral, and posterior tibial nerves.

Genetic epidemiology, demographic, and clinical characteristics of Charcot-Marie-tooth disease in the island of Gran Canaria (Spain)

Charcot-Marie-Tooth (CMT) disease is the most common hereditary neuromuscular disorder. This study involves the entire known CMT patient registry in Gran Canaria, represented by 256 patients belonging to 79 unrelated families, who were clinically and genetically characterized, along with physical and neurophysiological evaluation on 181 and 165 patients, respectively. Complete genotyping showed an estimated prevalence of CMT disease of 30.08/100 000 (95% confidence interval [CI] = 26.5;33.9), corresponding mainly (78.5%) to CMT1A (23.6/100 000) and hereditary neuropathy with liability to pressure palsies [HNPP] 17.5%; 5.29/100 000). Most patients (198) with CMT1A carried the 17p11.2 duplication including the PMP22 gene, 45 patients with HNPP were all affected by deletion of the 17p11.2 locus, and 10 patients presented with axonal phenotypes: CMT2A (MFN2), CMT2N (AARS), and CMT1X (GJB1). Despite showing a classical CMT1A phenotype, we found a much earlier age of onset in our CMT1A patients, along with increased frequency of appearance of postural hand tremor. Bilateral tongue atrophy was an additional phenotype observed. Being this CMT1A group, one of the largest cohorts known to date, this study provided a unique opportunity to further define the clinical phenotype of CMT1A patients carrying the 17p11.2 duplication in a homogeneous ethnic group.

Clinching the cause: A review of foot drop secondary to lumbar degenerative diseases

Foot drop is defined as weakness on dorsiflexion of the foot. The top two most common etiologies for foot drop include lumbar degenerative disease and common peroneal nerve injury. This review provides "updates" on understanding the lumbar etiologies of foot drop. Since the publication of "Preoperative motor strength and time to surgery are the most important predictors of improvement in foot drop due to degenerative lumbar disease" in the Journal of Neurological Sciences, three cohort studies have been published on spinal causes of foot drop. Classification, clinical features, diagnosis, and pathogenesis that may 'clinch' the cause of foot drop are discussed in the context of these recent publications.

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.

Bilateral peroneal neuropathy after bariatric surgery: A case report

The popularity of bariatric surgery (BS) began to increase due to the dramatic rise in severe obesity in the past decades. Postoperative follow-up after BS is important to avoid possible medical complications. Therefore, medical complications after BS should be well-known and defined. Herein, we present a case of bilateral peroneal neuropathy (PN) developed after successful BS. The patient lost 40 kg during 16 weeks of follow-up. The foot drop developed after 18 weeks after surgery on the left side and than 24 weeks after surgery on the right side. Peroneal neuropathy-associated weight loss is usually unilateral. Bilateral PN with weight loss is uncommon. The rate of weight loss is an important risk factor for PN. This case report highlights the importance of optimal dietary after BS to control the weight loss rate and nutrient deficiency.

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.

Peripheral neuropathies

Peripheral neuropathies are diseases of the peripheral nervous system that can be divided into mononeuropathies, multifocal neuropathies, and polyneuropathies. Symptoms usually include numbness and paresthesia. These symptoms are often accompanied by weakness and can be painful. Polyneuropathies can be divided into axonal and demyelinating forms, which is important for diagnostic reasons. Most peripheral neuropathies develop over months or years, but some are rapidly progressive. Some patients only suffer from mild, unilateral, slowly progressive tingling in the fingers due to median nerve compression in the wrist (carpal tunnel syndrome), while other patients can be tetraplegic, with respiratory insufficiency within 1-2 days due to Guillain-Barré syndrome. Carpal tunnel syndrome, with a prevalence of 5% and incidence of 1-2 per 1000 person-years, is the most common mononeuropathy. Population-based data for chronic polyneuropathy are relatively scarce. Prevalence is estimated at 1% and increases to 7% in persons over 65 years of age. Incidence is approximately 1 per 1000 person-years. Immune-mediated polyneuropathies like Guillain-Barré syndrome and chronic inflammatory demyelinating polyradiculoneuropathy are rare diseases, with an annual incidence of approximately 1-2 and 0.2-0.5 per 100 000 persons respectively. Most peripheral neuropathies are more prevalent in older adults and in men, except for carpal tunnel syndrome, which is more common in women. Diabetes is a common cause of peripheral neuropathy and is associated with both mono- and polyneuropathies. Among the group of chronic polyneuropathies, in about 20-25% no direct cause can be found. These are slowly progressive axonal polyneuropathies.

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.

Factors that increase external pressure to the fibular head region, but not medial region, during use of a knee-crutch/leg-holder system in the lithotomy position

Background

Paralysis of the common peroneal nerve is one of the relatively common nerve injuries related to the lithotomy position with the use of a knee-crutch/leg-holder system. Several risk factors have been implicated in lithotomy position-related common peroneal nerve paralysis during operation.

Materials and methods

In the present study, 21 young healthy volunteers participated in the investigation of the causes of the paralysis of the common peroneal nerve in the lithotomy position using a knee-crutch/leg-holder; Knee Crutch. We assessed the external pressure applied to the fibular head and medial regions using the Big-Mat pressure-distribution measurement system. Relationships between the peak contact pressure and physical characteristics, such as sex, height, weight, body mass index (BMI), and fibular head circumference, were analyzed.

Results

The peak contact pressure to the fibular head region was greater for males than for females. For all subjects, significant positive correlations were observed between the peak contact pressure to the fibular head region and weight, BMI, or fibular head circumference. However, there was no significant difference between the peak contact pressure to the fibular head region and height for any subjects. Moreover, there was no sex-related difference in the peak contact pressure to the fibular medial region, and no significant differences between the peak contact pressure to the fibular medial region and height, weight, BMI, or fibular head circumference.

Conclusion

External pressure to the fibular head region is greater for males than for females using a knee-crutch/leg-holder system in the lithotomy position. In addition, the external pressure to the fibular head region, but not the fibular medial region, increases with increasing weight, BMI, and fibular head circumference. Therefore, these patient-related characteristics may contribute to the risk of developing lower-extremity neuropathy, leading to injury or ischemia of the common peroneal nerve.

A rare cause of 'drop foot' in the pediatric age group: Proximal fibular osteochondroma a report of 5 cases

INTRODUCTION

The fibular nerve is the most frequent site of neural entrapment in the lower extremity and the third most common site in the body, following the median and ulnar nerves. The peroneal nerve is commonly injured upon trauma. Additionally, a dropped foot might be a symptom related to the central nervous system or spinal pathologies in pediatric patients. Entrapment of the peripheral nerve as an etiologic cause should be kept in mind and further analyzed in orthopedic surgery clinics.

PRESENTATION OF CASE

In this study, the evaluation and treatment results of five patients with no history of trauma, who underwent diagnostic procedures and treatment in various clinics (physical therapy and rehabilitation and neurosurgery), are reported. The patients underwent several treatments without diagnosis of the primary etiology. Upon initial consultation at our department, osteochondroma at the proximal fibula was detected after physical examination and radiologic assessment. During surgery, the peroneal nerve was dissected, starting from a level above the knee joint. Following nerve release, the osteochondroma was removed, including its cartilage cap. Consequently, recovery was observed in all five cases after surgery.

DISCUSSION

Many factors may cause non-traumatic neuropathies. However, due to their rare occurrence, lesions such as osteochondromas may be overlooked at non-orthopedic clinics. Nerve entrapment due to proximal fibular osteochondroma is rare. Surgical treatment planning plays a critical role in nerve entrapment cases.

CONCLUSION

Despite its frequent occurrence, a drop foot associated with peroneal nerve entrapment by an osteochondroma is not easily remembered and diagnosed. Especially in pediatric cases, inadequate clinical consultation and a lack of appropriate radiologic studies may result in a delay in diagnosing peroneal nerve lesions.

Atypical neurologic presentations of new onset type 1 diabetes mellitus in pediatric age group: a report of five unusual cases and review of the literature

Type 1 diabetes mellitus (T1DM) is one of the most common chronic diseases in childhood and is caused by insulin deficiency resulting from the autoimmune destruction of insulin producing beta cells of the pancreas. Most children in the US with new onset T1DM present with the classic signs and symptoms of hyperglycemia and 30% with diabetic ketoacidosis (DKA). Neurologic manifestations are relatively rare and mostly include lethargy, decreased level of consciousness, and coma as a result of DKA. In this article, five cases of new onset T1DM with exceedingly rare or unreported neurologic manifestations in the pediatric age group are presented, along with a review of the literature.

PMP22 related neuropathies: Charcot-Marie-Tooth disease type 1A and Hereditary Neuropathy with liability to Pressure Palsies

PMP22 related neuropathies comprise (1) PMP22 duplications leading to Charcot-Marie-Tooth disease type 1A (CMT1A), (2) PMP22 deletions, leading to Hereditary Neuropathy with liability to Pressure Palsies (HNPP), and (3) PMP22 point mutations, causing both phenotypes. Overall prevalence of CMT is usually reported as 1:2,500, epidemiological studies show that 20-64% of CMT patients carry the PMP22 duplication. The prevalence of HNPP is not well known. CMT1A usually presents in the first two decades with difficulty walking or running. Distal symmetrical muscle weakness and wasting and sensory loss is present, legs more frequently and more severely affected than arms. HNPP typically leads to episodic, painless, recurrent, focal motor and sensory peripheral neuropathy, preceded by minor compression on the affected nerve. Electrophysiological evaluation is needed to determine whether the polyneuropathy is demyelinating. Sonography of the nerves can be useful. Diagnosis is confirmed by finding respectively a PMP22 duplication, deletion or point mutation. Differential diagnosis includes other inherited neuropathies, and acquired polyneuropathies. The mode of inheritance is autosomal dominant and de novo mutations occur. Offspring of patients have a chance of 50% to inherit the mutation from their affected parent. Prenatal testing is possible; requests for prenatal testing are not common. Treatment is currently symptomatic and may include management by a rehabilitation physician, physiotherapist, occupational therapist and orthopaedic surgeon. Adult CMT1A patients show slow clinical progression of disease, which seems to reflect a process of normal ageing. Life expectancy is normal.

Peroneal neuropathy misdiagnosed as L5 radiculopathy: a case report

Objective

The purpose of this case report is to describe a patient who presented with a case of peroneal neuropathy that was originally diagnosed and treated as a L5 radiculopathy.

Clinical features

A 53-year old female registered nurse presented to a private chiropractic practice with complaints of left lateral leg pain. Three months earlier she underwent elective left L5 decompression surgery without relief of symptoms.

Intervention and outcome

Lumbar spine MRI seven months prior to lumbar decompression surgery revealed left neural foraminal stenosis at L5-S1. The patient symptoms resolved after she stopped crossing her legs.

Conclusion

This report discusses a case of undiagnosed peroneal neuropathy that underwent lumbar decompression surgery for a L5 radiculopathy. This case study demonstrates the importance of a thorough clinical examination and decision making that ensures proper patient diagnosis and management.

Compression and entrapment neuropathies

Peripheral nerve entrapments are frequent. They usually appear in anatomical tunnels such as the carpal tunnel. Nerve compressions may be due to external pressure such as the fibular nerve at the fibular head. Malignant or benign tumors may also damage the nerve. For each nerve from the upper and lower limbs, detailed clinical, electrophysiological, imaging, and therapeutic aspects are described. In the upper limbs, carpal tunnel syndrome and ulnar neuropathy at the elbow are the most frequent manifestations; the radial nerve is less frequently involved. Other nerves may occasionally be damaged and these are described also. In the lower limbs, the fibular nerve is most frequently involved, usually at the fibular head by external compression. Other nerves may also be involved and are therefore described. The clinical and electrophysiological examination are very important for the diagnosis, but imaging is also of great use. Treatments available for each nerve disease are discussed.

[Bilateral peroneal neuropathy following bariatric surgery]

We report the case of bilateral peroneal neuropathy following massive weight loss after bariatric surgery. A few months after a gastric by-pass, the patient developed sequentially within 6 months a L2-L3 herniated disc that required surgery, a severe right peroneal nerve palsy that led to decompressive surgery and finally contralateral peroneal nerve palsy also operated. The electrophysiological analysis confirmed the clinical suspicion of peroneal nerve compression at the fibular head. Postoperative course was favorable. Literature reports peroneal nerve palsy after slimming, mostly when weight loss is fast and marked although the issue is rarely bilateral.

Two cases of elderly-onset hereditary neuropathy with liability to pressure palsy manifesting bilateral peroneal nerve palsies

Hereditary neuropathy with liability to pressure palsy (HNPP) is characterized by recurrent focal neuropathies, which usually become symptomatic in the second or third decade of life. However, clinical phenotypic heterogeneity among patients with HNPP has recently been reported. Certain patients show polyneuropathy-type diffuse nerve injuries, whereas others remain asymptomatic at older ages. We present two cases of elderly-onset bilateral peroneal nerve palsies with diffuse muscle weakness in the lower limbs and glove-and-stocking type sensory disturbance. Both patients were diagnosed with HNPP by genetic analyses that detected deletions of chromosome 17p11.2 in peripheral myelin protein 22 genes. Their clinical courses suggested that the Japanese sitting style termed ‘seiza’, a way of sitting on the floor with the lower legs crossed under the thighs, was a precipitating factor for the bilateral peroneal nerve palsies.

Neurological complications following bariatric surgery

OBJECTIVE: It was to report on Brazilian cases of neurological complications from bariatric surgery. The literature on the subject is scarce. METHOD: Cases attended by neurologists in eight different Brazilian cities were collected and described in the present study. RESULTS: Twenty-six cases were collected in this study. Axonal polyneuropathy was the most frequent neurological complication, but cases of central demyelination, Wernicke syndrome, optical neuritis, radiculits, meralgia paresthetica and compressive neuropathies were also identified. Twenty-one patients (80%) had partial or no recovery from the neurological signs and symptoms. CONCLUSION: Bariatric surgery, a procedure that is continuously increasing in popularity, is not free of potential neurological complications that should be clearly presented to the individual undergoing this type of surgery. Although a clear cause-effect relation cannot be established for the present cases, the cumulative literature on the subject makes it important to warn the patient of the potential risks of this procedure.

Peroneal nerve dysfunction after total knee arthroplasty: characterization and treatment

The purpose of this study was to report on the presentation, evaluation, treatment, and outcome of patients who had a peroneal nerve dysfunction after total knee arthroplasty. Six patients were unable to achieve adequate range of motion after physical therapy, and the remaining 5 patients had sensory symptoms that interfered with daily activities despite adequate range of motion. All 11 patients had abnormal electrodiagnostic testing but had intact motor strength and were treated with surgical decompression of the nerve. The patients with motion problems had a mean increase in range of motion of 40 ° (range, 20 °-70 °) at final follow-up. All patients with dominant sensory symptoms had a resolution of leg and foot pain after treatment. Orthopedic surgeons should be aware of peroneal nerve dysfunction as a possible cause of unsatisfactory rehabilitation and/or persistent atypical lateral leg pain after total knee arthroplasty.

Predicting recovery after fibular nerve injury: which electrodiagnostic features are most useful?

OBJECTIVE

Although it is important to have strong predictors of outcome in peripheral mononeuropathies so that appropriate management can be instituted early, little is known about the prognostic value of electrodiagnostic results for these lesions. Our objective in this study was to evaluate the prognostic value of electrodiagnostic studies in fibular neuropathy.

DESIGN

In this retrospective study, 39 of 138 subjects with fibular neuropathy met the inclusion criteria. Electrodiagnostic results at the time of testing were evaluated for their value in predicting outcome. Good outcome was defined as grade 4 or higher strength on the Medical Research Council Scale in ankle dorsiflexion.

RESULTS

Compound muscle action potential responses from extensor digitorum brevis and tibialis anterior predicted prognosis: 81% of subjects with any tibialis anterior response and 94% with any extensor digitorum brevis response had a good outcome vs. those with absent responses (46% and 52%, respectively). Importantly, there was still a high likelihood of good outcome with absent compound muscle action potential responses. Tibialis anterior compound muscle action potential gave additional prognostic information when extensor digitorum brevis response was absent. Recruitment in tibialis anterior was predictive in traumatic cases. All patients with nontraumatic compression had a good outcome.

CONCLUSIONS

We conclude that electrodiagnostic studies produce useful prognostic information in fibular neuropathy, particularly in traumatic cases.

Entrapment and compressive neuropathies

Entrapment and compressive neuropathies of the upper and lower extremities are frequently encountered disorders in the office. Certain clinical clues in the history and examination, along with electrodiagnostic testing and imaging studies, often suggest the correct diagnosis. Some of the more common neuropathies are discussed, along with suggestions regarding testing and treatment.

Peroneal nerve orthodromic sensory conduction technique: normative data

In some definite patients, a standard neurophysiological tool may not solve a complete differential diagnosis in common nerve peroneal neuropathy. In this study we have assessed a new simple procedure to study the orthodromic sensory conduction of both the superficial peroneal nerves (SPN) and deep peroneal nerves (DPN) in a heterogeneous group of 55 normal subjects. The mean sensory orthodromic conduction velocity of the SPN was 58.35 m/s. The mean sensory orthodromic conduction velocity of the mixed nerve action potential (MNAP) of the DPN was 55.27 m/s. The sensory conduction velocity, the amplitude of sensory-evoked potentials of SPN and DPN across the fibular head and the normative values are discussed. Our results confirm that these recording methods are easy to repeat and reliable in identifying peroneal neuropathy.

Foot drop as a complication of weight loss after bariatric surgery: is it preventable?

BACKGROUND

Although rare, the relationship between peroneal nerve palsy and weight loss has been well documented over the last decades. Of the 160 patients operated for persisting foot drop in our institution, weight loss was considered to be the major contributing factor for 78 patients (43.5%).

METHODS

We compared patients who developed a foot drop after bariatric surgery with a control group of patients who underwent bariatric surgery (gastric banding) but did not develop peroneal neuropathy.

RESULTS

9 patients developed foot drop after bariatric surgery. The mean weight loss for these patients was 45 kg. Weight reduction took place during a mean period of 8.6 months. Our control group consists of 10 patients. The mean weight loss of these patients was 43.8 kg, and the weight reduction took place during a mean period of 21.7 months.

CONCLUSION

In contrast to earlier studies, we demonstrated that significant weight loss is correlated with a higher risk to develop foot drop and that the time period in which the weight loss is achieved is important. A rapid reduction of body weight is correlated with a higher risk to develop foot drop.