Diagnostic accuracy of ultrasound and MR imaging in peroneal neuropathy: A prospective, single-center study.

INTRODUCTION/AIMS: Magnetic resonance imaging (MRI) findings in peroneal neuropathy are not well documented and the prognostic value of imaging remains uncertain. Upper limits of cross-sectional area (CSA) on ultrasound (US) have been established, but uncertainty regarding generalizability remains. We aimed to describe MRI findings of the peroneal nerve in patients and healthy controls and to compare these results to US findings and clinical characteristics. METHODS: We prospectively included patients with foot drop and electrodiagnostically confirmed peroneal neuropathy, and performed clinical follow-up, US and MRI of both peroneal nerves. We compared MRI findings to healthy controls. Two radiologists evaluated MRI features in an exploratory analysis after images were anonymized and randomized. RESULTS: Twenty-two patients and 38 healthy controls were included. Whereas significant increased MRI CSA values were documented in patients (mean CSA 20 mm2 vs. 13 mm2 in healthy controls), intra- and interobserver variability was substantial (variability of, respectively, 7 and 9 mm2 around the mean in 95% of repeated measurements). A pathological T2 hyperintense signal of the nerve was found in 52.6% of patients (50% interobserver agreement). Increased CSA measurements (MRI/US), pathological T2 hyperintensity of the nerve and muscle edema were not predictive for recovery. DISCUSSION: Imaging is recommended in all patients with peroneal neuropathy to exclude compressive intrinsic and extrinsic masses but we do not advise routine MRI for diagnosis or prediction of outcome in patients with peroneal neuropathy due to high observer variability. Further studies should aim at reducing MRI observer variability potentially by semi-automation.

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.

Retrograde Placement of High Cervical Electrodes: A Technical Refinement and Case Series.

INTRODUCTION: Cervical cord stimulation is used in the treatment of chronic (neuropathic) pain syndromes refractory to conservative treatments. Several authors describe different techniques for the placement of cervical electrodes. Electrodes can be placed retrogade [Correction added on 03 April 2018 after first online publication: the word "plased" has been changed to "placed".]. In this article, we describe a refinement on how to dissect the dorsal meningo-vertebral ligaments to decrease the risk of complications. PATIENTS AND METHODS: Twenty-eight patients received a permanent cervical spinal cord stimulator. A C0-C1 retrograde insertion was performed with careful dissection of the meningo-vertebral ligaments. Complications were registered during the follow-up (mean 44.6 months [SD = 43, range 1-162 months]). RESULTS: Six complications were observed 93% of the patients reported a significant reduction in pain. CONCLUSIONS: We describe an additional surgical detail for the known procedure for retrograde placement of high cervical plate electrodes. This surgical detail might result in a lower risk of complications. We present a case series of 28 patients to support this hypothesis.

A randomized controlled trial comparing conservative versus surgical treatment in patients with foot drop due to peroneal nerve entrapment: results of an internal feasibility pilot study.

BACKGROUND: Based on the lack of literature to support any treatment strategy in patients with foot drop due to peroneal nerve entrapment, a prospective study randomizing patients between surgery and conservative treatment is warranted. Since studies comparing surgery to no surgery are often challenging, we first examined the feasibility of such a randomized controlled trial. METHODS/DESIGN: An internal feasibility pilot study was conducted to assess several aspects of process, resource, management, and scientific feasibility. The main objective was the assessment of the recruitment rate. The criterion to embark on a full study was the recruitment of at least 14 patients in 6 participating centers within 6 months. Cross-over rate, blinding measures, training strategies, and trial assessments were evaluated. The trial was entirely funded by the KCE Trials public funding program of the Belgian Health Care Knowledge Centre (ID KCE19-1232). RESULTS: The initial duration was prolonged due to the COVID-19 pandemic. Between April 2021 and October 2022, we included 19 patients of which 15 were randomized. Fourteen patients were treated as randomized. One drop-out occurred after randomization, prior to surgery. We did not document any cross-over or accidental unblinding. Training strategies were successful. Patients perceived the quality of life questionnaire as the least relevant assessment. Assessment of ankle dorsiflexion range of motion was prone to interobserver variability. All other trial assessments were adequate. DISCUSSION: Recruitment of the anticipated 14 patients was feasible although slower than expected. The Short-Form Health Survey (SF-36) and assessment of ankle dorsiflexion range of motion will no longer be included in the full-scale FOOTDROP trial. CONCLUSION: The FOOTDROP study is feasible. TRIAL REGISTRATION: ClinicalTrials.gov, identifier NCT04695834 . Registered 4 January 2021.

Controversies in treatment strategies in patients with foot drop due to peroneal nerve entrapment: Results of a survey among specialists.

Introduction: Peroneal nerve entrapment is a frequent cause of foot drop. Despite being frequent, no guidelines exist to recommend surgical or non-invasive treatment, leading to important variations in daily practice. Research question: To map variation in daily practice. Materials and methods: An online Qualtrics survey was distributed among neurosurgeons, neurologists, orthopaedic surgeons and physical medicine and rehabilitation physicians through various national and international scientific organizations, mapping current treatment strategies. Descriptive statistics and non-parametric tests were used to analyse data with SPSS. Results: Responses from 181 out of 221 participants from 35 countries were analysed. A large majority of participants agreed that good evidence supporting any treatment strategy is lacking (77.9%) and that daily practice is mostly guided by own beliefs and experience (84.0%). Both non-invasive treatment and neurolysis are well established treatment strategies (supported by respectively 92.3% and 93.4% of physicians). Timing of neurolysis and duration of non-invasive treatment varied considerably. Duration of non-invasive treatment was significantly shorter in the group of surgeons compared to non-surgeons (p â€‹= â€‹0.033). Most physicians consider neurolysis a valid treatment option. However, significant more non-surgeons than surgeons were opposed to surgical treatment (p â€‹= â€‹0.001). Discussion and conclusion: Important differences in attitudes were observed not only between, but also within specialisms, regardless of physician experience. This survey highlights important variations in daily practice for foot drop due to peroneal entrapment and emphasizes the need for future controlled studies.

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.