Peripheral Nerve Evaluation Research Articles

Imaging evaluation of peripheral nerves

Imaging evaluation of peripheral nerves

Sensory Symptoms without Structural Pathology in Patients with Gluten Sensitivity.

The patients were selected from the gluten neurology clinic based at the Royal Hallamshire Hospital, Sheffield, UK, on the basis of sensory symptoms but normal neuroaxis imaging and peripheral nerve evaluation. A total of 30 patients were identified with a mean age at presentation of 47 years. The prevalence of enteropathy was 78%. The sensory disturbance was characterised by tingling at 50%, numbness at 27%, pain at 20%, burning at 13% and "buzzing" feeling at 7%. The distribution of the sensory symptoms included hands and feet in 27% of the patients, torso in 27%, legs only in 23%, face in 17% and arms only in 10%. For five patients, the sensory disturbance was migratory and affected different parts of the body at any given time. After the introduction of a gluten-free diet, 77% of patients noted significant improvement in their sensory symptoms. In one-third of the patients, there was a complete resolution of the sensory symptoms. Unexplained sensory symptoms can be seen in patients with gluten sensitivity and respond to strict adherence to a gluten-free diet.

Outcomes and efficacy of magnetic resonance imaging-compatible sacral nerve stimulator for management of fecal incontinence: A multi-institutional study.

Fecal incontinence (FI) is an involuntary passage of fecal matter which can have a significant impact on a patient's quality of life. Many modalities of treatment exist for FI. Sacral nerve stimulation is a well-established treatment for FI. Given the increased need of magnetic resonance imaging (MRI) for diagnostics, the InterStim which was previously used in sacral nerve stimulation was limited by MRI incompatibility. Medtronic MRI-compatible InterStim was approved by the United States Food and Drug Administration in August 2020 and has been widely used. To evaluate the efficacy, outcomes and complications of the MRI-compatible InterStim. Data of patients who underwent MRI-compatible Medtronic InterStim placement at UPMC Williamsport, University of Minnesota, Advocate Lutheran General Hospital, and University of Wisconsin-Madison was pooled and analyzed. Patient demographics, clinical features, surgical techniques, complications, and outcomes were analyzed. Strengthening the Reporting of Observational studies in Epidemiology(STROBE) cross-sectional reporting guidelines were used. Seventy-three patients had the InterStim implanted. The mean age was 63.29 ± 12.2 years. Fifty-seven (78.1%) patients were females and forty-two (57.5%) patients had diabetes. In addition to incontinence, overlapping symptoms included diarrhea (23.3%), fecal urgency (58.9%), and urinary incontinence (28.8%). Fifteen (20.5%) patients underwent Peripheral Nerve Evaluation before proceeding to definite implant placement. Thirty-two (43.8%) patients underwent rechargeable InterStim placement. Three (4.1%) patients needed removal of the implant. Migration of the external lead connection was observed in 7 (9.6%) patients after the stage I procedure. The explanation for one patient was due to infection. Seven (9.6%) patients had other complications like nerve pain, hematoma, infection, lead fracture, and bleeding. The mean follow-up was 6.62 ± 3.5 mo. Sixty-eight (93.2%) patients reported significant improvement of symptoms on follow-up evaluation. This study shows promising results with significant symptom improvement, good efficacy and good patient outcomes with low complication rates while using MRI compatible InterStim for FI. Further long-term follow-up and future studies with a larger patient population is recommended.

Advanced Imaging of the Peripheral Nerves, From the AJR "How We Do It" Special Series.

Advanced imaging of peripheral nerves is occupying an increasingly important role in the diagnostic workup of peripheral nerve disorders. Advances in MR neurography (MRN) and high-resolution ultrasound have addressed historical challenges in peripheral nerve imaging related to nerves' small size and non-linear course, and difficult differentiation from surrounding tissues. Modern MRN depicts neuromuscular anatomy with exquisite contrast resolution, and MRN has become the workhorse imaging modality for peripheral nerve evaluation. MRN protocols vary across institutions and are adjusted in individual patients, although commonly include nerve-selective sequences and diffusion tensor imaging tractography. Ultrasound offers a dynamic, real-time high-resolution assessment of peripheral nerves, and is widely accessible and less costly than MRN. Ultrasound has greater ability to interrogate peripheral nerves at the fascicular level and provides complementary information to MRN. However, ultrasound of peripheral nerves requires substantial skill and experience and is operator-dependent. The two modalities have distinct advantages and disadvantages, and the selection between these depends on the clinical context. This article provides an overview of advanced imaging techniques used for evaluation of peripheral nerves, with attention to MRN and high-resolution ultrasound. We draw on our institutional experience in performing both modalities to highlight technical considerations for optimizing examinations.

Using ultrasound shear wave elastography to characterize peripheral nerve mechanics: a systematic review on the normative reference values in healthy individuals.

Ultrasound shear wave elastography (SWE) is an emerging non-invasive imaging technique for peripheral nerve evaluation. Shear wave velocity (SWV), a surrogate measure of stiffness, holds promise as a biomarker for various peripheral nerve disorders. However, to maximize its clinical and biomechanical value, it is important to fully understand the factors that influence nerve SWV measurements. This systematic review aimed to identify the normal range of SWV for healthy sciatic and tibial nerves and to reveal the factors potentially affecting nerve SWV. An electronic search yielded 17 studies eligible for inclusion, involving 548 healthy individuals (age range, 17 to 72 years). Despite very good reliability metrics, the reported SWV values differed considerably across studies for the sciatic (1.9-9.9 m/s) and tibial (2.3-9.1 m/s) nerves. Factors such as measurement proximity to joint regions, limb postures inducing nerve axial stretching, and transducer alignment with nerve fiber orientation were associated with increased SWV. These findings suggest regional-specific nerve mechanical properties, non-linear elastic behaviour, and marked mechanical anisotropy. The impact of age and sex remains unclear and warrants further investigation. These results emphasize the importance of considering these factors when assessing and interpreting nerve SWE. While increased SWV has been linked to pathological changes affecting nerve tissue mechanics, the significant variability observed in healthy nerves highlights the need for standardized SWE assessment protocols. Developing guidelines for enhanced clinical utility and achieving a comprehensive understanding of the factors that influence nerve SWE assessments are critical in advancing the field.

Progress in the nerve ultrasound of inflammatory peripheral neuropathies

Objective: In recent years, high-resolution nerve ultrasound has been increasingly used as a complementary tool to nerve conduction studies in the diagnosis of peripheral neuropathies. Inflammatory peripheral neuropathies include a heterogeneous group of neuropathies mainly including chronic inflammatory demyelinating polyneuropathies (CIDP), multifocal motor neuropathy (MMN), systemic vasculitic neuropathy (SVN), and Guillain-Barre syndrome (GBS). We describe the ultrasonic characteristics of different inflammatory neuropathies.
 Data sources and study selection: The MEDLINE database was searched to find studies on nerve sonography in inflammatory peripheral neuropathies. Reported studies up to December 2022 were included in this review.
 Results: In neuropathies, the changes in ultrasound include enlarged nerve size, nerve echo-intensity, fascicle diameter and vascularity. Most CIDP patients have moderately enlarged CSA, some have dramatically enlarged CSA, and few have CSA within the normal range. Since the enlargement patterns are different, ultrasound is useful to help differentiate CIDP from CMT1. In follow-ups after immune treatment, nerve CSAs in CIDP could decrease, increase, or remain unchanged. Regional enlargement next to normal segments predominated in MMN. Nerve enlargement and hyper vascularization were found in vasculitic neuropathy. In GBS patients, there were enlarged peripheral nerve and nerve roots, which became normal at follow-up.
 Conclusions: High-resolution nerve ultrasound is complementary to the diagnosis of inflammatory peripheral neuropathies. CSA enlargement and its distribution are the most useful and quantifiable parameters in the evaluation of peripheral nerves. For patients suspected to have inflammatory neuropathies, we advise measuring the CSA of several pre-determined sites in the median, ulnar nerve, C5-8 cervical roots, and brachial plexus.

Role of multisegmental nerve ultrasound in the diagnosis of leprosy neuropathy.

Leprosy is the most common treatable peripheral neuropathy worldwide. The detection of peripheral nerve impairment is essential for its diagnosis and treatment, in order to prevent stigmatizing deformities and disabilities. This study was performed to identify neural thickening through multisegmental ultrasound (US). We assessed US measurements of cross-sectional areas (CSAs) of ulnar, median and tibial nerves at two points (in the osteofibrous tunnel and proximal to the tunnel), and also of the common fibular nerve at the fibular head level in 53 leprosy patients (LP), and compared with those of 53 healthy volunteers (HV), as well as among different clinical forms of leprosy. US evaluation detected neural thickening in 71.1% (38/53) of LP and a mean number of 3.6 enlarged nerves per patient. The ulnar and tibial were the most frequently affected nerves. All nerves showed significantly higher measurements in LP compared with HV, and also greater asymmetry, with significantly higher values for ulnar and tibial nerves. We found significant CSAs differences between tunnel and pre-tunnel points for ulnar and tibial nerves, with maximum values proximal to the tunnel. All clinical forms of leprosy evaluated showed neural enlargement through US. Our findings support the role of multisegmental US as a useful method for diagnosing leprosy neuropathy, revealing that asymmetry, regional and non-uniform thickening are characteristics of the disease. Furthermore, we observed that neural involvement is common in different clinical forms of leprosy, reinforcing the importance of including US evaluation of peripheral nerves in the investigation of all leprosy patients.

Diffusion Tensor Imaging of Peripheral Nerves: Current Status and New Developments.

Diffusion tensor imaging (DTI) is an emerging technique for peripheral nerve imaging that can provide information about the microstructural organization and connectivity of these nerves and complement the information gained from anatomical magnetic resonance imaging (MRI) sequences. With DTI it is possible to reconstruct nerve pathways and visualize the three-dimensional trajectory of nerve fibers, as in nerve tractography. More importantly, DTI allows for quantitative evaluation of peripheral nerves by the calculation of several important parameters that offer insight into the functional status of a nerve. Thus DTI has a high potential to add value to the work-up of peripheral nerve pathologies, although it is more technically demanding. Peripheral nerves pose specific challenges to DTI due to their small diameter and DTI's spatial resolution, contrast, location, and inherent field inhomogeneities when imaging certain anatomical locations. Numerous efforts are underway to resolve these technical challenges and thus enable wider acceptance of DTI in peripheral nerve MRI.

The role of high-resolution ultrasound and MRI in the evaluation of peripheral nerves in the lower extremity.

Lower extremity peripheral neuropathy is a commonly encountered neurologic disorder, which can lead to chronic pain, functional disability, and decreased quality of life for a patient. As diagnostic imaging modalities have improved, imaging has started to play an integral role in the detection and characterization of peripheral nerve abnormalities by non-invasively and accurately identifying abnormal nerves as well as potential causes of neuropathy, which ultimately leads to precise and timely treatment. Ultrasound, which has high spatial resolution and can quickly and comfortably characterize peripheral nerves in real time along with associated denervation muscle atrophy, and magnetic resonance neurography, which provides excellent contrast resolution between nerves and other tissues and between pathologic and normal segments of peripheral nerves, in addition to assessing reversible and irreversible muscle denervation changes, are the two mainstay imaging modalities used in peripheral nerve assessment. These two modalities are complimentary, and one may be more useful than the other depending on the nerve and location of pathology. Imaging must be interpreted in the context of available clinical information and other diagnostic studies, such as electrodiagnostic tests. Here, we offer a comprehensive overview of the role of high-resolution ultrasound and magnetic resonance neurography in the evaluation of the peripheral nerves of the lower extremity and their associated neuropathies.

Role of high-resolution ultrasound and magnetic resonance neurography in the evaluation of peripheral nerves in the upper extremity.

Upper extremity entrapment neuropathies are common conditions in which peripheral nerves are prone to injury at specific anatomical locations, particularly superficial regions or within fibro-osseous tunnels, resulting in pain and potential disability. Although neuropathy is primarily diagnosed clinically by physical examination and electrophysiology, imaging evaluation with ultrasound and magnetic resonance neurography are valuable complementary non-invasive and accurate tools for evaluation and can help define the site and cause of nerve dysfunction which ultimately leads to precise and timely treatment. Ultrasound, which has higher spatial resolution, can quickly and comfortably characterize the peripheral nerves in real time and can evaluate for denervation related muscle atrophy. Magnetic resonance imaging on the other hand provides excellent contrast resolution between the nerves and adjacent tissues, also between pathologic and normal segments of peripheral nerves. It can also assess the degree of muscle denervation and atrophy. As a prerequisite for nerve imaging, radiologists and sonographers should have a thorough knowledge of anatomy of the peripheral nerves and their superficial and deep branches, including variant anatomy, and the motor and sensory territories innervated by each nerve. The purpose of this illustrative article is to review the common neuropathy and nerve entrapment syndromes in the upper extremities focusing on ultrasound and magnetic resonance neurography imaging.

The Long-term Outcomes of Sacral Neuromodulation for Fecal Incontinence: A Single Center Experience.

Sacral neuromodulation is an effective treatment for fecal incontinence. This study aimed to assess the long-term outcomes of sacral neuromodulation and establish the outcomes of patients with inactive devices. This is an observational study of patients treated for more than 5 years. A positive outcome was defined as a >50% reduction in fecal incontinence episodes or improvement in a symptom severity score. Data were reviewed from a prospectively managed database. This study was conducted at a single tertiary referral center. Data from 74 patients (72 female) were available at long-term follow up. Bowel diary, St. Mark's incontinence score, and Manchester Health Questionnaire data were prospectively recorded at baseline, after peripheral nerve evaluation, and at last follow-up. Patients were analyzed in cohorts based on time since sacral neuromodulation implantation: Group 1: 5-10 years (n = 20), Group 2: >10 years (n = 35), and Group 3: inactive SNM devices (n = 19). Median St. Mark's incontinence score and Manchester Health Questionnaire improved from baseline to last follow-up in Group 1 (p ≤ 0.05) and Group 2 (p ≤ 0.05), but in Group 3 results returned to baseline levels at last follow-up. Similarly, weekly fecal incontinence episodes improved in both active device groups at last follow-up. However, in Group 3 incontinence episodes were no different from baseline (p = 0.722). Despite active devices, fecal urgency episodes increased at last follow-up after more than 10 years since peripheral nerve evaluation (p ≤ 0.05). Complete continence was reported by 44% of patients, and at least a 50% improvement in 77% with active devices. This study is retrospective with some gaps in the available data at last follow-up. Sacral neuromodulation is an effective treatment for fecal incontinence in the long term, but all outcomes are adversely affected by device inactivity. Therefore, ongoing stimulation is required for continued benefit..

Pure small fiber neuropathy in alcohol dependency detected by skin biopsy.

Alcohol overconsumption is well known to cause damage to the peripheral nervous system. The aim of this study was the functional and structural evaluation of the small nerve fibers in alcohol-dependent subjects, with or without symptoms of peripheral neuropathy. Twenty-six consecutive alcohol-dependent subjects treated for detoxification voluntarily in the specialized unit of the Athens University Psychiatric Clinic were enrolled in this prospective study over 18 months. Every subject was assessed by peripheral nerve evaluation using the Neuropathy Symptoms Score (NSS) and Neuropathy Impairment Score (NIS), followed by nerve conduction studies (NCS), quantitative sensory testing (QST), and skin biopsy. Twenty-nine normal subjects, age- and gender-matched, constituted the control group. Peripheral neuropathy was diagnosed in 16 subjects (61.5%). Among these 16 subjects, pure large fiber neuropathy (LFN) was found in two subjects (12.5%), pure small fiber neuropathy (SFN) was found in eight subjects (50%), and both large and small fiber neuropathy was diagnosed in six patients (37.5%). The intraepidermal nerve fiber density (IENFD) of the patients' skin biopsy was significantly lower than that of the control group. Additionally, QST results showed a statistically significant sensory impairment in the patients. Our study confirms small fiber neuropathy due to alcohol abuse with a high prevalence of pure SFN that might have remained undetected without QST and IENFD.

PC46. MRI Neurography as an Adjunct for the Diagnosis of Meralgia Paresthetica

PURPOSE: Meralgia paresthetica (MP) is a sequela of Lateral Femoral Cutaneous Nerve (LFCN) compression characterized by numbness, tingling, and burning sensation in the outer thigh. Traditional methods of diagnosis are usually extremely limited to provide a certain diagnosis. MRI neurography (MRN) is a tissue-specific imaging that provides excellent characterization of nerve anatomy. We propose MRN as an adjunct for the diagnosis and management of meralgia paresthetica. METHODS: We reviewed 13 consecutive patients who were surgically treated for MP in the last 2 years. Treatment protocol offered patients with VAS scores 3-4 with nerve release, 5-7 either LFCN decompression or resection with regenerative peripheral nerve interface (RPNI), and 8-10 RPNI. Since MRN was only recently introduced into our practice, 7 out of 13 patients had MRN pre-operatively. RESULTS: Patients presented with hypersensitivity and burning pain to the LFCN distribution with an average VAS score of 7.8. Of the 7 patients with MRN, 6 patients had complete resolution of symptoms, 1 patient with history of complex regional pain syndrome still reported improvement of symptoms. The 6 patients that didn’t get MRN were treated according to VAS score, EMG, and clinical assessment. 5 of them had complete resolution of symptoms after surgery with 1 reporting significant improvement. CONCLUSION: MRN is a useful resource for the evaluation of peripheral nerves. The ability to provide a comprehensive evaluation of the regional neuromuscular structures helps the diagnosis and management of MP. Nevertheless, larger prospective studies are still warranted to further investigate its utilization and accuracy.

Quantitative Ultrasound Techniques Used for Peripheral Nerve Assessment.

This review article describes quantitative ultrasound (QUS) techniques and summarizes their strengths and limitations when applied to peripheral nerves. A systematic review was conducted on publications after 1990 in Google Scholar, Scopus, and PubMed databases. The search terms "peripheral nerve", "quantitative ultrasound", and "elastography ultrasound" were used to identify studies related to this investigation. Based on this literature review, QUS investigations performed on peripheral nerves can be categorized into three main groups: (1) B-mode echogenicity measurements, which are affected by a variety of post-processing algorithms applied during image formation and in subsequent B-mode images; (2) ultrasound (US) elastography, which examines tissue stiffness or elasticity through modalities such as strain ultrasonography or shear wave elastography (SWE). With strain ultrasonography, induced tissue strain, caused by internal or external compression stimuli that distort the tissue, is measured by tracking detectable speckles in the B-mode images. In SWE, the propagation speed of shear waves, generated by externally applied mechanical vibrations or internal US "push pulse" stimuli, is measured to estimate tissue elasticity; (3) the characterization of raw backscattered ultrasound radiofrequency (RF) signals, which provide fundamental ultrasonic tissue parameters, such as the acoustic attenuation and backscattered coefficients, that reflect tissue composition and microstructural properties. QUS techniques allow the objective evaluation of peripheral nerves and reduce operator- or system-associated biases that can influence qualitative B-mode imaging. The application of QUS techniques to peripheral nerves, including their strengths and limitations, were described and discussed in this review to enhance clinical translation.

The peripheral nerve evaluation: determining which symptoms lead to a successful test

Objective: To identify the symptom or set of symptoms most improved in patients undergoing a successful peripheral nerve evaluation (PNE) for refractory overactive bladder syndrome (OAB). Methods: An analysis was conducted on refractory OAB patients to determine which symptom (nocturia, daytime voids, urgency, leaks per day, pad use per day and time to reach the bathroom) most improved following a PNE. This was measured in two ways: 1) by patient responses to a questionnaire and 2) by determining changes in symptoms with use of a voiding diary. Patients completed a pre- and post-questionnaire by phone interview. Descriptive statistics were used to analyze demographic and baseline characteristics as well as responses to questionnaires. Changes in voiding patterns were analyzed using a paired-samples t-test. Results: Overall, 28 patients were included. Prior to their evaluation patients indicated they were most bothered by urgency (n=26, 92.8%), followed by number of leaks per 24 hours (n = 24, 85.7%). After their evaluation, symptom improvement was highest for number of voids at night (n = 20, 71.4%) followed by sense of urgency (n = 18, 64.3%). Paired-samples t-tests on pre- and post-PNE voiding diaries revealed significant improvements in number of daytime voids (p = 0.015), number of leaks per 24 hours (p = 0.001), and number of urges per 24 hours (p = 0.001). Conclusion: Voiding diaries alone cannot be used to accurately determine symptom improvement. Clinicians must take into account the degree to which their patients are bothered by their symptoms. In an elderly population, improvement in nocturia has important implications including decreased morbidity.

Cognitive impairment does not impact sacral neuromodulation implant rates for overactive bladder.

To evaluate the impact of cognitive impairment (CI) diagnoses on sacral neuromodulation (SNM) outcomes in older patients. We completed a retrospective review of all patients aged ≥55 years who underwent test-phase SNM (peripheral nerve evaluation (PNE) or stage 1) for overactive bladder (OAB) between 2014 and 2021 within a large multi-regional health system. Patient demographics, relevant comorbidities, CI diagnoses (dementia or mild CI), and SNM procedures were recorded. Logistic regression modeling was performed to evaluate the impact of CI on SNM implantation rates. Five-hundred and ten patients underwent SNMtest phase (161 PNE, 349 Stage 1) during the study period. The mean age was 71.0(8.5) years, and most (80.6%) were female. Overall, 52(10.1%) patients had a CI diagnosis at the time of SNM, and 30 (5.8%) were diagnosed at a median of 18.5 [9.25, 39.5] months after SNM. Patients with CI diagnoses were older, with more comorbidities, and were more likely to undergo PNE. Univariable comparison found no difference in implantation rate based on pre-SNM CI (85.4% vs. 76.9%, p = 0.16). Multivariable analysis identified PNE (OR 0.43, 95%CI 0.26-0.71), age (OR 0.96, 95%CI 0.93-0.98), and prior beta-3 agonist use (OR 0.60, 95%CI 0.37-0.99) but not CI or dementia as independent negative predictors of implantation. Implanted patients had a median follow-up of 25 [12.0, 55.0] months. Explant and revision rates did not differ according to CI. Patients with OAB and CI diagnoses proceed to SNM implant at rates similar to patients without CI diagnoses. A diagnosis of CI should not necessarily exclude patients from SNM therapy for refractory OAB.

Foot Drop: The Importance of Imaging as Part of the Peripheral Nerve Evaluation

Foot Drop: The Importance of Imaging as Part of the Peripheral Nerve Evaluation

Foot Drop: The Importance of Imaging as Part of the Peripheral Nerve Evaluation

Dr. Smith is Assistant Professor of Neurosurgery, Duke University Medical Center, Durham, North Carolina; Dr. Jack is Associate Staff, Neurological Surgery, Cleveland Clinic, Cleveland, Ohio; and Dr. Spinner is Chair of Neurosurgery, Department of Neurologic Surgery, Burton M Onofrio MD Professor of Neurosurgery, and Professor of Orthopedics and Anatomy, Mayo Clinic, 200 1st St SW, Rochester, MN 55905, E-mail: [email protected]. All authors, faculty, and staff have no relevant financial relationships with any ineligible organizations regarding this educational activity. Lippincott Continuing Medical Education Institute, Inc., is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. Category: Peripheral Nerve Lippincott Continuing Medical Education Institute, Inc., designates this enduring material for a maximum of 2.0 AMA PRA Category 1 Credits™. Physicians should claim only the credit commensurate with the extent of their participation in the activity. To earn CME credit, you must read the CME article and complete the quiz and evaluation on the enclosed form, answering at least 70% of the quiz questions correctly. This activity expires on December 29, 2024.

Novel electrode design reduces sensory threshold current drift during peripheral nerve evaluation in patients considered for sacral nerve stimulation

Objective: To retrospectively compare the efficacy and technical performance of a novel lead used for percutaneous nerve evaluation (PNE) during the testing phase for sacral nerve neuromodulation with the existing lead currently used. Materials and methods: Sixty-three PNE leads were inserted in 45 consecutive patients who underwent PNE with the novel helical electrodes, and the intra-operative and return clinic sensory threshold currents were recorded. This resulted in current measurements for 63 individual electrodes. Measurements were compared with 46 consecutive patients who previously underwent PNE using the standard lead with measurements for 63 individual electrodes. Current difference distributions for the two leads were compared using a Wilcoxon signed-rank test. Results: There was a statistically significant difference observed between the two types of PNE electrode. The new PNE lead demonstrated less drift in sensory threshold current during a 12-day test period in comparison to the old lead. Conclusion: The novel helical PNE electrodes demonstrate a significant improvement in current drift compared with the old style leads over a 12-day test period. Level of evidence: Level III

Super-resolved fluorescence imaging of peripheral nerve

Traditional histopathologic evaluation of peripheral nerve employs brightfield microscopy with diffraction limited resolution of ~ 250 nm. Though electron microscopy yields nanoscale resolution of the nervous system, sample preparation is costly and the technique is incompatible with living samples. Super-resolution microscopy (SRM) comprises a set of imaging techniques that permit nanoscale resolution of fluorescent objects using visible light. The advent of SRM has transformed biomedical science in establishing non-toxic means for investigation of nanoscale cellular structures. Herein, sciatic nerve sections from GFP-variant expressing mice, and regenerating human nerve from cross-facial autografts labelled with a myelin-specific fluorescent dye were imaged by super-resolution radial fluctuation microscopy, stimulated emission depletion microscopy, and structured illumination microscopy. Super-resolution imaging of axial cryosections of murine sciatic nerves yielded robust visualization myelinated and unmyelinated axons. Super-resolution imaging of axial cryosections of human cross-facial nerve grafts demonstrated enhanced resolution of small-caliber thinly-myelinated regenerating motor axons. Resolution and contrast enhancement afforded by super-resolution imaging techniques enables visualization of unmyelinated axons, regenerating axons, cytoskeleton ultrastructure, and neuronal appendages of mammalian peripheral nerves using light microscopes.