Nerve Cross-sectional Area Research Articles

Ultrasonographic evaluation of ulnar nerve morphology in patients with ulnar nerve instability.

Ulnar nerve instability (UNI) in the retroepicondylar groove is described as nerve subluxation or dislocation. In this study, considering that instability may cause chronic ulnar nerve damage by increasing the friction risk, we aimed to examine the effects of UNI on nerve morphology ultrasonographically. Asymptomatic patients with clinical suspicion of UNI were referred for further clinical and ultrasonographic examination. Based on ulnar nerve mobility on ultrasound, the patients were first divided into two groups: stable and unstable. The unstable group was further divided into two subgroups: subluxation and dislocation. The cross-sectional area (CSA) of the nerve was measured in three regions relative to the medial epicondyle (ME). In the ultrasonographic evaluation, UNI was identified in 59.1% (52) of the 88 elbows. UNI was bilateral in 50% (22) of the 44 patients. Mean CSA was not significantly different between groups. A statistically significant difference in ulnar nerve mobility was found between the group with CSA of <10 versus ≥10 mm2 (p = .027). Nerve instability was found in 85.7% of elbows with an ulnar nerve CSA value of ≥10 mm2 at the ME level. The probability of developing neuropathy in patients with UNI may be higher than in those with normal nerve mobility. Further prospective studies are required to elucidate whether asymptomatic individuals with UNI and increased CSA may be at risk for developing symptomatic ulnar neuropathy at the elbow.

Nerve ultrasound in Friedreich’s Ataxia: enlarged nerves as a biomarker of disease severity

ObjectiveIn Friedreich's ataxia research, the focus is on discovering treatments and biomarkers to assess disease severity and treatment effects. Our study examines high-resolution nerve ultrasound in these patients, seeking correlations with established clinical markers of disease severity. MethodTen patients with Friedreich’s Ataxia underwent a comprehensive clinical assessment with established scales (SARA, FARS, mFARS, INCAT, ADL 0-36, IADL). Additionally, they underwent nerve conduction studies and high-resolution nerve ultrasound. Quantitative evaluation of nerve cross-sectional area, conducted at 24 nerve sites using high-resolution nerve ultrasound, was compared with data obtained from 20 healthy volunteers. ResultsAll the patients had a severe sensory axonal neuropathy. High-resolution nerve ultrasound showed significant increase, in cross sectional area, of median and ulnar nerves at the axilla and arm. The cumulative count of affected nerve sites was directly associated with clinical disability, as determined by SARA, FARS, mFARS, ADL 0-36, and INCAT score, while displaying an inverse correlation with IADL. ConclusionsOur study shows that high-resolution ultrasound reveals notable nerve abnormalities, primarily in the upper limbs of patients diagnosed with Friedreich’s Ataxia. The observed correlation between these nerve abnormalities and clinical disability scales indicates the potential use of this technique as a biomarker for evaluating disease severity and treatment effects. SignificanceNerve Ultrasound is a potential biomarker of disease severity in Friedreich’s Ataxia.

Application of radiomics model based on ultrasound image features in the prediction of carpal tunnel syndrome severity.

The aim of our study is to develop and validate a radiomics model based on ultrasound image features for predicting carpal tunnel syndrome (CTS) severity. This retrospective study included 237 CTS hands (106 for mild symptom, 68 for moderate symptom and 63 for severe symptom). There were no statistically significant differences among the three groups in terms of age, gender, race, etc. The data set was randomly divided into a training set and a test set in a ratio of 7:3. Firstly, a senior musculoskeletal ultrasound expert measures the cross-sectional area of median nerve (MN) at the scaphoid-pisiform level. Subsequently, a recursive feature elimination (RFE) method was used to identify the most discriminative radiomic features of each MN at the entrance of the carpal tunnel. Eventually, a random forest model was employed to classify the selected features for prediction. To evaluate the performance of the model, the confusion matrix, receiver operating characteristic (ROC) curves, and F1 values were calculated and plotted correspondingly. The prediction capability of the radiomics model was significantly better than that of ultrasound measurements when 10 robust features were selected. The training set performed perfect classification with 100% accuracy for all participants, while the testing set performed accurate classification of severity for 76.39% of participants with F1 values of 80.00, 63.40, and 84.80 for predicting mild, moderate, and severe CTS, respectively. Comparably, the F1 values for mild, moderate, and severe CTS predicted based on the MN cross-sectional area were 76.46, 57.78, and 64.00, respectively.. This radiomics model based on ultrasound images has certain value in distinguishing the severity of CTS, and was slightly superior to using only MN cross-sectional area for judgment. Although its diagnostic efficacy was still inferior to that of neuroelectrophysiology. However, this method was non-invasive and did not require additional costs, and could provide additional information for clinical physicians to develop diagnosis and treatment plans.

Association Between Thenar Musculature and Carpal Tunnel Syndrome.

Background: Dynamic forces acting on the transverse carpal ligament (TCL) may influence the mechanics of the carpal tunnel (CT), thus affecting the occurrence of CT syndrome (CTS). Previous studies demonstrated an association between muscle overlying the CT and the diagnosis of CTS. Understanding the location of insertion/origin of the thenar musculature will allow mechanical analysis of the forces applied to the TCL during performance of individual tasks. Our purpose was to determine the location of muscle overlying the CT on magnetic resonance imaging (MRI) in CTS and controls. Methods: Case-control study of 21 normal adult wrist MRI scans. MRI measurements were performed on an axial cut at the level of the hook-of-hamate. Median nerve cross-sectional area (CSA), median nerve shape and increased signal intensity within the CT were associated with CTS. The amount and length of muscle crossing the midline and the CT on the same cut was measured and the association with the occurrence of CTS was analysed. Results: We found an inverse relationship between the amount of muscle crossing the midline and the size of the CT, and a direct relationship with occurrence of CTS p less than 0.01, but no differences regarding length of muscle crossing the midline. Conclusions: This study supports an association between the thenar musculature location relative to the CT and the predictors of CTS on MRI. Since the location of muscle origin/insertion is variable, their effect may differ accordingly, therefore, further study is needed to describe the exact location of origin/insertion and its differential dynamic or static effect on the pathogenesis of CTS. Level of Evidence: Level IV (Diagnostic).

Magnetic resonance neurography in spinal cord injury: Imaging findings and clinical significance.

It is unknown whether changes to the peripheral nervous system following spinal cord injury (SCI) are relevant for functional recovery or the development of neuropathic pain below the level of injury. Magnetic resonance neurography (MRN) at 3 T allows detection and localization of structural and functional nerve damage. This study aimed to combine MRN and clinical assessments in individuals with chronic SCI and nondisabled controls. Twenty participants with chronic SCI and 20 controls matched for gender, age, and body mass index underwent MRN of the L5 dorsal root ganglia (DRG) and the sciatic nerve. DRG volume, sciatic nerve mean cross-sectional area (CSA), fascicular lesion load, and fractional anisotropy (FA), a marker for functional nerve integrity, were calculated. Results were correlated with clinical assessments and nerve conduction studies. Sciatic nerve CSA and lesion load were higher (21.29 ± 5.82 mm2 vs. 14.08 ± 4.62 mm2 , p < 0.001; and 8.70 ± 7.47% vs. 3.60 ± 2.45%, p < 0.001) in individuals with SCI compared to controls, whereas FA was lower (0.55 ± 0.11 vs. 0.63 ± 0.08, p = 0.022). DRG volumes were larger in individuals with SCI who suffered from neuropathic pain compared to those without neuropathic pain (223.7 ± 53.08 mm3 vs. 159.7 ± 55.66 mm3 , p = 0.043). Sciatic MRN parameters correlated with electrophysiological results but did not correlate with the extent of myelopathy or clinical severity of SCI. Individuals with chronic SCI are subject to a decline of structural peripheral nerve integrity that may occur independently from the clinical severity of SCI. Larger volumes of DRG in SCI with neuropathic pain support existing evidence from animal studies on SCI-related neuropathic pain.

ART and AutoART ECAP measurements and cochlear nerve anatomy as predictors in adult cochlear implant recipients

PurposeThe purpose of this retrospective study is to compare the results of electrically evoked compound action potential (ECAP) measurements using automatic auditory response telemetry (AutoART) with those obtained by ART in adults. The study also aimed to evaluate the predictive value of intraoperative ART and AutoART ECAPs for speech intelligibility (SI) and hearing success (HS), and to determine if cochlear nerve (CN) cross-sectional area (CSA) obtained preoperatively by magnetic resonance imaging (MRI) scans could predict ART and AutoART ECAPs and SI and HS outcome.MethodsThe study analyzed and correlated ART and AutoART ECAP thresholds at electrodes E2, E6, and E10, as well as averaged ECAP thresholds over electrodes E1–E12, using data from 32 implants. Correlations were also examined for ART and AutoART ECAP slopes. In addition, averaged ART and AutoART ECAP thresholds and slopes over all 12 electrodes for each participant were correlated with CN CSA measured from MRI sequences. SI of the monosyllabic Freiburg Speech Test at 65 dB sound pressure level was examined along with averaged ART and AutoART thresholds and slopes over all 12 electrodes. A parallel analysis was performed for HS, derived from the difference between baseline and 6-month SI. Finally, correlations between CN CSA and SI, as well as CN CSA and HS were examined.ResultsThe results of the study showed a significant positive correlation between ART and AutoART ECAP thresholds and as well as slopes for E2, E6, E10 and averaged thresholds and slopes of E1–E12. However, no significant correlation was observed between ART and AutoART averaged ECAP thresholds and slopes and either SI and HS or CN CSA. Furthermore, no significant correlation was found between CN CSA and SI and HS.ConclusionWhile AutoART is a reliable and safe program for measuring ECAPs in adults, the study found no preoperative prognostic information on intraoperative ECAP results using parameters extracted from current MRI sequences or pre-/intraoperative information on subsequent hearing outcome using ECAP and CN CSA.

Glucagon-like peptide-1 receptor agonists reverse nerve morphological abnormalities in diabetic peripheral neuropathy.

Diabetic peripheral neuropathy (DPN) is a highly prevalent cause of physical disability. Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are used to treat type 2 diabetes and animal studies have shown that glucagon-like peptide-1 (GLP-1) receptors are present in the central and peripheral nervous systems. This study investigated whether GLP-1 RAs can improve nerve structure. Nerve structure was assessed using peripheral nerve ultrasonography and measurement of tibial nerve cross-sectional area, in conjunction with validated neuropathy symptom scores and nerve conduction studies. A total of 22 consecutively recruited participants with type 2 diabetes were assessed before and 1 month after commencing GLP-1 RA therapy (semaglutide or dulaglutide). There was a pathological increase in nerve size before treatment in 81.8% of the cohort (n=22). At 1 month of follow-up, there was an improvement in nerve size in 86% of participants (p<0.05), with 32% returning to normal nerve morphology. A 3 month follow-up study (n=14) demonstrated further improvement in nerve size in 93% of participants, accompanied by reduced severity of neuropathy (p<0.05) and improved sural sensory nerve conduction amplitude (p<0.05). This study demonstrates the efficacy of GLP-1 RAs in improving neuropathy outcomes, evidenced by improvements in mainly structural and morphological measures and supported by electrophysiological and clinical endpoints. Future studies, incorporating quantitative sensory testing and measurement of intraepidermal nerve fibre density, are needed to investigate the benefits for small fibre function and structure.

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.

Multimodal ultrasound evaluation of asymptomatic ulnar nerve dislocation at the cubital tunnel.

Ultrasonography has received broad acceptance as an effective peripheral nervous imaging examination. Shear wave elastography (SWE) can quantitatively assess the stiffness of nerves; however, little research has been conducted on elastography for ulnar nerve dislocation. The purpose of this study was thus to investigate the characteristics of multimodal ultrasound, including high-resolution ultrasonography and SWE, for asymptomatic ulnar nerve dislocation at cubital tunnel. In this prospective cross-sectional study, 41 participants were recruited in Shandong Provincial Hospital Affiliated to Shandong First Medical University in July 2022. The inclusion criteria for participants were being in good health and being 18-60 years of age. Meanwhile, the exclusion criterion was a history of upper limb pain or fractures, peripheral neuropathy, or systemic or immunological diseases. Finally, 38 participants were enrolled. Two ultrasound doctors measured the maximum diameter, the maximum cross-sectional area (CSA), and the shear modulus of the ulnar nerve at the cubital tunnel independently. Another two ultrasound doctors determined whether dislocation was present during dynamic elbow flexion and extension and divided the elbows into a dislocation group and a control group. The descriptive statistics and independent sample t-test were used for data analysis, and intragroup correlation coefficient (ICC) was used to determine the consistency of evaluation between observers. Ulnar nerve dislocation was observed in 15.8% (12/76) of the ulnar nerves. There was no significant difference in the maximum diameter between the dislocation group (0.194±0.022 cm) and the control group (0.181±0.023 cm) (t=1.888; P=0.063). The CSA and SWE of the ulnar nerve were 0.064±0.009 cm2 and 43.629±6.737 kPa in the dislocation group, respectively, and were 0.050±0.008 cm2 and 31.293±7.858 kPa in the control group, respectively. There were significant differences between the two groups in terms of CSA (P<0.001) and SWE (P<0.001). The ICCs of the maximum diameter, CSA, and SWE values between observers were 0.970, 0.900, and 0.915, respectively. Multimodal ultrasound consisting of high-resolution ultrasonography combined with elastography can comprehensively and quantitatively evaluate the morphological changes and mechanical properties of the dislocated ulnar nerve and monitor disease progress.

Ultrasonographic Assessment of Median Nerve Cross-Sectional Area in Obstetricians

Ultrasonographic Assessment of Median Nerve Cross-Sectional Area in Obstetricians

Echographic Optic Nerve Evaluation: A Novel Diagnostic Modality in Glaucoma

Introduction: Primary Open-Angle Glaucoma (POAG) is considered a leading cause of blindness among all others. Different technologies such as Scanning Laser Polarimetry (SLP) and Optical Coherence Tomography (OCT) closely correlate in measuring structural parameters of the Retinal Nerve Fiber Layer (RNFL) and Optic Nerve Head (ONH). Visual impairment related to glaucomatous damage is attributed to the RNFL. Earlier studies have shown that retro-bulbar optic nerve thickness is reduced in glaucoma and have suggested that this is also the result of RNFL destruction. Aim: To investigate the correlation between the orbital and intraocular portions of the optic nerve among POAG patients. Materials and Methods: This was a hospital-based crosssectional study done in a tertiary care ophthalmic institute from October 2019 to February 2021. One eye of 32 volunteers with newly diagnosed POAG underwent optic disc analysis using OCT and echographic measurements of the retrobulbar optic nerve. For statistical calculations, Statistical Package for Social Sciences (SPSS) Statistics version 20.0 software (IBM Corp., Armonk, NY, USA) was used. Spearman’s rho (rs) was used as the index of correlation between retrobulbar optic nerve dimensions and ONH topographical data. A correlation between OCT-based RNFL and optic disc parameters was compared with retrobulbar optic nerve dimensions measured with the help of Ultrasonography- Brightness (USG B) Scan. Results: Orbital Optic Nerve Diameter (OND) and Optic Nerve Cross-sectional Area (ONCSA) significantly and positively correlated with Neuro-retinal Rim (NR) area (OND: p-value=0.00001; ONCSA: p-value=0.00001) and average nerve fiber layer thickness (OND: p-value=0.0001; ONCSA: p-value=0.00002). The Retrobulbar ONCSA-to-disc area ratio (ONCSA/D) was found to have a statistically demonstrable positive correlation with Neuro-retinal Rim Area/Disc area ratio (NR/D) (p=0.00003). Conclusion: This study showed that retrobulbar optic nerve dimensions correlate well with SD-OCT-based ONH parameters. Echographic measurements of the retrobulbar optic nerve add a new biomarker in the diagnosis of glaucoma.

Diagnostic Ability of Nerve Conduction Study, Ultrasonography and Magnetic Resonance Imaging in Diagnosis of Carpel Tunnel Syndrome

Introduction: Current diagnostic criteria for Carpel Tunnel Syndrome (CTS) include a patient's medical history, physical exam results, and electrophysiological findings. The purpose of the study is to evaluate the diagnostic ability of nerve conduction study, ultrasonography and magnetic resonance imaging for the diagnosis of carpal tunnel syndrome with the use of clinical findings as the gold standard.&#x0D; Methodology: The study was conducted among 30 patients clinically diagnosed having CTS based on the criteria given by American Academy of Neurology and American Academy of Physical Medicine and Rehabilitation. All patients included in the study were underwent USG of affected wrist joint, CT scan as well MRI of the same.&#x0D; Results: Out of total 30 participants, 14 (46.7%) were found moderate severity followed by 11 (36.7%) were found mild severity. Only 5 (16.7%) were found severe carpel tunnel syndrome. Amongst all three investigation methods, nerve conduction study having the lowest sensitivity (83.33%). The sensitivity of the ultrasonography and MRI was 90% each.&#x0D; Conclusion: It is clear from this study that the sensitivity of the parameters utilized in NCS (maximum observed 83.33%) is lower than that of the median nerve cross-sectional area detected on USG (90%) and MRI (90%). The most sensitive, practical, and cost-effective metric of all those seen in the research turned out to be the median nerve cross sectional area evaluated at the wrist crease by USG.

The vagus nerve cross-sectional area on ultrasound in patients with type 2 diabetes.

Diabetic neuropathy, including autonomic neuropathy is a serious complication related to type 2 diabetes mellitus (T2D). The vagus nerve (VN) is the longest nerve in the autonomic nervous system, and since diabetic neuropathy manifests first in longer nerves, the VN is commonly affected in early diabetic autonomic neuropathy. The use of high-resolution ultrasound for peripheral and cranial nerve imaging has significantly increased over the past 2 decades. The aim of the study is to compare the cross-sectional area of the VN in patients with T2D to that of a control cohort without T2D. A total of 52 VN cross-sectional areas were recorded from patients with T2D. A total of 56 VN cross-sectional areas were also recorded from asymptomatic subjects without T2D. In each subject, high-resolution ultrasound imaging of the bilateral VNs was performed in the short-axis between the common carotid artery and the internal jugular vein. The VN cross-sectional areas were recorded and compared. In the patients with T2D, HbA1c and fasting blood glucose levels were obtained as well as the duration of T2D in years and correlated with the cross-sectional areas. The bilateral VN cross-sectional areas were similar in both cohorts. Additionally, no correlation was seen between the VN cross-sectional areas, demographics, or clinical data of T2D. Our study demonstrated normal VN cross-sectional areas in patients with T2D without any significant relation with the patients' demographic or clinical data.

Evaluation of Serum Neurofilament Light Chain and Nerve Ultrasound in Diabetic Neuropathy.

To assess the role of serum neurofilament light chain (NfL) levels in individuals with diabetic polyneuropathy (DPN) compared with controls, as well as to highlight the different sonographic changes in DPN and determine if NfL correlates with sonographic, clinical, and functional parameters. Diabetic individuals with signs or symptoms consistent with peripheral nerve involvement were recruited. They were evaluated by examination, functional neuropathy severity scores, laboratory assessments (including NfL), nerve conduction studies (NCS), and ultrasound. Ultrasound was performed of the bilateral median, ulnar, tibial, fibular, sural, and vagus nerves, and cervical roots 5 and 6. Results were compared with age, sex, and body mass index matched healthy controls. A total of 320 nerves from 20 patients and 480 nerves from 30 controls were evaluated. NfL was significantly elevated in those with diabetes with a mean and standard deviation of 6.95 ± 2.95 pg/mL in the diabetic group and 2.83 ± 0.77 pg/mL in controls (P < .001). Nerve cross-sectional area and serum NfL levels correlated significantly with clinical and functional parameters and with each other (P < .05). Individuals with DPN have significantly higher NfL levels than healthy controls, and NfL levels correlate with ultrasonographic parameters. These findings may be useful for the diagnosis, prognosis, and disease monitoring of those with DPN, though further exploration is needed.

Quantitative magnetic resonance neurography in chronic inflammatory demyelinating polyradiculoneuropathy: A longitudinal study over 6 years.

To evaluate magnetic resonance neurography (MRN) for the longitudinal assessment of patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). Prospective examination of twelve CIDP patients by neurological assessment, MRN, and nerve conduction studies in 2016 and 6 years later in 2022. Imaging parameters were compared with matched healthy controls and correlated with clinical and electrophysiological markers. The MRN protocol included T2-weighted imaging, diffusion tensor imaging (DTI), T2 relaxometry, and magnetization transfer imaging (MTI). Nerve cross-sectional area (CSA) was increased in CIDP patients compared to controls (plexus: p = 0.003; sciatic nerve: p < 0.001). Over 6 years, nerve CSA decreased in CIDP patients, most pronounced at the lumbosacral plexus (p = 0.015). Longitudinally, changes in CSA correlated with changes in the inflammatory neuropathy cause and treatment validated overall disability sum score (INCAT/ODSS) (p = 0.006). High initial nerve CSA was inversely correlated with changes in the INCAT/ODSS over 6 years (p < 0.05). The DTI parameter fractional anisotropy (FA) showed robust correlations with electrodiagnostic testing both cross-sectionally and longitudinally (p < 0.05). MTI as a newly added imaging technique revealed a significantly reduced magnetization transfer ratio (MTR) in CIDP patients (p < 0.01), suggesting underlying changes in macromolecular tissue composition, and correlated significantly with electrophysiological parameters of demyelination (p < 0.05). This study provides evidence that changes in nerve CSA and FA reflect the clinical and electrophysiological course of CIDP patients. Initial nerve hypertrophy might predict a rather benign course or better therapy response.

Reference Values of Nerve Cross-sectional Area Obtained by Ultrasound in the Upper Extremity Correlated with Electrodiagnosis in Thai Adults

OBJECTIVE To evaluate the ultrasonography cross-sectional area (CSA) reference values of nerves in the upper extremity correlated with electrodiagnosis in healthy Thai adults. METHODS A cross-sectional study was performed. Ninety participants were recruited and their CSA at 10 sites on the median, ulnar, and radial nerves were measured bilaterally. A nerve conduction study (NCS) was conducted and the correlations between the nerve CSA and age, sex, height, weight, body mass index (BMI), and NCS parameters were studied. RESULTS The mean CSA ranged from 5.8±1.4 to 9.5±1.5 mm2 along the median nerve and 4.5±0.8 to 7.7±1.7 mm2 along the ulnar nerve. The mean CSAs of the radial nerve at the elbow and spiral groove were 5.0±0.9 and 4.6±0.8 mm2, respectively. The CSA of the median nerve at the wrist and the CSA of the radial nerve at the spiral groove were positively correlated with weight and BMI, whereas the CSA of the median nerve at the elbow was positively correlated only with weight. There was an association between CSA values and electrodiagnosis parameters as the nerve CSA increased, as the latency was prolonged, and as the amplitude decreased. CONCLUSIONS The reference values of nerve CSA in the upper extremity at multiple sites can be helpful in the evaluation of peripheral nerve disorders in the Thai population. KEYWORDS cross-sectional area, ultrasonography, peripheral nerves, electrodiagnosis

Exploration of Neurofilament Light Chain and Nerve Ultrasound in Leprotic Neuropathy.

To explore neurofilament light chain (NfL) levels in leprotic neuropathy compared to controls, and to determine if the changes correlate with ultrasonographic nerve findings. Individuals with leprosy with signs or symptoms suggestive of peripheral nerve involvement were recruited. They were evaluated by clinical examination, functional scores, laboratory assessments (including NfL), nerve conduction studies (NCS), and ultrasound. Ultrasound was conducted in bilateral median, ulnar, tibial, fibular, sural, and vagus nerves as well as cervical roots 5 and 6. Results were compared to age, sex, and body mass index matched healthy controls. A total of 320 nerves from 20 patients and 480 nerves from 30 controls were evaluated. NfL was significantly elevated in those with leprosy with a mean and standard deviation of 7.50 + 2.83 compared with 3.42 + 1.18 in controls (P < .001). Ultrasound showed focal enlargement of the nerves, particularly at entrapment sites. Additionally, there were noticeable changes in neural Doppler signal, echogenicity, and epineural thickness among the measured nerve sites. NfL levels in those with leprosy correlated closely with nerve cross-sectional area at all sites (P < .05). Functional and clinical assessment scores correlated with NfL and sonographic cross-sectional area as well (P ≤ .05). NfL is elevated in leprotic neuropathy. Ultrasound showed specific morphological changes in individuals with leprosy, and nerve enlargement correlated with NfL levels. Thus, both modalities may be useful for the diagnosis, prognosis, and disease monitoring in those with leprotic neuropathy, and further investigations are warranted.

A diminished sciatic nerve structural integrity is associated with distinct peripheral sensory phenotypes in individuals with type 2 diabetes

Aims/hypothesisQuantitative sensory testing (QST) allows the identification of individuals with rapid progression of diabetic sensorimotor polyneuropathy (DSPN) based on certain sensory phenotypes. Hence, the aim of this study was to investigate the relationship of these phenotypes with the structural integrity of the sciatic nerve among individuals with type 2 diabetes.MethodsSeventy-six individuals with type 2 diabetes took part in this cross-sectional study and underwent QST of the right foot and high-resolution magnetic resonance neurography including diffusion tensor imaging of the right distal sciatic nerve to determine the sciatic nerve fractional anisotropy (FA) and cross-sectional area (CSA), both of which serve as markers of structural integrity of peripheral nerves. Participants were then assigned to four sensory phenotypes (participants with type 2 diabetes and healthy sensory profile [HSP], thermal hyperalgesia [TH], mechanical hyperalgesia [MH], sensory loss [SL]) by a standardised sorting algorithm based on QST.ResultsObjective neurological deficits showed a gradual increase across HSP, TH, MH and SL groups, being higher in MH compared with HSP and in SL compared with HSP and TH. The number of participants categorised as HSP, TH, MH and SL was 16, 24, 17 and 19, respectively. There was a gradual decrease of the sciatic nerve’s FA (HSP 0.444, TH 0.437, MH 0.395, SL 0.382; p=0.005) and increase of CSA (HSP 21.7, TH 21.5, MH 25.9, SL 25.8 mm2; p=0.011) across the four phenotypes. Further, MH and SL were associated with a lower sciatic FA (MH unstandardised regression coefficient [B]=−0.048 [95% CI −0.091, −0.006], p=0.027; SL B=−0.062 [95% CI −0.103, −0.020], p=0.004) and CSA (MH β=4.3 [95% CI 0.5, 8.0], p=0.028; SL B=4.0 [95% CI 0.4, 7.7], p=0.032) in a multivariable regression analysis. The sciatic FA correlated negatively with the sciatic CSA (r=−0.35, p=0.002) and markers of microvascular damage (high-sensitivity troponin T, urine albumin/creatinine ratio).Conclusions/interpretationThe most severe sensory phenotypes of DSPN (MH and SL) showed diminishing sciatic nerve structural integrity indexed by lower FA, likely representing progressive axonal loss, as well as increasing CSA of the sciatic nerve, which cannot be detected in individuals with TH. Individuals with type 2 diabetes may experience a predefined cascade of nerve fibre damage in the course of the disease, from healthy to TH, to MH and finally SL, while structural changes in the proximal nerve seem to precede the sensory loss of peripheral nerves and indicate potential targets for the prevention of end-stage DSPN.Trial registrationClinicalTrials.gov NCT03022721Graphical

Effectiveness of tibial transverse transport combined with modified neurolysis in treatment of diabetic foot ulcers

To investigate the effectiveness of tibial transverse transport (TTT) combined with modified neurolysis in treatment of diabetic foot ulcer (DFU) through a prospective randomized controlled study. The patients with DFU and diabetic peripheral neuropathy, who were admitted between February 2020 and February 2022, were selected as the research objects, of which 31 cases met the selection criteria and were included in the study. The patients were divided into two groups by random number table method. The 15 patients in the trial group were treated with TTT combined with modified neurolysis, and the 16 patients in the control group received treatment with TTT alone. There was no significant difference in gender, age, duration of DFU, ulcer area, Wagner classification, as well as preoperative foot skin temperature, visual analogue scale (VAS) score, ankle-brachial index (ABI), motor nerve conduction velocity (MNCV) of the common peroneal nerve, MNCV of the tibial nerve, MNCV of the deep peroneal nerve, two-point discrimination (2-PD) of heel, and cross-sectional area (CSA) of the common peroneal nerve between the two groups ( P>0.05). The time for ulcer healing, foot skin temperature, VAS scores, ABI, 2-PD of heel, and CSA of the common peroneal nerve before operation and at 6 and 12 months after operation were recorded and compared between groups. The differences in MNCV of the common peroneal nerve, MNCV of the tibial nerve, and MNCV of the deep peroneal nerve between pre-operation and 12 months after operation were calculated. All patients in both groups were followed up 12-24 months (mean, 13.9 months). The surgical incisions in both groups healed by first intention and no needle tract infections occurred during the bone transport phase. Ulcer wounds in both groups healed successfully, and there was no significant difference in the healing time ( P>0.05). During the follow-up, there was no ulcer recurrences. At 12 months after operation, the MNCV of the common peroneal nerve, the MNCV of the tibial nerve, and the MNCV of the deep peroneal nerve in both groups accelerated when compared to preoperative values ( P<0.05). Furthermore, the trial group exhibited a greater acceleration in MNCV compared to the control group, and the difference was significant ( P<0.05). The foot skin temperature, VAS score, ABI, 2-PD of heel, and CSA of the common peroneal nerve at 6 and 12 months after operation significantly improved when compared with those before operation in both groups ( P<0.05). The 2-PD gradually improved over time, showing significant difference ( P<0.05). The 2-PD of heel and VAS score of the trial group were superior to the control group, and the differences were significant ( P<0.05). There was no significant difference in ABI, foot skin temperature, and CSA of the common peroneal nerve between groups after operation ( P>0.05). Compared with TTT alone, the TTT combined with modified neurolysis for DFU can simultaneously solve both microcirculatory disorders and nerve compression, improve the quality of nerve function recovery, and enhance the patient's quality of life.

Proximal trigeminal nerve atrophy is associated with favourable outcomes and persistent facial numbness following percutaneous balloon compression for primary trigeminal neuralgia.

Whether nerve atrophy can affect the prognosis of primary trigeminal neuralgia (PTN) patients undergoing percutaneous balloon compression (PBC) remains unclear. This study aimed to determine the association between nerve characteristics observed on preoperative magnetic resonance imaging (MRI) and PBC outcomes. Between January 2019 and December 2022, a cohort of 58 patients with unilateral PTN treated with PBC were analysed retrospectively and included in this study. The relationship between MRI findings, including the proximal and distal nerve cross-sectional areas (CSAs), and favourable pain outcomes (BNI Grades I-III) was analysed through Kaplan‒Meier analysis. After a mean follow-up period of 23.8 ± 13.0months (range, 6-50months), 48 (82.8%) patients with PTN were pain free with or without medication. A smaller proximal CSA ratio (proximal CSA of the affected nerve/proximal CSA of the unaffected nerve) was significantly associated with favourable outcomes. The Kaplan-Meier survival analysis showed that patients with proximal nerve atrophy (proximal CSA ratio ≤ 87% after receiver operating characteristic curve analysis) had a higher estimated 4-year probability of maintaining a favourable outcome than those without nerve atrophy (94.4% vs. 30.8%, p = 0.005). In addition, patients with proximal nerve atrophy were more likely to suffer from postoperative persistent facial numbness. Proximal nerve atrophy is correlated with both favourable outcomes and persistent facial numbness following PBC. Prospective studies are required to determine the optimal duration and pressure of balloon compression in relation to the proximal CSA ratio to achieve better pain outcomes and less facial numbness.