Nerve Conduction Measurements Research Articles

Long latency reflexes of the median nerves in healthy adults.

Long latency reflexes (LLRs) are late responses in nerve conduction studies seen after peripheral nerve stimulation during submaximal muscle contraction. They follow a short latency reflex, also known as the H reflex, and are thought to involve transcortical pathways, providing a measure of proximal nerve and central conduction. For this reason, they have been evaluated in several central nervous system diseases, but reference values are not widely published and are mostly based on old studies with very small numbers of participants. Therefore, in this work we aim to provide comprehensive reference values for LLR testing. LLRs were tested in a cohort of 100 healthy participants, testing the median nerve bilaterally. Mean latencies for short latency reflex (SLR), LLR1, LLR2, and LLR3 were 27.00, 38.50, 47.60, and 67.34 milliseconds, respectively. The allowable side-to-side difference was approximately 3 to 4 milliseconds. No significant sex-related differences were seen. Height correlated moderately with the SLR latency, but only weakly with LLR1, LLR2, and LLR3. This work provides normal LLR values for comparison with future studies in disease. The technique used may allow for improved evaluation of central nervous system or proximal peripheral nerve disorders.

Serum neurofilament light chain as an early diagnostic biomarker for critical illness polyneuropathy.

Critical illness polyneuropathy (CIP) commonly occurs in critical care unit (CCU) patients, but timely diagnosis can be challenging. Therefore, new biomarkers, such as serum neurofilament light chain (sNfL), could help to improve early identification of patients with this condition. CIP was diagnosed or excluded with neurological assessment and nerve conduction measurement in a prospective study of CCU patients. sNfL and secondary predictors for neuropathy (neuron-specific enolase (NSE), S100, folic acid, and vitamin B<inf>12</inf>) were measured at admission. Cases and controls were compared regarding the predictors. Nineteen patients met the inclusion criteria. CIP was considered definitely or most likely present in seven (37%, cases) and definitely or most likely absent in 12 individuals (63%, controls). At admission, sNfL levels were significantly higher in the cases than in the controls: 405 (IQR 77 to 835) vs. 27 (IQR 12 to 90) pg/mL; difference of medians 375, 95% confidence interval [14, 736], pg/mL; P=0.04. We found no significant differences regarding the secondary predictors at baseline. Cases had longer durations of CCU stay (median 19 (IQR 11 to 44) vs. 8 (IQR five to ten) and increased mortality (57% vs. 33% deceased) compared to controls. Levels of serum neurofilament light chain are higher in patients who develop CIP soon after CCU admission and might be helpful in identifying those individuals early.

Nerve Conduction Studies and Measurement of Median Nerve Cross-Sectional Area in Patients Newly Diagnosed with Hypothyroidism

Aim: This study aimed to investigate the rate of carpal tunnel syndrome (CTS) and polyneuropathy in patients with new-diagnosed hypothyroidism and the relationship between median nerve conduction and the cross-sectional area of the median nerve by ultrasonography. Material and Methods: It was a prospective, cross-sectional and case-control study. This study included thirty-five new-diagnosed hypothyroidism cases and thirty-five healthy controls. Bilateral sensory and motor nerve potentials were noted in the lower and upper extremities. The cross-sectional area of the median nerve was examined at the entrance of the CT with the axial plan by ultrasonography. The relationship between the cross-sectional areas of the median nerve and nerve conduction parameters was investigated. Results: CTS was determined electrophysiologically in 8 (22.9%) patients. The control group had no CTS. There was no significant electrophysiological finding to support polyneuropathy in the patients. The cross-sectional areas of the median nerve were higher in the patient group but did not reach statistically significant (p&amp;gt;0.05). There was a positive correlation between the right and left cross-sectional area of median nerves and body mass index (BMI) (p&amp;lt;0.05). Conclusion: The rate of CTS is high in patients with newly diagnosed hypothyroidism. There is a positive correlation between cross-sectional nerve areas and BMI. There was no significant correlation between nerve conductions and median nerve ultrasonographic cross-sectional areas.

Cognitive function in individuals with and without painful and painless diabetic polyneuropathy-A cross-sectional study in type 1 diabetes.

Previous studies suggest that cognitive impairment is more prevalent in individuals with painful and painless diabetic peripheral neuropathy (DPN). However, the current evidence is not well described. This study investigated cognitive function in adults with type 1 diabetes mellitus (T1DM) and the association to painful/painless DPN and clinical parameters. This cross-sectional, observational, case-control study included 58 participants with T1DM, sub-grouped into 20 participants with T1DM and painful DPN, 19 participants with T1DM and painless DPN, 19 participants with T1DM without DPN, and 20 healthy controls were included. The groups were matched for sex and age. The participants performed Addenbrooke's examination III (ACE-III), which assesses attention, memory, verbal fluency, language and visuospatial skills. Working memory was evaluated using an N-back task. Cognitive scores were compared between the groups and correlated to age, diabetes duration, HbA1c and nerve conduction measurements. Compared to healthy controls, T1DM participants showed lower total ACE-III (p = .028), memory (p = .013) and language scores (p = .028), together with longer reaction times in the N-back task (p = .041). Subgroup analyses demonstrated lower memory scores in those with painless DPN compared with healthy controls (p = .013). No differences were observed between the three T1DM subgroups. Cognitive scores and clinical parameters were not associated. This study supports the notion of cognitive alterations in T1DM and indicates that cognitive function is altered in T1DM regardless of underlying neuropathic complications. The memory domain appears altered in T1DM, particularly in those with painless DPN. Further studies are needed to verify the findings.

Correlation between nerve conduction changes and BETA-2 microglobulin concentration in chronic kidney disease patients on hemodialysis combined with hemodiafiltration online.

This study aimed to investigate the correlation between beta-2 microglobulin (B2M) concentration and some nerve conduction indices and evaluate the changes in some nerve conduction indices after treatment with hemodialysis (HD) combined with hemodiafiltration online in end-stage renal disease patients. From July 2021 to July 2022, a cross-sectional study was conducted on 80 end-stage renal disease patients on HD at Can Tho General Hospital, Viet Nam. All the patients had B2M testing and nerve conduction measurements. Patients with nerve conduction disorders were treated and remeasured after 6 months to evaluate the treatment results. At baseline, there was a moderate negative correlation between B2M and the tibial nerve and motor branch of the ulnar conduction velocity (V) (r = -0.305 and -0.315, P < .05). There was a moderate positive correlation between B2M and motor latency of the tibial and peroneal nerve (r = 0.434 and 0.440, P < .05). After 6 months of using the combination of HD and hemodiafiltration online, the V (31.3 ± 7.96 up to 44.88 ± 9.67 m/s) and the amplitude (A) (1.71 ± 1.16 up to 2.61 ± 1.51 mV) of the peroneal nerve increased, the motor latency decreased (8.21 ± 2.65 down to 5.23 ± 3.58 ms). With the tibial nerve, motor conduction V increased from 30.53 ± 8.05 m/s to 43.56 ± 8.99 m/s and the A increased from 5.04 ± 3.16 mV to 7.75 ± 4.45 mV. With the ulnar nerve, the A increased, and motor latency decreased after 6 months. The nerve conduction indices also improved significantly in the median nerve.

Detailed statistical analysis plan for the neurological complications in endoscopic versus open radial artery harvest (NEO) randomised clinical trial.

Coronary artery bypass grafting can be conducted using the radial artery as a bypass graft. However, it remains unclear which harvesting method is superior, i.e. endoscopic or open radial artery, and which site for proximal anastomosis of the radial artery has the greatest benefits? The NEO Trial is a single site randomised clinical trial with a 2 × 2 factorial design. The first comparison assesses endoscopic versus open radial artery harvest with a primary outcome of hand function and secondary outcomes of neurological deficits through clinical exams and neurophysiological studies. The primary outcome is postoperatively hand function at three months. We anticipate a mean difference of 3 points with a standard deviation of 8 points, a power of 90%, and a type I error of 5%, resulting in a required sample size of 300 participants randomised 1:1. Secondary outcomes are neurological deficits (based on nerve conduction measurements, algometry test and von Frey hair test), clinical neurological examination of cutaneous sensibility, and registration of complications in the donor arm (haematoma formation, wound dehiscence, and/or infection). The second comparison assesses two different proximal anastomotic sites, i.e. aorto-radial anastomosis versus mammario-radial anastomosis. The primary outcome is a composite of cerebrovascular events and the secondary outcome is graft patency evaluation by multi-slice computer tomography-scan. These outcomes will be assessed at 1year postoperatively, and the results of this comparison will be exploratory only. Both comparisons will be analysed using intention-to-treat and intervention groups will be compared using linear regression, logistic regression, or Mann-Whitney U test depending on data type. Two independent statisticians will follow the present plan and conduct the analyses which will hereafter be fused into a final analysis based on consensus. This detailed analysis plan will increase the validity of the NEO trial results by predefining the statistical analysis in detail. ClinicalTrials.gov identifier: NCT01848886 . Registered 25 February 2013. Danish Ethics committee number: H-3-2012-116. Danish Data Protection Agency: 2007-58-0015/jr. n:30-0838.

Accuracy of neuropathic pain measurements in patients with symptoms of polyneuropathy: validation of painDETECT, Self-Completed Leeds Assessment of Neuropathic Symptoms and Signs, and Douleur Neuropathique 4.

Pain is a common symptom in patients referred to polyneuropathy assessment. Diagnostic evaluation and choice of treatment may depend on whether the pain is likely to be neuropathic or not. This study aimed to investigate the diagnostic accuracy of 3 tools commonly used to differentiate between neuropathic and nonneuropathic pain. To accomplish this, we included patients with bilateral distal lower extremity pain, referred to neurological outpatient clinics at 5 Norwegian University hospitals for polyneuropathy assessment. The patients filled in Norwegian versions of painDETECT, the Self-Completed Leeds Assessment of Neuropathic Symptoms and Signs (S-LANSS), and the clinician-rated Douleur Neuropathique 4 (DN4). All patients underwent a clinical examination and nerve conduction measurements and were classified according to the NeuPSIG neuropathic pain criteria (reference standard). In total, 729 patients were included, of which 63% had neuropathic pain by the reference standard. Only DN4 demonstrated high sensitivity (0.87), whereas all 3 tools had low specificity (≤0.65). Importantly, the tools' predictive ability was unsatisfactory; The probability of getting a correct test result was 3 quarters at best, and at worst, no better than two fifths. Consequently, we show that neither DN4, painDETECT, nor S-LANSS can be confidently used to assess neuropathic pain in a neurological outpatient population with symptoms of polyneuropathy.

Migren ile Karpal Tünel Sendromu Birlikteliği

Aim: Migraine and carpal tunnel syndrome (CTS) are two common health problems that have some common features and are frequently encountered in society. Is it possible for these two tables, which have so much in common, to coexist? If so, is this association meaningful? The study was designed in order to find answers to these questions.&#x0D; Method: This study was performed with a total of 345 subject as 178 patients having carpal tunnel syndrome (CTS) and 167 migraine patients. The first group was composed of those diagnosed with CTS based on the nerve conduction measurements in the electrophysiology laboratory. These patients were classified according to the international headache classification criteria and those with and without migraine were determined in the light of the data in the questionnaire. The second group, called as migraine group, comprised of those admitted to the neurology outpatient clinic and diagnosed with migraine. The study was designed as a cross-sectional and comparative study.&#x0D; Results: Of the 345 patients who remained in the study after exclusion criteria, 178 were in the CTS group and 167 were in the migraine group. Although approximately 80,3% of those with CTS had migraine, only 12,6% of those diagnosed with migraine had CTS.&#x0D; Conclusion and Suggestions: We consider that migraine headaches may create a predisposition to contract CTS in the future. Additional studies are needed to support this view.

Correlations between Electro-Diagnostic Findings, the Severity of Initial Infection, and the Rehabilitation Outcomes among COVID-19 Patients.

Simple SummaryPatients with Coronavirus-2019 (COVID-19) often have reduced muscle strength and loss of sensory function. We examined several properties of the function of the nerve located at the arm and leg of 19 COVID-19 hospitalized patients before and after their rehabilitation period. We also evaluated the severity of their illness, their gait, muscle strength, and level of disability. We isolated several factors in the function of their nerves, which can be used to predict their prognosis and rehabilitation outcomes. Our findings are important since clinicians can use examinations of nerve function at early stages of the illness in order to devise an optimal treatment plan for the patient, thereby reducing the hospitalization period and promoting patient’s independence.Patients with Coronavirus-2019 (COVID-19) manifest many neuromuscular complications. We evaluated the correlations between electromyography and nerve conduction measurements among COVID-19 patients and the severity of the initial infection, as well as the rehabilitation outcomes, and searched for the factors which best predict the rehabilitation outcomes. A total of 19 COVID-19 patients (16 men; mean ± SD age 59.1 ± 10.4), with WHO clinical progression scale of 6.8 ± 2.3, received rehabilitation for 3.9 ± 2.5 months. The Functional Independence Measure (FIM), the 10 m walk test, the 6 minute walk test, and grip force were collected before and after the rehabilitation period. Motor Nerve Conduction (MNC), Sensory Nerve Conduction (SNC) and electromyographic abnormalities were measured. All of the MNC measures of the median nerve correlated with the WHO clinical progression scale and duration of acute hospitalization. The MNC and SNC measures correlated with the rehabilitation duration and with FIM at discharge. The MNC distal latency of the median and the peroneal nerves and the MNC velocity of the median and tibial nerves predicted 91.6% of the variance of the motor FIM at discharge. We conclude that nerve conduction measurements, especially in COVID-19 patients with severe illness, are important in order to predict prognosis and rehabilitation outcomes.

Neurotransmission Recovery by Melatonin Measured by CMAP.

Compound muscle action potential (CMAP) recordings provide a sensitive electromyographic approach to measure nerve conduction and assess neuromuscular junction functionality in humans and rodents. In humans, it represents a diagnostic tool for neuromuscular disorders. In rodents, this approach is widely employed to dissect the molecular mechanisms driving peripheral nerve degeneration/regeneration, as well as to evaluate the effect of candidate pro-regenerative compounds. The method described here allows recording CMAP from the gastrocnemius muscle of mice after sciatic nerve stimulation. We report some representative traces of CMAP recorded from adult, healthy mice, after sciatic nerve compression and during neurotransmission recovery stimulated by melatonin administration.

Surgical Procedures Required for Measurement Reduce Nerve Conduction Velocity: An In Vivo and In Vitro Comparative Study

Background: Although in vitro methods have disadvantages, they are still commonly used to measure nerve conduction velocity (NCV) in experimental studies. Therefore, this study was designed to demonstrate the effect of the surgical procedures required for in vitro methods on nerve fibers and the effect of in vivo and in vitro methods on the results of electrophysiological measurements. Methods: Rats were assigned to the in vivo (control-1, injury-1, and diabetic-1) and in vitro (control-2, injury-2, and diabetic-2) groups. The NCV and compound action potential amplitudes were measured, and the nerve fibers were histologically examined. Results: Damaged axons and myelin sheaths were observed in the control-2 group. The electrophysiological values of the in vitro groups were lower than those of the in vivo groups. Furthermore, these values were lower for the diabetic and injury groups than for the control groups. Conclusions: This study showed that the surgical procedures required for the in vitro method reduced the measured values. Owing to the previous and current disadvantages of the in vitro method, the in vivo method was more sensitive for the NCV measurement. Moreover, measurements can be performed using the current in vivo method for small nerve fibers.

Pilot study on the effects of low intensity focused ultrasound in a swine model of neuropathic pain.

The authors' laboratory has previously demonstrated beneficial effects of noninvasive low intensity focused ultrasound (liFUS), targeted at the dorsal root ganglion (DRG), for reducing allodynia in rodent neuropathic pain models. However, in rats the DRG is 5 mm below the skin when approached laterally, while in humans the DRG is typically 5-8 cm deep. Here, using a modified liFUS probe, the authors demonstrated the feasibility of using external liFUS for modulation of antinociceptive responses in neuropathic swine. Two cohorts of swine underwent a common peroneal nerve injury (CPNI) to induce neuropathic pain. In the first cohort, pigs (14 kg) were iteratively tested to determine treatment parameters. liFUS penetration to the L5 DRG was verified by using a thermocouple to monitor tissue temperature changes and by measuring nerve conduction velocity (NCV) at the corresponding common peroneal nerve (CPN). Pain behaviors were monitored before and after treatment. DRG was evaluated for tissue damage postmortem. Based on data from the first cohort, a treatment algorithm was developed, parameter predictions were verified, and neuropathic pain was significantly modified in a second cohort of larger swine (20 kg). The authors performed a dose-response curve analysis in 14-kg CPNI swine. Specifically, after confirming that the liFUS probe could reach 5 cm in ex vivo tissue experiments, the authors tested liFUS in 14-kg CPNI swine. The mean ± SEM DRG depth was 3.79 ± 0.09 cm in this initial cohort. The parameters were determined and then extrapolated to larger animals (20 kg), and predictions were verified. Tissue temperature elevations at the treatment site did not exceed 2°C, and the expected increases in the CPN NCV were observed. liFUS treatment eliminated pain guarding in all animals for the duration of follow-up (up to 1 month) and improved allodynia for 5 days postprocedure. No evidence of histological damage was seen using Fluoro-Jade and H&E staining. The results demonstrate that a 5-cm depth can be reached with external liFUS and alters pain behavior and allodynia in a large-animal model of neuropathic pain.

210-OR: Cerebral Morphometric Alterations in Painless and Painful Diabetic Peripheral Neuropathy

Aims: Neuroimaging studies have found structural alterations in brain regions involved in the somatomotor system in diabetic peripheral neuropathy (DPN) and painful-DPN (pDPN). However, most of these studies have had small cohorts of subjects, without consideration of pDPN phenotypes. Here we present the largest DPN neuroimaging study, which examines differences in brain morphology in DPN and phenotypes of painful-DPN. Methods: 229 participants were enrolled, 177 with diabetes (46 no-DPN, 56 painless-DPN and 75 pDPN; 25 irritable [IR] and 50 non-irritable [NIR] phenotype), and 52 healthy volunteers underwent detailed clinical, neurophysiological and quantitative sensory testing (DFNS) assessments, and 3-dimensional T1-weighted brain MRI (3.0T, Phillips). Brain volumetry was performed using Freesurfer. Results: At the post-central gyrus, in comparison with HV (1.92mm±0.11) and NoDPN (1.90mm±0.14), there was a significantly reduced cortical thickness in DPN (1.85mm±0.14), in pDPN (1.87mm±0.12) cortical thickness was reduced compared with HV. At the precentral gyrus, both DPN (2.29mm±0.16) and pDPN (2.28mm±0.16) had significantly reduced cortical thickness compared with HV (2.37mm±0.14) and NoDPN (2.36mm±0.13). At the insula, compared with HV (2.93mm±0.15) the cortical thickness was reduced in DPN (2.85mm±0.18) and pDPN (2.84mm±0.17). The cortical thickness at the pre and postcentral gyrus, and insula correlated with measures of nerve conduction. Moreover, the mean anterior cingulate cortical (ACC) thickness was significantly reduced in the IR- (2.40mm±0.23) compared to NIR-pDPN (2.58mm±0.20; p=0.003). Conclusions: Key somatomotor brain regions have a reduced cortical thickness in patients with DPN and pDPN, which correlate with neurophysiological measures suggestive of an ascending axonopathy. Moreover, the cortical thickness at the ACC differentiated IR and NIR, suggesting neuroplasticity in this region may play a role determining clinical phenotypes in pDPN. Disclosure G. P. Sloan: None. D. Selvarajah: None. K. Teh: None. P. Shillo: None. I. D. Wilkinson: None. S. Tesfaye: Advisory Panel; Self; Angellini, Bayer AG, Eva Pharma, Wörwag Pharma, Speaker’s Bureau; Self; Abbott, AstraZeneca, Grunenthal Group, MSD Corporation, Novo Nordisk, Pfizer Inc.

T2 mapping of the median nerve in patients with carpal tunnel syndrome and healthy volunteers.

We investigated the changes in MRI T2 mapping values in subjects with carpal tunnel syndrome (CTS) compared to healthy controls. We enrolled 71 patients with CTS and 26 healthy controls. Median nerve T2 values were measured at the distal carpal tunnel, hamate bone, proximal carpal tunnel, and forearm levels. These were compared between patients and controls and correlated with median nerve cross-sectional area (CSA) and nerve conduction measurements. The mean T2 values at the proximal carpal tunnel levels were higher in the CTS group (56.7 ms) than in the control group (51.2 ms, P = .02) and also were higher than at the distal carpal tunnel (51.0 ms, P < .001) and forearm levels (47.6 ms, P < .001). T2 values were not significantly associated with CSA or nerve conduction measurements. T2 mapping of the carpal tunnel provides qualitative information on median nerve pathology but does not reflect CTS severity.

Clinical Features of Ulnar Tunnel Syndrome and the Diagnostic Value of Nerve Conduction Measurements.

ABSTRACTObjectives:The purposes of this study were to assess the clinical features of ulnar tunnel syndrome (UTS) and to investigate the diagnostic value of nerve conduction measurements for UTS.Methods:Eighteen patients with UTS were reviewed retrospectively. Fifteen patients had intrinsic muscle atrophy and motor weakness, and 15 had numbness with hypesthesia. The compound muscle action potentials (CMAPs) from the first dorsal interosseous (FDI) muscle and the abductor digiti minimi (ADM) muscle and the sensory nerve action potential (SNAP) from the little finger were recorded and analyzed. All patients underwent ulnar tunnel release surgery and neurolysis. Static two-point discrimination test results and pinch strengths were assessed before and after surgery.Results:Before surgery, FDI-CMAP was recorded in 17 patients, and ADM-CMAP in 16, and all showed delayed latency and/or low amplitude. SNAP was recorded in eight patients and two showed delayed latency. The causes of ulnar nerve lesions were ganglion in five patients, traumatic adhesion in four, ulnar artery aberrancy in four, pisohamate arch in three, anomalous muscle in one, and ulnar vein varix in one. The sites of the lesions were in zone 1 of the ulnar tunnel anatomy in 12 patients, in zone 2 in 2, and in zones 1 and 2 in 4. After surgery, all patients obtained recovery of motor function and sensation; however, postoperative FDI-CMAP and ADM-CMAP did not improve to the normal range.Conclusions:The causes of UTS were ganglion, traumatic adhesion, ulnar artery aberrancy, and pisohamate arch. Both FDI-CMAP and ADM-CMAP were valuable for electrophysiological diagnosis of UTS.

Proximal fibular nerve conduction studies to tibialis anterior: Optimal E2 (reference electrode) placement.

Several E2 (reference electrode) positions are described for fibular (peroneal) nerve conduction studies to tibialis anterior (TA). This study compared the contribution of different E2 sites to the TA motor response, using remote referential recordings and different bipolar montages. The medial knee contributes minimal electrical activity to the bipolar TA recordings, whereas tibial, ankle, and toe references resulted in very similar, moderate amplitude contributions consistent with far field potentials. These observations were very similar in controls and in patients with lower leg symptoms and signs. Standard montages using distal leg or foot E2 sites result in lower amplitudes with distortion arising from the E2 electrode, compared with the TA-Knee montage. Optimal measurement of the TA motor response is achieved using a medial knee reference, without compromising measures of fibular nerve conduction across the knee.

Associations between hand function and electrophysiological measurements in hand osteoarthritis patients of different ages with or without carpal tunnel syndrome

Osteoarthritis is a common degenerative disease that most frequently involves the hand. The objective was to compare clinical functional outcome measures including hand grip, pinch strength, and dexterity with various electrophysiological measures in patients of different ages with hand osteoarthritis with or without the presence of carpal tunnel syndrome (CTS). Patients with hand osteoarthritis (208 patients, 404 hands) who underwent hand-function tests and motor and sensory nerve conduction studies (NCS) between June 2015 and June 2016 were enrolled. The patients’ hands were assigned to carpal tunnel syndrome (CTS) (206 hands; mean age, 56.37 ± 10.52; male:female, 46:160) or control groups (198 hands; mean age, 57.88 ± 9.68; male:female, 55:143). The strength of hand grip and lateral pinch, the time required to complete the nine-hole pegboard test (9HPT), and motor and sensory nerve conduction parameters were measured and compared across age groups and between hands with or without CTS. The CTS group showed significantly lower hand grip and lateral pinch strength, and a longer time to complete the 9HPT in comparison with the control group. Female patients showed significantly lower hand grip and lateral pinch strength than male patients. However, there was no difference in the 9HPT completion time between genders. Multivariate regression analysis identified the amplitude of the median compound muscle action potential (CMAP), age, and male gender as independent predictors of grip strength (adjusted R2 = 0.679), and amplitude of median CMAP and male gender as independent predictors of KP strength (adjusted R2 = 0.603). Velocity of median CMAP, amplitude of median sensory nerve action potential, and age were identified as independent predictors of 9HPT time (adjusted R2 = 0.329). Nerve conduction measurements were significantly related to hand-function test results, and CTS induced significant deficits in strength and performance of the affected hand.

Treatment of Drop Foot Using an Implantable Peroneal Underknee Stimulator

An implantable peroneal stimulator has been developed to improve the rehabilitation of the drop foot patients who cannot use or refuse the use of conventionally applied peroneal braces. The small size promotes convenient attachment on the stimulation site after a minor surgical intervention. During the past two years twenty implants have been applied. The influence of different stimulation parameters upon the correction of anomalies during walking has been studied using clinical and computer-supported assessment. Possible noxious effects on the peroneal nerve have been studied by measuring nerve conduction velocity. The stimulator is well accepted by patients. Clinical observations show a significant correction of equinovarus and improved gait.

126-OR: Baseline Omega-3 Status Is Associated with Nerve Regeneration following 1 Year of Omega-3 Nutrition Therapy in Patients with Diabetic Neuropathy

We have recently demonstrated that omega-3 nutrition therapy is associated with small nerve fiber regeneration in individuals with type 1 diabetes (T1D). It is unclear if baseline omega-3s relate to the presence of diabetic sensorimotor polyneuropathy (DSP) or nerve regeneration. Forty individuals with T1D participated in a 12-month single-arm open label study of seal oil omega-3 (10 mL/d; 750 mg EPA, 560 mg DPA acid, and 1,020 mg DHA). The primary outcome was the 1-year change in corneal nerve fiber length (CNFL) measured by in vivo corneal confocal microscopy, with sensory and nerve conduction measures as secondary outcomes. Plasma PUFAs were measured at 0, 4, 8 and 12-months. The 40 participants (53% female) had mean±SD age 48±14 years, body mass index 28.1±5.8 kg/m2, diabetes duration 27±18 years and 23(59%) had DSP. At baseline, participants with DSP had lower DHA concentration compared to those without (1.73±0.89% vs. 2.27±0.70, p=0.049). At 12-months, omega-3 nutrition therapy increased group mean plasma EPA by 185%, DPA by 29%, DHA by 79% (p&amp;lt;0.001) and decreased the omega-6 to omega-3 ratio by 45% (p&amp;lt;0.001). On average, CNFL increased 29±46% over the study, indicating small nerve fiber regeneration. This change was associated with the increase in total omega-3 (r=0.41, p=0.013), DPA (r=0.33, p=0.047) and DHA (r=0.42, p=0.012). There were 26(65%) participants that responded to therapy with a change in CNFL &amp;gt;0% and 9(22%) with a clinically significant loss of CNFL &amp;gt;-6%. At baseline, responders had higher total omega-3 (4.38±1.35% vs. 3.12±0.56%, p=0.010), EPA (0.91±0.47% vs. 0.59±0.23%, p=0.040) and DHA (2.16±0.90% vs. 1.34±0.40%, p=0.009).The change in these variables was not different between responders and non-responders (p&amp;gt;0.05). One year of seal oil omega-3 nutrition therapy increased blood omega-3s, while small nerve fiber regeneration appears to be related to baseline omega-3 status. Disclosure E.J.H. Lewis: Board Member; Spouse/Partner; Nutarniq Corp. Employee; Self; Nutarniq Corp. Stock/Shareholder; Self; Nutarniq Corp. B.A. Perkins: Consultant; Self; Abbott, Boehringer Ingelheim International GmbH, Insulet Corporation. Research Support; Self; Boehringer Ingelheim International GmbH, Novo Nordisk A/S. Other Relationship; Self; Medtronic. L. Lovblom: None. A. Metherel: None. T. Wolever: None. V. Bril: Advisory Panel; Self; Alexion Pharmaceuticals, Inc., Alnylam Pharmaceuticals, Takeda Canada. Consultant; Self; Akcea Therapeutics, CSL Behring, Sanofi. Research Support; Self; Biogen, Grifols, Momenta Pharmaceuticals. Funding Diabetes Canada (OG-2-13-4093-VB)

Associations between acute glucose control and peripheral nerve structure and function in type 1 diabetes.

To examine the associations between continuous overlapping net glycaemic action (CONGA), percentage time in hyperglycaemia (%HG) or normoglycaemia (%NG) and peripheral nerve structure and function in type 1 diabetes. Twenty-seven participants with type 1 diabetes underwent continuous glucose monitoring followed by corneal confocal microscopy and nerve excitability assessments. CONGA, %HG (>10.0 mmol/l) and %NG (3.9-10.0 mmol/l) were correlated against corneal nerve fibre length and density in the central cornea and inferior whorl region, corneal microneuromas, and a nerve excitability score while controlling for age, sex, diabetes duration and HbA1c . An increase in CONGA [median 2.5 (2.0-3.1) mmol/l] or %HG (mean 46 ± 18%) was associated with a worse nerve excitability score (r = -0.433, P = 0.036 and r = -0.670, P = 0.0012, respectively). By contrast, greater %NG (51 ± 17%) correlated with better nerve excitability scores (r = 0.672, P = 0.0011). Logistic regression revealed that increasing %HG increased the likelihood of abnormal nerve function [odds ratio (OR) 1.11, 95% confidence interval (CI) 1.01-1.23; P = 0.037). An increase in CONGA and %HG were associated with worsening nerve conduction measures, whereas longer %NG correlated with improved nerve conduction variables. CONGA and %HG were associated with inferior whorl corneal nerve fibre length (r = 0.483, P = 0.034 and r = 0.591, P = 0.021, respectively) and number of microneuromas (r = 0.433, P = 0.047 and r = 0.516, P = 0.020, respectively). Short-term measures of glucose control are associated with impaired nerve function and alterations in corneal nerve morphology.