Nerve Conduction Research Articles

Understanding neuropathic pain: the role of neurophysiological tests in unveiling underlying mechanisms

AbstractNeuropathic pain, arising from lesions of the somatosensory nervous system, presents with diverse symptoms including ongoing pain, paroxysmal pain, and provoked pain, usually accompanied by sensory deficits. Understanding the pathophysiological mechanisms behind these symptoms is crucial for targeted treatment strategies. Neurophysiological techniques such as nerve conduction studies, reflexes, and evoked potentials help elucidate these mechanisms by assessing large myelinated non-nociceptive fibres and small nociceptive fibres. This argumentative review highlights the importance of tailored neurophysiological assessments for improving our understanding of the pathophysiological mechanisms behind neuropathic pain symptoms.

Ultrasound acting as a guiding light in the diagnosis of posterior interosseous nerve entrapment at ligament of Frohse – A case report

Posterior interosseous nerve (PIN) entrapment syndrome is a relatively rare compression neuropathy which leads to weakness of the extensor muscles of hand. This becomes a cause of morbidity to the patient with resultant difficulty in conducting day-to-day activities. Thickening of proximal edge of the superficial head of the supinator muscle which forms the ligament of Frohse can lead to compression of the PIN as it enters the supinator canal. Although nerve conduction studies can indicate the diagnosis, they cannot identify the exact site and cause of compression which is crucial for deciding the further management. Magnetic resonance imaging can identify the cause of entrapment in some cases; however, this is extremely difficult given the small size of the PIN and arcade of Frohse. Ultrasound overcomes these limitations and provides a cost and time effective, efficient, and sensitive diagnostic tool for detecting nerve entrapment. Here, we would like to emphasize the emerging importance of ultrasound by describing a case of ligament of Frohse thickening causing PIN entrapment which was effectively diagnosed by ultrasound and confirmed on surgical exploration, treated with surgical ligament release with a full recovery.

The Enigma of the Motor Nerve Conduction Study.

In motor nerve conduction studies (MNCS), proximal stimulation should give a longer duration and lower amplitude compound muscle action potential (CMAP) due to higher temporal dispersion. Yet the CMAP waveforms at the distal and proximal stimulation sites appear remarkably similar. The objective of this study was to confirm this anomaly and investigate its possible cause by studying the median and ulnar nerves. Recordings from 50 subjects with normal electrodiagnostic studies were reviewed. The conduction velocity (CV) was measured using different points on the negative phase of the CMAP including its peak and baseline crossing. Collision studies were performed in three healthy subjects to measure the dispersion when nerve action potentials (APs) propagated from elbow to wrist. CV was relatively unaffected by the measurement point on the CMAP. The CMAP duration with elbow stimulation increased minimally compared to wrist stimulation. This was inconsistent with the dispersion of the AP from wrist to elbow measured in collision studies. The insignificant change in the CMAP in spite of axon AP dispersion is an enigma. We hypothesize that the terminal conduction time (TCT) (i.e., conduction in terminal axon branches, neuromuscular transmission, etc.) is independent of axon CV, represents a significant portion of the latency, masks AP dispersion, and reduces CMAP dispersion. This yields similar CMAPs with distal and proximal stimulation. The onset latency at the distal stimulation site does not depend on CV. Thus, onset latency and CV may not reflect the conduction properties of the fastest conducting axons.

Sensory-Motor Polyneuropathy in an 11-year- old Girl with a Pathogenic Variant in SMC1A: A Case Report.

Pathogenic variants in the SMC1A gene are often dominant-negative and cause an X-linked form of Cornelia de Lange syndrome (CdLS) with growth retardation and typical facial features. However, rare SMC1A variants cause a developmental and epileptic encephalopathy (DEE) with intractable early-onset epilepsy that is absent in CdLS. Here we describe an 11-year-old girl with epilepsy, walking disorder, and neurodevelopmental disorder. A neurophysiological examination of nerve conduction velocity showed a mixed, sensory-motor, chronic 4-limb polyneuropathy. Whole-exome sequencing identified the variant c.3145C > T p.(Arg1049*) in SMC1A (NM_006306.3), which can be classified as pathogenic. To the best of our knowledge, among 79 individuals with SMC1A-related DEE reported in the literature, altered peripheral nerve conduction has never been described. In this article, we propose that severe sensory-motor polyneuropathy could be an expansion of the SMC1A-related phenotype.

Development of a near infrared region based non-invasive therapy device for diabetic peripheral neuropathy.

Diabetic Peripheral Neuropathy (DPN) is a nerve damage that is treated with painkillers and steroids which have the drawback of interference with other medications and the dangers of side effects. Novelty of the proposed work is to develop a Near Infrared Region (NIR) based non-invasive therapy device called 'DPNrelief-1.0V'developed with a 890 nm wavelength diodes. DPNrelief-1.0V delivers a total dosage of 6.174 J/cm2 with heat absorption by tissue of 61.74 Joules at 30 minutes. The device was tested by carrying out a pilot study with 8 patients where 4 were treatment group and control group. The DPNrelief-1.0V is validated by Nerve Conduction Study (NCS) test. The degenerated nerves pre-therapy showed less amplitude, Conduction Velocity (CV) and latency which was improved post-therapy by 100% in amplitude of nerve signal, 100% in CV and a decrease of 36.2% in latency. Independent t-test was conducted to find the difference between control and treatment, wherein a p value < 0.05 was obtained depicting significant difference between two groups. Furthermore, the performance of the device is validated by one-way test repeated measures Analysis of Variance (ANOVA), wherein a p value of < 0.05 was obtained depicting a difference in nerve condition pre-and post-therapy. The performance of DPNrelief-1.0V has outperformed Anodyne therapy device with lesser dosage, treatment time and portability and in curing the symptoms of DPN. DPNrelief-1.0V finds its potential in the field of medicine for treating DPN.

Multi-Layered Implant Approach for Hemilaryngectomy Reconstruction in a Porcine Model.

Partial laryngectomies result in voice, swallowing, and airway impairment for thousands of patients in the United States each year. Treatment options for dynamic restoration of laryngeal function are limited. Thus, there is a need for new reconstructive approaches. Here, we evaluated early (4 week) outcomes of multi-layered mucosal-myochondral (MMC) implants when used to restore laryngeal form and function after hemilaryngectomy in a porcine model. Six Yucatan minipigs underwent transmural hemilaryngectomies followed by reconstruction with customized MMC implants aiming to provide site-appropriate localization of regenerated laryngeal tissues, while supporting laryngeal function. All implants were fabricated from polymeric collagen, with a subset of muscle and cartilage implants containing motor endplate-expressing muscle progenitor cells or cartilage-like cells differentiated from adipose stem cells, respectively. Vocalization and laryngeal electromyography (L-EMG) measurements with nerve conduction studies were performed post-operatively and compared with baseline along with gross and histological analyses of the healing response. All animals (n = 6) survived and maintained airway patency, safe swallowing, and phonation, without the use of tracheostomy and/or gastrostomy tubes. Histological evaluation indicated no adverse tissue reaction or implant degradation, showing progressive regenerative remodeling with mucosa reformation and ingrowth of new muscle and cartilage. Preliminary L-EMG suggested weak but detectable motor unit action potentials. Although vocalization duration, frequency, and intensity decreased post-operatively, all animals retained vocal capacity and parameter recovery was evident over the study duration. Engineered collagen polymeric implants in the presence or absence of autologous cell populations may serve as a feasible reconstructive option to restore dynamic function after hemilaryngectomy. Long-term follow-up is needed to further assess functional outcomes. NA Laryngoscope, 2024.

Clinical and neurophysiological aspects of peripheral neuropathy in patients with myelodysplastic syndromes.

Myelodysplastic syndromes (MDS) are a heterogeneous group of clonal disorders, manifesting multiple clinical autoimmune inflammatory phenomena, including rarely peripheral neuropathy. Twenty-four patients diagnosed with MDS and 29 healthy subjects were enrolled in this prospective study in a 5-year period. Every subject was assessed by symptoms questionnaire and clinical neurological examination followed by nerve conduction studies, quantitative sensory testing and skin biopsy. Peripheral neuropathy was diagnosed in 12 subjects (50%). Our study indicated that peripheral neuropathy involving large and small nerve fibres, with a symmetrical length-dependent pattern, is not uncommon between patients with MDS.

Effectiveness of Kabat Technique versus Mirror Book Therapy on clinical and electrophysiological parameters in patients with Bell’s palsy: a comparative interventional study

Abstract Background Bell’s palsy significantly impacts facial function, aesthetics, and quality of life. Objective To compare the effects of the Kabat Technique (KT) and Mirror Book Therapy (MBT) on clinical and electrophysiological parameters in patients with Bell’s palsy. Methods This randomized controlled trial included 31 patients divided into two groups: KT (n = 16) and MBT (n = 15). Both groups received their respective interventions (6 days/week for 3 weeks) in addition to conventional physiotherapy. Sunnybrook Facial Grading Score and Nerve Conduction Test (amplitude and latency of frontalis, nasalis, and mentalis muscles) were assessed pre- and post-intervention. Results Statistical analysis (SPSS v20) revealed significant intragroup improvements in all outcome measures (p &lt; 0.05). Intergroup comparison showed MBT had superior improvements in amplitude of frontalis and reduced latency of nasalis. Both groups demonstrated significant improvement in the Sunnybrook grade shift. Conclusion This study suggests that KT and MBT, combined with conventional physiotherapy, positively impact clinical and electrophysiological parameters in Bell's Palsy patients. MBT showed superior results in select Nerve Conduction Test parameters.

The Effects of Thermal and Pulsed Ultrasound on Pain and Function in Patients with Carpal Tunnel Syndrome: A Randomized Controlled Trial

ABSTRACT Objective While ultrasound therapy is common for carpal tunnel syndrome, the relative merits of thermal versus pulsed ultrasound remain unclear. This study compares their therapeutic effects. Design Randomized, double-blinded, placebo-controlled trial. Ninety-two adults aged 30-60 years with mild-moderate carpal tunnel syndrome (characteristic symptoms, positive clinical tests, abnormal electrophysiology) were randomized into 4 groups receiving 4 weeks night splinting plus 12 ultrasound sessions: Group A: 1 MHz, 1.0 W/cm2 continuous ultrasound for 5 minutes; Group B: 1 MHz, 25% duty cycle, 1.0 W/cm2 pulsed ultrasound for 15 minutes; Group C: 5 minutes thermal plus 15 minutes pulsed ultrasound; Group D: sham ultrasound for 15 minutes. Pain (VAS), function (DASH-Arabic), nerve conduction, and grip strength were measured at baseline, 4, and 8 weeks. Results Thermal and pulsed ultrasound groups improved in all outcomes versus placebo over 8 weeks (p &lt; 0.05). Pulsed ultrasound decreased pain and distal motor latency more than placebo (p &lt; 0.05). Thermal ultrasound increased sensory nerve action potentials versus placebo (p &lt; 0.05). Conclusion Thermal and pulsed ultrasound with splinting improved pain, disability, grip strength, and nerve conduction in carpal tunnel syndrome. Pulsed ultrasound was optimal for pain and motor function, while thermal ultrasound enhanced sensory nerve function.

Charcot‐Marie‐Tooth disease in children

AbstractCharcot‐Marie‐Tooth (CMT) disease represents a diverse group of inherited neuropathies with a broad spectrum of symptoms. It is the most prevalent inherited neuropathy, with an estimated prevalence ranging from 9.7 to 82 cases per 100,000 individuals. Despite this, CMT comprises only 118 of 853 inherited neuropathy entries in the Online Mendelian Inheritance in Man (OMIM) database. This comprehensive review offers a thorough examination of CMT's clinical features, subtypes, genetic underpinnings, and pathomechanisms in pediatric cases. CMT typically manifests as progressively worsening muscle weakness and atrophy, primarily affecting the distal extremities. Patients may also experience foot and ankle deformities, hand atrophy, and other systemic issues. To accurately diagnose CMT, a detailed family history, comprehensive clinical evaluation, nerve conduction studies, and relevant genetic testing are essential. Importantly, establishing a differential diagnosis is crucial during evaluation to rule out other conditions with similar presentations. This review aims to provide clinicians with a valuable resource for diagnosing and managing CMT, emphasizing the need for a streamlined and standardized approach considering advancements in genetic testing and the identification of various subtypes.

Sural-to-medial femoral cutaneous amplitude ratio in early diagnosis of uremic neuropathy.

Medial femoral cutaneous (MFC) sensory nerve action potentials (SNAPs) can be easily recorded using distal stimulation. This study aimed to identify a new parameter using MFC SNAPs for the early electrophysiological diagnosis of length-dependent axonal polyneuropathy (LDAP) associated with uremic neuropathy. Patients with chronic renal failure who were referred to the electrodiagnostic laboratory due to symptoms suggesting polyneuropathy were included. Assessments encompassed neurological examination, Michigan Neuropathy Screening Instrument (MNSI), and Semmes-Weinstein monofilament test. Antidromic radial, median, ulnar, MFC, sural, and superficial peroneal sensory; median, ulnar, tibial, and peroneal motor nerve conduction studies were performed. Sural-to-radial amplitude ratio (SRAR) and sural-to-medial femoral cutaneous amplitude ratio (SMFCAR) were calculated, and their diagnostic sensitivities were compared with the age and sex matched healthy controls. Thirty-two chronic renal failure patients (mean age 60.0 ± 9.6 years) and 37 controls (60.6 ± 9 years) were included. MNSI indicated clinical polyneuropathy in 59.4% of patients, while sural SNAP amplitude was diagnostic in 78%. Median SRAR and SMFCAR values were significantly lower in patients than controls (p < .001 for both). The cut-off values for SMFCAR and SRAR were <1.82 and <0.30, respectively, both with a sensitivity of 59% and a specificity of 94%. Sural SNAP is the most sensitive parameter in the diagnosis of LDAP. SMFCAR is not superior to SRAR. If the sural SNAP amplitude is normal, SMFCAR can serve as an alternative to SRAR in dialysis patients with bilateral arteriovenous fistulae or in those unable to undergo radial NCS.

An all-atom model of the human cardiac sodium channel in a lipid bilayer

Voltage-gated sodium channels (NaV) are complex macromolecular proteins that are responsible for the initial upstroke of an action potential in excitable cells. Appropriate function is necessary for many physiological processes such as heartbeat, voluntary muscle contraction, nerve conduction, and neurological function. Dysfunction can have life-threatening consequences. During the past decade, there have been significant advancements with ion channel structural characterization by CryoEM, yet descriptions of cytosolic components are often lacking. Many investigations have biophysically characterized reconstituted cytosolic components and their interactions. However, extrapolating the structural alterations and allosteric communication within an intact ion channel can be challenging. To address this, we have developed an all-atom model of the human cardiac sodium channel (NaV1.5) in a lipid bilayer with explicit salt and water. Our simulations contain descriptions of cytosolic components that are poorly predicted by AlphaFold and lacking in many CryoEM structures. Leveraging the latest advancements of the Amber force fields (ff19sb and Lipid21) and water model (OPC), our simulations improved protein backbone torsion angles and generated structural information across time (four independent one-microsecond simulations). Our analysis provided descriptions of lipid and solvent contacts and insight into the C-Terminal Domain - inactivation gate and inactivation gate - latch receptor interactions.

Effect of Chronic Consumption of Fluoridated Water on Sciatic Nerve Conduction Velocity in Male Wistar Rats.

The long-term effect of fluoridated water consumption during development on the velocity of nerve impulse conduction in the sciatic nerve of rats was assessed. Thirty male Wistar rats, 21 days old, were randomly assigned to five groups. Three groups were given fluoridated water ad libitum (as the only source) at different concentrations (10, 100, and 150 ppm), designated as groups F10, F100, and F150, respectively. The study included a control group (C) that received fluoridated water at the maximum level established by the World Health Organization (1.5 ppm of fluorides) and another group that received deionized water (DW). The animals were treated until they reached 90 days of age. Electrophysiological recordings were performed on the rats' sciatic nerves to determine nerve conduction velocity, and blood plasma was extracted for fluoride concentration analysis. The study found that the F150 group had a lower nerve impulse conduction velocity in the sciatic nerve compared to the C group (P = 0.0015). Additionally, there was a negative correlation between the concentration of fluorides in plasma and the nerve conduction velocity (r = -0.5132, P = 0.0037). These findings indicate that chronic consumption of high concentrations of fluoride leads to a decrease in nerve conduction velocity. This, in conjunction with potential alterations in the central nervous system, may explain the deficits in learning and memory tests that have been documented in numerous studies evaluating individuals exposed to fluoride consumption. These results provide valuable information for understanding the effects and action mechanisms of fluoride in exposed individuals.

AAV1.tMCK.NT-3 gene therapy improves phenotype in Sh3tc2-/- mouse model of Charcot-Marie-Tooth Type 4C.

Charcot-Marie-Tooth Type 4C (CMT4C) is associated with mutations in the SH3 domain and tetratricopeptide repeats 2 (SH3TC2) gene, primarily expressed in Schwann cells (SCs). Neurotrophin-3 (NT-3) is an important autocrine factor for SC survival and differentiation, and it stimulates neurite outgrowth and myelination. In this study, scAAV1.tMCK.NT-3 was delivered intramuscularly to 4-week-old Sh3tc2-/- mice, a model for CMT4C, and treatment efficacy was assessed at 6-month post-gene delivery. Efficient transgene production was verified with the detection of NT-3 in serum from the treated cohort. NT-3 gene therapy improved functional and electrophysiological outcomes including rotarod, grip strength and nerve conduction velocity. Qualitative and quantitative histopathological studies showed that hypomyelination of peripheral nerves and denervated status of neuromuscular junctions at lumbrical muscles were also improved in the NT-3-treated mice. Morphometric analysis in mid-sciatic and tibial nerves showed treatment-induced distally prominent regenerative activity in the nerve and an increase in the estimated SC density. This indicates that SC proliferation and differentiation, including the promyelination stage, are normal in the Sh3tc2-/- mice, consistent with the previous findings that Sh3tc2 is not involved in the early stages of myelination. Moreover, in size distribution histograms, the number of myelinated axons within the 3- to 6-µm diameter range increased, suggesting that treatment resulted in continuous radial growth of regenerating axons over time. In conclusion, this study demonstrates the efficacy of AAV1.NT-3 gene therapy in the Sh3tc2-/- mouse model of CMT4C, the most common recessively inherited demyelinating CMT subtype.

Infantile Krabbe disease (0-12 months), progression, and recommended endpoints for clinical trials.

Krabbe disease is due to deficiency of galactocerebrosidase, resulting in progressive neurodegeneration due to demyelination. The purpose of this study is to document disease progression in the newly classified infantile-onset (0-12 months). We evaluated the outcomes of hematopoietic stem cell transplantation (HSCT) and described meaningful clinical endpoints. Patients with infantile Krabbe disease were prospectively evaluated between 2000 and 2022. All patients underwent comprehensive and standardized protocols. Descriptive statistics and Kaplan-Meier survival curves were used for analysis. One hundred and thirty-seven children with infantile Krabbe disease were included (68 males and 69 females). Of the 137, 96 were not treated and 41 underwent hematopoietic stem cell transplantation. Twenty-three were asymptomatic and 18 symptomatic. Initial symptoms included irritability, developmental delay or loss of milestones, feeding difficulties, spasticity, and reflux with an average survival of 2.2. Abnormalities in nerve conduction studies, auditory brainstem responses, and brain MRIs were evident in both groups of patients. Age at transplantation and signs and symptoms determined functional outcomes. Symptomatic and asymptomatic transplanted patients showed an increase in galactocerebrosidase and a decrease in psychosine, but did not reach the normal range. The median survival for transplanted symptomatic patients was 5 years while asymptomatic was extended to 15.5 years. Infantile Krabbe disease with onset before 12 months is rapidly progressive. Irreversible brain damage occurs unless timely HSCT is performed. HSCT does not prevent the progression of peripheral nerve disease. This study can be used to monitor patients and evaluate the effects of future therapies.

Evaluation of the Impact of Advanced Glycation End-Products on Peripheral Neuropathy Outcomes in Type 2 Diabetes

Background: Type 2 diabetes (T2DM) affects over 500 million people worldwide, and over 50% of this group experience the most common complication, diabetic peripheral neuropathy (DPN). The presence of advanced glycation end-products (AGEs) has been linked with the development of DPN. The present study assessed AGE levels in participants with type 2 diabetes and explored the hypothesis that there may be increased AGE levels in more severe DPN. Methods: A total of 124 participants with T2DM were consecutively recruited, and they underwent skin autofluorescence, clinical assessment for peripheral neuropathy, peripheral nerve ultrasound, nerve conduction studies, and axonal excitability assessment. Results: AGE accumulation showed weak but significant correlations with neuropathy severity and reduced nerve conduction function. However, after adjusting for confounding variables, a linear regression analysis did not reveal significant associations between the AGE levels and neuropathy outcomes. Conclusions: The present study suggests that the accumulation of AGE is not associated with the clinical, electrophysiological, and morphological measures of neuropathy in T2DM.

Comparative efficacy and safety of Chinese patent medicines as an adjunctive therapy for diabetic peripheral neuropathy: systematic review and network meta-analysis of randomized controlled trials

Context Diabetic peripheral neuropathy (DPN) is the most common complication of diabetes mellitus. Chinese patent medicines (CPMs) are widely used in clinical practice to treat DPN. Objective This study aims to summarize the latest evidence on the harms and benefits of CPMs as adjunctive therapy for DPN. Materials and methods We conducted searches for randomized controlled trials (RCTs) evaluating CPMs in conjunction with mecobalamin (Mec) or alpha-lipoic acid (αLA) across eight databases up to July 2024. The surface under the cumulative ranking area (SUCRA) was utilized to assess the clinical efficacy rate (CER), the peroneal motor nerve conduction velocity (pMNCV), the peroneal sensory nerve conduction velocity (pSNCV), the median motor nerve conduction velocity (mMNCV), and the median sensory nerve conduction velocity (mSNCV). Results The search yielded 128 eligible studies with 31 CPMs with Mec and 39 eligible studies with 17 CPMs with αLA. SUCRA rankings indicated that, when combined with Mec, Mailuoning liquid (lMLN) was the most effective regimen for CER, Honghua injection (iHH) for pMNCV, Maixuekang capsule (cMXK) for pSNCV, Dengzhanxixin injection (iDZXX) for mMNCV, and Tongxinluo capsule (cTXL) for mSNCV. Combined with αLA, Danhong injection (iDH) showed the highest efficacy for CER, pSNCV, and mSNCV, while Xueshuantong injection (iXShT) was the most effective for pMNCV and mMNCV. Conclusion This network meta-analysis confirms the efficacy and safety of 37 CPMs combined with Mec or αLA for treating DPN. However, given the potential risk of bias and the very low certainty of the evidence, these recommendations should be adopted with caution.

Screening for Diabetic Peripheral Neuropathy: Subjective Versus Objective Measures.

This study compared subjective screening modalities recommended in diabetic foot screening guidelines for the detection of diabetic peripheral neuropathy (DPN) with an objective measure, the NC-Stat DPNCheck®. We assessed 63 participants (mean age 54.5 years ± 10.5) utilising subjective screening tools (Semmes-Weinstein 10-g monofilament, 128-Hz traditional tuning fork, neurothesiometer, O'Brien 128-Hz electronic tuning fork) and compared results with the objective automated sural nerve conduction test NC-Stat DPNCheck®. A significant difference was found in the number of limbs classified with DPN between all screening tools (P < .05). Therefore, this suggests that some screening modalities are more sensitive in diagnosing DPN than others, highlighting the importance of using multiple screening tools to a comprehensive understanding of the patient's neurological status. The findings also emphasize the need to incorporate objective measures in diabetic foot screening and encourage future research to establish a gold standard tool for DPN diagnosis.

Levodopa Impairs Lysosomal Function in Sensory Neurons In Vitro

Parkinson’s disease (PD) is the second-most common neurodegenerative disease worldwide. Patients are diagnosed based upon movement disorders, including bradykinesia, tremor and stiffness of movement. However, non-motor signs, including constipation, rapid eye movement sleep behavior disorder, smell deficits and pain are well recognized. Peripheral neuropathy is also increasingly recognized, as the vast majority of patients show reduced intraepidermal nerve fibers, and sensory nerve conduction and sensory function is also impaired. Many case studies in the literature show that high-dose levodopa may induce or exacerbate neuropathy in PD, which is thought to involve levodopa’s metabolism to homocysteine. Here, we treated primary cultures of dorsal root ganglia and a sensory neuronal cell line with levodopa to examine effects on cell morphology, mitochondrial content and physiology, and lysosomal function. High-dose levodopa reduced mitochondrial membrane potential. At concentrations observed in the patient, levodopa enhanced immunoreactivity to beta III tubulin. Critically, levodopa reduced lysosomal content and also reduced the proportion of lysosomes that were acidic, thereby impairing their function, whereas homocysteine tended to increase lysosome content. Levodopa is a critically important drug for the treatment of PD. However, our data suggest that at concentrations observed in the patient, it has deleterious effects on sensory neurons that are not related to homocysteine.

Nerve conduction in cats: a pilot study to determine most appropriate use of opioid

Nerve conduction in cats: a pilot study to determine most appropriate use of opioid