Essential tremor amplitude modulation by median nerve stimulation.

Essential tremor is a common neurological disorder, characterised by involuntary shaking of a limb. Patients are usually treated using medications which have limited effects on tremor and may cause side-effects. Surgical therapies are effective in reducing essential tremor, however, the invasive nature of these therapies together with the high cost, greatly limit the number of patients benefiting from them. Non-invasive therapies have gained increasing traction to meet this clinical need. Here, we test a non-invasive and closed-loop electrical stimulation paradigm which tracks peripheral tremor and targets thalamic afferents to modulate the central oscillators underlying tremor. To this end, 9 patients had electrical stimulation delivered to the median nerve locked to different phases of tremor. Peripheral stimulation induced a subtle but significant modulation in five out of nine patients-this modulation consisted mainly of amplification rather than suppression of tremor amplitude. Modulatory effects of stimulation were more pronounced when patient's tremor was spontaneously weaker at stimulation onset, when significant modulation became more frequent amongst subjects. This data suggests that for selected individuals, a more sophisticated control policy entailing an online estimate of both tremor phase and amplitude, should be considered in further explorations of the treatment potential of tremor phase-locked peripheral stimulation.

An advanced stage of carpal tunnel syndrome - is night-time splinting still effective?

OBJECTIVES: There is no consensus on whether conservative treatment with night splints is indicated also in moderate and severe stages of carpal tunnel syndrome (CTS). The goal of this study was to compare the efficacy of night-time splinting at different stages of CTS. MATERIAL AND METHODS: Forty-five patients with electrodiagnostic (EDX) features of CTS included in the study were divided into 2 groups based on nerve conduction studies. The patients in the first group had only median nerve sensory fiber involvement, whereas the patients in the second group had also motor fiber involvement. The custom-made volar night splint was the only treatment for all of the included patients. The patients were assessed before the fabrication of orthosis and after 12 weeks of its use. The parameters measured were hand grip strength and the Visual Analogue Scale for pain and paraesthesia. The patients further completed the Boston Carpal Tunnel Syndrome Questionnaire (BCTQ) and a shorter version of the Disabilities of the Arm, Shoulder and Hand Questionnaire (QuickDASH). RESULTS: In the first group, a statistically significant improvement was established in paraesthesia and hand grip strength (p = 0.019, p = 0.024, respectively), but there was no statistically significant improvement in pain, and the results of both BCTQ and QuickDASH. In the second group, a statistically significant improvement was found in paraesthesia, the BCTQ Symptom Severity Scale and QuickDASH results (p = 0.008, p < 0.001, p = 0.011, respectively), whereas no statistically significant improvement was established in pain, hand grip strength and the BCTQ Functional Status Scale. However, when comparing the change in the outcome measures between the 2 groups, no statistically significant differences were found. CONCLUSIONS: This study has shown that 12-week night-time splinting is beneficial not only for patients with mild CTS but also for those with advanced CTS, and those awaiting surgical treatment. Therefore, splinting is recommended for all patients with CTS. Int J Occup Med Environ Health. 2020;33(6):771-80.

Peripheral and Central Adaptations After a Median Nerve Neuromobilization Program Completed by Individuals With Carpal Tunnel Syndrome: An Exploratory Mechanistic Study Using Musculoskeletal Ultrasound Imaging and Transcranial Magnetic Stimulation.

OBJECTIVE: Neuromobilization exercises are increasingly advocated in the conservative management of individuals with carpal tunnel syndrome (CTS), as they may mitigate CTS-related signs and symptoms via potential peripheral (ie, musculoskeletal) and central (ie, neurophysiological) adaptations. However, the mechanisms underlying these adaptations have not been studied extensively. Hence, this exploratory and mechanistic study aims to evaluate the potential peripheral and central adaptations that may result in individuals with CTS who have completed a neuromobilization program. METHODS: Fourteen individuals with CTS were evaluated before and 1 week after the completion of a 4-week neuromobilization program that incorporated median nerve sliding exercises. Pain and upper limb functional abilities were assessed using standardized questionnaires. The biological integrity and mechanical properties of the median nerve and the corticospinal excitability were quantified using musculoskeletal ultrasound imaging and transcranial magnetic stimulation, respectively. RESULTS: Upon completion of the program, participants reported both large and moderate improvements in pain (P ≤ .03) and upper limb functional abilities (P = .02), respectively. The biological integrity and mechanical properties of the median nerve remained unchanged (P ≥ .22), whereas a small significant increase in corticospinal excitability (P = .04) was observed. CONCLUSION: The proposed neuromobilization program appears promising to improve pain and upper limb functional abilities in individuals with CTS. These improvements may be preferentially mediated via central, rather than peripheral, adaptations. Future studies, especially with a larger sample size, longer intervention duration, and additional measurement times, are needed to strengthen current evidence.

Effective self-stretching of carpal ligament for the treatment of carpal tunnel syndrome: A double-blinded randomized controlled study.

INTRODUCTION: Carpal tunnel syndrome (CTS) is the most common nerve entrapment syndrome worldwide. There are limited studies on the effectiveness of carpal ligament stretching on symptomatic and electrophysiologic outcomes. PURPOSE OF THE STUDY: The purpose of this study was to evaluate the effect of self-myofascial stretching of the carpal ligament on symptom outcomes and nerve conduction findings in persons with CTS. STUDY DESIGN: This is a prospective, double-blinded, randomized, placebo-controlled trial. METHODS: Eighty-three participants diagnosed with median mononeuropathy across the wrist by nerve conduction study were randomized 1:1 to sham treatment or self-carpal ligament stretching. Participants were instructed to perform the self-treatment four times a day for six weeks. Seventeen participants in the sham treatment group and 19 participants in the carpal ligament stretching group completed the study. Pre- and post-treatment outcome measures included subjective complaints, strength, nerve conduction findings, and functional scores. RESULTS: Groups were balanced on age, sex, hand dominance, symptom duration, length of treatment, presence of nocturnal symptoms, and compliance with treatment. Even though the ANOVA analyses were inconclusive about group differences, explorative post hoc analyses revealed significant improvements in numbness (P = .011, Cohen's d = .53), tingling (P = .007, Cohen's d = .60), pinch strength (P = .007, Cohen's d = -.58), and symptom severity scale (P = .007, Cohen's d = .69) for the treatment group only. CONCLUSIONS: The myofascial stretching of the carpal ligament showed statistically significant symptom improvement in persons with CTS. Larger comparative studies that include other modalities such as splinting should be performed to confirm the effectiveness of this treatment option.

Short-latency afferent inhibition and somato-sensory evoked potentials during the migraine cycle: surrogate markers of a cycling cholinergic thalamo-cortical drive?

BACKGROUND: Short-latency afferent inhibition (SAI) consists of motor cortex inhibition induced by sensory afferents and depends on the excitatory effect of cholinergic thalamocortical projections on inhibitory GABAergic cortical networks. Given the electrophysiological evidence for thalamo-cortical dysrhythmia in migraine, we studied SAI in migraineurs during and between attacks and searched for correlations with somatosensory habituation, thalamocortical activation, and clinical features. METHODS: SAI was obtained by conditioning the transcranial magnetic stimulation-induced motor evoked potential (MEP) with an electric stimulus on the median nerve at the wrist with random stimulus intervals corresponding to the latency of individual somatosensory evoked potentials (SSEP) N20 plus 2, 4, 6, or 8 ms. We recruited 30 migraine without aura patients, 16 between (MO), 14 during an attack (MI), and 16 healthy volunteers (HV). We calculated the slope of the linear regression between the unconditioned MEP amplitude and the 4-conditioned MEPs as a measure of SAI. We also measured SSEP amplitude habituation, and high-frequency oscillations (HFO) as an index of thalamo-cortical activation. RESULTS: Compared to HV, SAI, SSEP habituation and early SSEP HFOs were significantly reduced in MO patients between attacks, but enhanced during an attack. There was a positive correlation between degree of SAI and amplitude of early HFOs in HV, but not in MO or MI. CONCLUSIONS: The migraine cycle-dependent variations of SAI and SSEP HFOs are further evidence that facilitatory thalamocortical activation (of GABAergic networks in the motor cortex for SAI), likely to be cholinergic, is reduced in migraine between attacks, but increased ictally.

Comparisons of electrophysiological and clinical findings between young and elderly patients with Carpal Tunnel Syndrome.

BACKGROUND: Few studies have been published on differences between young and old patients with Carpal Tunnel Syndrome regarding clinical and electrophysiological findings. We compared the findings in participants of two age ranges. METHODS: For one year from August 2016, we performed a two-group cross-sectional study in an outpatient clinic of physical medicine and rehabilitation at a University Hospital. Two samples of young and old women with a diagnosis of the syndrome without known risk factors affecting electrophysiological findings were selected. We measured sensory and motor amplitudes and latencies, the conduction velocity of the median nerve, severity, and recurrence of the manifestations, weakness, atrophy, and severity of the syndrome. RESULTS: We had two groups of 24 young (<35 years) and 24 old (>65 years) patients with CTS. Severity of symptoms was higher in young participants [Mean (SD) 3.0(0.6) vs. 2.0(0.8), P<0.001]. Muscular weakness was not different [young 2.6(0.88) vs. old 1.9(1.6), P=0.541]. Five young and nine old participants showed thenar wasting (P=0.104). The severity of CTS was similar (P=0.129). For the group young patients, mean sensory amplitude was higher [14.07(10.98) vs. 7.58(5.08), P=0.012], while mean latency was lower [3.86(0.57) vs. 5.15(1.17), P<0.001]. In motor studies, mean latency was more prolonged in the group old patients [3.86(0.57) vs. 5.15(1.17), P<0.001]. CONCLUSION: Clinical symptoms are more severe among young people, while the pathophysiological process is more intense in the elderly. Patients should not be clinically judged merely by subjective manifestations. Both diagnostic workup and treatment should be designed holistically with all the evidence taken into consideration.

Severe hyperhomocysteinemia and peripheral neuropathy as side effects of nitrous oxide in two patients with sickle cell disease.

Nitrous oxide (N2O) is a widely used anesthetic agent. We report two patients with sickle cell disease (SCD) who presented with complications following the use of N2O. Patient 1, a 15-year-old girl, presented severe hyperhomocysteinemia, pancytopenia, vitamin B12 deficiency, and peripheral polyneuropathy after massive use of N2O for pain management. At the 1-year follow-up, hyperhomocysteinemia and B12 deficiency had resolved, but she had persisting mild symptoms of polyneuropathy. Patient 2, a 17-year-old boy, presented only severe hyperhomocysteinemia, only partially corrected by initial B12 supplementation. Careful monitoring of N2O use, especially in patients with SCD, is mandatory to prevent complications.

Median Nerve Electrical Stimulation-Induced Changes in Effective Connectivity in Patients With Stroke as Assessed With Functional Near-Infrared Spectroscopy.

Background. The cortical plastic changes in response to median nerve electrical stimulation (MNES) in stroke patients have not been entirely illustrated. Objective. This study aimed to investigate MNES-related changes in effective connectivity (EC) within a cortical network after stroke by using functional near-infrared spectroscopy (fNIRS). Methods. The cerebral oxygenation signals in the bilateral prefrontal cortex (LPFC/RPFC), motor cortex (LMC/RMC), and occipital lobe (LOL/ROL) of 20 stroke patients with right hemiplegia were measured by fNIRS in 2 conditions: (1) resting state and (2) MNES applied to the right wrist. Coupling function together with dynamical Bayesian inference was used to assess MNES-related changes in EC among the cerebral low-frequency fluctuations. Results. Compared with the resting state, EC from LPFC and RPFC to LOL was significantly increased during the MNES state in stroke patients. Additionally, MNES triggered significantly higher coupling strengths from LMC and LOL to RPFC. The interregional main coupling direction was observed from LPFC to bilateral motor and occipital areas in responding to MNES, suggesting that MNES could promote the regulation function of ipsilesional prefrontal areas in the functional network. MNES can induce muscle twitch of the stroke-affected hand involving a decreased neural coupling of the contralesional motor area on the ipsilesional MC. Conclusions. MNES can trigger sensorimotor stimulations of the affected hand that sequentially involved functional reorganization of distant cortical areas after stroke. Investigating MNES-related changes in EC after stroke may help further our understanding of the neural mechanisms underlying MNES.

Local effects of acupuncture on the median and ulnar nerves in patients with carpal tunnel syndrome: a pilot mechanistic study protocol.

BACKGROUND: While acupuncture's mechanism of action is not fully understood, there is consensus that the nervous system plays a key role in processing its effects. This research is based on the structural theory of acupuncture, which aims to correlate the location of acupuncture points to peripheral nerves, spinal segments, and spinal plexuses. This mechanistic study explores the close anatomical association between the Pericardium meridian/median nerve and the Heart meridian/ulnar nerve in an attempt to produce electrophysiologic data measuring acupuncture's direct, nerve-specific effect on the underlying nerves. Specifically, the purpose of this research is to use nerve conduction studies (NCSs) and quantitative sensory testing (QST) to assess for any local, nerve-specific effect of three acupuncture modalities on two anatomically distinct nerves in the forearm - the median and ulnar nerves - in subjects with carpal tunnel syndrome (CTS). The choice of CTS as an injured nerve model allows for comparisons between the response in an injured nerve (median) to that of a healthy one (ulnar). METHODS: Subjects with mild to moderate CTS will be randomized to three intervention groups: manual acupuncture and low- and high-frequency electroacupuncture. Each subject will receive two treatments, 1 week apart, to points in the forearm, which overlay the median nerve (Pericardium meridian) or the ulnar nerve (Heart meridian). Acupuncture will be administered in random order to minimize learning effects in sensory testing. During Week 1, baseline NCS and QST (vibration and cold detection thresholds) will be obtained in both nerve territories, followed by acupuncture and post-acupuncture NCS and QST measurements in both nerve territories. During Week 2, repeat baseline QST and NCS measurements will be obtained, followed by acupuncture to points overlying the nerve not treated in Week 1, followed by post-acupuncture NCS and QST measurements in both nerve distributions. DISCUSSION: This works aims to capture and characterize the local effects of acupuncture on an underlying nerve and compare them to those on a neighboring nerve. Quantifying acupuncture's effects using physiologic parameters and discrete values could standardize treatment regimens and help assess their therapeutic effect. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03036657 . Registered on 30 January 2017. Retrospectively registered.

Manual therapy prevents onset of nociceptor activity, sensorimotor dysfunction, and neural fibrosis induced by a volitional repetitive task.

Painful and disabling musculoskeletal disorders remain prevalent. In rats trained to perform repetitive tasks leading to signs and dysfunction similar to those in humans, we tested whether manual therapy would prevent the development of the pathologies and symptoms. We collected behavioral, electrophysiological, and histological data from control rats, rats that trained for 5 weeks before performing a high-repetition high-force (HRHF) task for 3 weeks untreated, and trained rats that performed the task for 3 weeks while being treated 3x/week using modeled manual therapy (MMT) to the forearm (HRHF + MMT). The MMT included bilateral mobilization, skin rolling, and long axis stretching of the entire upper limb. High-repetition high-force rats showed decreased performance of the operant HRHF task and increased discomfort-related behaviors, starting after training. HRHF + MMT rats showed improved task performance and decreased discomfort-related behaviors compared with untreated HRHF rats. Subsets of rats were assayed for presence or absence of ongoing activity in C neurons and slow Aδ neurons in their median nerves. Neurons from HRHF rats had a heightened proportion of ongoing activity and altered conduction velocities compared with control and MMT-treated rats. Median nerve branches in HRHF rats contained increased numbers of CD68 macrophages and degraded myelin basic protein, and showed increased extraneural collagen deposition, compared with the other groups. We conclude that the performance of the task for 3 weeks leads to increased ongoing activity in nociceptors, in parallel with behavioral and histological signs of neuritis and nerve injury, and that these pathophysiologies are largely prevented by MMT.

Is Complex Decongestive Physical Therapy Safe for Median Nerve at the Level of Carpal Tunnel in Breast Cancer Related Lymphedema?

BACKGROUND: Multilayer bandaging used in complex decongestive therapy (CDT) may increase tissue pressure resulting in nerve entrapments. The aim of this study was to discover if median nerve damage is a consequence of CDT in patients with breast cancer-related lymphedema (BCRL). METHODS AND RESULTS: Eighty-two arms of 41 patients with BCRL were included. Mean age was 56.05 (8.16) years and all stages of lymphedema were equally included. Fifteen sessions of CDT was applied to all patients. The calculated volume of extremities, the quality of life (cancer adaptation of Ferrans-Powell), neuropathic pain (NP; Douleur Neuropathique 4), and disability (quick disabilities of arm, shoulder, and hand [Q-DASH]) tests were recorded before and after therapy. Skin and subcutaneous tissue thicknesses of volar and dorsal sides and median nerve cross-sectional area (CSA) at the level of carpal tunnel were measured using ultrasonography (US), before and after therapy. Carpal tunnel syndrome (CTS; 41.37%) and polyneuropathy (10.34%) were common findings confirmed by electromyography. Neuropathic pain profile was also found in 34.14% of patients. The arm volume of affected side, quality of life, and skin and subcutaneous tissue thicknesses were improved after therapy (p < 0.05). However, median nerve CSA, the NP, and Q-DASH scores were not changed after therapy. CONCLUSIONS: Although lymphedema is a painless condition, NP and CTS should not be ignored in patients with BCRL. US is an alternative, precise, and high technological method for evaluating treatment response. CDT is an effective and safe treatment according to volumetric calculations, US measurements of tissue thicknesses, and median nerve size.

Attenuation of hypertension by C-fiber stimulation of the human median nerve and the concept-based novel device.

High blood pressure (BP) is a highly controllable risk factor for cardiovascular diseases; however, awareness of this condition and the rates of controlled hypertension are low. Experimental animal studies have shown that stimulation of the median nerve or PC6 acupoint over the wrist has effects on cardiovascular activities, including reductions in systolic and diastolic BPs. A proof-of-concept study was conducted in humans to investigate whether stimulation of median nerve near PC6 acupoint decreased high BP, identify the optimal stimulation parameters for the BP-lowering effects of median nerve stimulation, and determine the specific peripheral nerves or types of afferent fibers mediating the BP-lowering effects. Median nerve stimulation was carried out bilaterally or unilaterally with different stimulation parameters, and the BP and heart rate were monitored. The afferent mechanisms underlying the effects of median nerve stimulation on hypertension were investigated via microneurography, A-fiber blocking experiments, and localized chemical or electrical stimulation. Bilateral median nerve stimulation at either low or high frequencies produced profound but transient reductions in systolic BP, which were elicited when median nerve stimulation was unilaterally applied at interelectrode distances of 2 and 4 cm. Systolic BP was also reduced by electrical stimulation of the thumb on the palm side. Although microneurographic recordings revealed the excitation of both A- and C-fibers following median nerve stimulation, the median nerve-mediated reductions in BP were not affected by A-fiber blockade, and they were mimicked by the activation of C-fibers with capsaicin. The present results indicate that activation of C-fibers in the median nerve generates BP-lowering effects in humans. Based on our clinical study, an optimized median nerve stimulator was built and combined with a wrist BP monitor for simultaneous BP measurements and median nerve stimulation.

The carpal tunnel syndrome in children.

INTRODUCTION: Carpal tunnel syndrome (CTS) in children represents a complex challenge for the hand surgeon because of its rarity, poor patient cooperation, frequently associated malformation syndromes and mental retard, atypical symptoms and nuanced and poor sensitivity of instrumental tests. The most frequently associated causes with the CTS in children are rare congenital malformations and diseases, requiring an overall assessment of the young patient and a high degree of suspicion for the potentially associated canalicular syndrome. On the other hand, the associated syndromes may be the main ally for a diagnosis that starts from the knowledge of the literature and the surgeon's suspicion by observing the child wailing. Early diagnosis and decompression treatment is mandatory. MATERIALS AND METHODS: The authors report a case series of 26 children and analyze the etiology and diagnostic algorithms. Patient assessment was based on complete clinical examination and medical history collection of these young patients with the involvement of the family and educators. RESULTS: In all 26 patients treated, along an average period of 23 months (minimum 12, maximum 30), no signs of recurrence or persistence of median nerve disturbances were recorded. CONCLUSIONS: In conclusion, we believe that anamnesis, a careful physical examination and analysis of instrumental examinations, should be accompanied by a thorough knowledge of rare diseases in the context of congenital malformations. The carpal tunnel syndrome, while well known and treated by each orthopedic surgeon, reveals a mysterious aspect in the context of the "fabulous" world of childhood illnesses, even more difficult than rare congenital diseases.

Effects of face/head and whole body cooling during passive heat stress on human somatosensory processing.

We herein investigated the effects of face/head and whole body cooling during passive heat stress on human somatosensory processing recorded by somatosensory-evoked potentials (SEPs) at C4' and Fz electrodes. Fourteen healthy subjects received a median nerve stimulation at the left wrist. SEPs were recorded at normothermic baseline (Rest), when esophageal temperature had increased by ~1.2°C (heat stress: HS) during passive heating, face/head cooling during passive heating (face/head cooling: FHC), and after HS (whole body cooling: WBC). The latencies and amplitudes of P14, N20, P25, N35, P45, and N60 at C4' and P14, N18, P22, and N30 at Fz were evaluated. Latency indicated speed of the subcortical and cortical somatosensory processing, while amplitude reflected the strength of neural activity. Blood flow in the internal and common carotid arteries (ICA and CCA, respectively) and psychological comfort were recorded in each session. Increases in esophageal temperature due to HS significantly decreased the amplitude of N60, psychological comfort, and ICA blood flow in the HS session, and also shortened the latencies of SEPs (all, P < 0.05). While esophageal temperature remained elevated, FHC recovered the peak amplitude of N60, psychological comfort, and ICA blood flow toward preheat baseline levels as well as WBC. However, the latencies of SEPs did not recover in the FHC and WBC sessions. These results suggest that impaired neural activity in cortical somatosensory processing during passive HS was recovered by FHC, whereas conduction velocity in the ascending somatosensory input was accelerated by increases in body temperature.

Efficacy of Manual Therapy Including Neurodynamic Techniques for the Treatment of Carpal Tunnel Syndrome: A Randomized Controlled Trial.

OBJECTIVE: The purpose of this randomized trial was to compare the efficacy of manual therapy, including the use of neurodynamic techniques, with electrophysical modalities on patients with mild and moderate carpal tunnel syndrome (CTS). METHODS: The study included 140 CTS patients who were randomly assigned to the manual therapy (MT) group, which included the use of neurodynamic techniques, functional massage, and carpal bone mobilizations techniques, or to the electrophysical modalities (EM) group, which included laser and ultrasound therapy. Nerve conduction, pain severity, symptom severity, and functional status measured by the Boston Carpal Tunnel Questionnaire were assessed before and after treatment. Therapy was conducted twice weekly and both groups received 20 therapy sessions. RESULTS: A baseline assessment revealed group differences in sensory conduction of the median nerve (P < .01) but not in motor conduction (P = .82). Four weeks after the last treatment procedure, nerve conduction was examined again. In the MT group, median nerve sensory conduction velocity increased by 34% and motor conduction velocity by 6% (in both cases, P < .01). There was no change in median nerve sensory and motor conduction velocities in the EM. Distal motor latency was decreased (P < .01) in both groups. A baseline assessment revealed no group differences in pain severity, symptom severity, or functional status. Immediately after therapy, analysis of variance revealed group differences in pain severity (P < .01), with a reduction in pain in both groups (MT: 290%, P < .01; EM: 47%, P < .01). There were group differences in symptom severity (P < .01) and function (P < .01) on the Boston Carpal Tunnel Questionnaire. Both groups had an improvement in functional status (MT: 47%, P < .01; EM: 9%, P < .01) and a reduction in subjective CTS symptoms (MT: 67%, P < .01; EM: 15%, P < .01). CONCLUSION: Both therapies had a positive effect on nerve conduction, pain reduction, functional status, and subjective symptoms in individuals with CTS. However, the results regarding pain reduction, subjective symptoms, and functional status were better in the MT group.

Alpha-lipoic Acid After Median Nerve Decompression at the Carpal Tunnel: A Randomized Controlled Trial.

PURPOSE: The postoperative course of median nerve decompression in carpal tunnel syndrome may be associated with complications. The aim of this study was to explore the possible effects of alpha-lipoic acid (ALA) in the postoperative period after surgical decompression of the median nerve at the wrist. METHODS: We conducted a double-blind prospective, randomized, controlled trial. A total of 64 patients with proven carpal tunnel syndrome were enrolled and randomly assigned into 1 of 2 groups: group A (n = 32) patients had surgical decompression of the median nerve followed by ALA for 40 days, and group P (n = 32) patients had surgical decompression followed by placebo. The primary end point of the study was a comprehensive indicator of sensory and motor nerve conduction velocity (electrophysiology score) at 3 months after surgery, Other end points were static 2-point discrimination, Boston Carpal Tunnel score, presence or absence of pillar pain, and use of analgesics beyond the second postoperative day. RESULTS: Alpha-lipoic acid did not improve nerve conduction velocity or Boston Carpal Tunnel score significantly. However, a statistically significant reduction in the postoperative incidence of pillar pain was noted in the ALA group. In addition, static 2-point discrimination improved in both groups. CONCLUSIONS: Postoperative administration of ALA for 40 days after median nerve decompression may result in a lower incidence of pillar pain. This treatment is relatively well tolerated, which may support its value as standard postoperative supplementation after carpal tunnel decompression if further studies on larger samples confirm these preliminary findings. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic I.

Rewiring the primary somatosensory cortex in carpal tunnel syndrome with acupuncture.

Carpal tunnel syndrome is the most common entrapment neuropathy, affecting the median nerve at the wrist. Acupuncture is a minimally-invasive and conservative therapeutic option, and while rooted in a complex practice ritual, acupuncture overlaps significantly with many conventional peripherally-focused neuromodulatory therapies. However, the neurophysiological mechanisms by which acupuncture impacts accepted subjective/psychological and objective/physiological outcomes are not well understood. Eligible patients (n = 80, 65 female, age: 49.3 ± 8.6 years) were enrolled and randomized into three intervention arms: (i) verum electro-acupuncture 'local' to the more affected hand; (ii) verum electro-acupuncture at 'distal' body sites, near the ankle contralesional to the more affected hand; and (iii) local sham electro-acupuncture using non-penetrating placebo needles. Acupuncture therapy was provided for 16 sessions over 8 weeks. Boston Carpal Tunnel Syndrome Questionnaire assessed pain and paraesthesia symptoms at baseline, following therapy and at 3-month follow-up. Nerve conduction studies assessing median nerve sensory latency and brain imaging data were acquired at baseline and following therapy. Functional magnetic resonance imaging assessed somatotopy in the primary somatosensory cortex using vibrotactile stimulation over three digits (2, 3 and 5). While all three acupuncture interventions reduced symptom severity, verum (local and distal) acupuncture was superior to sham in producing improvements in neurophysiological outcomes, both local to the wrist (i.e. median sensory nerve conduction latency) and in the brain (i.e. digit 2/3 cortical separation distance). Moreover, greater improvement in second/third interdigit cortical separation distance following verum acupuncture predicted sustained improvements in symptom severity at 3-month follow-up. We further explored potential differential mechanisms of local versus distal acupuncture using diffusion tensor imaging of white matter microstructure adjacent to the primary somatosensory cortex. Compared to healthy adults (n = 34, 28 female, 49.7 ± 9.9 years old), patients with carpal tunnel syndrome demonstrated increased fractional anisotropy in several regions and, for these regions we found that improvement in median nerve latency was associated with reduction of fractional anisotropy near (i) contralesional hand area following verum, but not sham, acupuncture; (ii) ipsilesional hand area following local, but not distal or sham, acupuncture; and (iii) ipsilesional leg area following distal, but not local or sham, acupuncture. As these primary somatosensory cortex subregions are distinctly targeted by local versus distal acupuncture electrostimulation, acupuncture at local versus distal sites may improve median nerve function at the wrist by somatotopically distinct neuroplasticity in the primary somatosensory cortex following therapy. Our study further suggests that improvements in primary somatosensory cortex somatotopy can predict long-term clinical outcomes for carpal tunnel syndrome.

Effects of 12 Weeks of Chiropractic Care on Central Integration of Dual Somatosensory Input in Chronic Pain Patients: A Preliminary Study.

OBJECTIVE: The purpose of this preliminary study was to assess whether the dual somatosensory evoked potential (SEP) technique is sensitive enough to measure changes in cortical intrinsic inhibitory interactions in patients with chronic neck or upper extremity pain and, if so, whether changes are associated with changes in pain scores. METHODS: The dual peripheral nerve stimulation SEP ratio technique was used for 6 subjects with a history of chronic neck or upper limb pain. SEPs were recorded after left or right median and ulnar nerve stimulation at the wrist. SEP ratios were calculated for the N9, N13, P14-18, N20-P25, and P22-N30 peak complexes from SEP amplitudes obtained from simultaneous median and ulnar stimulation divided by the arithmetic sum of SEPs obtained from individual stimulation of the median and ulnar nerves. Outcome measures of SEP ratios and subjects' visual analog scale rating of pains were recorded at baseline, after a 2-week usual care control period, and after 12 weeks of multimodal chiropractic care (chiropractic spinal manipulation and 1 or more of the following: exercises, peripheral joint adjustments/manipulation, soft tissue therapy, and pain education). RESULTS: A significant decrease in the median and ulnar to median plus ulnar ratio and the median and ulnar amplitude for the cortical P22-N30 SEP component was observed after 12 weeks of chiropractic care, with no changes after the control period. There was a significant decrease in visual analog scale scores (both for current pain and for pain last week). CONCLUSION: The dual SEP ratio technique appears to be sensitive enough to measure changes in cortical intrinsic inhibitory interactions in patients with chronic neck pain. The observations in 6 subjects revealed that 12 weeks of chiropractic care improved suppression of SEPs evoked by dual upper limb nerve stimulation at the level of the motor cortex, premotor areas, and/or subcortical areas such as basal ganglia and/or thalamus. It is possible that these findings explain one of the mechanisms by which chiropractic care improves function and reduces pain for chronic pain patients.

Device-based Therapy for Hypertension.

Hypertension continues to be a major contributor to global morbidity and mortality, fuelled by an abundance of patients with uncontrolled blood pressure despite the multitude of pharmacological options available. This may occur as a consequence of true resistant hypertension, through an inability to tolerate current pharmacological therapies, or non-adherence to antihypertensive medication. In recent years, there has been a rapid expansion of device-based therapies proposed as novel non-pharmacological approaches to treating resistant hypertension. In this review, we discuss seven novel devices-renal nerve denervation, baroreflex activation therapy, carotid body ablation, central iliac arteriovenous anastomosis, deep brain stimulation, median nerve stimulation, and vagal nerve stimulation. We highlight how the devices differ, the varying degrees of evidence available to date and upcoming trials. This review also considers the possible factors that may enable appropriate device selection for different hypertension phenotypes.