Effect of neuronavigated repetitive Transcranial Magnetic Stimulation on pain, cognition and cortical excitability in fibromyalgia syndrome.

BACKGROUND: Fibromyalgia syndrome is a widespread chronic pain condition identified by body-wide pain, fatigue, cognitive fogginess, and sleep issues. In the past decade, repetitive transcranial magnetic stimulation has emerged as a potential management tool.. In the present study, we enquired whether repetitive transcranial magnetic stimulation could modify pain, corticomotor excitability, cognition, and sleep. METHODS: Study is a randomized, sham-controlled, double-blind, clinical trial; wherein after randomizing thirty-four fibromyalgia patients into active or sham therapy (n = 17 each), each participant received repetitive transcranial magnetic stimulation therapy. In active therapy was given at 1 Hz for 20 sessions were delivered on dorsolateral prefrontal cortex (1200 pulses, 150 pulses per train for 8 trains); while in sham therapy coil was placed at right angle to the scalp with same frequency. Functional magnetic resonance imaging was used to identify the therapeutic site. Pain intensity, corticomotor excitability, cognition, and sleep were examined before and after therapy. RESULTS: Baseline demographic and clinical parameters for both active and sham groups were comparable. In comparison to sham, active repetitive transcranial magnetic stimulation showed significant difference in pain intensity (P < 0.001, effect size = 0.29, large effect) after intervention. Other parameters of pain perception, cognition, and sleep quality also showed a significant improvement after the therapy in active therapy group only, as compared to sham. CONCLUSIONS: Findings suggest that repetitive transcranial magnetic stimulation intervention is effective in managing pain alongside cognition and sleep disturbances in patients of fibromyalgia. It may prove to be an important tool in relieving fibromyalgia-associated morbidity.

A comparative study to evaluate abdominal wall dynamics in patients with incisional hernia compared to healthy controls.

BACKGROUND: Incisional hernia is a common complication following abdominal surgery. It causes change in function of core abdominal muscles leading to change in abdominal wall dynamics. This study aims to objectively measure and compare preoperative abdominal wall dynamics with surface electromyography (sEMG) in incisional hernia patients with healthy individuals. MATERIALS AND METHODS: In this prospective comparative study, two groups of participants as cases and controls were evaluated for their abdominal wall dynamics by using sEMG. Both cases and controls were evenly matched in terms of age and gender. Statistical analysis was done with STATA 14.1 and p value of < 0.05 was considered significant. RESULTS: Demographic profile was comparable between the two groups. Mean BMI of cases was higher than controls. The most common index procedure was lower segment cesarean section. The strength and power of all three abdominal wall muscles (rectus abdominis, external oblique, internal oblique) were significantly diminished among cases compared to controls. CONCLUSIONS: Abdominal wall dynamics can be objectively and correctly interpreted from sEMG of abdominal wall core muscles in patients with incisional hernia. This study shows that there is a decrease in abdominal wall strength and power in patients suffering from incisional hernia in comparison with healthy controls.

Introducing virtual classrooms for undergraduate physiology teaching during the COVID-19 pandemic: acceptance by students and subjective impact on learning.

The COVID-19 pandemic and worldwide lockdowns brought major changes in education systems. There was a sudden obligatory shift toward utilization of digital resources for teaching and learning purposes. Medical education, specifically physiology teaching, comprises hands-on training in the laboratory. It is challenging to offer a course like physiology in a virtual format. The objective of this study was to assess the effectiveness and influence of virtual classroom technology on online physiology education in a sample size of 83 first-year MBBS undergraduates. A questionnaire comprising questions related to technology accessibility and utilization, comprehensibility and effectiveness of instructions, faculty proficiency, and learning outcomes was administered to the group. The responses were collected and analyzed. Validation through principal components and factor analysis showed that online teaching is not very effective and has a limited application in the physiology education of undergraduate MBBS students. Our study also revealed that virtual physiology teaching of undergraduate medical students during the COVID-19 pandemic had a moderate level of effectiveness.NEW & NOTEWORTHY In the present qualitative study, we have conducted and validated an online physiology teaching platform at a medical college to continue medical education during the peak times of the COVID-19 pandemic and prolonged lockdowns. Furthermore, we have evaluated the effectiveness of online physiology teaching through multidimensional feedback from undergraduate MBBS students. It is experimental evidence of inadequate sustainability, moderate efficacy, limited application, and poor first-hand experience gained by the students in virtual physiology teaching in a preclinical and clinical setting.

Neuronavigation based 10 sessions of repetitive transcranial magnetic stimulation therapy in chronic migraine: an exploratory study.

INTRODUCTION: Chronic migraine is a disease of altered cortical excitability. Repetitive transcranial magnetic stimulation provides a novel non-invasive method to target the nociceptive circuits in the cortex. Motor cortex is one such potential target. In this study, we targeted the left motor cortex using fMRI-guided neuronavigation. MATERIALS AND METHODS: Twenty right-handed patients were randomized into real and sham rTMS group. Baseline subjective pain assessments were done using visual analog scale (VAS) and questionnaires: State-Trait Anxiety Inventory, Becks Depression Inventory, and Migraine Disability Assessment (MIDAS) questionnaire. Objectively, pain was assessed by means of thermal pain thresholds using quantitative sensory testing. For corticomotor excitability parameters, resting motor thresholds and motor-evoked potentials were mapped. For rTMS total, 600 pulses in 10 trains at 10 Hz with an intertrain interval of 60 s were delivered in each session. Ten such sessions were given 5 days per week over 2 consecutive weeks. The duration of each session was 10 min. Real rTMS was administered at 70% of Resting MT. All the tests were repeated post-intervention and after 1 month of follow-up. There are no studies reporting the use of fMRI-based TMS for targeting the motor cortex in CM patients. RESULTS: We observed a significant reduction in the mean VAS rating, headache frequency, and MIDAS questionnaire in real rTMS group which was maintained after 1 month of follow-up. CONCLUSION: Ten sessions of fMRI-based rTMS over the left motor cortex may provide long-term pain relief in CM, but further studies are warranted to confirm our preliminary findings.

Repetitive transcranial magnetic stimulation in chronic tension-type headache: A pilot study.

Background & objectives: Tension-type headache (TTH) is the most common type of primary headache disorder. Its chronic form is often the most ignored and challenging to treat. Transcranial magnetic stimulation (TMS) is a novel technique in the treatment of chronic pain. The aim of this pilot study was to explore the effect of low-frequency repetitive TMS (rTMS) on pain status in chronic TTH (CTTH) by subjective and objective pain assessment. Methods: Patients (n=30) diagnosed with CTTH were randomized into rTMS (n=15) and placebo (n=15) groups in this study. Pre-intervention detailed history of patients was taken. Numerical Rating Scale (NRS) for Pain and questionnaires [Headache Impact Test-6 (HIT-6), McGill Pain Questionnaire, Pain Beliefs Questionnaire, Coping Strategies Questionnaire, State-Trait Anxiety Inventory Test, Hamilton Rating Scale for Depression and WHO-Quality of Life Questionnaire-Brief version] were filled, and objective assessments such as nociceptive flexion reflex (NFR) and conditioned pain modulation were done. The tests were repeated after 20 sessions (5 days/week). In the rTMS group, 1200 pulses in eight trains of 150 pulses each were given at 1Hz over the right dorsolateral prefrontal cortex (RDLPFC). In the placebo group, the rTMS coil was placed such that magnetic stimulation did not reach the cortex. Results: The NRS score decreased significantly (P<0.001) and NFR thresholds increased significantly (P=0.011) in the rTMS group when compared to placebo group. Interpretation & conclusions: Subjective improvements in the NRS, HIT-6, McGill Present Pain Intensity, trait of anxiety and psychological pain beliefs were observed. The increase in the thresholds of NFR served as an objective marker for improvement in pain status. Further studies need to be done to confirm our preliminary findings.

Assessing the effectiveness of high frequency repetitive transcranial magnetic stimulation for post-mastectomy pain in breast cancer patients: A randomized controlled trial.

BACKGROUND: Post-mastectomy pain Syndrome (PMPS), characterized by chronic neuropathic pain stemming from intercostobrachial nerve lesions, presents a formidable clinical challenge. With the incidence of breast cancer surging, effective interventions for PMPS are urgently needed. To address this, we conducted this double-blind, placebo-controlled, randomized clinical trial to study the efficacy of repetitive Transcranial Magnetic Stimulation (rTMS) therapy over the motor cortex on pain, quality of life and thermal sensitivity in PMPS patients. METHODS: We delivered 15 rTMS sessions over three weeks in a cohort of 34 PMPS patients. These patients were allocated randomly to either rTMS therapy or sham therapy groups. Pain assessments, utilizing the Visual Analogue Scale (VAS) and Short Form McGill Pain Questionnaire (SF-MPQ), alongside quality-of-life evaluations through the Functional Assessment of Cancer Therapy-Breast (FACT-B), were recorded before and after the 15 sessions. Additionally, we assessed thermal sensitivity using Quantitative Sensory Testing (QST). RESULTS: Our findings demonstrate the superior efficacy of rTMS therapy (over sham therapy) in reducing VAS and SF-MPQ scores (p < 0.0001), improving physical (p = 0.037), emotional (p = 0.033), and functional well-being (p = 0.020) components of quality of life, as quantified by FACT-B. Our investigation also unveiled marked enhancements in thermal sensitivity within the rTMS therapy group, with statistically significant improvements in cold detection threshold (p = 0.0001), warm detection threshold (p = 0.0033), cold pain threshold (p = 0.0078), and hot pain tolerance threshold (p = 0.0078). CONCLUSION: The study underscores the profound positive impact of rTMS therapy on pain, quality of life, and thermal sensitivity in patients having PMPS, opening new avenues for pain management strategies.

Repetitive Transcranial Magnetic Stimulation of the Dorsolateral Prefrontal Cortex for Phantom Limb Pain.

BACKGROUND: Phantom limb pain (PLP) is a prevalent and distressing occurrence in 60-80% of individuals who have undergone amputations. Recent research underscores the significance of maladaptive cortical plasticity in the genesis of PLP, emphasizing the importance of targeting cortical areas for therapeutic interventions. Repetitive transcranial magnetic stimulation (rTMS), a noninvasive tool for cortical stimulation, demonstrates effectiveness in treating various chronic pain conditions of neuropathic origin. Nevertheless, there exists a limited body of research investigating the application of rTMS as a therapeutic intervention specifically for managing PLP. Notably, the dorsolateral prefrontal cortex (DLPFC) plays a crucial role in central pain processing, suggesting its potential as a key therapeutic target in PLP treatment. There is a lack of adequate data regarding the effectiveness of DLPFC-targeting rTMS in alleviating the pain experienced by PLP patients. OBJECTIVE: In this study, our aim was to investigate the impact of 10 sessions of DLPFC-targeting rTMS on the pain status of individuals experiencing PLP. STUDY DESIGN: Randomized controlled trial. SETTING: Traumatic amputees reporting to the tertiary care center with PLP. METHODS: The study was approved by the Institute Ethics Committee (IECPG-299/27.04.2022) and registered in the Clinical Trials Registry of India (CTRI/2022/07/043938). Nineteen patients suffering from PLP were recruited and randomized into real or sham rTMS groups. In the real rTMS group, patients received 10 sessions of rTMS at the DLPFC contralateral to the amputation site. The rTMS, administered at 90% of the resting motor threshold (RMT), was delivered as 8 trains of 150 pulses per train at the rate of one Hz and an inter-train interval of 60 seconds. The total number of pulses per session was 1,200. The sham group received 10 sessions of sham rTMS through the perpendicular placement of an rTMS coil over the DLPFC. These sessions lasted for the same duration and included the same sounds as the real group but involved no active stimulation. The patients' pain status was evaluated using the Visual Analog Scale (VAS) at baseline, at the end of each session of real or sham rTMS and at the 15th, 30th, and 60th day after the the completion of real or sham therapy. RESULTS: A significant decrease in VAS scores was noted after 10 sessions of real rTMS that targeted the DLPFC, in contrast to the sham rTMS group. The real rTMS group's reduction in VAS scores also persisted during the follow-up. LIMITATIONS: A few patients had to drop out due to physical restrictions and financial constraints. Consequently, only a small number of individuals were able to complete the study protocol successfully. CONCLUSION: A regimen of 10 sessions of real rTMS of the DLPFC was associated with significant pain relief in patients with PLP, and the effects were sustained for 2 months. Therefore, the present study shows that rTMS of the DLPFC has potential as an effective therapeutic intervention for sustained pain relief in PLP patients.

Low-Frequency Repetitive Transcranial Magnetic Stimulation for Chronic Tension-Type Headache: A Randomized Controlled Study.

BACKGROUND: Nearly 1-3% of the population is affected by chronic tension-type headaches (CTTH). However, it is still difficult to treat owing to the lack of knowledge of the disease's pathophysiology. Available literature suggests a role for pericranial muscle activity and abnormal modulation of central pain. Repetitive transcranial magnetic stimulation (rTMS) therapy done at the dorsolateral prefrontal cortex (DLPFC) can help modulate pericranial muscle overactivity and central pain modulation in subjects with CTTH. AIM: This randomized controlled study aimed to assess the effect of rTMS used in the low-frequency dorsolateral prefrontal cortex on pain and muscle activity in subjects with a chronic tension-type headache. MATERIALS AND METHODS: The present randomized controlled clinical study was commenced in a health care center on 20 subjects with chronic tension-type headaches who were given either sham or low-frequency repetitive transcranial magnetic stimulation at the right dorsolateral prefrontal cortex. The therapy effect was evaluated statistically using Welch's corrected t-test. RESULTS: The study results depicted that daily use of rTMS therapy for two weeks led to a considerable reduction in the intensity of the pain, the activity of pericranial muscles, and headache impact, along with an increase in the nociceptive excitability thresholds in subjects with CTTH, with p=0.001 compared to the sham group. CONCLUSION: Considering its limitations, the present study depicts that rTMS is an efficacious management tool for reducing pain associated with CTTH and can serve as the cornerstone for additional investigations.

Effect of Motor Imagery on Corticomotor Excitability and Pain Status in Rheumatoid Arthritis Patients.

OBJECTIVES: Rheumatoid arthritis (RA) has been defined by the American College of Rheumatology in 1987 as a chronic inflammatory disease characterised by joint swelling, joint tenderness, and destruction of synovial joints leading to severe disability and premature mortality. There is a paucity of literature assessing corticomotor excitability in RA patients. This study aimed to assess the effect of motor imagery on corticomotor excitability and pain status in RA patients. The specific objectives were to study the effect of motor imagery on corticomotor excitability and pain status in RA patients. We also wanted to compare the corticomotor excitability between RA patients with healthy controls. The correlation between the measures of corticomotor excitability and pain status in RA patients has also been done. METHODS: The study was designed as a pilot clinical trial with a case-control design. Forty participants were recruited for the study. Twenty RA patients were recruited from the Department of Rheumatology and Department of Physical Medicine and Rehabilitation (PMR), AIIMS, New Delhi, and 20 healthy controls. Testing was performed at the Pain Research & rTMS Lab, Department of Physiology, AIIMS, New Delhi. The study was approved by the Institute Ethics Committee, AIIMS New Delhi, and registered in the Clinical Trials Registry-India (CTRI). For the subjective assessment of pain, the visual analogue scale (VAS), Short-Form McGill Pain Questionnaire, WHO-Quality of Life Brief questionnaire (WHO-QOL-BREF), and Rheumatoid Arthritis Pain Scale were used. For the objective assessment of pain, hot and cold pain thresholds were assessed using thermo-tactile quantitative sensory testing (QST) using the method of limits and corticomotor excitability using a transcranial magnetic stimulation device. All participants were also asked to perform motor imagery tasks which consisted of a metronome-paced thumb opposition paradigm.  Results: The resting motor threshold (RMT) decreased significantly after motor imagery when compared to the mental calculation group. The amplitude of motor evoked potential (MEP) and QST parameter value was comparable in both the groups before and after motor imagery and mental calculation. RMT was found to be significantly higher whereas MEP values were found to be significantly lower in RA compared to controls. CONCLUSION: We conclude that patients suffering from RA have decreased corticomotor excitability compared to controls. Motor imagery was effective in improving corticomotor excitability in these patients and can be used as rehabilitation in RA to relieve their pain.

Brain Stimulation and Constraint Induced Movement Therapy in Children With Unilateral Cerebral Palsy: A Randomized Controlled Trial.

BACKGROUND: There is a crucial need to devise optimum rehabilitation programs for children with cerebral palsy (CP). OBJECTIVE: This study aimed to assess the feasibility, safety, and efficacy of combining 6-Hz primed, low-frequency, repetitive transcranial magnetic stimulation (rTMS) with modified constraint-induced movement therapy (mCIMT) in improving upper limb function in children with unilateral CP. METHODS: Children aged 5 to 18 years with unilateral CP were randomized (23 in each arm) to receive 10 sessions of mCIMT with real rTMS (intervention arm) or mCIMT with sham rTMS (control arm), on alternate weekdays over 4 weeks. The primary outcome was the difference in mean change in Quality of Upper Extremity Skills Test (QUEST) scores. Secondary outcomes were changes in QUEST domain scores, speed and strength measures, CP quality of life (CP-QOL) scale scores, and safety of rTMS. RESULTS: All 46 children completed the trial except one. At 4 weeks, the mean change in total QUEST scores was significantly higher in the intervention arm as compared to the control arm (11.66 ± 6.97 vs 6.56 ± 4.3, d = 5.1, 95% CI 1.7-8.5, P = .004). Change in "weight bearing" and "protective extension" domain score was significantly higher for children in the intervention arm. These improvements were sustained at 12 weeks (P = .028). CP-QOL scores improved at 12 weeks. No serious adverse events were seen. CONCLUSION: A 6-Hz primed rTMS combined with mCIMT is safe, feasible, and superior to mCIMT alone in improving the upper limb function of children with unilateral CP. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03792789.

Comparative evaluation of intraoperative dexmedetomidine versus lidocaine for reducing postoperative cognitive decline in the elderly: a prospective randomized controlled trial.

INTRODUCTION: Neuroinflammation, neuronal cytotoxicity, and apoptosis due to exposure to anaesthetic agents are often implicated in postoperative cognitive dysfunction (POCD). Lidocaine and dexmedetomidine have been shown to suppress the neuron-specific markers of inflammation, and we aimed to compare their neuroprotective efficacy in elderly patients. MATERIAL AND METHODS: This prospective randomized control study compared the incidence of POCD in ASA I/II patients aged 60 to 80 years without any history of substance abuse or any disorder affecting cognition. Dexmedetomidine and lidocaine were administered intraoperatively, and their effects on POCD were correlated with serum levels of IL-1, IL-6, TNF-a, amyloid-ß, and S100 on postoperative day 3. POCD was assessed by the Stroop test, Trail making test-B, Porteus Maze test, Mini-Mental State Examination (MMSE), and Montreal Cognitive Assessment (MoCA) on the day before surgery and the third postoperative day, along with blood samples. RESULTS: Demographic parameters, anaesthesia duration, exposure to anaesthetic gases, intraoperative opioid use, and blood transfusion were similar in the lidocaine ( n = 31) and dexmedetomidine ( n = 29) groups. The incidence of POCD was 29.03% in the lidocaine group and 24.1% in the dexmedetomidine group ( P = 0.77). On postoperative day 3, IL-1 levels increased by 449% with lidocaine and 202% with dexmedetomidine ( P = 0.03). TNF-a, IL-6, and S-100ß levels increased similarly in both groups. There was no significant correlation between percentage changes in neuropsychological tests and biomarkers. CONCLUSIONS: There was no significant difference in the incidence of POCD, but dexmedetomidine had a better anti-inflammatory effect in terms of lesser rise of postoperative IL-1 compared to lidocaine.

Longitudinal changes in electromyographic activity of masseter and anterior temporalis muscles before and after alloplastic total joint replacement in patients with temporomandibular ankylosis: a prospective study.

The purpose of the study was to evaluate the longitudinal changes in electromyographic (EMG) activity of the masseter and temporalis muscles before and after temporomandibular joint (TMJ) total joint replacement (TJR) in ankylosis patients. A prospective longitudinal study was designed on patients undergoing unilateral or bilateral TMJ-TJR. EMG activity at rest and maximal voluntary contraction (MVC) was recorded for the muscles preoperatively (T0), and at one-week (T1) and six-month (T2) follow up. The study sample was composed of 10 (male: female 2.3:1) patients undergoing TMJ-TJR. The number of unilateral and bilateral cases was three and seven, respectively. In both unilateral and bilateral cases a statistically significant reduction in EMG activity of the masseter and anterior temporalis muscles was observed at T1. At T2, EMG activity of the muscles was found to be approaching the preoperative value. In unilateral cases, when the affected side at T0, T1, and T2 was compared with T0 for the unaffected side, statistically significant differences were seen for the masseter. In the case of the temporalis, similar results were seen except at T2 for the postural rest position. The results indicate that re-attachment of the masseter and temporalis muscles occurs progressively post TMJ-TJR.

Objective evidence for chronic back pain relief by Medical Yoga therapy.

Chronic low back pain (CLBP) is a musculoskeletal ailment that affects millions globally. The pain is disturbing associated with impaired motor activity, reduced flexibility, decreased productivity and strained interpersonal relationships leading to poor quality of life. Inflammatory mediators in vicinity of nociceptors and amplification of neural signals cause peripheral and central sensitization presented as hyperalgesia and/or allodynia. It could be attributed to either diminished descending pain inhibition or exaggerated ascending pain facilitation. Objective measurement of pain is crucial for diagnosis and management. Nociceptive flexion reflex is a reliable and objective tool for measurement of a subject's pain experience. Medical Yoga Therapy (MYT) has proven to relieve chronic pain, but objective evidence-based assessment of its effects is still lacking. We objectively assessed effect of MYT on pain and quality of life in CLBP patients. We recorded VAS (Visual analogue scale), McGill Pain questionnaire and WHOQOL BREF questionnaire scores, NFR response and Diffuse noxious inhibitory control tests. Medical yoga therapy consisted of an 8-week program (4 weeks supervised and 4 weeks at home practice). CLBP patients (42.5 ± 12.6 years) were randomly allocated to MYT (n = 58) and SCT groups (n = 50), and comparisons between the groups and within the groups were done at baseline and at end of 4 and 8 weeks of both interventions. (VAS) scores for patients in both the groups were comparable at baseline, subjective pain rating decreased significantly more after MYT compared to SCT (p = < 0.0001*, p = 0.005*). McGill Pain questionnaire scores revealed significant reduction in pain experience in MYT group compared to SCT. Nociceptive Flexion Reflex threshold increased significantly in MYT group at end of 4 weeks and 8 weeks, p < 0.0001#, p = < 0.0001∞ respectively) whereas for SCT we did not find any significant change in NFR thresholds. DNIC assessed by CPT also showed significant improvement in descending pain modulation after MYT compared to SCT both at end of 4 and 8 weeks. Quality of life also improved significantly more after MYT. Thus, we conclude with objective evidence that Medical Yoga Therapy relieves chronic low back pain, stress and improves quality of life better than standard care.

Correlating cognition and cortical excitability with pain in fibromyalgia: a case control study.

BACKGROUND: Fibromyalgia is a chronic pain disorder characterized by widespread musculoskeletal symptoms, primarily attributed to sensitization of somatosensory system carrying pain. Few reports have investigated the impact of fibromyalgia symptoms on cognition, corticomotor excitability, sleepiness, and the sleep quality - all of which can deteriorate the quality of life in fibromyalgia. However, the existing reports are underpowered and have conflicting directions of findings, limiting their generalizability. Therefore, the present study was designed to compare measures of cognition, corticomotor excitability, sleepiness, and sleep quality using standardized instruments in the recruited patients of fibromyalgia with pain-free controls. METHODS: Diagnosed cases of fibromyalgia were recruited from the Rheumatology department for the cross-sectional, case-control study. Cognition (Mini-Mental State Examination, Stroop color-word task), corticomotor excitability (Resting motor threshold, Motor evoked potential amplitude), daytime sleepiness (Epworth sleepiness scale), and sleep quality (Pittsburgh sleep quality index) were studied according to the standard procedure. RESULTS: Thirty-four patients of fibromyalgia and 30 pain-free controls were recruited for the study. Patients of fibromyalgia showed decreased cognitive scores (p = 0.05), lowered accuracy in Stroop color-word task (for color: 0.02, for word: 0.01), and prolonged reaction time (< 0.01, < 0.01). Excessive daytime sleepiness in patients were found (< 0.01) and worsened sleep quality (< 0.01) were found. Parameters of corticomotor excitability were comparable between patients of fibromyalgia and pain-free controls. CONCLUSIONS: Patients of fibromyalgia made more errors, had significantly increased reaction time for cognitive tasks, marked daytime sleepiness, and impaired quality of sleep. Future treatment strategies may include cognitive deficits and sleep disturbances as an integral part of fibromyalgia management.

Repetitive transcranial magnetic stimulation of the prefrontal cortex for fibromyalgia syndrome: a randomised controlled trial with 6-months follow up.

OBJECTIVES: Fibromyalgia Syndrome (FMS), is a chronic pain disorder with poorly understood pathophysiology. In recent years, repetitive transcranial magnetic stimulation (rTMS) has been recommended for pain relief in various chronic pain disorders. The objective of the present research was to study the effect of low frequency rTMS over the right dorsolateral prefrontal cortex (DLPFC) on pain status in FMS. METHODS: Ninety diagnosed cases of FMS were randomized into Sham-rTMS and Real-rTMS groups. Real rTMS (1 Hz/1200 pulses/8 trains/90% resting motor threshold) was delivered over the right DLPFC for 5 consecutive days/week for 4 weeks. Pain was assessed by subjective and objective methods along with oxidative stress markers. Patients were followed up for 6 months (post-rTMS;15 days, 3 months and 6 months). RESULTS: In Real-rTMS group, average pain ratings and associated symptoms showed significant improvement post rTMS. The beneficial effects of rTMS lasted up to 6 months in the follow-up phase. In Sham-rTMS group, no significant change in pain ratings was observed. CONCLUSION: Right DLPFC rTMS can significantly reduce pain and associated symptoms of FMS probably through targeting spinal pain circuits and top-down pain modulation . TRIAL REGISTRATION: Ref No: CTRI/2013/12/004228.

Aberrant pain modulation in trigeminal neuralgia patients.

Objectives The present study attempts to understand the role of supraspinal nociceptive pain modulation in typical trigeminal neuralgia (TN) patients by using a conditioned pain modulation paradigm and estimation of plasma levels of two important neuromodulators; Calcitonin Gene-Related Peptide and ß-endorphin. Methods Twenty TN patients and 20 healthy, age and gender-matched subjects participated in the study. The participants' hot pain thresholds (HPT) were measured over their affected side on the face. Testing sites were matched for healthy controls. For the conditioned pain modulation their contralateral foot was immersed in noxious cold (5 °C) water bath (conditioning stimuli) for 30 s and HPT (testing stimuli) was determined before, during and till 5 min after the immersion. Plasma Calcitonin Gene-Related Peptide and ß-endorphin levels were estimated to understand their role in disease pathogenesis and pain modulation. Results Change in HPT during foot immersion was significantly higher in healthy controls compared to TN patients (p<0.0001). The changes recorded in HPT in patients, were significant only in 2nd and 3rd minute post immersion. While in healthy controls, the effect lasted till the 4th minute. The concentration of beta-endorphin was significantly lower in TN patients (p=0.003) when compared to healthy controls. Conclusions The results suggest that there is an impairment in supraspinal pain modulation also known as Diffuse Noxious Inhibitory Controls in typical TN and that the reduced levels of ß-endorphin may contribute to the chronic pain state experienced by patients.

Can aberrant spinal nociception be a marker of chronicity of pain in fibromyalgia syndrome?

Pain sensitivity is a recognized feature of fibromyalgia syndrome (FMS) but the contribution of spinal nociceptive circuitry to this phenomenon is unknown. Therefore, the objectives were to study the changes in spinal nociception i.e. nociceptive flexion reflex (NFR) in patients with FMS and to investigate correlation if any, between NFR threshold, pain duration and tender points in FMS. One hundred and three patients with FMS and 74 healthy volunteers participated in the study. To record NFR, sural nerve was stimulated in the retro malleolar region and the reflex response was recorded from the short head of biceps femoris muscle. NFR was elicited at significantly lower [21.0(18.0-25.0)V] thresholds in FMS group when compared to healthy subjects [30.0(24.75-35.0)V; p = 0.001] indicating hyperalgesic response to electrocutaneous stimulation in FMS patients. The latency and other parameters of NFR were comparable in both the groups. No significant correlation was found among NFR threshold and pain duration or tender points. On the basis of results of present study, it may be concluded that the functional deficit of the spinal nociceptive system can contribute to hyperalgesia in FMS. This is first study that correlates a marker of central hyper-excitability (NFR threshold) with clinical symptoms (pain duration and tender points) of FMS.

Gender specificity of sucrose induced analgesia in human adults.

Sweet, palatable substances such as sucrose are reported to calm infants undergoing routine investigative procedures. The analgesic effect persists in pre pubertal children and adults with a hint of gender dependent variation in the analgesic response. The present study was therefore designed to explore gender specificity of sucrose induced analgesia in adult volunteers utilizing the nociceptive flexion reflex, an objective tool for pain assessment. Nociceptive flexion reflex was recorded, both before and after (up to 15 min) ingestion of 100 ml of 25% sucrose solution in 6 male and 6 female volunteers. In the male volunteers the maximum amplitude of the response was 20.8 +/- 7.7 microV before sucrose ingestion and 22.6 +/- 9.1 microV, 6.6 +/- 0.7 microV, 6.2 +/- 1.1 microV, 7.5 +/- 0.9 microV at 0, 5, 10 and 15 minutes post sucrose ingestion respectively. In female volunteers, the maximum amplitude of the response was 33.7 +/- 17.7 microV before sucrose ingestion and 43.6 +/- 17.2 microV, 7.1 +/- 1.2 microV, 25.9 +/- 16.1 microV, 50.6 +/- 16.3 microV at the same time intervals post sucrose ingestion. The maximum amplitude values were significantly lower in the males at 10 and 15 minutes after sucrose ingestion (P < 0.05). This is the first objective report of gender specificity in sucrose induced analgesia in adult humans. The gender dependent variation in sucrose induced analgesia is prolonged in male (15 min) and short lived in female (5 min) volunteers. This knowledge may have important implications in pain management.