Surgical Treatment for Spasticity: Selective Dorsal Rhizotomy ­ Technique and Literature Review

Spasticity is amotor disorder that leads to a resistance to passive jointmovement. Cerebral palsy is the most important cause of spasticity and can be caused by several factors, including multiple gestations, alcoholism, infections, hemorrhages, drowning, and traumatic brain injuries, among others. There aremany scales that help tomeasure andmonitor the degree of impairment of these patients. The initial treatment should focus on the causal factor, such as tumors, inflammation, degenerative diseases, hydrocephalus, etc. Subsequently, the treatment of spastic musculature includes oral or intrathecal myorelaxants, spinal cord electrostimulation, neurotomies, Lissauer tract lesion, dentatotomy and selective dorsal rhizotomy. The latter is a safetechnique, possibleto beperformed inmost centers with neurosurgical support, and it is effective in the treatment of severe spasticity. In this article, the authors describe the surgical technique and conduct a review the literature.

Physical Compatibility of Nafamostat with Analgesics, Sedatives, and Muscle Relaxants for Treatment of Coronavirus Disease 2019.

BACKGROUND: Severe coronavirus disease 2019 (COVID-19) may require continuous administration of analgesics, sedatives, and muscle relaxants. Nafamostat has recently been reported as a therapeutic agent for COVID-19. However, there is a lack of information on the compatibility of nafamostat with the aforementioned drug classes. This study evaluated the physical compatibility of nafamostat with these drug classes. METHODS: Nafamostat was combined with 1-3 target drugs (fentanyl, morphine, midazolam, dexmedetomidine, and rocuronium). Fifteen physical compatibility tests were conducted. Nafamostat was dissolved in 5% glucose solution; the final concentration was 10 mg/mL. All other medications were diluted in 0.9% sodium chloride to obtain clinically relevant concentrations. The power of hydrogen (pH) of all medications was measured during each test. Compatibility tests were conducted with 4 test solutions in which nafamostat and the target drugs were compounded at equal volume ratios (1:1, 1:1:1, or 1:1:1:1). Visual appearance, turbidity, and pH were evaluated immediately after mixing and at 1 and 3 hours. Physical incompatibilities were defined as gross precipitation, cloudiness, appearance of the Tyndall effect, or a turbidity change of ≥0.5 nephelometric turbidity units (NTU) based on nafamostat. RESULTS: The mean pH of nafamostat was 3.13 ± 0.03. The combination of nafamostat, fentanyl, and dexmedetomidine had the highest pH (3.39 ± 0.01; 3 hours after mixing). All drugs were compatible with nafamostat until 3 hours after admixture, with a mean turbidity value of ≤0.03 NTU. CONCLUSIONS: Infusions combining nafamostat with the tested sedatives, analgesics, and muscle relaxants could be safely administered.

Optimal management of severe symptomatic gastroesophageal reflux disease.

Gastroesophageal reflux disease (GERD) is a common disorder, and empirical proton pump inhibitor (PPI) treatment is often the first step of management; however, up to 40% of patients remain symptomatic despite PPI treatment. Refractory reflux refers to continued symptoms despite an adequate trial of PPI, and management remains challenging. The differential diagnosis is important; other oesophageal (e.g. eosinophilic oesophagitis) and gastroduodenal disorders (e.g. functional dyspepsia) should be ruled out, as this changes management. A combination of clinical assessment, endoscopic evaluation and in selected cases oesophageal function testing can help characterize patients with refractory reflux symptoms into oesophageal phenotypes so appropriate therapy can be more optimally targeted. Medical options then may include adding a H2 receptor antagonist, alginates, baclofen or antidepressant therapy, and there is emerging evidence for bile acid sequestrants and diaphragmatic breathing. The demonstration of a temporal association of symptoms with reflux events on pH-impedance testing (reflux hypersensitivity) serves to focus the management on modulating oesophageal perception and reducing the reflux burden, or identifies those with no obvious pathophysiologic abnormalities (functional heartburn). Anti-reflux surgery based on randomized controlled trial evidence has a role in reflux hypersensitivity or continued pathological acid reflux despite PPI in carefully considered, fully worked up cases that have failed medical therapy; approximately two of three cases will respond but there is a small risk of complications. In patients with persistent volume reflux despite medical therapy, given the lack of alternatives, anti-reflux surgery is a consideration. Promising newer approaches include endoscopic techniques. This review aims to summarize current diagnostic approaches and critically evaluates the evidence for the efficacy of available treatments.

A review of the effects of baclofen and of THC:CBD oromucosal spray on spasticity-related walking impairment in multiple sclerosis.

INTRODUCTION: Multiple sclerosis (MS) is a complex disease with a heterogeneous and unpredictable clinical course. Mobility impairment after progressive paralyses and muscle tone spasticity is common. Areas covered: The prevalence, assessment, and pharmacological management of gait impairment and spasticity in MS and their effects on health-related quality of life (HRQoL) are discussed. The roles of oral and intrathecal baclofen and of delta-9-tetrahydrocannabinol/cannabidiol (THC:CBD) oromucosal spray in treating MS spasticity-related gait impairment are reviewed. Expert commentary: Mobility impairment and spasticity are experienced by approximately 90% and 80% of MS patients, respectively, during the disease course. Prevalence and severity of gait impairment and spasticity increase as disease progresses. The symptoms are related and both impact negatively on HRQoL. Oral baclofen and tizanidine are generally used for first-line treatment of MS spasticity but are ineffective in approximately 40% of cases. Second-line therapy includes add-on THC:CBD spray for patients with resistant MS spasticity. Results of studies evaluating baclofen for treating MS spasticity gait impairment are equivocal. In studies of patients with resistant MS spasticity, THC:CBD spray consistently improved the timed 10-meter walk test and significantly improved multiple spatial-temporal and kinematic gait parameters. THC:CBD oromucosal spray warrants further investigation as a treatment for MS spasticity-related gait impairment.

A mixed treatment comparison on efficacy and safety of treatments for spasticity caused by multiple sclerosis: a systematic review and network meta-analysis.

OBJECTIVES: This study is aimed at providing a quantitative evaluation on different therapies of spasticity caused by multiple sclerosis. DATA SOURCES: PubMed and Embase database. REVIEW METHODS: We searched for randomized controlled trials that met the requirements. Percentages of improved patients' spasticity scale, mild adverse effect and severe adverse effect were extracted as outcomes. The forest plots accompanied with surface under the cumulative ranking curves were used to reveal the efficacy and safety of these therapies. RESULTS: In all, 23 randomized controlled trials with a total of 2720 patients were included in our study. Cannabinoids and botulinum toxin had shown a significantly better efficacy than placebo in the percentage of improved patients. Botulinum toxin also showed such significant difference compared with tizanidine and baclofen. No significant difference was found in spasticity scale. Cannabinoids, tizanidine and diazepam had significantly more mild adverse effect reports than placebo. Surface under the cumulative ranking curves suggested that cannabinoids, botulinum toxin and transcutaneous electric nerve stimulation were preferable therapies. CONCLUSIONS: We recommended botulinum toxin as the optimal intervention for multiple sclerosis-related spasticity. Cannabinoids and transcutaneous electric nerve stimulation could also be considered as multiple sclerosis-related spasticity treatments but their safety remained to be verified.

Interventions for managing skeletal muscle spasticity following traumatic brain injury.

BACKGROUND: Skeletal muscle spasticity is a major physical complication resulting from traumatic brain injury (TBI), which can lead to muscle contracture, joint stiffness, reduced range of movement, broken skin and pain. Treatments for spasticity include a range of pharmacological and non-pharmacological interventions, often used in combination. Management of spasticity following TBI varies from other clinical populations because of the added complexity of behavioural and cognitive issues associated with TBI. OBJECTIVES: To assess the effects of interventions for managing skeletal muscle spasticity in people with TBI. SEARCH METHODS: In June 2017, we searched key databases including the Cochrane Injuries Group Specialised Register, CENTRAL, MEDLINE (Ovid), Embase (Ovid) and others, in addition to clinical trials registries and the reference lists of included studies. SELECTION CRITERIA: We included randomised controlled trials (RCTs) and cross-over RCTs evaluating any intervention for the management of spasticity in TBI. Only studies where at least 50% of participants had a TBI (or for whom separate data for participants with TBI were available) were included. The primary outcomes were spasticity and adverse effects. Secondary outcome measures were classified according to the World Health Organization International Classification of Functioning, Disability and Health including body functions (sensory, pain, neuromusculoskeletal and movement-related functions) and activities and participation (general tasks and demands; mobility; self-care; domestic life; major life areas; community, social and civic life). DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane. Data were synthesised narratively; meta-analysis was precluded due to the paucity and heterogeneity of data. MAIN RESULTS: We included nine studies in this review which involved 134 participants with TBI. Only five studies reported between-group differences, yielding outcome data for 105 participants with TBI. These five studies assessed the effects of a range of pharmacological (baclofen, botulinum toxin A) and non-pharmacological (casting, physiotherapy, splints, tilt table standing and electrical stimulation) interventions, often in combination. The studies which tested the effect of baclofen and tizanidine did not report their results adequately. Where outcome data were available, spasticity and adverse events were reported, in addition to some secondary outcome measures.Of the five studies with results, three were funded by governments, charities or health services and two were funded by a pharmaceutical or medical technology company. The four studies without useable results were funded by pharmaceutical or medical technology companies.It was difficult to draw conclusions about the effectiveness of these interventions due to poor reporting, small study size and the fact that participants with TBI were usually only a proportion of the overall total. Meta-analysis was not feasible due to the paucity of data and heterogeneity of interventions and comparator groups. Some studies concluded that the intervention they tested had beneficial effects on spasticity, and others found no difference between certain treatments. The most common adverse event was minor skin damage in people who received casting. We believe it would be misleading to provide any further description of study results given the quality of the evidence was very low for all outcomes. AUTHORS' CONCLUSIONS: The very low quality and limited amount of evidence about the management of spasticity in people with TBI means that we are uncertain about the effectiveness or harms of these interventions. Well-designed and adequately powered studies using functional outcome measures to test the interventions used in clinical practice are needed.

Evolution of multiple sclerosis spasticity-associated symptoms: latest data.

In addition to muscle stiffness and increasing mobility restrictions, symptoms commonly associated with multiple sclerosis (MS) spasticity are spasms, sleep disturbances, pain, fatigue and bladder dysfunction. Treatment options include trigger factor avoidance, physiotherapy and antispasticity medication. Oral antispasticity agents commonly used in Germany are baclofen, tizanidine and gabapentin, but physician and patient satisfaction with their effectiveness is low. Over the past few years, randomized controlled trials, observational studies and registry data have demonstrated the positive risk:benefit profile of add-on 9-delta-tetra-hydrocannabinol:cannabidiol oromucosal spray for moderate-to-severe resistant MS spasticity. Herein, evidence for this novel therapeutic option is reviewed. A case study illustrates the level of improvement in daily functioning that is possible in treatment responders.

THC:CBD Observational Study Data: Evolution of Resistant MS Spasticity and Associated Symptoms.

BACKGROUND: The prospective observational MObility ImproVEment (MOVE) 2 study is collecting real-life clinical outcomes data on patients with treatment-resistant multiple sclerosis (MS) spasticity treated with THC:CBD oromucosal spray in routine clinical practice. The MOVE 2 study has been ongoing in Italy, involving more than 30 MS centres across the country, since 2013. METHODS: Web-based real-time data collection techniques are combined with traditional patients' diaries to capture a wide spectrum of outcomes associated with this innovative cannabis-based medication. After surpassing the recruitment threshold of 300 patients, an interim analysis was performed to determine whether the data collected to date align with those from MOVE 2-Germany and the largest phase III randomized controlled trial (RCT) of THC:CBD oromucosal spray. RESULTS: In the Italian cohort, THC:CBD oromucosal spray was added mainly to oral baclofen. Similar to MOVE 2-Germany, during 3 months' observation, treatment discontinuations were limited and patients recorded meaningful improvements on the patient-based 0-10 numerical rating scale and physician-rated modified Ashworth scale at mean daily doses that were about one-third lower than those used in the RCT. Also, similar to MOVE 2-Germany, the proportion of patients reporting adverse events was about one-third of the rate recorded in the RCT. CONCLUSIONS: While MOVE 2-Italy continues, this interim analysis has enabled us to better define the place in therapy of THC:CBD oromucosal spray within the context of daily management of our patients with MS spasticity.

Catatonia.

Catatonia is associated with psychomotor symptoms and severe disturbances of executive functioning. While the prognosis is good in most cases, malignant catatonia still continues to occur. The first-line choice for drug therapy is lorazepam, which usually results in a good response. In catatonic stupor, i.e. immobility and stupor, the first-line therapy is electrotherapy, preferably at an earliest possible stage. In mania, catatonia may become manifest also as psychomotor excitement. Electrotherapy can be used primarily in malignant catatonia, with dantrolene and bromocriptin also finding use in a critical situation.

[POSSIBILITY OF ENHANCING OF THE TRANSPAPILLARY INTERVENTIONS EFFICACY, APPLYING OPTIMIZATION OF THEIR ANESTHESIOLOGICAL SUPPORT].

In 2015 yr еndoscopic transpapillary interventions (ЕТI), performed for diseases of the hepatopancreatoduodenal zone organs, were done in 697 patients. In 315 (45.2%) of them ЕТI were diagnostic, in 382 (54.8%) ­ performed with treatment objective. Меdicinal support for the ЕТI conduction in 631 (90.5%) patients have included conduction of superficial sedation and local anesthesia of pharynx. Аnesthesiological support was applied in 66 (9.5%) patients, including total intravenous anesthesia ­ in 11 (16.6%), еndotracheal narcosis ­ in 55 (83.4%). Using of general anesthesia in comparison to superficial sedation creates more favorable conditions for the ЕТI performance, what have permitted to reduce their duration and complications rate twice.

The Effect of Alpinia zerumbet Essential Oil on Post-Stroke Muscle Spasticity.

The essential oil of Alpinia zerumbet (EOAz) presents myorelaxant and antispasmodic actions on cardiac and smooth muscles. The aim of this study was to investigate the effect of EOAz on the skeletal muscle contraction in post-stroke spasticity. Fifteen adults with unilateral hemiparesis and spasticity resulting from stroke were submitted to surface electromyography readings of the gastrocnemius muscle, before and after 10 daily applications (dermal 0.05 mL per muscle belly) of EOAz. The healthy contralateral muscles without applying the oil were used as controls. The analysis showed that, in both lateral and medial gastrocnemius, the values of all studied variables (root mean square, maximum amplitude and median power frequency) were significantly decreased in pathological legs during muscle contraction (Wilcoxon test, p < 0.05). Moreover, spastic muscles presented different results before and after dermal application of EOAz: The mean values of root mean square and median power frequency were significantly increased in lateral and medial gastrocnemius, and also, the maximum amplitude increased in medial gastrocnemius (Mann-Whitney test, p < 0.05). The results suggest that EOAz acts in the skeletal spastic muscle contraction by promoting relaxation and improvement of the muscular performance. Thus, the EOAz can be useful for the clinical management of secondary effects in patients with cerebral vascular disease.

Successful treatment of Solanum dulcamara intoxication in a Labrador retriever puppy.

A 10-week-old intact male Labrador retriever dog was presented for acute onset of weakness, ataxia, and generalized muscle tremors. The puppy was suffering respiratory and central nervous system (CNS) depression, was mildly pyrexic, and vomited plant material that was identified as creeping nightshade (Solanum dulcamara). He responded well to supportive care and was discharged successfully. To the authors' knowledge, this is the first report of Solanum dulcamara toxicity occurring in a dog.

Traitement réussi d'une intoxication parSolanum dulcamarachez un chiot Labrador retriever. Un chien Labrador retriever mâle intact âgé de 10 semaines a été présenté pour l'apparition aiguë de faiblesse, d'ataxie et des tremblements musculaires généralisés. Le chiot souffrait d'une dépression du système respiratoire et du système nerveux central (SNC), présentait une pyrexie légère et vomissait du matériau végétal qui a été identifié comme étant de la morelle douce-amère (Solanum dulcamara). Il a bien répondu à des soins de soutien et a reçu un congé pour un traitement réussi. À la connaissance des auteurs, c'est le premier rapport d'une toxicité de Solanum dulcamara se produisant chez un chien.(Traduit par Isabelle Vallières).

Antinociceptive, muscle relaxant and sedative activities of gold nanoparticles generated by methanolic extract of Euphorbia milii.

BACKGROUND: Nanotechnology has potential future for enhancing therapeutic efficacy and reducing the unwanted effects of herbal drugs. The biological research on Euphorbia species has been supported by the use of some plants in traditional medicines. Many species of Euphorbia have been reported as having strong sedative and analgesic effects. In the present research work gold nanoparticles of Euphorbia milii methanolic extract (Au-EM) were synthesized, characterized and tested for antinociceptive, muscle relaxant and sedative activities. METHODS: Au-EM was prepared by stirring 1 mM warm trihydrated tetrachloroaurate solution with E. milii methanolic extract without using any external reducing agents. The gold nanoparticles were characterized by UV-Visible spectroscopy, infrared spectrophotometery, atomic force microscopy and scanning electron microscopy while their stability was evaluated against varying pH and different volumes of sodium chloride (NaCl). The metal sensing capacity of Au-EM was tested towards cobalt, copper, lead, mercury and nickel. Au-EM was evaluated in BALB/c mice at a dose of 10 and 20 mg/kg for antinociceptive, muscle relaxant and sedative activities in comparison with the crude E. milii methanolic extract. RESULTS: Au-EM showed remarkable stability in different NaCl and pH solutions. Au-EM produced significant (P < 0.01) antinociceptive effect at doses of 10 and 20 mg/kg as compared to the crude E. milii methanolic extract. In the rotarod test, Au-EM showed significant muscle relaxant effect at 10 mg/kg (P < 0.05) and 20 mg/kg (P < 0.01) after 30, 60 and 90 min. In an open field test significant sedative effect (P < 0.05) of Au-EM was observed at 10 and 20 mg/kg. Moreover significant detection sensitivity was demonstrated towards all the tested heavy metals. CONCLUSIONS: These results concluded that the gold nanoparticles improved the potency of E. milii methanolic extract and exhibited significant analgesic, muscle relaxant and sedative properties. The significant metals sensing ability and enhanced stability in different NaCl and pH solutions may enable us to explore different formulations of E. milii gold nanoparticles for potentially effective and safe nano-herbal therapy.

Common questions about the diagnosis and management of fibromyalgia.

Fibromyalgia has a distinct pathophysiology involving central amplification of peripheral sensory signals. Core symptoms are chronic widespread pain, fatigue, and sleep disturbance. Most patients with fibromyalgia have muscle pain and tenderness, forgetfulness or problems concentrating, and significant functional limitations. Fibromyalgia is diagnosed using an updated set of clinical criteria that no longer depend on tender point examination; laboratory testing may rule out other disorders that commonly present with fatigue, such as anemia and thyroid disease. Patients with fibromyalgia should be evaluated for comorbid functional pain syndromes and mood disorders. Management of fibromyalgia should include patient education, symptom relief, and regular aerobic physical activity. Serotoninnorepinephrine reuptake inhibitors, tricyclic antidepressants, antiepileptics, and muscle relaxants have the strongest evidence of benefit for improving pain, fatigue, sleep symptoms, and quality of life. Multiple complementary and alternative medicine therapies have been used but have limited evidence of effectiveness. Opioids should be used to relieve pain in carefully selected patients only if alternative therapies are ineffective.

Deep dry needling of trigger points located in the lateral pterygoid muscle: Efficacy and safety of treatment for management of myofascial pain and temporomandibular dysfunction.

BACKGROUND: To determine whether deep dry needling (DDN) of trigger points (TPs) in the lateral pterygoid muscle (LPM) would significantly reduce pain and improve function, compared with methocarbamol/paracetamol medication. MATERIAL AND METHODS: Forty-eight patients with chronic myofascial pain located in the LPM were selected and randomly assigned to one of two groups (DDN test group, n=24; drug-treated control group, n=24). The test group received three applications of needling of the LPM once per week for three weeks, while control group patients were given two tablets of a methocarbamol/paracetamol combination every six hours for three weeks. Assessments were carried out pre-treatment, 2 and 8 weeks after finishing the treatment. RESULTS: A statistically significant difference (p<0.05) was detected for both groups with respect to pain reduction at rest and with mastication, but the DDN test group had significantly better levels of pain reduction. Moreover, statistically significant differences (p<0.05) up to day 70 in the test group were seen with respect to maximum mouth opening, laterality and protrusion movements compared with pre-treatment values. Pain reduction in the test group was greater as a function of pain intensity at baseline. The evaluation of efficacy as assessed both by patients/investigators was better for the test group. 41% of the patients receiving the combination drug treatment described unpleasant side effects (mostly drowsiness). CONCLUSIONS: DDN of TPs in the LPM showed better efficacy in reducing pain and improving maximum mouth opening, laterality, and protrusion movements compared with methocarbamol/paracetamol treatment. No adverse events were observed with respect to DDN.

Shakuyaku-kanzo-to (Shao-Yao-Gan-Cao-Tang) as Treatment of Painful Muscle Cramps in Patients with Lumbar Spinal Stenosis and Its Minimum Effective Dose.

Shakuyaku-kanzo-to (Shao-Yao-Gan-Cao-Tang) is a Kampo medicine, which is known to be effective against muscle cramps as well as crampy pain in the gastrointestinal smooth muscle and skeletal muscle. However, glycyrrhizin in this medicine also causes adverse drug reactions such as hypokalemia, hypertension, and edema. We analyzed the therapeutic efficacy of Shakuyaku-kanzo-to for painful muscle cramps associated with lumbar spinal stenosis and clarified its minimum effective dose. 58 patients with lumbar spinal stenosis and painful muscle cramps were included. We evaluated the therapeutic efficacy of Shakuyaku-kanzo-to (n=16) comparing with eperisone hydrochloride (n=14). We then examined the minimum effective dose of Shakuyaku-kanzo-to in the remaining 28 patients. Shakuyaku-kanzo-to reduced the frequency of painful muscle cramps to less than 50% in 13 of 16 patients. However, eperisone hydrochloride reduced it to the same level in 4 of 14 patients. The onset of the maximum therapeutic effect of Shakuyaku-kanzo-to was less than 3 days from the start of treatment in 11 of 15 patients. Regarding the minimum effective dose for painful muscle cramps, 2.5 g of Shakuyaku-kanzo-to used as needed had a therapeutic effect that was equivalent to the regular use of 7.5 g/day (given in divided doses three times daily). Our data show that Shakuyaku-kanzo-to is effective for painful muscle cramps associated with lumbar spinal stenosis. The dosage of 2.5 g of Shakuyaku-kanzo-to as needed had a therapeutic effect that was equal to the regular use of 7.5 g/day.

Impact of vitamin D supplementation on health-care use in a 25-hydroxyvitamin D-tested population in France: a population-based descriptive cohort study.

OBJECTIVE: Chronic vitamin D deficiency has been associated in some patients with diffuse musculoskeletal pain. These unspecific symptoms may partly explain why vitamin D deficiency is often diagnosed late. Our aim was to analyse health-care claims after vitamin D supplementation in patients likely to have vitamin D deficiency. DESIGN: Ambulatory health-care claims were compared before and after a vitamin D supplementation prescribed following a 25-hydroxyvitamin D assay. SETTING: Health Insurance Fund (FHIF) database of the Rhône-Alpes area, France. SUBJECTS: Among patients reimbursed for a 25-hydroxyvitamin D assay between 1 December 2008 and 31 January 2009, those supplemented with vitamin D after the assay were matched on the date of assay to patients who did not receive vitamin D. RESULTS: Among the 3023 patients who had a 25-hydroxyvitamin D assay, 935 were consequently supplemented and matched to 935 patients not supplemented. Their median age was 50·0 and 49·5 years, respectively. Patients supplemented decreased their muscle relaxant consumption whereas no change was observed in the reference group, the difference between the two groups was significant (P=0·03). Second and third Pain Relief Ladder prescriptions decreased in both groups but not significantly differently between groups (P=0·58). There was a decrease in prescriptions of biological examination in both groups with no significant difference. CONCLUSIONS: Besides a decrease in muscle relaxant prescriptions in the supplemented group, it was difficult to assess the impact of vitamin D supplementation in patients likely to have vitamin D deficiency. Prospective cohort studies and randomized trials are needed to assess the efficiency of screening and supplementing vitamin D deficiency.

Advances in the management of multiple sclerosis spasticity: multiple sclerosis spasticity nervous pathways.

BACKGROUND: Spasticity arises from hyperexcitability of the neural stretch reflex arc secondary to injury of the corticospinal tract. In response to injury, the density of glutamatergic inputs from afferent 1A fibers to motor neurons increases dramatically and adaptive changes occur in the morphology of microglia cells in the spinal cord. SUMMARY: Involvement of the endocannabinoid system in pathophysiological mechanisms responsible for spasticity has been demonstrated in animal models of MS. Stimulation of cannabinoid (CB)1 receptors reduces the hyperglutamatergic drive from sensory afferents to spinal cord motor neurons and blocks the synaptic effects of activated microglia and pro-inflammatory mediators (e.g. TNF-α) on glutamatergic transmission. Enhancing corticospinal tract excitability through intermittent theta burst stimulation inhibits the stretch reflex and spasticity by promoting long-term potentiation, a form of synaptic plasticity that requires stimulation of CB1 receptors. Evidence indicates that the antispasticity effects of THC:CBD oromucosal spray (Sativex®) are associated with enhanced cortical long-term potentiation. Key Messages: Glutamatergic and GABAergic pathways are involved in the regulation of muscle tone. CB1 receptors, which are associated with movement, postural control, and pain and sensory perception, influence glutamatergic pathways. THC:CBD oromucosal spray was shown to reverse motor cortex plasticity from long-term depression through long-term potentiation of synaptic transmission, thereby restoring, at least in part, effective corticospinal inputs to spinal circuits.

Advances in the management of multiple sclerosis spasticity: recent clinical trials.

BACKGROUND: Most patients with multiple sclerosis (MS) experience spasticity as the clinical course evolves. Associated symptoms include (often painful) spasms, urinary dysfunction and sleep disturbances. THC:CBD oromucosal spray (Sativex®) is approved for symptom improvement in adult patients with moderate to severe MS-related spasticity who have not responded adequately to other antispasticity medication and who demonstrate clinically significant improvement in spasticity-related symptoms during an initial trial of therapy. SUMMARY: In pivotal clinical trials of THC:CBD oromucosal spray, a meaningful proportion of patients with treatment-resistant MS spasticity achieved clinically relevant improvement with active treatment versus placebo. The utility of a 4-week trial of therapy to identify patients who respond to treatment was demonstrated in an enriched-design study. THC:CBD oromucosal spray was well tolerated in these studies, with no evidence of effects typically associated with recreational cannabis use. In a subsequent post approval clinical trial, THC:CBD oromucosal spray had no statistically significant effect on cognition and mood compared with placebo. Moreover, after 50 weeks' treatment, approximately two-thirds of patients, physicians and caregivers reported improvement from baseline in spasticity based on global impressions of change. Key Messages: In phase III clinical trials, approximately one-third of MS patients with treatment-resistant spasticity had a clinically relevant and statistically significant response to THC:CBD oromucosal spray. In addition to a reduction in spasticity, responders experienced meaningful relief from associated symptoms. THC:CBD oromucosal spray was generally well tolerated and efficacy was maintained over the longer term. A post-approval clinical trial indicated no effect of THC:CBD oromucosal spray on cognition or mood after 50 weeks of use.