Theoretical and Therapeutic Implications of the Spasticity-Plus Syndrome Model in Multiple Sclerosis

Isokinetic and electromyographic characterization of ankle plantarflexors' hypertonia in people with multiple sclerosis

BACKGROUND

This study aimed at quantifying ankle plantarflexors' resistance to passive motion (RPM) by isokinetic dynamometry and muscle activity through surface electromyography (sEMG) in persons with multiple sclerosis (PwMS) with limb stiffness and spasticity.

METHODS

Slow and fast ankle dorsiflexions (from 5°/s to 210°/s) were imparted passively by an isokinetic dynamometer, and sEMG activity of plantarflexors was recorded at the same time as the square root of the moving average. Based on RPM evaluated at 5°/s, ankles were classified as more- and less-resistant as measured by average peak torque (APT).

RESULTS

Measurements were obtained bilaterally from 24 PwMS (median EDSS: 5.5) with median Modified Ashworth Scale (MAS) score of 1.75. Compared to the lowest velocity inducing EMG-evident responses (120°/s), RPM increased significantly at 180°/s (+137.8 %; p < 0.0005) and 210°/s (+85.3 %; p < 0.0005) in the less-resistant side, and only at 210°/s (+113.8 %; p < 0.0005) in the more-resistant side. sEMG activity increased significantly and similarly between limbs at increasing velocities. Significant velocity-dependent increases were detected in both limbs, with no difference by side, at 180°/s (+34.5 %; p = 0.005) and 210°/s (+48.4 %; p = 0.004). Regression analyses confirmed side (β=0.542; p < 0.0001) and speed (β=0.238; p < 0.0001) as significant predictors of APT change, but only speed for sEMG (speed: β=0.215; p = 0.019; side: β=0.012; p = 0.893). Bivariate correlations revealed that RPM was associated negatively with MAS and positively with sEMG.

CONCLUSION

Spasticity presented bilaterally in PwMS, with different mixed pictures of passive and reflex stiffness, both requiring attention. Combining isokinetics and sEMG allows detecting even subtle, subclinical alterations that can prompt and drive early tailored management.

Practical tool to identify Spasticity-Plus Syndrome amongst patients with multiple sclerosis. Algorithm development based on a conjoint analysis

Introduction

The Spasticity-Plus Syndrome (SPS) in multiple sclerosis (MS) refers to a combination of spasticity and other signs/symptoms such as spasms, cramps, bladder dysfunction, tremor, sleep disorder, pain, and fatigue. The main purpose is to develop a user-friendly tool that could help neurologists to detect SPS in MS patients as soon as possible.

Methods

A survey research based on a conjoint analysis approach was used. An orthogonal factorial design was employed to form 12 patient profiles combining, at random, the eight principal SPS signs/symptoms. Expert neurologists evaluated in a survey and a logistic regression model determined the weight of each SPS sign/symptom, classifying profiles as SPS or not.

Results

72 neurologists participated in the survey answering the conjoint exercise. Logistic regression results of the survey showed the relative contribution of each sign/symptom to the classification as SPS. Spasticity was the most influential sign, followed by spasms, tremor, cramps, and bladder dysfunction. The goodness of fit of the model was appropriate (AUC = 0.816). Concordance between the experts' evaluation vs. model estimation showed strong Pearson's (r = 0.936) and Spearman's (r = 0.893) correlation coefficients. The application of the algorithm provides with a probability of showing SPS and the following ranges are proposed to interpret the results: high (> 60%), moderate (30-60%), or low (< 30%) probability of SPS.

Discussion

This study offers an algorithmic tool to help healthcare professionals to identify SPS in MS patients. The use of this tool could simplify the management of SPS, reducing side effects related with polypharmacotherapy.

Spasticity-Plus syndrome in multiple sclerosis patients in a tertiary hospital in Spain

Introduction

Spasticity is a common symptom in multiple sclerosis (MS) and it is often associated with other symptoms such as spasms/cramps and pain. The concept of Spasticity-Plus syndrome takes into account that spasticity is accompanied by one or more symptoms (spasms/cramps, pain, bladder dysfunction, sleep disorders, fatigue and/or tremor). As these symptoms share a common cannabinoid control, therapy acting on cannabinoid receptors may be useful. The main study objectives were to determine the number of MS patients who met Spasticity-Plus syndrome criteria and to identify the most common symptoms.

Methods

Clinical records of MS patients treated with nabiximols in a tertiary hospital from 2002 to 2022 were reviewed retrospectively.

Results

Of the 73 patients included in the study, 53.4% were women, and most had secondary progressive MS (64.4%). All patients met the criteria for Spasticity-Plus syndrome: 100% had spasticity and at least another symptom. Pain was the second most common symptom (91.8%), followed by spasms/cramps (79.4%), and fatigue (76.7%). Sleep disturbances (p < 0.0001) and tremor (p < 0.027) were more frequent in patients with relapsing-remitting MS than in patients with progressive MS. No statistically significant differences were found for spasticity, pain, spasms/cramps, and fatigue between MS phenotypes. Regarding symptoms clusters, 94.4% of the patients had three or more symptoms. Spasticity was more frequently associated with pain (91.8%) and spasms/cramps (79.4%).

Conclusion

Spasticity-Plus syndrome was present in all the study population of patients with different MS phenotypes, and treated with nabiximols.

Symptom burden, management and treatment goals of people with MS spasticity: Results from SEEN-MSS, a large-scale, self-reported survey

BACKGROUND

Spasticity occurs frequently in people with multiple sclerosis (PwMS) and may affect non-physical aspects of life. However, there is a paucity of data assessing the full impact of spasticity in PwMS.

OBJECTIVE

This survey of PwMS and spasticity (PwMSS) was undertaken to understand the impact of spasticity in physical, functional, emotional, and social domains.

METHODS

SEEN-MSS (Symptoms and Emotions Exploration Needed in Multiple Sclerosis Spasticity), an online survey, was developed in collaboration with three US-based MS organizations (conducted February-April 2021).

RESULTS

Survey was completed by 1,177 PwMSS, 78% female, mean age 56.8yrs, 16.8yrs from MS diagnosis, 11.5yrs with spasticity. Considering day-to-day goals of treatment, respondents reported that managing symptoms(46%) was nearly as important as slowing disease progression(54%). Most reported spasticity was a constant reminder of their MS. Participants reported that spasticity limited daily activities (92%), caused pain (92%), impaired sleep (89%) and negatively impacted emotional well-being (87%). Spasticity fostered a sense of dependence (61%), isolation (40%), decline in self-confidence (75%), self-image (70%), and social connection (62%).

CONCLUSIONS

Spasticity has wide-reaching negative impacts on multiple aspects of life, causing substantial burden for PwMSS. Results emphasize the need to fully understand the burden of spasticity and addressing individual needs of PwMSS.

Persistence with Botulinum Toxin Treatment for Spasticity Symptoms in Multiple Sclerosis

Botulinum toxin (BT) is an effective treatment for spasticity symptoms in multiple sclerosis (MS). Despite its wide use in clinical practices, only few studies have explored long-term persistence. We aim to evaluate the rate of discontinuation of BT treatment and the correlation with MS, spasticity, and injection variables. This retrospective study on 3-year prospectively collected data included 122 MS patients receiving BT injections for spasticity. We collected MS clinical variables (disease durations, Expanded Disability Status Scales [EDSSs], disease-modifying treatments [DMT], and Symbol Digit Modalities Tests [SDMTs]), modified Ashworth scales [MASs], concomitant treatments, and injection variables (formulation, dose, number of injections, and intervals between injections). A total of 14 out of the 122 patients discontinued BT after a mean time of 3.0 ± 1.5 years. In the Cox regression model including the MS clinical variables, the probability of BT discontinuations increased in patients with DMT changes during follow-ups (HR = 6.34; 95%Cl = 2.47, 18.08; p < 0.01) and with impaired SDMTs (HR = 1.20; 95%Cl = 1.04, 1.96; p < 0.01). In the model including the spasticity variables, there were no associations between BT discontinuation and MAS or other spasticity treatments. In the model including the injection variables, the probability of discontinuation decreased by 80% for each cumulative injection (HR = 0.16; 95%Cl = 0.05, 0.45; p < 0.01), but increased by 1% for each additional day over the 3-month interval between injections (HR = 1.27; 95%Cl = 1.07, 1.83; p < 0.01). BT discontinuation was associated with concomitant MS-related issues (e.g., treatment failure and DMT change) and the presence of cognitive impairment, which should be accounted for when planning injections. The interval between injections should be kept as short as possible from regulatory and clinical perspectives to maximize the response across all of the spasticity symptoms and to reduce discontinuation in the long term.