Treatment satisfaction with botulinum toxin: a comparison between blepharospasm and cervical dystonia

Exploration of potential immune mechanisms in cervical dystonia

BACKGROUND

Although there are many possible causes for cervical dystonia (CD), a specific etiology cannot be identified in most cases. Prior studies have suggested a relationship between autoimmune disease and some cases of CD, pointing to possible immunological mechanisms.

OBJECTIVE

The goal was to explore the potential role of multiple different immunological mechanisms in CD.

METHODS

First, a broad screening test compared neuronal antibodies in controls and CD. Second, unbiased blood plasma proteomics provided a broad screen for potential biologic differences between controls and CD. Third, a multiplex immunoassay compared 37 markers associated with immunological processes in controls and CD. Fourth, relative immune cell frequencies were investigated in blood samples of controls and CD. Finally, sequencing studies investigated the association of HLA DQB1 and DRB1 alleles in controls versus CD.

RESULTS

Screens for anti-neuronal antibodies did not reveal any obvious abnormalities. Plasma proteomics pointed towards certain abnormalities of immune mechanisms, and the multiplex assay pointed more specifically towards abnormalities in T lymphocytes. Abnormal immune cell frequencies were identified for some CD cases, and these cases clustered together as a potential subgroup. Studies of HLA alleles indicated a possible association between CD and DRB1*15:03, which is reported to mediate the penetrance of autoimmune disorders.

CONCLUSIONS

Altogether, the association of CD with multiple different blood-based immune measures point to abnormalities in cell-mediated immunity that may play a pathogenic role for a subgroup of individuals with CD.

An Exploratory, Randomized, Double-Blind Clinical Trial of Dipraglurant for Blepharospasm

BACKGROUND

Blepharospasm is treated with botulinum toxin, but obtaining satisfactory results is sometimes challenging.

OBJECTIVE

The aim is to conduct an exploratory trial of oral dipraglurant for blepharospasm.

METHODS

This study was an exploratory, phase 2a, randomized, double-blind, placebo-controlled trial of 15 participants who were assigned to receive a placebo or dipraglurant (50 or 100 mg) and assessed over 2 days, 1 and 2 hours following dosing. Outcome measures included multiple scales rated by clinicians or participants, digital video, and a wearable sensor.

RESULTS

Dipraglurant was well tolerated, with no obvious impact on any of the measurement outcomes. Power analyses suggested fewer subjects would be required for studies using a within-subject versus independent group design, especially for certain measures. Some outcome measures appeared more suitable than others.

CONCLUSION

Although dipraglurant appeared well tolerated, it did not produce a trend for clinical benefit. The results provide valuable information for planning further trials in blepharospasm. © 2024 International Parkinson and Movement Disorder Society.

Individual Response to Botulinum Toxin Therapy in Movement Disorders: A Time Series Analysis Approach

On a group level, satisfaction with botulinum neurotoxin (BoNT) treatment in neurological indications is high. However, it is well known that a relevant amount of patients may not respond as expected. The aim of this study is to evaluate the BoNT treatment outcome on an individual level using a statistical single-case analysis as an adjunct to traditional group statistics. The course of the daily perceived severity of symptoms across a BoNT cycle was analyzed in 20 cervical dystonia (CD) and 15 hemifacial spasm (HFS) patients. A parametric single-case autoregressive integrated moving average (ARIMA) time series analysis was used to detect individual responsiveness to BoNT treatment. Overall, both CD and HFS patients significantly responded to BoNT treatment with a gradual worsening of symptom intensities towards BoNT reinjection. However, only 8/20 CD patients (40%) and 5/15 HFS patients (33.3%) displayed the expected U-shaped curve of BoNT efficacy across a single treatment cycle. CD (but not HFS) patients who followed the expected outcome course had longer BoNT injection intervals, showed a better match to objective symptom assessments, and were characterized by a stronger certainty to control their somatic symptoms (i.e., internal medical locus of control). In addition to standard evaluation procedures, patients should be identified who do not follow the mean course-of-treatment effect. Thus, the ARIMA single-case time series analysis seems to be an appropriate addition to clinical treatment studies in order to detect individual courses of subjective symptom intensities.

Comparison of Botulinum neurotoxin efficiency in dystonia associated with Parkinson's disease and atypical parkinsonism: a retrospective study with a self-reported improvement scale

Botulinum neurotoxin (BoNT) is a useful therapeutic option to treat dystonic manifestations. Data on its efficiency on dystonia associated with Parkinson's disease (PD) or atypical parkinsonism (AP) are scarce and no comparison of the efficiency of BoNT has been performed between these diseases and between the different localizations of dystonia in these pathologies. We retrospectively collected from patients' medical records the result of 611 BoNT injections in 63 dystonic parkinsonian patients (44 PD and 19 AP) using a self-reported clinical improvement scale and duration of effect. Using these data, we modeled the degree of improvement and its duration after BoNT treatment with a linear mixed model. This allowed us to assess the influence of clinical parameters on the reported treatment efficiency. On a scale from 0 to 100, patients with PD and AP, respectively, report a mean improvement of 69% and 55% after BoNT injection and it is similar regarding the different localizations of dystonia. Duration of effect is, however, longer in PD compared to AP (P = 0.023). Patients' demographic and clinical characteristics had no effect on the degree of improvement or duration of effect. Overall, our results support the use of BoNT in the various dystonic phenomena associated with degenerative parkinsonian syndromes. Shorter delays between injection sessions should be considered in AP compared to PD.Trial registration: This study was registered on Clinicaltrial.gov (NCT04948684).

Duration and onset of effect of incobotulinumtoxinA for the treatment of blepharospasm in botulinum toxin-naïve subjects

OBJECTIVE

Blepharospasm is a focal dystonia whereby excessive eyelid muscle contractions cause involuntary eye closure. Botulinum neurotoxin type A (BoNT-A) injections are an approved treatment. This randomized placebo-controlled trial (NCT01896895; EudraCT number 2012-004821-26) assessed the efficacy, safety, and treatment effect duration of incobotulinumtoxinA (Xeomin, Merz Pharmaceuticals GmbH), a BoNT-A formulation without complexing proteins, in BoNT-A-naïve adults with blepharospasm.

METHODS

Subjects received incobotulinumtoxinA 50 U, 25 U (total dose) or placebo during a main study period (MP; 6-20 weeks). Patients needing a second injection received incobotulinumtoxinA ≤70 U in an open-label extension period (EP; 6-20 weeks). Treatment effect durations were time from first injection to EP injection or final MP visit and from EP injection to end-of-study visit. Times to effect onset and to waning of effect (MP) were time from injection to first subject-assessed onset effect and time from injection to subject-reported waning of effect, respectively.

RESULTS

Of 61 subjects, 39 entered the EP. During the MP, median duration of treatment effect was longer with incobotulinumtoxinA 50 U (20 weeks) versus incobotulinumtoxinA 25 U (11 weeks) or placebo (6 weeks). Median duration of treatment effect was 20 weeks during the EP. Median time to effect onset was 5, 7, and 14 days with 50 U, 25 U, and placebo, respectively (p = .022 for 50 U versus placebo). Median time to waning of treatment effect was comparable between groups.

CONCLUSION

Subjects reported an effect onset from 5 days after injection lasting up to 20 weeks (maximum observation period). Data indicate that incobotulinumtoxinA re-treatment of blepharospasm may not be required at fixed 12-week intervals and provide evidence for a patient-tailored approach.

Subjective versus objective symptom intensities ratings in cervical dystonia and hemifacial spasm across a botulinum neurotoxin cycle

BACKGROUND

Subjective symptom complaints often do not match the expert's ratings in focal dystonia. Nonetheless, perceived symptom intensities drive compliance and outcome of botulinum neurotoxin (BoNT) treatment.

METHODS

Perception of symptom development across a BoNT cycle was obtained in 21 cervical dystonia (CD) and 15 hemifacial spasm (HFS) patients at four time points during a BoNT cycle. Subjective assessments were recorded by means of a quality-of-life questionnaire and a patient diary containing items related to subjective severity of disease, mood, pain, social impairment, and quality of life. Medical investigation used the Tsui score and TWSTRS, and a HFS rating score, respectively.

RESULTS

In both patient groups, subjective intensities were strongly associated with psychological variables. Only in CD did objective assessment moderately correlate with subjective ratings solely at the beginning and the end of the BoNT cycle. Overall, the beneficial effects of BoNT treatment were only loosely associated with subjective experiences in both groups.

CONCLUSION

The emotional situation should be assessed regularly in patients undergoing BoNT therapy.

Cervical dystonia: factors deteriorating patient satisfaction of long-term treatment with botulinum toxin

OBJECTIVES

Botulinum toxin (BoNT) is an effective first-line treatment for cervical dystonia (CD). Despite generally good therapeutic efficacy, approximately 20-40% of CD patients do not achieve acceptable relief of the dystonic symptoms. The aim of this study was to identify factors of low patient satisfaction of long-term BoNT therapy for CD.

METHODS

In this case-control study CD patients treated with BoNT intramuscular injections for up to 24 years were assessed by two independent assessors in three validated scales: TWSTRS, Tsui and VAS for pain measurement. Data on received BoNT doses and treatment duration were obtained from medical history. All of participants rated their long-term treatment satisfaction compared to the therapy onset on a 0-3 scale.

RESULTS

Study was completed by 58 participants who were treated with BoNT for 9.0 ± 6.3 years and received a median of 19 injection cycles. None/low therapy satisfaction was reported by 20.7% of participants. Compared to moderate/good treatment satisfaction, CD patients with none/low BoNT efficacy had increased incidence of cervical pain (p =.018), enhanced mean VAS score for pain (p =.037) and had higher coexistence of oromandibular dystonia (p =.018). In addition, worse treatment satisfaction correlated with shorter time intervals between treatment cycles, enhanced scores of Tsui total, TWSTRS total, as well as TWSTRS subscales: severity, disability and pain.

CONCLUSION

Cervical pain and coexistence of oromandibular dystonia deteriorated long-term treatment satisfaction in CD patients. Higher scores of Tsui and TWSTRS subscales were correlated with worse subjective BoNT treatment response.