Working capacity and cervical dystonia

Deep Brain Stimulation for Focal or Segmental Craniocervical Dystonia in Patients Who Have Failed Botulinum Neurotoxin Therapy-A Narrative Review of the Literature

(1) Background: The first-line treatment for patients with focal or segmental dystonia with a craniocervical distribution is still the intramuscular injection of botulinum neurotoxin (BoNT). However, some patients experience primary or secondary treatment failure from this potential immunogenic therapy. Deep brain stimulation (DBS) may then be used as a backup strategy in this situation. (2) Methods: Here, we reviewed the current study literature to answer a specific question regarding the efficacy and safety of the use of DBS, particularly for cervical dystonia (CD) and Meige syndrome (MS) in patients with documented treatment failure under BoNT. (3) Results: There are only two studies with the highest level of evidence in this area. Despite this clear limitation, in the context of the narrowly defined research question of this paper, it is possible to report 161 patients with CD or MS who were included in studies that were able to show a statistically significant reduction in dystonic symptoms using DBS. Safety and tolerability data appeared adequate. However, much of the information is based on retrospective observations. (4) Conclusions: The evidence base in this area is in need of further scientific investigation. Most importantly, more randomized, controlled and double-blind trials are needed, possibly including a head-to-head comparison of DBS and BoNT.

Abnormal Network Homogeneity in the Right Superior Medial Frontal Gyrus in Cervical Dystonia

Background: Increasing evidence from modern neuroimaging has confirmed that cervical dystonia (CD) is caused by network abnormalities. Specific brain networks are known to be crucial in patients suffering from CD. However, changes in network homogeneity (NH) in CD patients have not been characterized. Therefore, the purpose of this study was to investigate the NH of patients with CD.

Methods: An automated NH method was used to analyze resting-state functional magnetic resonance (fMRI) data from 19 patients with CD and 21 gender- and age-matched healthy controls (HC). Correlation analysis were conducted between NH, illness duration and symptom severity measured by the Tsui scale.

Results: Compared with the HC group, CD patients showed a lower NH in the right superior medial frontal gyrus. No significant correlations were found between abnormal NH values and illness duration or symptom severity.

Conclusion: Our findings suggest the existence of abnormal NH in the default mode network (DMN) of CD patients, and thereby highlight the importance of the DMN in the pathophysiology of CD.

A single-center series of 482 patients with functional motor disorders

Functional motor disorders (FMD) are common and disabling. They are known to predominantly affect women and young to middle-aged patients, although they also occur during childhood or in the elderly. Demographic and clinical characteristics of patients with FMD are poorly known, since large series of consecutive patients are scarce.

METHODS

In a chart review study, we retrospectively abstracted data from consecutive FMD patients who were referred to the Neurophysiology Department of the Salpêtrière University Hospital between 2008 and 2016 for treatment with repeated transcranial magnetic stimulation.

RESULTS

482 patients were included. Most patients were women (73.7%). Median age at symptoms onset was 35.5 years and symptoms were mostly characterized by acute (47.3%) or subacute (46%) onset. Only 23% of patients were active workers, while 58.3% were unemployed because of FMD. Half of the patients had functional motor weakness (n = 241) whereas the other half had movement disorders (n = 241), mainly with tremor (21.1%) or dystonia (20.5%). Among all patients, 66.4% had psychiatric comorbidity and 82.6% reported a history of trauma in the 6 months before symptoms onset. No difference was found in age or gender according to clinical phenotypes.

CONCLUSION

This large series will contribute to better characterize FMDs.

Improvement of head and neck range of motion induced by chronic pallidal deep brain stimulation for cervical dystonia

BACKGROUND

Deep brain stimulation (DBS) of the globus pallidus internus (GPi) has become an accepted treatment for severe cervical dystonia (CD). Assessment of therapeutic efficacy of DBS mostly focused on head position at rest but hardly on limitations of head and neck mobility, which represent a functionally important impairment in CD.

OBJECTIVE

We aimed to determine prospectively head and neck range of motion (ROM) preoperatively and during chronic bilateral GPi DBS in a series of 11 patients with idiopathic CD or segmental dystonia with prominent CD using a computerized motion analysis.

METHODS

Maximum horizontal rotation of the head in the transverse plane and lateral inclination in the frontal plane were measured preoperatively and at a median of 7 months of chronic GPi DBS, using an ultrasound-based three-dimensional measuring system combined with surface electromyography of cervical muscles.

RESULTS

Horizontal rotation of the head increased from 78.8° ± 31.5° (mean ± SD) preoperatively to 100.7° ± 24.7° with GPi DBS (p < 0.01), thereby improvement of head rotation to the anti-dystonic side (+ 14,2° ± 12,2°) was greater than to the pro-dystonic side (+ 7,8° ± 9,2°; p < 0.05). Movement-related agonistic-antagonistic EMG modulation during head rotation was enhanced with GPi DBS in both sternocleidomastoid (modulation index (MI) 35.8% ± 26.7% preoperatively vs. 67.3% ± 16.9% with GPi DBS, p < 0.01), and splenius capitis muscles (MI 1.9% ± 24.5% preoperatively vs. 44.8% ± 11.6% with GPi DBS, p < 0.01).

CONCLUSION

Chronic bilateral GPi DBS significantly improves head ROM in CD, likely due to enhanced agonist-antagonist EMG activity with reduced co-contraction. Computerized motion analysis provides an objective measurement to assess the improvement of head and neck mobility in CD.

Psychological Traits and Behavioural Influences in Patients with Dystonia-An Observational Cohort Study in a Romanian Neurology Department

(1) Background: Emerging evidence indicates that non-motor symptoms significantly influence the quality of life in dystonic patients. Therefore, it is essential to evaluate their psychological characteristics and personality traits. (2) Methods: Subjects with idiopathic dystonia and a matched control group were enrolled in this prospective observational cohort study. Inclusion criteria for patient group included idiopathic dystonia diagnosis, evolution exceeding 1 year, and signed informed consent. Inclusion criteria for the control group included lack of neurological comorbidities and signed informed consent. All subjects completed the DECAS Personality Inventory along with an additional form of demographic factors. Data (including descriptive statistics and univariate and multivariate analysis) were analyzed with SPSS. (3) Results: In total, 95 participants were included, of which 57 were in the patient group. Females prevailed (80%), and the mean age was 54.64 ± 12.8 years. The most frequent clinical features of dystonia were focal distribution (71.9%) and progressive disease course (94.73%). The patients underwent regular treatment with botulinum toxin (85.95%). In addition, patients with dystonia obtained significantly higher openness scores than controls, even after adjusting for possible confounders (p = 0.006). Personality traits were also different between the two groups, with patients more often being fantasists (p = 0.007), experimenters (p = 0.022), sophists (p = 0.040), seldom acceptors (p = 0.022), and pragmatics (p = 0.022) than control subjects. (4) Conclusion: Dystonic patients tend to have different personality profiles compared to control subjects, which should be taken into consideration by the treating neurologist.

Non-Motor Symptoms in Cervical Dystonia: A Review

Dystonia is a movement disorder characterized by sustained or intermittent muscle contractions causing abnormal, often repetitive movements, postures, or both. Dystonic movements are typically patterned, associated with twisting of body parts, and may have tremulousness. Dystonia is usually initiated or worsened by voluntary action and associated with overflow muscle activation. Cervical dystonia (CD) is the most prevalent form of dystonia. CD is a condition characterized by cranial muscle overactivity leading to abnormal intermittent or continuous posturing of the head. Non-motor symptoms are comorbidity of dystonia, which significantly hampers the quality of life among these patients. The symptoms can be as a result of the dystonia itself. However, studies have highlighted the involvement of cortical-striatal-thalamocortical circuits in primary dystonia that could be the pathophysiological basis for the non-motor symptoms. The non-motor symptoms that are commonly associated with dystonia are anxiety, depression, restless leg syndrome, excessive daytime sleepiness, cognitive disturbances, and poor sleep. This review attempts to summarize the literature on non-motor symptoms in patients with CD.

Comorbidity and retirement in cervical dystonia

BACKGROUND

Cervical dystonia (CD) is the most common form of dystonia. The onset of CD is usually before 60 years of age and it may cause severe functional and psychosocial impairment in everyday life. Recently non-motor symptoms have been reported to occur in CD substantially affecting the quality of life.

METHODS/PATIENTS

We studied comorbidities of patients with primary focal CD in Finland based on ICD-10 codes obtained from the care registry and patient records of 937 confirmed adult isolated focal CD patients between the years 2007-2016. The retirement months and diagnosis of retirement were calculated from pension registry information. The results were compared with 3746 age and gender-matched controls.

RESULTS

Most prominent comorbidities with primary focal CD were depression (14%), anxiety (7%), and back pain (11%). The retirement age was significantly younger in CD patients compared to control group controls (59.0 years, 95% CI 58.5-59.5 vs. 61.7 years, 95% CI 61.6-61.9) years, p < 0.001). For dystonia patients the most common diagnoses for retirement due to sickness were dystonia (51%), depression (14%), and anxiety (8%). Patients with anxiety and depression retired earlier than other dystonia patients.

DISCUSSION

Cervical dystonia considerably reduces working ability and leads to earlier retirement. Anxiety and depression are most notable comorbidities and their co-occurrence further reduces working ability. Our results suggest that more health care resources should be administered in treatment of CD to longer maintain working ability of CD patients. Further, psychiatric comorbidities should be taken into consideration in CD treatment.

A randomized study of botulinum toxin versus botulinum toxin plus physical therapy for treatment of cervical dystonia

BACKGROUND

Physical therapy (PT) for cervical dystonia is not well studied, and the underlying physiological effects are not known.

METHODS

We enrolled 26 subjects comprising of 16 cervical dystonia and 10 healthy controls for normative physiological data. We randomized cervical dystonia patients who reported suboptimal benefits on botulinum toxin (BoNT) injections to BoNT alone (BoNT arm) or BoNT plus PT (PT-BoNT arm). PT-BoNT arm received manual PT on the injection day followed by six weeks of home-exercise program. Home-exercise program comprised of stretching, range-of-motion and isometric exercises. The primary outcome was change from baseline in Toronto Western spasmodic torticollis rating scale (TWSTRS) that was recorded six weeks after exercise program. TWSTRS was video evaluated by blinded raters. We probed sensorimotor plasticity with transcranial magnetic stimulation (TMS) using a paired associative stimulation (PAS) paradigm.

RESULTS

TWSTRS score improved (severity 31%, p = 0.002; pain 28%, p = 0.01) and PAS plasticity decreased (p = 0.01) in PT-BoNT arm compared to BoNT arm. PAS values for PT-BoNT arm were found to approach values of healthy control values. Change in PAS measure correlated significantly with TWSTRS change (severity, r = 0.56, p = 0.04; pain, r = 0.61, p = 0.03. TWSTRS disability score only approached significance (p = 0.14) when comparing the two treatment arms.

CONCLUSION

PT is a potential adjunct in patients with cervical dystonia who report suboptimal benefits with BoNT therapy. PT related benefits in cervical dystonia are likely mediated through modulation of sensorimotor plasticity.

Dystonia

Dystonia is a neurological condition characterized by abnormal involuntary movements or postures owing to sustained or intermittent muscle contractions. Dystonia can be the manifesting neurological sign of many disorders, either in isolation (isolated dystonia) or with additional signs (combined dystonia). The main focus of this Primer is forms of isolated dystonia of idiopathic or genetic aetiology. These disorders differ in manifestations and severity but can affect all age groups and lead to substantial disability and impaired quality of life. The discovery of genes underlying the mendelian forms of isolated or combined dystonia has led to a better understanding of its pathophysiology. In some of the most common genetic dystonias, such as those caused by TOR1A, THAP1, GCH1 and KMT2B mutations, and idiopathic dystonia, these mechanisms include abnormalities in transcriptional regulation, striatal dopaminergic signalling and synaptic plasticity and a loss of inhibition at neuronal circuits. The diagnosis of dystonia is largely based on clinical signs, and the diagnosis and aetiological definition of this disorder remain a challenge. Effective symptomatic treatments with pharmacological therapy (anticholinergics), intramuscular botulinum toxin injection and deep brain stimulation are available; however, future research will hopefully lead to reliable biomarkers, better treatments and cure of this disorder.

Measuring Disability in Patients With Cervical Dystonia According to the International Classification of Functioning, Disability and Health

Cervical Dystonia (CD) is a rare movement disorder characterized by an abnormal head position. This cross-sectional study describes the health status and severity of disability using an internationally agreed language by applying the International Classification of Functioning, Disability and Health (ICF). Two disease-specific rating scales were administered to 30 patients with CD. By linking the individual answers to the ICF model, the frequency and severity of reported impairments and restrictions were estimated using a count-based method. Results showed that patients most frequently reported impairments linked to "neuromusculoskeletal and movement-related functions" and "mental functions." Most restrictions in activities were related to "interpersonal interactions and relations," "major life areas," and "community, social, and civic life." One third of the reported impairments can be labeled as severe disability. The findings show that CD causes disability in multiple levels of a patients' functioning in life, well beyond the cervical area.

Impact of Cervical Dystonia on Work Productivity: An Analysis From a Patient Registry

BACKGROUND

Cervical dystonia is thought to result in high disease burden, but limited information exists on its impact on employment and work productivity. We utilized data from the Cervical Dystonia Patient Registry for the Observation of OnabotulinumtoxinA Efficacy (ClinicalTrials.gov identifier: NCT00836017) to assess the impact of cervical dystonia on employment and work productivity and examine the effect of onabotulinumtoxinA treatments on work productivity.

METHODS

Subjects completed a questionnaire on employment status and work productivity at baseline and final visit. Baseline data were examined by severity of cervical dystonia, predominant subtype, presence of pain, prior exposure to botulinum toxin, and/or utility of a sensory trick. Work productivity results at baseline and final visit were compared in subjects who were toxin-naïve at baseline and received three onabotulinumtoxinA treatments.

RESULTS

Of 1,038 subjects, 42.8% were employed full- or part-time, 6.1% unemployed, 32.7% retired, and 11.8% disabled. Of those currently employed, cervical dystonia affected work status of 26.0%, caused 29.8% to miss work in the past month (mean, 5.1 ± 6.4 days), and 57.8% reported decreased productivity. Half of those unemployed were employed when symptoms began, and 38.5% attributed lost employment to cervical dystonia. Pain, increasing severity, and anterocollis/retrocollis had the largest effects on work status/productivity. Preliminary analyses showed that absenteeism and presenteeism were significantly decreased following onabotulinumtoxinA treatments in the subpopulation that was toxin-naïve at baseline.

CONCLUSIONS

This analysis confirms the substantial negative impact of cervical dystonia on employment, with cervical dystonia-associated pain being a particularly important driver. OnabotulinumtoxinA treatment appears to improve work productivity.

An international survey of patients with cervical dystonia

This was an international survey undertaken to assess cervical dystonia (CD) patients own perceptions of their illness and its management. A total of 1,071 self-identified respondents with CD in 38 countries completed the online survey between March and December 2012. The mean time since diagnosis was 9.6 years and over half (54 %) of patients surveyed were not diagnosed in the first year. When asked how the symptoms of CD affected them, two-thirds (66 %) of patients reported they experienced a lot of pain, and 61 % said that they suffered depression and mood alterations; only 7 % reported no impact on their lives. Despite problems with the diagnosis, almost 70 % of respondents reported being satisfied with the overall relationship with their doctor. Patient treatment expectations were high, with 63 % expecting freedom from spasms and 62 % expecting freedom from pain. Over half (53 %) expected to be able to return to a normal routine (53 %). The most common treatment reported was botulinum toxin (BoNT) (86 %), followed by oral medication (58 %) and physiotherapy/physical therapy (37 %). Among patients treated on BoNT, 56 % were fairly/very satisfied, 25 % were fairly/very dissatisfied and 20 % were neither satisfied nor dissatisfied with the outcome. In conclusion, this international survey highlights the broad impact of CD on several aspects of patient life. Taken overall, the survey suggests that that patients need to be better informed about their condition, treatments available and the limitations of those treatments. It may be that realistically managing patient expectations of treatment would reduce the dissatisfaction of some patients.

The physical, social and emotional aspects are the most affected in the quality of life of the patients with cervical dystonia

OBJECTIVE

Describe the functional, clinical and quality of life (QoL) profiles in patients with cervical dystonia (CD) with residual effect or without effect of botulinum toxin (BTX), as well as verify the existence of correlation between the level of motor impairment, pain and QoL.

METHOD

Seventy patients were assessed through the Craniocervical dystonia questionnaire-24 (CDQ-24) and the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS).

RESULTS

The greater the disability, pain and severity of dystonia, the worse the QoL (p<0.0001). Greater severity relates to greater disability (p<0.0001). Pain was present in 84% of the sample, being source of disability in 41%. The most frequent complaints were: difficulty in keeping up with professional and personal demands (74.3%), feeling uneasy in public (72.9%), hindered by pain (68.6%), depressed, annoyed or bitter (47.1%), lonely or isolated (32.9%).

CONCLUSION

The physical, social and emotional aspects are the most affected in the QoL of these patients.

Enhanced dorsal premotor-motor inhibition in cervical dystonia

OBJECTIVE

This study aims to understand whether the enhanced dPMI, seen in writer's cramp patients previously, extends to other populations of focal dystonia patients (e.g. cervical dystonia) as an endophenotypic marker.

METHODS

We studied 9 healthy subjects and 9 patients with CD. dPMI was tested by applying conditioning transcranial magnetic stimulation to the left dorsal premotor cortex and then a test pulse to the ipsilateral motor cortex at an interval of 6ms. We also looked at the duration of the cortical silent period (CSP)-a measure of cortical excitability.

RESULTS

CD patients had enhanced dPMI at rest (mean 57.0%, SD 16.2) in contrast to healthy volunteers (mean 124.1%, SD 35.7) (p<0.001). CSP latencies (in ms) in CD patients (mean 108.0, SD 33.1) were significantly shorter than in healthy volunteers (mean 159.1, SD 55.2) (p<0.05).

CONCLUSIONS

CD patients showed enhanced dPMI in a hand muscle-distant from their affected body part-similar to writer's cramp patients. This enhanced inhibition was independent of disease severity and neck posture. This suggests that enhanced dPMI may be an endophenotypic marker of dystonia.

SIGNIFICANCE

The abnormal dorsal premotor-motor connection in cervical dystonia is a potential novel and important avenue for therapeutic targeting.

The effectiveness of physiotherapy for cervical dystonia: a systematic literature review

Cervical dystonia is a form of adult-onset, focal dystonia characterized by involuntary contractions of the neck muscles, leading to a disabling, abnormal head posture. CD has a great impact on the activities of daily living (ADL) and quality of life. Currently, the most widely used and recommended first line treatment is botulinum toxin type A (BoNT/A) injections. Physiotherapy is a potentially useful adjuvant, but little is known about its effectiveness. Consequently, our objective was to investigate the effectiveness of physiotherapy alone or as an adjuvant treatment to BoNT/A injections in cervical dystonia (CD) by means of a systematic literature review. Two online databases, PubMed and Web of Science, were searched for articles describing the effectiveness of physiotherapy treatment for CD. After screening, based on predefined in- and exclusion criteria, 16 studies were retained. Their methodological quality was assessed according to Cochrane guidelines. The methodological quality of most studies was low. Examples of shortcomings are small sample sizes, lack of randomization or blinding, and diversity in therapeutic techniques and outcome measures. Only seven studies were clinical trials; the remaining were either case reports or case series. The reported physiotherapy treatments included EMG biofeedback training, muscular elongation, postural exercises and electrotherapy. Improvements in head position, pain, cervical range of motion, quality of life and ADL have been reported, which is promising. Cautious interpretation on the effectiveness of physiotherapy as an adjuvant therapy is required. Before firm conclusions can be drawn, additional high quality trials are needed.

The cost-effectiveness of periodic safety update reports for biologicals in Europe

We analyzed the cost-effectiveness of all Periodic Safety Update Reports (PSURs) submitted for biologicals in Europe from 1995 to 2009 by comparing two regulatory scenarios: full regulation (PSUR reporting) and limited regulation (no PSUR reporting, but all other parts of the pharmacovigilance framework remain in place). During this period, PSUR reporting resulted in the detection of 2 out of a total of 24 urgent safety issues for biologicals: (i) distant spread of botulinum toxin and (ii) edema/fluid collection associated with off-label use of dibotermin-alfa. We used Markov-chain life tables to calculate costs and health effects of PSURs. The incremental cost-effectiveness ratio (ICER) of full regulation (PSUR reporting) vs. limited regulation (no PSUR reporting) for the base-case scenario was \[euro]342,110 per quality-adjusted life year (QALY) gained. It is possible to assess the cost-effectiveness of regulatory requirements using the same methods as those used in assessing the cost-effectiveness of medical interventions.

Botulinum toxin as treatment for focal dystonia: a systematic review of the pharmaco-therapeutic and pharmaco-economic value

Focal dystonia is a common, invalidating neurologic condition characterized by involuntary, sustained muscle contractions causing twisting movements and abnormal postures in one body part. Currently, botulinum toxin is the treatment of first choice. We performed a systematic review towards the pharmaco-therapeutic and pharmaco-economic value of botulinum toxin as treatment for focal dystonia, which yielded the following results. Botulinum toxin is the most effective treatment for reducing dystonic symptoms measured with dystonia-specific and general questionnaires, and pain in patients with focal dystonia. Seventy-one percent of patients with cervical dystonia had a reduction in neck pain compared to 12 % in placebo groups. Adverse events occur in 58 % of patients during treatment with botulinum toxin compared to 46 % treated with placebo. Especially dry mouth, neck weakness, dysphagia, and voice changes are common. Adverse events are usually mild and self-limiting. Health-related quality of life, measured with the SF-36 is 20-50 points lower in patients with focal dystonia compared to controls and the effect of botulinum toxin on health-related quality of life is unclear. Botulinum toxin treatment is expensive because the drug itself is expensive. Yearly costs for treating a patient with focal dystonia with botulinum toxin range from EUR 347 to EUR 3,633 and the gain in QALYs with BTX treatment is small. Focal dystonia impairs the productivity and the ability to work. At start of botulinum toxin treatment only 47-50 % was working. Botulinum toxin partly improves this. Overall, we conclude that botulinum toxin is an expensive drug with good effects. From a societal perspective, the costs may well weigh up to the regained quality of life. However, the available literature concerning costs, health-related quality of life and labor participation is very limited. An extensive cost-effectiveness study should be performed incorporating all these aspects.