A Systematic Review of Cognition in Cervical Dystonia.

Growing evidence points to a spectrum of non-motor symptoms, including cognitive difficulties that have a greater impact on functional outcomes and quality of life than motor symptoms in cervical dystonia (CD). Some cognitive impairments have been reported; however, findings are inconsistent, and described across mixed groups of dystonia. The current review aimed to examine the evidence for cognitive impairments in CD. MEDLINE, EMBASE, PsychINFO and Web of Science databases were searched. Studies were included if they met the following criteria (i) cross-sectional or longitudinal studies of adults with CD, (ii) where the results of standardised measures of cognitive or neuropsychological function in any form were assessed and reported, (iii) results compared to a control group or normative data, and (iv) were published in English. Results are presented in a narrative synthesis. Twenty studies were included. Subtle difficulties with general intellectual functioning, processing speed, verbal memory, visual memory, visuospatial function, executive function, and social cognition were identified while language, and attention and working memory appear to be relatively spared. Several methodological limitations were identified that should be considered when interpreting the evidence to describe a specific profile of cognitive impairment in CD. Clinical and research implications are discussed.

Botulinum toxin and conservative treatment strategies in people with cervical dystonia: an online survey.

Isolated cervical dystonia is a focal, idiopathic dystonia affecting the neck muscles. Treatment usually consists of botulinum neurotoxin (BoNT) injections into the dystonic muscles. Our aim is to investigate the use of BoNT treatment and conservative treatments by people living with cervical dystonia. An online survey in English was conducted between June and August 2022. Participants were eligible to participate if they were living with cervical dystonia, were over 18 years old and could read and understand English. The survey consisted of demographic questions, characteristics of dystonia, questions relating to BoNT use and the perceived utility of conservative treatments. The data were analysed descriptively, and open-ended questions were grouped into similar topics represented by direct quotes. We received 128 responses from people with cervical dystonia, with an average age of 59 years and 77% women. Most participants (52%) described their cervical dystonia as mild to moderate with an average pain score of 5/10. Eighty-two (64%) participants were having regular BoNT injections, with overall positive perceived effects. Common activities reported to improve the symptoms were the use of heat packs, massage, relaxation, physiotherapy and participation in general exercise. Common coping strategies reported were getting sufficient rest, having the support of friends and family, and remaining engaged in enjoyable hobbies. We found that most participants received regular BoNT injections and that heat packs, exercise, massage, physiotherapy and relaxation were mostly perceived as effective in reducing the symptoms of cervical dystonia.

Therapy with botulinum neurotoxin for Parkinson's disease.

Botulinum neurotoxin (BoNT) has been in use since the 1970's. Its effect is reached mainly by inhibiting the release of acetylcholine in the synaptic gap of motor neurons or at the motor end plate and the parasympathetic ganglia. In the case of Parkinson's disease, it is used to treat several motor and non-motor symptoms. Within recent years increasingly numerous possible fields of application of BoNT have been found for the treatment of Parkinson's disease, and for some specific symptoms it has in fact become the therapy of choice, while for others it is but one of the therapeutic options that come into consideration when others are not sufficiently effective. In the following, we intend to outline the indications, the possible side effects and also the approvals for therapies with botulinum toxin in the primary and secondary symptoms of Parkinson's disease.

Excessive psychological stress preceding the onset of idiopathic cervical dystonia.

Idiopathic cervical dystonia (ICD) is the largest subgroup of dystonia. Psychological stress as a triggering factor has long been discussed, but detailed descriptions are lacking. We report on a group of 13 patients with ICD and preceding excessive psychological stress (age at ICD onset 39.0 ± 13.9 years, 7 females, 6 males). The observation period was 7.8 ± 5.0 years. Excessive psychological stress included partner conflicts (divorce and separation, domestic violence), special familial burdens, legal disputes and migration. It started 8.3 ± 3.9 months before ICD onset. In 85% of our patients (typical cases), ICD developed within 5.8 ± 4.4 weeks, then lasted 18.5 ± 8.3 months, before it started to remit 2.7 ± 0.8 years after its onset to 54.5 ± 35.3% of its maximal severity. Idiopathic dystonia is thought to be based upon a genetic predisposition triggered by epigenetic factors. Our study suggests that excessive psychological stress could be one of them. Pathophysiologic elements are only vaguely identified, but could include the endoplasmic reticulum stress response, cerebellar 5HT-2A receptors and the metabolism of heat shock proteins. Whilst the clinical presentation of ICD preceded by excessive psychological stress is typical, its course is atypical with rapid onset and fast and substantial remission.

The natural course of idiopathic cervical dystonia.

Idiopathic cervical dystonia (ICD) is by far the largest subgroup of dystonia. Still, its natural course is largely unknown. We studied the natural course of 100 ICD patients from our botulinum toxin clinics (age at ICD onset 45.8 ± 13.5 years, female/male ratio 2.0) over a period of 17.5 ± 11.5 years with follow-ups during botulinum toxin therapy and with semi-structured interviews. Two courses of ICD could be distinguished by symptom development of more or less than 6 months. ICD-type 2 was less frequent (19% vs 81%, p < 0.001), had a more rapid onset (8.7 ± 8.0 weeks vs 3.8 ± 3.5 years), a higher remission rate (92% vs 5%, p < 0.001) and a higher prevalence of excessive psychological stress preceding ICD (63% vs 1%, p < 0.001). In both ICD-types, the plateau phase was non-progressive. Significant differences in patient age at ICD onset, latency and extent of remission, female/male ratio and prevalence of family history of dystonia could not be detected. ICD is a non-progressive disorder. ICD-type 1 represents the standard course. ICD-type 2 features rapid onset, preceding excessive psychological stress and a high remission rate. These findings will improve prognosis, treatment strategies and understanding of underlying disease mechanisms. They contradict the widespread fear of patients of a constant and continued decline of their condition. Excessive psychological stress may be an epigenetic factor triggering the manifestation of genetically predetermined dystonia.

The effectiveness of physiotherapy for patients with isolated cervical dystonia: an updated systematic review and meta-analysis.

BACKGROUND: Cervical dystonia is a movement disorder typically characterized by a patterned and twisting movement of sustained or intermittent muscle contractions. Recently, new clinical trials are emerging, highlighting the potential benefit of physiotherapy (PT) on disease outcomes. Thus, the objective of this review is to update the effectiveness of PT on cervical dystonia disease outcomes and subsequently perform a meta-analysis. METHODS: Interventional studies published in English with adult patients with isolated cervical dystonia following a physiotherapy program were included. Relevant articles were searched in PubMed (MEDLINE), Web of Science, and Scopus. Cochrane and Joanna Briggs Institute risk of bias checklists were used for quality reporting. Meta-analysis was done using Review Manager 5.3 statistical software and a pooled mean difference for pain was presented. RESULTS: Fourteen articles were included in the review and two articles were included in the meta-analysis. The meta-analysis revealed that PT intervention had a significant effect on pain reduction scale (-5.00, 95% CI -6.26, -3.74) when used as an additional therapy with botulinum toxin (BoNT) injection. Additionally, findings indicate a possible positive effect of PT disease severity, disability, and quality of life. CONCLUSIONS: Physiotherapy in addition to BoNT is recommended to decrease pain. The findings suggest a reduction of disease severity, disability, and improvement in quality of life. The variety in the type and duration of PT interventions did not allow a clear recommendation of a specific type of PT.

Regional structural abnormalities in thalamus in idiopathic cervical dystonia.

BACKGROUND: The thalamus has a central role in the pathophysiology of idiopathic cervical dystonia (iCD); however, the nature of alterations occurring within this structure remain largely elusive. Using a structural magnetic resonance imaging (MRI) approach, we examined whether abnormalities differ across thalamic subregions/nuclei in patients with iCD. METHODS: Structural MRI data were collected from 37 patients with iCD and 37 healthy controls (HCs). Automatic parcellation of 25 thalamic nuclei in each hemisphere was performed based on the FreeSurfer program. Differences in thalamic nuclei volumes between groups and their relationships with clinical information were analysed in patients with iCD. RESULTS: Compared to HCs, a significant reduction in thalamic nuclei volume primarily in central medial, centromedian, lateral geniculate, medial geniculate, medial ventral, paracentral, parafascicular, paratenial, and ventromedial nuclei was found in patients with iCD (P < 0.05, false discovery rate corrected). However, no statistically significant correlations were observed between altered thalamic nuclei volumes and clinical characteristics in iCD group. CONCLUSION: This study highlights the neurobiological mechanisms of iCD related to thalamic volume changes.

Topological alterations in white matter anatomical networks in cervical dystonia.

BACKGROUND: Accumulating neuroimaging evidence indicates that patients with cervical dystonia (CD) have changes in the cortico-subcortical white matter (WM) bundle. However, whether these patients' WM structural networks undergo reorganization remains largely unclear. We aimed to investigate topological changes in large-scale WM structural networks in patients with CD compared to healthy controls (HCs), and explore the network changes associated with clinical manifestations. METHODS: Diffusion tensor imaging (DTI) was conducted in 30 patients with CD and 30 HCs, and WM network construction was based on the BNA-246 atlas and deterministic tractography. Based on the graph theoretical analysis, global and local topological properties were calculated and compared between patients with CD and HCs. Then, the AAL-90 atlas was used for the reproducibility analyses. In addition, the relationship between abnormal topological properties and clinical characteristics was analyzed. RESULTS: Compared with HCs, patients with CD showed changes in network segregation and resilience, characterized by increased local efficiency and assortativity, respectively. In addition, a significant decrease of network strength was also found in patients with CD relative to HCs. Validation analyses using the AAL-90 atlas similarly showed increased assortativity and network strength in patients with CD. No significant correlations were found between altered network properties and clinical characteristics in patients with CD. CONCLUSION: Our findings show that reorganization of the large-scale WM structural network exists in patients with CD. However, this reorganization is attributed to dystonia-specific abnormalities or hyperkinetic movements that need further identification.

Content overlap of 91 dystonia symptoms among the seven most commonly used cervical dystonia scales.

INTRODUCTION: Dystonia is a movement disorder characterized by sustained or intermittent muscle contractions. Cervical dystonia (CD) is the most common focal dystonia. There are several instruments assessing the symptoms of CD. However, different scales assess different features which may lead to poor patient evaluation. AIM: The aim of the study was to evaluate the degree of overlap of most often used CD rating scales identified by the literature review. METHODS: A thorough search of the Medline database was conducted in September 2021. Then the frequency of each scale was calculated, and 7 most common scales were included in the content overlap analysis using Jaccard index (0 - no overlap, 1 - full overlap). RESULTS: Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS), Tsui score, Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS), Cervical Dystonia Impact Profile 58 (CDIP-58), Craniocervical Dystonia Questionnaire 24 (CDQ-24), Cervical Dystonia Severity Rating Scale (CDSS), Cervical Dystonia Severity Rating Scale (DDS) and The Dystonia Non-Motor Symptoms Questionnaire (DNMSQuest) were the most common scales. 91 CD symptoms were distinguished from 134 items used in the scales. The mean overlap among all scales was 0.17. 52 (62%) symptoms were examined by more than one scale. The CIDP-58 captured the highest number of symptoms (63.0%), while the CDSS captured the lowest number (8.0%). None of the symptoms were examined by seven instruments. CONCLUSIONS: There was a very weak overlap among scales. High inconsistency between the scales may lead to highly different dystonia severity assessment in clinical practice. Thus, the instruments should be combined.

Idiopathic cervical dystonia and non-motor symptoms: a pilot case-control study on autonomic nervous system.

PURPOSE: Non-motor symptoms, such as sleep disturbances, fatigue, neuropsychiatric manifestations, cognitive impairment, and sensory abnormalities, have been widely reported in patients with idiopathic cervical dystonia (ICD). This study aimed to clarify the autonomic nervous system (ANS) involvement in ICD patients, which is still unclear in the literature. METHODS: We conducted a pilot case-control study to investigate ANS in twenty ICD patients and twenty age-sex-matched controls. The Composite Autonomic System Scale 31 was used for ANS clinical assessment. The laser Doppler flowmetry quantitative spectral analysis, applied to the skin and recorded from indices, was used to measure at rest, after a parasympathetic activation (six deep breathing) and two sympathetic stimuli (isometric handgrip and mental calculation), the power of high-frequency and low-frequency oscillations, and the low-frequency/high-frequency ratio. RESULTS: ICD patients manifested higher clinical dysautonomic symptoms than controls (p < 0.05). At rest, a lower high-frequency power band was detected among ICD patients than controls, reaching a statistically significant difference in the age group of ≥ 57-year-olds (p < 0.05). In the latter age group, ICD patients showed a lower low-frequency/high-frequency ratio than controls at rest (p < 0.05) and after mental calculation (p < 0.05). Regardless of age, during handgrip, ICD patients showed (i) lower low-frequency/high-frequency ratio (p < 0.05), (ii) similar increase of the low-frequency oscillatory component compared to controls, and (iii) stable high-frequency oscillatory component, which conversely decreased in controls. No differences between the two groups were detected during deep breathing. CONCLUSION: ICD patients showed ANS dysfunction at clinical and neurophysiological levels, reflecting an abnormal parasympathetic-sympathetic interaction likely related to abnormal neck posture and neurotransmitter alterations.

Stigma, coping strategies, distress and wellbeing in individuals with cervical dystonia: a cross-sectional study.

Cervical dystonia (CD) is a movement disorder which causes sustained muscle contractions in the neck leading to abnormal postures and repetitive movements. As it is a highly visible condition, people with CD can experience stigma, which may lead to unhelpful coping strategies and increased psychological distress. This study investigated whether adaptive and maladaptive coping strategies mediate the relationship between stigma and psychological outcomes in people with CD. A total of 114 adults with CD completed measures of stigma, coping, health-related quality of life (HRQOL), psychological distress (depression, anxiety, stress), and psychological wellbeing at one time point. Participants' levels of distress were high, compared to the general population. Correlational analyses showed increased stigma and maladaptive coping (e.g. substance use, behavioural disengagement) were both significantly related to increased distress, lower wellbeing and lower HRQOL, whereas higher adaptive coping (e.g. acceptance, humour) was only related to higher wellbeing. In a parallel mediation model, maladaptive coping strategies mediated the relationship between stigma and distress, HRQOL and wellbeing, but adaptive coping strategies did not. These findings suggest that maladaptive coping may play an important role in explaining the relationship between stigma and some aspects of distress and wellbeing in CD. Interventions which focus on reducing different aspects of maladaptive coping may be helpful to improve wellbeing as well as reducing stigma.

Genetic Update and Treatment for Dystonia.

A neurological condition called dystonia results in abnormal, uncontrollable postures or movements because of sporadic or continuous muscular spasms. Several varieties of dystonia can impact people of all ages, leading to severe impairment and a decreased standard of living. The discovery of genes causing variations of single or mixed dystonia has improved our understanding of the disease's etiology. Genetic dystonias are linked to several genes, including pathogenic variations of VPS16, TOR1A, THAP1, GNAL, and ANO3. Diagnosis of dystonia is primarily based on clinical symptoms, which can be challenging due to overlapping symptoms with other neurological conditions, such as Parkinson's disease. This review aims to summarize recent advances in the genetic origins and management of focal dystonia.

[Pain and cervical dystonia]. / Schmerzen bei zervikaler Dystonie.

BACKGROUND: Dystonia is a hyperkinetic movement disorder that results in twisting, cramps and tremors due to sustained or intermittent muscle contractions. Cervical dystonia is the most common form of dystonia, in which the head, neck and/or shoulder areas are affected. In addition to these motor symptoms, pain and psychiatric symptoms are frequent in (cervical) dystonia. OBJECTIVE: Description of the incidence and evaluation of pain in cervical dystonia, summary and discussion of treatment options and effects. MATERIAL AND METHODS: In this review article the results in the scientific literature on pain in dystonia are summarized and discussed. RESULTS: Compared to other forms of dystonia, pain occurs most frequently in patients with cervical dystonia. A large proportion of patients with cervical dystonia suffer from pain, which contributes most to impairment of the patient. The motor symptoms of dystonia are usually treated with botulinum toxin injections. These have a muscle relaxing effect and also relieve pain. The study situation on the occurrence and treatment of pain in other forms of dystonia is so far very limited. Pain can dominate the clinical picture in patients with cervical dystonia. Evaluation of pain in cervical dystonia can be performed using standardized questionnaires. CONCLUSION: It is important to ask patients with cervical dystonia about pain and to consider it in treatment planning and evaluation. Vice versa, if pain is present the possibility of a causative dystonia should also be considered. For pain assessment there are some newly developed questionnaires to assess pain in a standardized way in patients with dystonia. Further research is needed to better understand the pathomechanisms of pain in dystonia.

Intramuscular nerve distribution of the sternocleidomastoid muscle for the botulinum toxin injection.

PURPOSE: The aim of this study is to define the intramuscular nerve distribution of the sternocleidomastoid muscle (SCM) and the innervation zones (IZ) to describe the optimal botulinum toxin injection sites. METHODS: The cricoid cartilage (CC), laryngeal prominence (LP) and hyoid bone (HB) and angle of mandible (AM) were determined as landmarks. The length of the muscles were measured between the sternoclavicular joint and tip of the mastoid process. SCM was evaluated in two parts as anterior and posterior divided by the line where the length of the muscle was measured. Measurements were made to define the relationships of the SCM with common carotid artery, internal and external jugular veins. IZ were described according to these vessels. Afterwards, Modified Sihler's staining technique was applied to expose the intramuscular nerve distribution. RESULTS: The average length of SCM was 160,1 mm. Motor entry point of the accessory nerve fibers were between the AM-HB lines, in the range of 30-40% of the muscle length, and in the posterior part of the muscles. IZ were between the HB-CC lines in the anterior and posterior part. When this interval was examined according to the vessels, the optimal injection sites were between the LP-CC lines. CONCLUSIONS: This study shows the position of the intramuscular nerve fibers endings of the SCM according to the chosen landmarks and the relationship of the IZ with the vessels to prevent complications. These results can be used as a guide for safe and effective botulinum toxin injections with optimal quantities.

KinesioTaping: impact on non-motor symptoms in cervical dystonia patients treated with botulinum toxin injection.

AIM OF THE STUDY: To assess whether combined therapy with botulinum toxin injections (BoNT) and KinesioTaping could be helpful in managing non-motor symptoms (NMS) of cervical dystonia (CD). MATERIAL AND METHODS: Seventeen patients with CD were enrolled in this single-centre, prospective, evaluator-blinded, randomised, crossover trial. We compared three forms of treatment: BoNT treatment alone, or combined with KinesioTaping, or combined with ShamTaping. NMS were assessed using the 14-item self-reported questionnaire proposed by Klingelhoefer, the Hospital Anxiety and Depression Scale (HADS) and the Pittsburgh Sleep Quality Index (PSQI). RESULTS: There were no significant differences between the groups concerning mean results of HADS and PSQI scales, or mean total number of NMS after the procedures. The mean change from baseline HADS and PSQI scores, and total number of NMS after the procedure, also did not differ significantly between groups. ShamTaping combined with BoNT significantly increased the prevalence of pain. CONCLUSIONS AND CLINICAL IMPLICATIONS: Our study did not confirm the effectiveness of combined therapy of BoNT and KinesioTaping in the management of NMS in patients with CD. Due to a potential negative effect of improper taping on pain in CD, patients with CD should only experience KinesioTaping as an adjunctive therapy, and if it is performed by a trained, experienced physiotherapist.

Fixel-Based Analysis Reveals Whole-Brain White Matter Abnormalities in Cervical Dystonia.

BACKGROUND: Cervical dystonia (CD) is a form of isolated focal dystonia typically associated to abnormal head, neck, and shoulder movements and postures. The complexity of the clinical presentation limits the investigation of its pathophysiological mechanisms, and the neural networks associated to specific motor manifestations are still the object of debate. OBJECTIVES: We investigated the morphometric properties of white matter fibers in CD and explored the networks associated with motor symptoms, while regressing out nonmotor scores. METHODS: Nineteen patients affected by CD and 21 healthy controls underwent diffusion-weighted magnetic resonance imaging. We performed fixel-based analysis, a novel method evaluating fiber orientation within specific fiber bundles, and compared fiber morphometric properties between groups. Moreover, we correlated fiber morphometry with the severity of motor symptoms in patients. RESULTS: Compared to controls, patients exhibited decreased white matter fibers in the right striatum. Motor symptom severity negatively correlated with white matter fibers passing through inferior parietal areas and the head representation area of the motor cortex. CONCLUSIONS: Abnormal white matter integrity at the basal ganglia level may affect several functional networks involved, for instance, in motor preparation and execution, visuomotor coordination, and multimodal integration. This may result in progressive maladaptive plasticity, culminating in overt symptoms of dystonia. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

The Pain in Dystonia Scale (PIDS)-Development and Validation in Cervical Dystonia.

BACKGROUND: A better understanding of pain in adult-onset idiopathic dystonia (AOID) is needed to implement effective therapeutic strategies. OBJECTIVE: To develop a new rating instrument for pain in AOID and validate it in cervical dystonia (CD). METHODS: Development and validation of the Pain in Dystonia Scale (PIDS) comprised three phases. In phase 1, international experts and participants with AOID generated and evaluated the preliminary items for content validity. In phase 2, the PIDS was drafted and revised by the experts, followed by cognitive interviews to ensure self-administration suitability. In phase 3, the PIDS psychometric properties were assessed in 85 participants with CD and retested in 40 participants. RESULTS: The final version of PIDS evaluates pain severity (by body-part), functional impact, and external modulating factors. Test-retest reliability showed a high-correlation coefficient for the total score (0.9, P < 0.001), and intraclass correlation coefficients were 0.7 or higher for all items in all body-parts subscores. The overall PIDS severity score showed high internal consistency (Cronbach's α, 0.9). Convergent validity analysis revealed a strong correlation between the PIDS severity score and the Toronto Western Spasmodic Torticollis Rating Scale pain subscale (0.8, P < 0.001) and the Brief Pain Inventory-short form items related to pain at time of the assessment (0.7, P < 0.001) and impact of pain on daily functioning (0.7, P < 0.001). CONCLUSION: The PIDS is the first specific questionnaire developed to evaluate pain in all patients with AOID, here, demonstrating high-level psychometric properties in people with CD. Future work will validate PIDS in other forms of AOID. © 2023 International Parkinson and Movement Disorder Society.

Proprioceptive Modulation of Pallidal Physiology in Cervical Dystonia.

BACKGROUND: There is a growing body of evidence suggesting that botulinum toxin can alter proprioceptive feedback and modulate the muscle-spindle output for the treatment of dystonia. However, the mechanism for this modulation remains unclear. METHODS: We conducted a study involving 17 patients with cervical dystonia (CD), seven of whom had prominent CD and 10 with generalized dystonia (GD) along with CD. We investigated the effects of neck vibration, a form of proprioceptive modulation, on spontaneous single-neuron responses and local field potentials (LFPs) recorded from the globus pallidum externus (GPe) and internus (GPi). RESULTS: Our findings demonstrated that neck vibration notably increased the regularity of neck-sensitive GPi neurons in focal CD patients. Additionally, in patients with GD and CD, the vibration enhanced the firing regularity of non-neck-sensitive neurons. These effects on single-unit activity were also mirrored in ensemble responses measured through LFPs. Notably, the LFP modulation was particularly pronounced in areas populated with burst neurons compared to pause or tonic cells. CONCLUSION: The results from our study emphasize the significance of burst neurons in the pathogenesis of dystonia and in the efficacy of proprioceptive modulation for its treatment. Moreover, we observed that the effects of vibration on focal CD were prominent in the α band LFP, indicating modulation of pallido-cerebellar connectivity. Moreover, the pallidal effects of vibration in GD with CD involved modulation of cerebro-pallidal θ band connectivity. Our analysis provides insight into how vibration-induced changes in pallidal activity are integrated into the downstream motor circuit. © 2023 International Parkinson and Movement Disorder Society.

Iron accumulation and axonal damage of cerebellum in idiopathic cervical dystonia.

BACKGROUND AND PURPOSE: Postmortem brain study indicated that cerebellar Purkinje cell (PC) loss might be a pathological finding in patients with inherited and idiopathic cervical dystonia (ICD). The analysis of conventional magnetic resonance imaging brain scans failed to yield support for this finding. Previous studies have identified that iron overload can be the consequence of neuron death. The objectives of this study were to investigate iron distribution and demonstrate changes in axons in the cerebellum, providing evidence for PC loss in patients with ICD. METHODS: Twenty-eight patients with ICD (20 females) and 28 age- and sex-matched healthy controls were recruited. A spatially unbiased infratentorial template was applied to perform cerebellum optimized quantitative susceptibility mapping and diffusion tensor analysis based on magnetic resonance imaging. Voxel-wise analysis was performed to assess cerebellar tissue magnetic susceptibility and fractional anisotropy (FA) alterations, and the clinical relevance of these findings was investigated in the patients with ICD. RESULTS: Increased susceptibility values revealed by quantitative susceptibility mapping in the right lobule CrusI, CrusII, VIIb, VIIIa, VIIIb and IX were found in the patients with ICD. A reduced FA value was found across almost all the cerebellum; an FA value of the significant clusters within the right lobule VIIIa significantly correlated with the motor severity of patients with ICD (r = -0.575, p = 0.002). CONCLUSIONS: Our study provided evidence for cerebellar iron overload and axonal damage in patients with ICD, which may indicate PC loss and related axonal changes. These results provide evidence for the neuropathological findings in patients with ICD and further highlight the cerebellar involvement in the pathophysiology of dystonia.

Dystonia phenomenology and treatment response in migraine.

OBJECTIVE: To describe the phenomenology of cervical dystonia (CD) in patients with migraine and the effect of its treatment on migraine frequency. BACKGROUND: Preliminary studies demonstrate that treatment of CD with botulinum toxin in those with migraine can improve both conditions. However, the phenomenology of CD in the setting of migraine has not been formally described. METHODS: We conducted a single-center, descriptive, retrospective case series of patients with a verified diagnosis of migraine who were referred to our movement disorder center for evaluation of co-existing, untreated CD. Patient demographics, characteristics of migraine and CD, and effects of cervical onabotulinumtoxinA (BoTNA) injections were recorded and analyzed. RESULTS: We identified 58 patients with comorbid CD and migraine. The majority were female (51/58 [88%]) and migraine preceded CD in 72% (38/53) of patients by a mean (range) of 16.0 (0-36) years. Nearly all the patients had laterocollis (57/58) and 60% (35/58) had concurrent torticollis. Migraine was found to be both ipsilateral and contralateral to the dystonia in a comparable proportion of patients (11/52 [21%] vs. 15/52 [28%]). There was no significant relationship between migraine frequency and dystonia severity. Treatment of CD with BoTNA reduced migraine frequency in most patients (15/26 [58%] at 3 months and 10/16 [63%] at 12 months). CONCLUSIONS: In our cohort, migraine often preceded dystonia symptoms and laterocollis was the most described dystonia phenotype. The lateralization and severity/frequency of these two disorders were unrelated, but dystonic movements were a common migraine trigger. We corroborated previous reports that cervical BoTNA injections reduced migraine frequency. Providers treating patients with migraine and neck pain who are not fully responding to typical therapies should screen for possible CD as a confounding factor, which when treated can reduce migraine frequency.