Symptom Locus and Symptom Origin Incongruity in Runner’s Dystonia – Case Study of an Elite Female Runner

Objectives: Runner’s dystonia is a task-specific dystonia that occurs in the lower limbs and trunk, with diverse symptomatology. We aimed to identify the origin of a dystonic movement abnormality using combined three-dimensional kinematic analysis and electromyographic (EMG) assessment during treadmill running.Participant: A 20-year-old female runner who complained of right-foot collision with the left-leg during right-leg swing-phase, which mimicked right-ankle focal dystonia.Results: Kinematic and EMG assessment of her running motion was performed, which showed a significant drop of the left pelvis during right-leg stance-phase, and a simultaneous increase of right hip adductor muscle activity. This resulted in a pronounced adduction of the entire right lower limb with respect to the pelvis segment. Trajectories of right foot were seen to encroach upon left-leg area.Discussion: These findings suggested that the symptom of this runner was most likely a form of segmental dystonia originating from an impaired control of hip and pelvis, rather than a distal focal ankle dystonia.Conclusion: We conclude that, for individualized symptom assessment, deconstructing the symptom origin from its secondary compensatory movement is crucial for characterizing dystonia. Kinematic and EMG evaluation will therefore be a prerequisite to distinguish symptom origin from secondary compensatory movement.

Is Generalized and Segmental Dystonia Accompanied by Impairments in the Dopaminergic System?

Background: The pathogenesis of dystonia is remarkably diverse. Some types of dystonia, such as DYT5 (DYT-GCH1) and tardive dystonia, are related to dysfunction of the dopaminergic system. Furthermore, on pathological examination, cell loss in the substantia nigra (SN) of patients with dystonia has been reported, suggesting that impaired dopamine production may be involved in DYT5 and in other types of dystonia.Objectives: To investigate functional dopaminergic impairments, we compared patients with dystonia and those with Parkinson's disease (PD) with normal controls using neuromelanin-sensitive magnetic resonance imaging (NM-MRI) and dopamine transporter single photon emission computed tomography (DAT SPECT).Methods: A total of 18, 18, and 27 patients with generalized or segmental dystonia, patients with PD, and healthy controls, respectively, were examined using NM-MRI. The mean area corresponding to NM in the SN (NM-SN) was blindly quantified. DAT SPECT was performed on 17 and eight patients with dystonia and PD, respectively. The imaging data of DAT SPECT were harmonized with the Japanese database using striatum phantom calibration. These imaging data were compared between patients with dystonia or PD and controls from the Japanese database in 256 healthy volunteers using the calibrated specific binding ratio (cSBR). The symptoms of dystonia were evaluated using the Fahn–Marsden Dystonia Rating Scale (FMDRS), and the correlation between the results of imaging data and FMDRS was examined.Results: The mean areas corresponding to NM in the SN (NM-SN) were 31 ± 4.2, 28 ± 3.8, and 43 ± 3.8 pixels in patients with dystonia, PD, and in healthy controls, respectively. The mean cSBRs were 5 ± 0.2, 2.8 ± 0.2, 9.2 (predictive) in patients with dystonia, PD, and in healthy controls, respectively. The NM-SN area (r = −0.49, p < 0.05) and the cSBR (r = −0.54, p < 0.05) were inversely correlated with the FMDRS. There was no significant difference between the dystonia and PD groups regarding NM-SN (p = 0.28). In contrast, the cSBR was lower in patients with PD than in those with dystonia (p < 0.5 × 10−6).Conclusions: Impairments of the dopaminergic system may be involved in developing generalized and segmental dystonia. SN abnormalities in patients with dystonia were supposed to be different from degeneration in PD.

Symptom locus and symptom origin incongruity in runner’s dystonia. – case study of an elite female runner

Objectives: Runner's dystonia is a task specific dystonia that occurs in the lower limbs and trunk, with diverse symptomatology. We aimed to identify the origin of a dystonic movement abnormality using combined three-dimensional kinematic analysis and electromyographic (EMG) assessment during treadmill running. Participant: A twenty-year-old female runner who complained of right-foot collision with the left-leg during right-leg swing-phase, that mimicked right-ankle focal dystonia. Results: Kinematic and EMG assessment of her running motion was performed which showed a significant drop of the left pelvis during right-leg stance-phase, and a simultaneous increase of right hip adductor muscle activity. This resulted in a pronounced adduction of the entire right lower limb with respect to the pelvis segment. Trajectories of right-foot were seen to encroach upon left-leg area. Discussion: These findings suggested that the symptom of this runner was most likely a form of segmental dystonia originating from an impaired control of hip and pelvis, rather than a distal focal ankle dystonia. Conclusion: We conclude that, for individualized symptom assessment, deconstructing the symptom origin from its secondary compensatory movement is crucial for characterizing dystonia. Kinematic and EMG evaluation will therefore be a prerequisite to distinguish symptom origin from secondary compensatory movement.

Oromandibular Dystonia: A Clinical Examination of 2,020 Cases

Objective: The goal of this study is to better characterize the phenotypic heterogeneity of oromandibular dystonia (OMD) for the purpose of facilitating early diagnosis.Methods: First, we provide a comprehensive summary of the literature encompassing 1,121 cases. Next, we describe the clinical features of 727 OMD subjects enrolled by the Dystonia Coalition (DC), an international multicenter cohort. Finally, we summarize clinical features and treatment outcomes from cross-sectional analysis of 172 OMD subjects from two expert centers.Results: In all cohorts, typical age at onset was in the 50s and 70% of cases were female. The Dystonia Coalition cohort revealed perioral musculature was involved most commonly (85%), followed by jaw (61%) and tongue (17%). OMD more commonly appeared as part of a segmental dystonia (43%), and less commonly focal (39%) or generalized (10%). OMD was found to be associated with impaired quality of life, independent of disease severity. On average, social anxiety (LSA score: 33 ± 28) was more common than depression (BDI II score: 9.7 ± 7.8). In the expert center cohorts, botulinum toxin injections improved symptom severity by more than 50% in ~80% of subjects, regardless of etiology.Conclusions: This comprehensive description of OMD cases has revealed novel insights into the most common OMD phenotypes, pattern of dystonia distribution, associated psychiatric disturbances, and effect on QoL. We hope these findings will improve clinical recognition to aid in timely diagnosis and inform treatment strategies.

Globus Pallidus Internus Deep Brain Stimulation Using Frame-Based vs. Frameless Stereotaxy in Dystonia: A Single-Center Experience

Objective: Bilateral globus pallidus internus deep brain stimulation (GPi-DBS) is an established and effective therapy for primary refractory dystonia. However, the comparison of frameless vs. frame-based DBS surgery technique is still controversial. This retrospective study aims to compare the clinical outcome of two GPi-DBS surgical techniques for patients affected by primary generalized or multi-segmental dystonia.Methods: For lead's stereotaxic placement, 10 patients underwent frame-based surgery and the other 10 subjects DBS surgery with a frameless technique. Clinical features were evaluated at baseline and 6 and 12 months after surgery by means of the Burke–Fahn–Marsden Dystonia Rating Scale.Results: Frame-based GPi-DBS and frameless stereotaxic group revealed a comparable clinical outcome with no surgical complications.Conclusions: Frameless technique is safe and well-tolerated by patients and showed similar effectiveness of the frame-based stereotaxic surgery during GPi-DBS for primary dystonia. Notably, it could be a valid alternative solution because of the great advantage in improving the patient's discomfort during awake surgery.

An Unexpected Smile: risus sardonicus and wing-beating tremor in a first office visit

Context: We present a noteworthy reminder of Wilson disease’s classical manifestations, which may become rarer in clinical practice as availability of genetic tests increases, allowing timely diagnosis and treatment. Case report: A 29 year-old woman developed progressive and asymmetric upper limb tremor and dystonia over 1 year, along with speech and feeding impairment in the last two weeks. Examination revealed segmental dystonia with risus sardonicus, open-jaw oromandibular and severe left arm dystonia, along with wing-beating tremor. Bilateral Kayser-Fleischer ring, low serum ceruloplasmin level, high urinary copper level, bilateral putaminal lesions on brain MRI and detection of ATP7B mutation confirmed Wilson disease (WD). A nasoenteric tube was inserted and D-penicillamine was started. Conclusion: This case illustrates the hallmark neuro-ophtalmological signs of WD: wing-beating tremor, risus sardonicus and Kayser-Fleischer ring. The former is probably associated with lesions in the dentato-rubro-thalamic pathway¹ and means a low frequency, high amplitude, posture-induced proximal arm tremor. Risus sardonicus means a fixed smile due to risorius muscle dystonia². Although it is a well-known manifestation of cephalic tetanus, it is also frequent in WD¹. Finally, the Kayser-Fleischer ring is caused by copper accumulation in the Descemet membrane and occurs in almost 100% of patients with neurological WD².

Delineation of the Clinical Features and Treatment Response of Oromandibular Dystonia: A Multicenter Summary of 2,057 Cases.

Objective: To better characterize oromandibular dystonia (OMD) to facilitate early diagnosis and test the hypothesis that botulinum toxin treatment alleviates symptoms, regardless of etiology, to provide guidance on treatment strategies. Methods: To better characterize this condition we utilize a three-pronged approach. First, we provide a comprehensive summary of the worlds literature encompassing 1157 cases in 27 separate manuscripts. Next, we describe the clinical features of 727 OMD subjects enrolled by the Dystonia Coalition (DC), an international multicenter database. Finally, we provide details of the treatment approach and response from two expert centers where large numbers of OMD patients are followed. Cases from expert centers were utilized to analyze whether response to botulinum toxin varied by etiology of OMD. Results: In all cohorts, typical age at onset was in the 50s and approximately 70% of cases were female. Although the literature OMD more commonly described as a focal dystonia, analysis of the DC database revealed it more commonly appears as part of a segmental dystonia. Expert center review of 173 cases revealed botulinum toxin injections improved symptom severity by more than 50% in approximately 78% of subjects. Among the patients at expert centers, analysis revealed that treatment response did not vary by etiology. Conclusions: Botulinum toxin injections are an effective treatment for OMD, regardless of etiology. By providing a more comprehensive description of OMD and the therapeutic efficacy of botulinum toxin for this type of dystonia, we hope to improve clinical recognition to aid in timely diagnosis and inform treatment strategies.

Patient Selection Criteria for Deep Brain Stimulation for Dystonia

Dystonia is defined as a movement disorder characterized by sustained or intermittent muscle contractions causing abnormal, often repetitive, movements, postures, or both. Dystonic movements are typically patterned and twisting and may be tremulous. Dystonia is often initiated or worsened by voluntary action and associated with overflow muscle activation. A recent revision now classifies dystonia into two axes: (1) clinical characteristics (age at onset, temporal pattern, body distribution, whether focal, segmental, or generalized; and associated features) and (2) etiology, whether idiopathic/genetic or secondary to other neurological/medical diseases. Pharmacological treatments for dystonia remain generally unsatisfactory and consist of various combinations of levodopa, anticholinergics, muscle-relaxing drugs as well as botulinum toxin injections in focal and segmental dystonia. Overall in outcomes are poor because of limited efficacy and the potential for significant side effects such as sedation and cognitive impairment. A humanitarian-device exemption from the Food and Drug Administration was issued for the treatment of medically refractory symptoms of generalized dystonia with the use of DBS. Bilateral GPi DBS surgery is effective for both generalized and focal dystonia including cervical dystonia and tardive dystonia. DBS may be the best available treatment for disabling symptoms of generalized, cervical, tardive, and other dystonia that have failed to respond to oral drugs and botulinum toxin injections (when applicable) as long as contractures have not developed, because in this situation, DBS will be ineffective. Rigorous patient selection and careful management of comorbidities are essential for favorable outcomes.