Search Results (12)

Background: Runner’s dystonia (RD), a rare task-specific lower-limb dystonia affecting high-mileage runners, presents as abnormal lower-extremity muscle contractions during running. Treatment of RD is challenging and often confounded by significant diagnostic delays due to overlapping symptomatology with other conditions. This case series examines the relationship between stiff knee gait RD and musculoskeletal (MSK) knee pathology. Methods: Eight RD cases, evaluated at the NIH Movement Disorders Clinic since 2018, were retrospectively reviewed. Patients underwent neurological, biomechanical, and MSK evaluations, including 3D motion analysis, surface electromyography, and knee ultrasound. Therapeutic interventions, including botulinum neurotoxin (BoNT) injections, were assessed. Results: Seven patients demonstrated stiff knee gait subtypes, with all having ipsilateral and/or contralateral knee effusions or tendinopathies. Three patients who received MSK interventions (e.g., aspiration, corticosteroid injections) combined with BoNT therapy experienced significant symptom improvement. One patient with isolated foot dystonia displayed different biomechanical patterns without knee pathology. Conclusions: RD patients with stiff knee gait often exhibit knee pathology, most likely due to altered biomechanics and running history. Addressing both issues is essential for optimizing treatment outcomes, reducing pain, and improving function, especially since pain can trigger dystonia. Future research should determine the ideal sequence of interventions for RD patients with MSK issues to develop effective, personalized treatment algorithms. Full article

Since its first approval by the Food and Drug Administration in 1989 for strabismus, botulinum toxin indications of use have been widely expanded. Due to its anticholinergic properties, this toxin is currently approved in adult patients for the treatment of a wide range of neuromuscular, otolaryngologic, orthopedic, gastrointestinal, and urologic disorders. Approved pediatric indications of use include the treatment of blepharospasm associated with dystonia, strabismus, lower-limb spasticity, focal spasticity in patients with cerebral palsy, and neurogenic detrusor overactivity. Alongside these approved indications, botulinum toxin is extensively used off-label. Although several clinical studies have shown that botulinum toxin is effective and well-tolerated in children, uncertainties persist regarding its long-term effects on growth and appropriate dosing in this population. As such, further research is needed to better define the botulinum toxin risk–benefit profile and expand approved uses in pediatrics. This narrative review aimed to provide a broad overview of the evidence concerning the clinical effectiveness and safety of BoNT with respect to its principal authorized and non-authorized pediatric therapeutic indications, as well as to describe perspectives on its future use in children. Full article

Fatty acid hydroxylase-associated neurodegeneration (FAHN/SPG35) is caused by pathogenic variants in FA2H and has been linked to a continuum of specific motor and non-motor neurological symptoms, leading to progressive disability. As an ultra-rare disease, its mutational spectrum has not been fully elucidated. Here, we present the prototypical workup of a novel FA2H variant, including clinical and in silico validation. An 18-year-old male patient presented with a history of childhood-onset progressive cognitive impairment, as well as progressive gait disturbance and lower extremity muscle cramps from the age of 15. Additional symptoms included exotropia, dystonia, and limb ataxia. Trio exome sequencing revealed a novel homozygous c.75C>G (p.Cys25Trp) missense variant in the FA2H gene, which was located in the cytochrome b5 heme-binding domain. Evolutionary conservation, prediction models, and structural protein modeling indicated a pathogenic loss of function. Brain imaging showed characteristic features, thus fulfilling the complete multisystem neurodegenerative phenotype of FAHN/SPG35. In summary, we here present a novel FA2H variant and provide prototypical clinical findings and structural analyses underpinning its pathogenicity. Full article

This review provides an up-to-date literature account on the efficacy of Botulinum toxin treatment for common motor disorders of Parkinson Disease. The reviewed disorders include the common motor disorders in PD such as tremor, focal foot dystonia, rigidity and freezing of gait (FOG). In the area of Parkinson tremor, two newly described evaluation/injection techniques (Yale method in USA and Western University method in Canada) offer efficacy with low incidence of hand and finger weakness as side effects. Blinded studies conducted on foot dystonia of PD indicate that botulinum toxin injections into toe flexors are efficacious in alleviating this form of dystonia. Small, blinded studies suggest improvement of Parkinson rigidity after botulinum toxin injection; proof of this claim, however, requires information from larger, blinded clinical trials. In FOG, the improvement reported in open label studies could not be substantiated in blinded investigations. However, there is room for further controlled studies that include the proximal lower limb muscles in the injection plan and/or use higher doses of the injected toxin for this indication. Full article

Parkinson’s disease (PD) is a progressive neurodegenerative disease determining spinal deformities and muscle rigidity, weakness and dystonia that can be related to a change in muscular output during sit-to-stand tasks (STS). Purpose: The aim of this study was to determine the impacts of spinal alignment on lower limbs performance during STS tasks in Parkinson’s disease (PD) patients and healthy controls. Methods: In total, 43 consecutive PD patients (“PD” Group, 25 males and 18 females; age 73.7 ± 7.1) and 42 people not affected by any type of neurological disease (“CON” Group, 22 males, 20 females; age 69.8 ± 6.0) participated in the observational study. The clinical assessment included: IPAQ (International Physical Activity Questionnaire), Hoehn Yahr score, plumb-line distance from the spinous process of C7, kyphosis apex and the spinous process of L3 and S1. We used the Muscle Quality Index test (MQI) to assess muscle power output during STS in both groups. Results: The MQI test measurements of absolute and relative lower limb power was significantly lower in the PD group, in addition to a negative correlation with age and a positive correlation with PL-L3 in that group of patients. Conclusions: A final consideration regarding our results leads to the possibility that the preservation of lumbar lordosis may be one of the factors for maintaining efficient biomechanics of the lower limb muscles, with the preservation of the physiological contractile characteristics of these muscles being the objective for a multidisciplinary rehabilitation based on postural exercises of the spine and a program of training exercises for the lower limb muscles. Full article

Cerebral palsy (CP) is a group of non-progressive disorders of motor function in children resulting from an injury to an immature brain. In addition to abnormal limb and trunk movement, individuals with CP can experience involuntary muscle contractions of the lower facial muscle groups, causing oromandibular dystonia (OMD). Contraction of the lateral pterygoids and submandibular muscles depresses the mandible. OMD involving the lateral pterygoids can therefore lead to involuntary jaw opening posture, affecting the ability to feed and speak effectively. We present a case series of five patients with CP and OMD that received novel ultrasound-guided onabotulinumtoxinA to the lateral pterygoid muscles. Our goal was to determine if chemodenervation would improve the mouth-closing ability, thus in turn improving the ability to swallow, chew, manage secretions, and communicate. We describe this unique injection method and report a subjective improvement in eating abilities and communication, in addition to a positive upward trend in most patients’ weights, with no significant adverse side effects. Full article

This is an overview of the sensorimotor impairments in dystonia, a syndrome characterized by sustained or intermittent aberrant movement patterns leading to abnormal movements and/or postures with or without a tremulous component. Dystonia can affect the entire body or specific body regions and results from a plethora of etiologies, including subtle changes in gray and white matter in several brain regions. Research over the last 25 years addressing topics of sensorimotor control has shown functional sensorimotor impairments related to sensorimotor integration, timing, oculomotor and head control, as well as upper and lower limb control. In the context of efforts to update the classification of dystonia, sensorimotor research is highly relevant for a better understanding of the underlying pathology, and potential mechanisms contributing to global and regional dysfunction within the central nervous system. This overview of relevant research regarding sensorimotor control in humans with idiopathic dystonia attempts to frame the dysfunction with respect to what is known regarding motor control in patients and healthy individuals. We also highlight promising avenues for the future study of neuromotor control that may help to further elucidate dystonia etiology, pathology, and functional characteristics. Full article

Foot dystonia (FD) is a disabling condition causing pain, spasm and difficulty in walking. We treated fourteen (14) adult patients experiencing FD with onabotulinum toxin A injection into the dystonic foot muscles. We analyzed the spatiotemporal gait utilizing the GaitRite system pre- and 3 weeks post-botulinum toxin injection along with measuring dystonia by the Fahn–Marsden Dystonia Scale (FMDS), pain by the Visual Analog Scale (VAS) and other lower limb functional outcomes such as gait velocity, the Berg Balance Scale (BBS), the Unified Parkinson’s Disease Rating Scale–Lower Limb Score (UPDRS–LL), the Timed Up and Go (TUG) test and the Goal Attainment Scale (GAS). We found that stride length increased significantly in both the affected (p = 0.02) and unaffected leg (p = 0.01) after treatment, and the improvement in stride length was roughly the same in each leg. Similar results were found for step length (p = 0.02) with improvement in the step length differential (p = 0.01). The improvements in the lower limb functional outcomes were also significant—FMDS, VAS, TUG, and UPDRS–LL decreased significantly after treatment (all p < 0.001), and BBS (p = 0.001), GAS (p < 0.001) except cadence (p = 0.37). BT injection improved walking in foot dystonia as evidenced through gait analysis, pain and lower limb functional outcomes. Main study limitations were small sample size and lack of control. Full article

Runner’s dystonia (RD) is a task-specific focal dystonia of the lower limbs that occurs when running. In this retrospective case series, we present surface electromyography (EMG) and joint kinematic data from thirteen patients with RD who underwent instrumented gait analysis (IGA) at the Functional and Biomechanics Laboratory at the National Institutes of Health. Four cases of RD are described in greater detail to demonstrate the potential utility of EMG with kinematic studies to identify dystonic muscle groups in RD. In these cases, the methodology for muscle selection for botulinum toxin therapy and the therapeutic response is discussed. Lateral heel whip, a proposed novel presentation of lower-limb dystonia, is also described. Full article

Selection of muscles for botulinum toxin injection for limb dystonia is particularly challenging. Limb dystonias vary more widely in the pattern of dystonic movement and involved muscles than cervical dystonia or blepharospasm. The large variation in how healthy individuals perform skilled hand movements, the large number of muscles in the hand and forearm, and the presence of compensatory actions in patients with dystonia add to the complexity of choosing muscles for injection. In this article, we discuss approaches to selecting upper and lower extremity muscles for chemodenervation treatment of limb dystonia. Full article

Shape memory alloys (SMAs) are a very promising class of metallic materials that display interesting nonlinear properties, such as pseudoelasticity (PE), shape memory effect (SME) and damping capacity, due to high mechanical hysteresis and internal friction. Our group has applied SMA in the field of neuromuscular rehabilitation, designing some new devices based on the mentioned SMA properties: in particular, a new type of orthosis for spastic limb repositioning, which allows residual voluntary movement of the impaired limb and has no predetermined final target position, but follows and supports muscular elongation in a dynamic and compliant way. Considering patients in the sub-acute phase after a neurological lesion, and possibly bedridden, the paper presents a mobiliser for the ankle joint, which is designed exploiting the SME to provide passive exercise to the paretic lower limb. Two different SMA-based applications in the field of neuroscience are then presented, a guide and a limb mobiliser specially designed to be compatible with diagnostic instrumentations that impose rigid constraints in terms of electromagnetic compatibility and noise distortion. Finally, the paper discusses possible uses of these materials in the treatment of movement disorders, such as dystonia or hyperkinesia, where their dynamic characteristics can be advantageous. Full article

We describe the case of a male patient who developed electromyographically confirmed myokymia, dystonia and tremor and clinically confirmed focal dystonia and tremor, secondary to electrical injury. Dystonia is a rare complication of electrical injury. Myokymic discharges secondary to electrical injury are previously unreported. Dystonia and tremor EMG findings were present not only at the clinically affected muscles of the lower limb but also at the clinically unaffected upper limb muscles. This is the first case report to link myokymia as a secondary complication of an electrical injury. Full article