Restoring balance in focal limb dystonia with botulinum toxin

A Case of Tardive Dystonia with Task Specificity Confined to the Lower Extremities only during Walking

Background

Task-specific dystonia (TSD) confined to the lower extremities (LE) is relatively rare. This report describes dystonia confined to the LE only during forward walking. This case required careful neurological and diagnostic assessment because the patient was taking several neuropsychiatric drugs that cause symptomatic dystonia, such as aripiprazole (ARP).

Case

A 53-year-old man visited our university hospital with a complaint of abnormalities in the LE that appeared only during walking. Neurological examinations other than walking were normal. Brain magnetic resonance imaging revealed meningioma in the right sphenoid ridge. The patient had been treated for depression with neuropsychiatric medications for a long time, and his abnormal gait appeared about 2 years after additional administration of ARP. After the meningioma was removed, his symptoms remained. Surface electromyography showed dystonia in both LE during forward walking, although his abnormal gait appeared to be accompanied by spasticity. The patient was tentatively diagnosed with tardive dystonia (TD). Although dystonia did not disappear clinically, it was alleviated after discontinuing ARP. Administration of trihexyphenidyl hydrochloride and concomitant rehabilitation improved his dystonia until return to work, but some residual gait abnormalities remained.

Discussion

We report an unusual case of TD with task specificity confined to the LE. The TD was induced by the administration of ARP in combination with multiple psychotropic medications. Careful consideration was required for clinical diagnosis, rehabilitation, and assessment of its relevance to TSD.

Botulinum Toxin in Movement Disorders: An Update

Since its initial approval in 1989 by the US Food and Drug Administration for the treatment of blepharospasm and other facial spasms, botulinum toxin (BoNT) has evolved into a therapeutic modality for a variety of neurological and non-neurological disorders. With respect to neurologic movement disorders, BoNT has been reported to be effective for the treatment of dystonia, bruxism, tremors, tics, myoclonus, restless legs syndrome, tardive dyskinesia, and a variety of symptoms associated with Parkinson's disease. More recently, research with BoNT has expanded beyond its use as a powerful muscle relaxant and a peripherally active drug to its potential central nervous system applications in the treatment of neurodegenerative disorders. Although BoNT is the most potent biologic toxin, when it is administered by knowledgeable and experienced clinicians, it is one of the safest therapeutic agents in clinical use. The primary aim of this article is to provide an update on recent advances in BoNT research with a focus on novel applications in the treatment of movement disorders. This comprehensive review of the literature provides a critical review of evidence-based clinical trials and highlights recent innovative pilot studies.

Dynamic decomposition of motion in essential and parkinsonian tremor

BACKGROUND

Treatment options for essential (ET) and Parkinson disease (PD) tremor are suboptimal, with significant side effects. Botulinum toxin type A (BoNT A) is successfully used in management of various focal movement disorders but is not widely used for tremor.

METHOD

This study examines complexity of wrist tremor in terms of involvement of its three anatomical degrees of freedom (DOF) in two common situations of rest and posture. The study examines tremor in 11 ET and 17 PD participants by kinematic decomposition of motion in 3-DOF.

RESULTS

Tremor decomposition showed the motion involved more than one DOF (<70% contribution in one DOF) in most ET (rest: 100%, posture: 64%) and PD (rest: 77%, posture: 77%) patients. Task variation resulted in change in both amplitude and composition in ET, but not in PD. Amplitude significantly increased from rest to posture in ET. Directional bias was observed at the wrist for ET (pronation), and PD (extension, ulnar deviation, pronation). Average agreement between clinical visual and kinematic selection of muscles was 55% across all subjects.

CONCLUSION

This study shows the complexity of tremor and the difficulty in visual judgment of tremor, which may be key to the success of targeted focal treatments such as BoNT A.

Role of botulinum toxin in hand and upper limb disorders relevant to hand therapy

Introduction

This article reviews the mechanism of action of botulinum toxin and provides an overview of its use in hand disorders relevant to hand therapy such as hyperhidrosis, spasticity, dystonia, tremor, Parkinson's, obstetrical brachial plexus palsy, flexor tendon rehabilitation, lateral epicondylitis, Raynaud's and carpal tunnel syndrome.

Methods

A narrative review of the literature retrieved through electronic databases using keywords botulinum toxin, hand, therapy, and reviewing the bibliographic references cited.

Results

Sixty-five original articles and meta-analyses were reviewed. The number and quality of the published reports for each disorder are very variable but generally botulinum toxin is reported to be an effective adjunct to therapy in the treatment of a wide variety of hand and upper limb pathologies.

Discussion

A surprising number of hand and upper limb conditions have been successively treated with botulinum toxin, but most require botulinum toxin to be used in conjunction with hand therapy to achieve more effective outcomes for longer duration. Neuromuscular disorders seem to be most responsive to botulinum toxin treatment. Therapists should be aware of the potential benefits of botulinum toxin injections for a wide range of hand disorders and when appropriate discuss these with patients and other health professionals.

Conclusion

Botulinum toxin has an effective and growing role in hand therapy.

Botulinum toxin injection to facilitate rehabilitation of muscle imbalance syndromes in sports medicine

Intramuscular injection of Botulinum toxin to produce reduction of focal muscle overactivity, and localized muscle spasm, has been utilized therapeutically for almost two decades. Muscle overactivity in neurologically normal muscle, where an imbalance exists between a relatively overactive muscle and its less active synergist or antagonist, can inhibit control of the antagonist producing a functional muscle imbalance. This brief review provides an overview of the role of muscle imbalance in sports-related pain and dysfunction, and outlines the potential for intramuscular injection of Botulinum toxin to be used as an adjunct to specific muscle re-education and functional rehabilitation in this patient group. A comprehensive understanding of normal movement and the requirements of the sporting activity are essential to allow accurate diagnosis of abnormal motor patterns and to re-educate more appropriate movement strategies. Therapeutic management of co-impairments may include stretching of tight soft tissues, specific re-education aimed at isolation of the non-dominant weak muscles and improvement in their activation, 'unlearning' of faulty motor patterns, and eventual progression onto functional exercises to anticipate gradual return to sporting activity. Intramuscular injection of Botulinum toxin, in carefully selected cases, provides short term reduction of focal muscle overactivity, and may facilitate activation of relatively 'inhibited' muscles and assist the restoration of more appropriate motor patterns.