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Toxins Apr 2020Blepharospasm and oromandibular dystonia are focal dystonias characterized by involuntary and often patterned, repetitive muscle contractions. There is a long history of... (Review)
Review
Blepharospasm and oromandibular dystonia are focal dystonias characterized by involuntary and often patterned, repetitive muscle contractions. There is a long history of medical and surgical therapies, with the current first-line therapy, botulinum neurotoxin (BoNT), becoming standard of care in 1989. This comprehensive review utilized MEDLINE and PubMed and provides an overview of the history of these focal dystonias, BoNT, and the use of toxin to treat them. We present the levels of clinical evidence for each toxin for both, focal dystonias and offer guidance for muscle and site selection as well as dosing.
Topics: Blepharospasm; Botulinum Toxins; Dystonic Disorders; Humans; Mandibular Diseases; Muscular Diseases; Neuromuscular Agents
PubMed: 32331272
DOI: 10.3390/toxins12040269 -
Neurobiology of Disease Dec 2019Dystonia and Parkinson's disease are closely linked disorders sharing many pathophysiological overlaps. Dystonia can be seen in 30% or more of the patients suffering... (Review)
Review
Dystonia and Parkinson's disease are closely linked disorders sharing many pathophysiological overlaps. Dystonia can be seen in 30% or more of the patients suffering with PD and sometimes can precede the overt parkinsonism. The response of early dystonia to the introduction of dopamine replacement therapy (levodopa, dopamine agonists) is variable; dystonia commonly occurs in PD patients following levodopa initiation. Similarly, parkinsonism is commonly seen in patients with mutations in various DYT genes including those involved in the dopamine synthesis pathway. Pharmacological blockade of dopamine receptors can cause both tardive dystonia and parkinsonism and these movement disorders syndromes can occur in many other neurodegenerative, genetic, toxic and metabolic diseases. Pallidotomy in the past and currently deep brain stimulation largely involving the GPi are effective treatment options for both dystonia and parkinsonism. However, the physiological mechanisms underlying the response of these two different movement disorder syndromes are poorly understood. Interestingly, DBS for PD can cause dystonia such as blepharospasm and bilateral pallidal DBS for dystonia can result in features of parkinsonism. Advances in our understanding of these responses may provide better explanations for the relationship between dystonia and Parkinson's disease.
Topics: Deep Brain Stimulation; Dystonia; GTP Cyclohydrolase; Humans; Levodopa; Parkinson Disease; alpha-Synuclein
PubMed: 31078682
DOI: 10.1016/j.nbd.2019.05.001 -
Toxins Jan 2021Since 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... (Review)
Review
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.
Topics: Botulinum Toxins; Dyskinesias; Humans; Movement Disorders; Neurotoxins; Restless Legs Syndrome
PubMed: 33430071
DOI: 10.3390/toxins13010042 -
Toxins Mar 2016Botulinum neurotoxin has revolutionized the treatment of spasticity and is now administered worldwide. There are currently three leading botulinum neurotoxin type A... (Review)
Review
Botulinum neurotoxin has revolutionized the treatment of spasticity and is now administered worldwide. There are currently three leading botulinum neurotoxin type A products available in the Western Hemisphere: onabotulinum toxin-A (ONA) Botox(®), abobotulinum toxin-A (ABO), Dysport(®), and incobotulinum toxin A (INCO, Xeomin(®)). Although the efficacies are similar, there is an intense debate regarding the comparability of various preparations. Here we will address the clinical issues of potency and conversion ratios, as well as safety issues such as toxin spread and immunogenicity, to provide guidance for BoNT-A use in clinical practice. INCO was shown to be as effective as ONA with a comparable adverse event profile when a clinical conversion ratio of 1:1 was used. The available clinical and preclinical data suggest that a conversion ratio ABO:ONA of 3:1-or even lower-could be appropriate for treating spasticity, cervical dystonia, and blepharospasm or hemifacial spasm. A higher conversion ratio may lead to an overdosing of ABO. While uncommon, distant spread may occur; however, several factors other than the pharmaceutical preparation are thought to affect spread. Finally, whereas the three products have similar efficacy when properly dosed, ABO has a better cost-efficacy profile.
Topics: Acetylcholine Release Inhibitors; Animals; Botulinum Toxins, Type A; Dystonic Disorders; Humans; Muscle Spasticity; Neuromuscular Agents; Neurotoxins
PubMed: 26959061
DOI: 10.3390/toxins8030065 -
Toxins Sep 2022Headaches are a very common condition that most people will experience many times during their lives. This article presents the primary headaches, which are a large... (Review)
Review
Headaches are a very common condition that most people will experience many times during their lives. This article presents the primary headaches, which are a large group of diseases where the headache is not a symptom of another known disease. Tension-type headache affects approximately 80% of the general population, and the prevalence of migraine is estimated at 10-12%. Clinical data and experience to date have demonstrated that botulinum toxin may be an effective prophylactic treatment for chronic headache types. It has been used in neurology for the treatment of dystonia and blepharospasm. Now it has been approved to treat chronic migraine and has been shown to confer significant benefit in refractory cases. Based on clinical experience botulinum toxin has also been tried in other headache disorders. While it is intuitively attractive to think that due to its effect on pain by sensory modulation, there may also be efficacy in its use in chronic tension-type headache and cluster headache, so far, there is little evidence to support this. Botulinum toxin is effective in pain control through its interaction with the SNARE complex, which inhibits the release of neurotransmitters, such as glutamate, substance P and calcitonin gene-related peptide. OnabotulinumtoxinA is effective not only in headache frequency and pain intensity but in other parameters, including quality of life.
Topics: Botulinum Toxins, Type A; Calcitonin Gene-Related Peptide; Glutamates; Headache; Humans; Migraine Disorders; Neuromuscular Agents; Quality of Life; SNARE Proteins; Substance P; Tension-Type Headache; Treatment Outcome
PubMed: 36136557
DOI: 10.3390/toxins14090619 -
Experimental Neurology Dec 2021The dystonias are a group of disorders characterized by excessive muscle contractions leading to abnormal repetitive movements or postures. In blepharospasm, the face is...
BACKGROUND
The dystonias are a group of disorders characterized by excessive muscle contractions leading to abnormal repetitive movements or postures. In blepharospasm, the face is affected, leading to excessive eye blinking and spasms of muscles around the eyes. The pathogenesis of blepharospasm is not well understood, but several imaging studies have implied subtle structural defects in several brain regions, including the cerebellum.
OBJECTIVE
To delineate cerebellar pathology in brains collected at autopsy from 7 human subjects with blepharospasm and 9 matched controls.
METHODS
Sections from 3 cerebellar regions were sampled and processed using Nissl and silver impregnation stains. Purkinje neurons were the focus of the evaluation, along with as several other subtle pathological features of cerebellar dysfunction such as Purkinje neuron axonal swellings (torpedo bodies), proliferation of basket cell processes around Purkinje neurons (hairy baskets), empty baskets (missing Purkinje neurons), and displacement of cell soma from their usual location (ectopic Purkinje neurons).
RESULTS
The results revealed a significant reduction in Purkinje neuron and torpedo body density, but no changes in any of the other measures.
CONCLUSIONS
These findings demonstrate subtle neuropathological changes similar to those reported for subjects with cervical dystonia. These findings may underly some of the subtle imaging changes reported for blepharospasm.
Topics: Aged; Aged, 80 and over; Blepharospasm; Cerebellum; Female; Humans; Male; Middle Aged; Purkinje Cells
PubMed: 34464652
DOI: 10.1016/j.expneurol.2021.113855 -
Frontiers in Neurology 2023Blepharospasm is a focal dystonia characterized by involuntary tetanic contractions of the orbicularis oculi muscle, which can lead to functional blindness and loss of... (Review)
Review
Blepharospasm is a focal dystonia characterized by involuntary tetanic contractions of the orbicularis oculi muscle, which can lead to functional blindness and loss of independent living ability in severe cases. It usually occurs in adults, with a higher incidence rate in women than in men. The etiology and pathogenesis of this disease have not been elucidated to date, but it is traditionally believed to be related to the basal ganglia. Studies have also shown that this is related to the decreased activity of inhibitory neurons in the cerebral cortex caused by environmental factors and genetic predisposition. Increasingly, studies have focused on the imbalance in the regulation of neurotransmitters, including dopamine, serotonin, and acetylcholine, in blepharospasm. The onset of the disease is insidious, and the misdiagnosis rate is high based on history and clinical manifestations. This article reviews the etiology, epidemiological features, and pathogenesis of blepharospasm, to improve understanding of the disease by neurologists and ophthalmologists.
PubMed: 38274886
DOI: 10.3389/fneur.2023.1336348 -
Industrial Psychiatry Journal 2016Meige's syndrome consists of idiopathic blepharospasm and oromandibular dystonia. The exact etiology is not known and various hypotheses have been proposed for its...
Meige's syndrome consists of idiopathic blepharospasm and oromandibular dystonia. The exact etiology is not known and various hypotheses have been proposed for its causation. The hypothesis suggesting dopaminergic and cholinergic hyperactivity is most widely accepted. There is no curative drug for Meige's syndrome although a variety of treatments have been proposed. We report a case which responded to tetrabenazine.
PubMed: 28659707
DOI: 10.4103/0972-6748.207853