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Clinical & Experimental Ophthalmology Mar 2020Cannabis is the most consumed illicit drug worldwide. As more countries consider bills that would legalize adult use of cannabis, health care providers, including eye... (Review)
Review
Cannabis is the most consumed illicit drug worldwide. As more countries consider bills that would legalize adult use of cannabis, health care providers, including eye care professionals (ophthalmologists, optometrists), will need to recognize ocular effects of cannabis consumption in patients. There are only 20 studies on the eyelid effects of cannabis usage as a medical treatment or a recreational drug. These include ptosis induction, an "eyelid tremor" appearance and blepharospasm attenuation. Six articles describe how adequately dosed cannabis regimens could be promising medical treatments for blepharospasm induced by psychogenic factors. Fourteen articles report eyelid tremors in intoxicated drivers and ptosis as a secondary effect in cannabinoid animal experimental models. The exact mechanism of cannabinoids connecting cannabis to the eyelids is unclear. Further studies should be conducted to better understand the cannabinoid system in relation to the eyelid and eventually develop new, effective and safe therapeutic targets derived from cannabis.
Topics: Animals; Blepharoptosis; Blepharospasm; Cannabinoids; Cannabis; Eyelids; Humans
PubMed: 31747112
DOI: 10.1111/ceo.13687 -
Annals of Burns and Fire Disasters Dec 2017Polyamphoteric washing solutions (PWS) have been used for several years, mainly in industries, for cases of chemical ocular or cutaneous splashes by acid or alkali. We...
Polyamphoteric washing solutions (PWS) have been used for several years, mainly in industries, for cases of chemical ocular or cutaneous splashes by acid or alkali. We collected 37 cases reporting the use of PWS for ocular and cutaneous chemical splashes from several centres. Among the 37 cases, 55.26% resulted from occupational exposure. Among ocular exposures, initial clinical symptoms included pain (20 cases), blepharospasm (4 cases), hyperaemia (15 cases), palpebral oedema (2 cases) and blurred vision (7 cases). Among cutaneous exposures, 2 injuries were classified as deep, and 11 as superficial. Mean (SD) pain (VAS) before PWS was 6,29 +/- 2,74; mean (SD) pain after PWS was 1,47 +/- 1,73. Early application of PWS to the eye or skin reduces the intensity of pain that is associated with chemical damage. Early application of amphoteric solution appears to reduce the incidence of sequelae, provided its pre-hospital and hospital use is early. However, further studies are needed.
PubMed: 29983684
DOI: No ID Found -
Indian Journal of Psychological Medicine Jan 2021Oculogyric crisis (OGC) is a form of acute dystonia characterized by sustained dystonic, conjugate, and upward deviation of the eyes. It was initially reported in... (Review)
Review
BACKGROUND
Oculogyric crisis (OGC) is a form of acute dystonia characterized by sustained dystonic, conjugate, and upward deviation of the eyes. It was initially reported in patients with postencephalitic parkinsonism. But later, other factors such as medications, movement disorders, metabolic disorders, and focal brain lesions were also found to be associated with OGC.
METHODS
The literature regarding OGC was searched via PubMed, Google Scholar, and through citations in relevant articles till December 2019, with keywords including OGC, oculogyric eye movements, tonic eye movement, neuroleptics and OGC, antipsychotics and OGC, and all combinations of these. Only original articles (abstract or full text) that were published in the English language were reviewed.
RESULTS
Hypodopaminergic state is implicated in the pathogenesis of OGC. Common risk factors are younger age, male sex, severe illness, high neuroleptic dose, parenteral administration of neuroleptics, high potency of neuroleptic drugs, abrupt discontinuation of anticholinergic medication, and family history of dystonia.
CONCLUSION
OGC is an acute dystonic reaction leading to tonic upward deviation of eyes. It is associated with various neurometabolic, neurodegenerative, and movement disorders and medications such as antipsychotics, antiemetics, antidepressants, antiepileptics, and antimalarials. OGC can adversely impact the compliance and prognosis of the primary illness. Hence, it needs to be managed at earlier stages with appropriate medication, primarily anticholinergics.
PubMed: 34349300
DOI: 10.1177/0253717620942096 -
Drug Design, Development and Therapy 2015IncobotulinumtoxinA (Xeomin(®)) is a purified botulinum neurotoxin type A formulation, free from complexing proteins, with proven efficacy and good tolerability for the... (Review)
Review
BACKGROUND
IncobotulinumtoxinA (Xeomin(®)) is a purified botulinum neurotoxin type A formulation, free from complexing proteins, with proven efficacy and good tolerability for the treatment of neurological conditions such as blepharospasm, cervical dystonia (CD), and post-stroke spasticity of the upper limb. This article provides a comprehensive overview of incobotulinumtoxinA based on randomized controlled trials and prospective clinical studies.
SUMMARY
IncobotulinumtoxinA provides clinical efficacy in treating blepharospasm, CD, and upper-limb post-stroke spasticity based on randomized, double-blind, placebo-controlled trials with open-label extension periods (total study duration up to 89 weeks). Adverse events were generally mild or moderate. The most frequent adverse events, probably related to the injections, included eyelid ptosis and dry eye in the treatment of blepharospasm, dysphagia, neck pain, and muscular weakness in patients with CD, and injection site pain and muscular weakness when used for treating spasticity. In blepharospasm and CD, incobotulinumtoxinA was investigated in clinical trials permitting flexible intertreatment intervals based on the individual patient's clinical need; the safety profile of intervals shorter than 12 weeks was comparable to intervals of 12 weeks and longer. There were no cases of newly formed neutralizing antibodies during the Phase III and IV incobotulinumtoxinA trials. Phase III head-to-head trials of incobotulinumtoxinA versus onabotulinumtoxinA for the treatment of blepharospasm and CD have demonstrated therapeutic equivalence of both formulations. Additional Phase III trials of incobotulinumtoxinA in conditions such as lower-limb spasticity, spasticity in children with cerebral palsy, and sialorrhea in various neurological disorders are ongoing.
CONCLUSION
IncobotulinumtoxinA is an effective, well-tolerated botulinum neurotoxin type A formulation. Data from randomized clinical trials and further observational studies are expected to help physicians to optimize treatment by tailoring the choice of formulation, dose, and treatment intervals to the patient's clinical needs.
Topics: Botulinum Toxins, Type A; Humans; Nervous System Diseases; Randomized Controlled Trials as Topic
PubMed: 25897202
DOI: 10.2147/DDDT.S79193 -
Neurology India 2018Botulinum toxin has gained immense popularity since its introduction for therapeutic use. It is used in a variety of movement disorders like hemi-facial spasm, focal... (Review)
Review
Botulinum toxin has gained immense popularity since its introduction for therapeutic use. It is used in a variety of movement disorders like hemi-facial spasm, focal dystonias like blepharospasm, cervical dystonia, oromandibular dystonia, limb dystonias. It is also being used in patients with tremors, tics and for a variety of indications in Parkinson's disease as well. There are eight subtypes of toxins available, but type A and B are the ones used in movement disorder clinics. The toxin mainly acts by inhibiting the release of acetylcholine at the neuromuscular junction and causing weakness. Type B toxin has more effect over the autonomic nervous system and hence is preferred for hyper-secretory disorders. The use of electromyography and ultrasound further improve the accuracy of the procedure. It is a relatively safe therapeutic option with its effect lasting for around three months. It has very few side effects. The key is to start with the lowest possible dose and then gradually increase the dose depending upon the patient's response. Selecting the right muscles for injection is of utmost importance and is guided by the knowledge of anatomy of the muscles.
Topics: Botulinum Toxins; Humans; Movement Disorders; Treatment Outcome
PubMed: 29503330
DOI: 10.4103/0028-3886.226441 -
Neurologic Clinics May 2020The dystonias are a large and heterogenous group of disorders characterized by excessive muscle contractions leading to abnormal postures and/or repetitive movements.... (Review)
Review
The dystonias are a large and heterogenous group of disorders characterized by excessive muscle contractions leading to abnormal postures and/or repetitive movements. Their clinical manifestations vary widely, and there are many potential causes. Despite the heterogeneity, helpful treatments are available for the vast majority of patients. Symptom-based therapies include oral medications, botulinum toxins, and surgical interventions. For some subtypes of dystonia, specific mechanism-based treatments are available. Advances in understanding the biological basis for many types of dystonia have led to numerous recent clinical trials, so additional treatments are likely to become available in the very near future.
Topics: Dystonia; Humans
PubMed: 32279713
DOI: 10.1016/j.ncl.2020.01.003 -
Journal Francais D'ophtalmologie Feb 2021To localize the brain structures involved in blepharospasm.
PURPOSE
To localize the brain structures involved in blepharospasm.
MATERIALS AND METHODS
This is a retrospective consecutive series of brain MRI's of patients with secondary blepharospasm whose immediate past medical history included cerebrovascular accident or head trauma.
RESULTS
Six patients, including 4 with CVA with ischemic or hemorrhagic lesions of the thalamus and caudate nuclei and 2 with head trauma with contusive sequellae to the tectal plate and frontal cortical and cerebellar atrophy.
CONCLUSION
According to the literature, brain lesions associated with blepharospasm involve mainly the thalamus, head of the caudate nucleus, corpus striatum, globus pallidus, internal capsule, cerebral cortex and cerebellum. This study demonstrates that blepharospasm is associated with a lesion of a complex neural network - cortex-thalamus-globus pallidus-cortex - and does not correspond to a single, unique lesion. This network is connected with ascending and descending sensory-motor pathways and motor nuclei.
Topics: Blepharospasm; Brain; Humans; Magnetic Resonance Imaging; Retrospective Studies; Thalamus
PubMed: 33431190
DOI: 10.1016/j.jfo.2020.06.011 -
Frontiers in Neurology 2021Blepharospasm (BSP) and hemifacial spasm (HFS) are both facial hyperkinesia however BSP is thought to be caused by maladaptation in multiple brain regions in contrast...
Blepharospasm (BSP) and hemifacial spasm (HFS) are both facial hyperkinesia however BSP is thought to be caused by maladaptation in multiple brain regions in contrast to the peripherally induced cause in HFS. Plausible coexisting pathophysiologies between these two distinct diseases have been proposed. In this study, we compared brain resting state functional connectivity (rsFC) and quantitative thermal test (QTT) results between patients with BSP, HFS and heathy controls (HCs). This study enrolled 12 patients with BSP, 11 patients with HFS, and 15 HCs. All subjects received serial neuropsychiatric evaluations, questionnaires determining disease severity and functional impairment, QTT, and resting state functional MRI. Image data were acquired using seed-based analyses using the CONN toolbox. A higher cold detection threshold was found in the BSP and HFS patients compared to the HCs. The BSP and HFS patients had higher rsFC between the anterior cerebellum network and left occipital regions compared to the HCs. In all subjects, impaired cold detection threshold in the QTT of lower extremities had a correlation with higher rsFC between the anterior cerebellar network and left lingual gyrus. Compared to the HCs, increased rsFC in right postcentral gyrus in the BSP patients and decreased rsFC in the right amygdala and frontal orbital cortex in the HFS subjects were revealed when the anterior cerebellar network was used as seed. Dysfunction of sensory processing detected by the QTT is found in the BSP and HSP patients. Altered functional connectivity between the anterior cerebellar network and left occipital region, especially the Brodmann area 19, may indicate the possibility of shared pathophysiology among BSP, HFS, and impaired cold detection threshold. Further large-scale longitudinal study is needed for testing this theory in the future.
PubMed: 34975723
DOI: 10.3389/fneur.2021.759869 -
Applied Microbiology and Biotechnology Jan 2022Different serotypes of botulinum toxins (BoNTs) act upon different types of SNARE proteins. This property is used in aesthetic medicine to treat certain eye disorders... (Review)
Review
Different serotypes of botulinum toxins (BoNTs) act upon different types of SNARE proteins. This property is used in aesthetic medicine to treat certain eye disorders such as crossed eyes (strabismus) and uncontrolled blinking (blepharospasm), to treat muscle spasms or movement disorders, and, for the two last decades, more and more often, to provide support in cancer therapy, especially so as to obtain analgesic effects upon spastic conditions. The limited literature data also suggests that the addition of BoNTs to the culture of cancer cell lines reduces cell growth, and mitotic activity, and promotes their apoptosis. BoNTs have several advantages that can be emphasized: BoNTs act on both perfusion and oxygenation; moreover, BoNTs are considered to be safe and free of systemic side effects upon administration. Recently, advances in molecular biology techniques have allowed a wide variety of novel BoNT constructs with alternative functions. These constructs could be assessed as potential new classes of anti-cancer drugs. This creates new potential perspectives in the wider use of non-toxic modified BoNT constructs in cancer therapy. In the light of the mentioned premises and existing literature reports, the aim of this review is to summarize current data and reports considering BoNT use in cancer therapy. KEY POINTS : •Botulinum toxin (BoNTs) may be useful in cancer treatment. •Botulinum toxin can serve as an analgesic after cancer radiotherapy. •Botulinum toxin has the ability to inhibit tumor growth and promote apoptosis of neoplastic cells.
Topics: Analgesics; Botulinum Toxins; Botulinum Toxins, Type A; Neoplasms; Serogroup
PubMed: 34951660
DOI: 10.1007/s00253-021-11741-w -
Brain Communications 2024The thalamus is considered a key region in the neuromechanisms of blepharospasm. However, previous studies considered it as a single, homogeneous structure, disregarding...
The thalamus is considered a key region in the neuromechanisms of blepharospasm. However, previous studies considered it as a single, homogeneous structure, disregarding potentially useful information about distinct thalamic nuclei. Herein, we aimed to examine (i) whether grey matter volume differs across thalamic subregions/nuclei in patients with blepharospasm and blepharospasm-oromandibular dystonia; (ii) causal relationships among abnormal thalamic nuclei; and (iii) whether these abnormal features can be used as neuroimaging biomarkers to distinguish patients with blepharospasm from blepharospasm-oromandibular dystonia and those with dystonia from healthy controls. Structural MRI data were collected from 56 patients with blepharospasm, 20 with blepharospasm-oromandibular dystonia and 58 healthy controls. Differences in thalamic nuclei volumes between groups and their relationships to clinical information were analysed in patients with dystonia. Granger causality analysis was employed to explore the causal effects among abnormal thalamic nuclei. Support vector machines were used to test whether these abnormal features could distinguish patients with different forms of dystonia and those with dystonia from healthy controls. Compared with healthy controls, patients with blepharospasm exhibited reduced grey matter volume in the lateral geniculate and pulvinar inferior nuclei, whereas those with blepharospasm-oromandibular dystonia showed decreased grey matter volume in the ventral anterior and ventral lateral anterior nuclei. Atrophy in the pulvinar inferior nucleus in blepharospasm patients and in the ventral lateral anterior nucleus in blepharospasm-oromandibular dystonia patients was negatively correlated with clinical severity and disease duration, respectively. The proposed machine learning scheme yielded a high accuracy in distinguishing blepharospasm patients from healthy controls (accuracy: 0.89), blepharospasm-oromandibular dystonia patients from healthy controls (accuracy: 0.82) and blepharospasm from blepharospasm-oromandibular dystonia patients (accuracy: 0.94). Most importantly, Granger causality analysis revealed that a progressive driving pathway from pulvinar inferior nuclear atrophy extends to lateral geniculate nuclear atrophy and then to ventral lateral anterior nuclear atrophy with increasing clinical severity in patients with blepharospasm. These findings suggest that the pulvinar inferior nucleus in the thalamus is the focal origin of blepharospasm, extending to pulvinar inferior nuclear atrophy and subsequently extending to the ventral lateral anterior nucleus causing involuntary lower facial and masticatory movements known as blepharospasm-oromandibular dystonia. Moreover, our results also provide potential targets for neuromodulation especially deep brain stimulation in patients with blepharospasm and blepharospasm-oromandibular dystonia.
PubMed: 38638150
DOI: 10.1093/braincomms/fcae117