Diagnostic criteria for blepharospasm: A multicenter international study

An Exploratory, Randomized, Double-Blind Clinical Trial of Dipraglurant for Blepharospasm

BACKGROUND

Blepharospasm is treated with botulinum toxin, but obtaining satisfactory results is sometimes challenging.

OBJECTIVE

The aim is to conduct an exploratory trial of oral dipraglurant for blepharospasm.

METHODS

This study was an exploratory, phase 2a, randomized, double-blind, placebo-controlled trial of 15 participants who were assigned to receive a placebo or dipraglurant (50 or 100 mg) and assessed over 2 days, 1 and 2 hours following dosing. Outcome measures included multiple scales rated by clinicians or participants, digital video, and a wearable sensor.

RESULTS

Dipraglurant was well tolerated, with no obvious impact on any of the measurement outcomes. Power analyses suggested fewer subjects would be required for studies using a within-subject versus independent group design, especially for certain measures. Some outcome measures appeared more suitable than others.

CONCLUSION

Although dipraglurant appeared well tolerated, it did not produce a trend for clinical benefit. The results provide valuable information for planning further trials in blepharospasm. © 2024 International Parkinson and Movement Disorder Society.

Evaluation of nerve innervation distribution of orbicularis oculi muscle for botulinum neurotoxin application using Sihler's method

BACKGROUND

Blepharospasm is the involuntary and forced closure of the eyelids due to spasm-like contraction of the orbicularis oculi muscle around the eye. The study aimed to reveal the nerve innervation of the orbicularis oculi muscle for Botulinum neurotoxin (BoNT) treatment of blepharospasm by Sihler's staining technique.

METHODS

This study used six cephalus (12 orbicularis oculi muscles) with an average age of 69,6 (62-88) years. Then, the orbicularis oculi muscles were removed by dissection, and Sihler's staining technique was applied to the muscles. The limit for dissection of the muscle is the orbital opening level, where the nerves enter the muscle, and the muscle attaches to the bone.

RESULTS

In the region above the palpebral fissure, the nerves entering the muscle were densely located in the superolateral quadrant between 9 and 12 o'clock in the right eye and between 12 and 3 o'clock in the left eye. In the region under the palpebral fissure, the nerves' density in the orbicularis oculi muscle was higher between 4 and 7 o'clock in the right eye and between 5 and 8 o'clock in the left eye.

CONCLUSION

This study unveiled the nerve branches associated with the orbicularis oculi muscle. It pinpointed precise crossing points of these nerve branches, which can be targeted for applying BoNT in treating blepharospasm. Consequently, by utilizing minimal BoNT, it is anticipated that the quantity of toxin administered will decrease, leading to more efficient outcomes and reduced expenses. Furthermore, this approach can aid in averting potential undesired complications during BoNT administration.

Accuracy and replicability of identifying eyelid tremor as an indicator of recent cannabis smoking

INTRODUCTION

Cannabis intoxication may increase the risk of motor vehicle crashes. However, reliable methods of assessing cannabis intoxication are limited. The presence of eyelid tremors is among the signs of cannabis use identified under the Drug Evaluation and Classification Program of the International Association of Chiefs of Police. Our objectives were to assess the accuracy and replicability of identifying eyelid tremor as an indicator of recent cannabis smoking using a blinded, controlled study design.

METHODS

Adult subjects (N = 103) were recruited into three groups based on their cannabis use history: daily, occasional, and no current cannabis use. Participants' closed eyelids were video recorded for 30 seconds by infrared videography goggles before and at a mean ± standard deviation time of 71.4 ± 4.6 minutes after the onset of a 15-minute interval of ad libitum cannabis flower smoking or vaping. Three observers with expertise in neuro-ophthalmology and medical toxicology were trained on exemplar videos of eyelids to reach a consensus on how to grade eyelid tremor. Without knowledge of subjects' cannabis use history or time point (pre- or post-smoking), observers reviewed each video for eyelid tremor graded as absent, slight, moderate, or severe. During subsequent data analysis, this score was further dichotomized as a consensus score of absent (absent/slight) or present (moderate/severe).

RESULTS

Kappa and intraclass correlation coefficient statistics demonstrated moderate agreement among the coders, which ranged from 0.44-0.45 and 0.58-0.61, respectively. There was no significant association between recent cannabis use and the observers' consensus assessment that eyelid tremor was present, and cannabis users were less likely to have tremors (odds ratio: 0.75; 95 percent confidence interval: 0.25, 2.40). The assessment of eyelid tremor as an indicator of recent cannabis smoking had a sensitivity of 0.86, specificity of 0.18, and accuracy of 0.64.

DISCUSSION

Eyelid tremor has fair sensitivity but poor specificity and accuracy for identification of recent cannabis use. Inter-rater reliability for assessment of eyelid tremor was moderate for the presence and degree of tremor. The weak association between recent cannabis use and eyelid tremor does not support its utility in identifying recent cannabis use.

LIMITATIONS

Videos were recorded at only one time point after cannabis use. Adherence to abstinence could not be strictly supervised. Due to regulatory restrictions, we were unable to control the cannabis product used or administer a fixed Δ9-tetrahydrocannabinol dose. Participants were predominately non-Hispanic and White.

CONCLUSIONS

In a cohort of participants with a range of cannabis use histories, acute cannabis smoking was not associated with the presence of eyelid tremor, regardless of cannabis use history, at 70 minutes post-smoking. Additional research is needed to identify the presence of eyelid tremor accurately, determine the relationship between cannabis dose and timeline in relation to last cannabis use to eyelid tremor, and determine how it should be, if at all, utilized for cannabis Drug Recognition Evaluator examinations.

The effect on blink frequency of a selective blue-filtering photochromic lens in patients with benign essential blepharospasm

Objective

The aim of this clinical study was to assess the impact of a non-invasive selective blue-filtering photochromic lens coating Crizal Prevencia on the treatment and response of benign essential blepharospasm (BEB).

Patients and methods

Twenty-four patients were recruited in the outpatient clinic of the Medical University of Vienna in a randomized, double-blind, cross-over study design. Blink frequencies were assessed in patients with BEB before and 14 days after intervention with either a filtering ophthalmic lens or a placebo lens, respectively. Outcome parameters include sub-group analysis of a blink frequency under six different conditions: three photopic conditions, one resting condition, one reading condition, and one video game condition.

Results

From 24 recruited patients, 15 patients were available for final analysis. Comparing the optical blue filtering lens to placebo, showed a reduced blink frequency in specific subtests, but not compared to baseline.

Discussion

In conclusion, optical filtering glasses might have a beneficial effect on BEB and provide a non-invasive therapeutic add-on option, in addition to botulinum neurotoxin therapy, for patients with BEB and should necessarily be further investigated in a multicenter setting, resulting in larger sample sizes to gain valid information about the effect of photochromic blue filter glasses in BEB.Clinical trial registration: https://drks.de/search/en/trial/DRKS00032135, DRKS00032135.

Interrater reliability of motor severity scales for hemifacial spasm

To compare the inter-rater reliability (IRR) of five clinical rating scales for video-based assessment of hemifacial spasm (HFS) motor severity. We evaluated the video recordings of 45 HFS participants recruited through the Dystonia Coalition. In Round 1, six clinicians with expertise in HFS assessed the participants' motor severity with five scales used to measure motor severity of HFS: the Jankovic rating scale (JRS), Hemifacial Spasm Grading Scale (HSGS), Samsung Medical Center (SMC) grading system for severity of HFS spasms (Lee's scale), clinical grading of spasm intensity (Chen's scale), and a modified version of the Abnormal Involuntary Movement Scale (Tunc's scale). In Round 2, clinicians rated the same cohort with simplified scale wording after consensus training. For each round, we evaluated the IRR using the intraclass correlation coefficient [ICC (2,1) single-rater, absolute-agreement, 2-way random model]. The scales exhibited IRR that ranged from "poor" to "moderate"; the mean ICCs were 0.41, 0.43, 0.47, 0.43, and 0.65 for the JRS, HSGS, Lee's, Chen's, and Tunc's scales, respectively, for Round 1. In Round 2, the corresponding IRRs increased to 0.63, 0.60, 0.59, 0.53, and 0.71. In both rounds, Tunc's scale exhibited the highest IRR. For clinical assessments of HFS motor severity based on video observations, we recommend using Tunc's scale because of its comparative reliability and because clinicians interpret the scale easily without modifications or the need for consensus training.

Eye-Closure Rate Modulation in Blepharospasm

Background

Blepharospasm (BSP) is a type of focal dystonia and a number of patients with BSP have relatives also affected by BSP. The objective of this study was to quantify eye closure rates during activities of daily living in individuals with BSP and individuals without BSP with and without a first-degree relative with BSP.

Methods

37 patients with BSP (BSP group), 10 asymptomatic volunteers with a first-degree relative with BSP (RELATIVES group) and 25 asymptomatic volunteers without relatives with BSP (HV group) were recruited. The number of eye closures for each task were counted per 60 seconds, with a video recording. Within and between groups statistical comparisons of eye-closure rates were performed.

Results

The eye-closure rates of the RELATIVES group were not different from the BSP group for the majority of the tasks (except for watching television), and the HV group (for all tasks). The rate of eye closures in the BSP group compared to HV, was significantly increased in two tasks, resting and watching television.

Discussion

Eye closure rate varies considerably during activities of daily living in all groups. Individuals with first degree relative with BSP are more likely to have increased eye closure rate at rest.

Genetic Screening of a Hungarian Cohort with Focal Dystonia Identified Several Novel Putative Pathogenic Gene Variants

Dystonia is a rare movement disorder which is characterized by sustained or intermittent muscle contractions causing abnormal and often repetitive movements, postures, or both. The two most common forms of adult-onset focal dystonia are cervical dystonia (CD) and benign essential blepharospasm (BSP). A total of 121 patients (CD, 74; BSP, 47) were included in the study. The average age of the patients was 64 years. For the next-generation sequencing (NGS) approach, 30 genes were selected on the basis of a thorough search of the scientific literature. Assessment of 30 CD- and BSP-associated genes from 121 patients revealed a total of 209 different heterozygous variants in 24 genes. Established clinical and genetic validity was determined for nine heterozygous variations (three likely pathogenic and six variants of uncertain significance). Detailed genetic examination is an important part of the work-up for focal dystonia forms. To our knowledge, our investigation is the first such study to be carried out in the Middle-European region.

Clinical features of dystonia and the science of classification

This chapter describes advances in understanding the clinical features of dystonia since initial clinical recognition and its organization into a coherent and systematic clinical set. The clinical features of dystonia were at first considered an odd neurological movement disorder. Etymology of the word misleadingly underlined muscle tone. The main clinical features of dystonia were recognized gradually. They encompass dystonic movements, dystonic postures, alleviating maneuvers, overflow and mirroring. These features are observed in patients who present a variety of syndromes where dystonia occurs in isolation or combined with other movement disorders, or with other neurologic or systemic features. A large number of syndromic combinations is observed in the clinic and some of the syndomes are highlighted here. Practitioners are required to exert dedicated skills to recognize dystonia and correctly diagnose and classify their patients.

Debunking the Puzzle of Eyelid Apraxia: The Muscle of Riolan Hypothesis

PURPOSE

Apraxia of eyelid opening (AEO) has been defined by the presence of an intermittent nonparalytic bilateral loss of the volitional ability to open the eyes or to maintain the eyelids in a sustained elevated position. It is not known whether the condition represents an apraxia, a dystonia, or a freezing phenomenon, and several different nomenclatorial terms have been suggested for this condition including the so-called AEO (scAEO), blepahrocolysis, focal eyelid dystonia, and so on. The primary goal of this review is to attempt to clarify the pathogenetic mechanisms underlying scAEO as a clinical phenomenon. This review also addresses the issue of whether scAEO is part of the spectrum of blepharospasm (BSP) which includes BSP, dystonic blinks and other dystonic eyelid conditions, or whether it is a separate phenomenologically heterogeneous disease with clinical features that merely overlap with BSP.

METHODS

A literature review was conducted in PubMed, MEDLINE, PubMed Central (PMC), NCBI Bookshelf, and Embase for several related keywords including the terms "apraxia of eyelid opening," "pretarsal blepharospasm," "blepharocolysis," "eyelid freezing," "eyelid akinesia," "levator inhibition," "blepharospasm-plus," as well as "blepharospasm." The clinical findings in patients with scAEO who fulfilled the classic diagnostic criteria of the disease that were originally set by Lepore and Duvoisin were included, while patients with isolated blepharospasm or dystonic blinks (DB) were excluded. In addition, electromyographic (EMG) studies in patients with scAEO were reviewed in detail with special emphasis on studies that performed synchronous EMG recordings both from the levator muscle (LPS) and the pretarsal orbicularis oculi muscle (OO).

RESULTS

The apraxia designation is clearly a misnomer. Although scAEO behaves clinically as a hypotonic freezing phenomenon, it also shares several cardinal features with focal dystonias. The authors broadly categorized the EMG data into 3 different patterns. The first pattern (n = 26/94 [27.6%]) was predominantly associated with involuntary discharges in the OO muscle and has been termed pretarsal blepharospasm (ptBSP). The commonest pattern was pattern no. 2 (n = 53/94 [56.38%]), which was characterized by involuntary discharges in the OO muscle, together with a disturbed reciprocal innervation of the antagonist levator muscle and is dubbed disturbed reciprocal innervation (DRI). This EMG pattern is difficult to discern from the first pattern. Pattern no. 3 (n = 15/94 [15.9%]) is characterized by an isolated levator palpebrae inhibition (ILPI). This levator silence was observed alone without EMG evidence of contractions in the pretarsal orbicularis or a disturbed reciprocal relation of both muscles.

CONCLUSION

EMG evidence shows that the great majority (84%) of patients show a dystonic pattern, whereas ILPI (16%) does not fit the dystonic spectrum. The authors propose that a spasmodic contraction of the muscle of Riolan may be the etiological basis for levator inhibition in patients with ILPI. If this is true, all the 3 EMG patterns observed in scAEO patients (ptBSP, DRI, and ILPI) would represent an atypical form of BSP. The authors suggest coining the terms Riolan muscle BSP ( rmBSP ) for ILPI, and the term atypical focal eyelid dystonia ( AFED ) instead of the term scAEO, as both terms holistically encompass both the clinical and EMG data and concur with the authors' theorem.

What Is Hemidystonia?

Background

Hemidystonia is defined as dystonia restricted to one side of the body. It is traditionally believed to result from a lesion in the contralateral hemisphere.

Objectives

To describe a series of hemidystonia patients without lesions on brain imaging.

Methods

We searched for individuals with potential hemidystonia who were included in the Dystonia Coalition or Movement Disorder Society Genetic mutation database (MDSgene), and conducted a systematic review.

Results

We found 10 individuals classified as hemidystonia or with homolateral limb dystonia among 3696 cases enrolled by the Dystonia Coalition, 9 cases in MDSgene, and one idiopathic case in the literature. None had evidence of a brain lesion. Body distributions used to define hemidystonia varied considerably and were not always restricted to one side of the body.

Conclusions

Hemidystonia may be idiopathic or genetic, without any obvious brain lesion. The varied use of the term suggests the need for more specific clinical criteria to define "half the body."

Validation of a guideline to reduce variability in diagnosing cervical dystonia

BACKGROUND

Cervical dystonia is characterized by a variable pattern of neck muscle involvement. Due to the lack of a diagnostic test, cervical dystonia diagnosis is based on clinical examination and is therefore subjective. The present work was designed to provide practical guidance for clinicians in confirming or refuting suspected cervical dystonia.

METHODS

Participants were video recorded according to a standardized protocol to assess 6 main clinical features possibly contributing to cervical dystonia diagnosis: presence of repetitive, patterned head/neck movements/postures inducing head/neck deviation from neutral position (item 1); sensory trick (item 2); and red flags related to conditions mimicking dystonia that should be absent in dystonia (items 3-6). Inter-/intra-rater agreement among three independent raters was assessed by k statistics. To estimate sensitivity and specificity, the gold standard was cervical dystonia diagnosis reviewed at each site by independent senior neurologists.

RESULTS

The validation sample included 43 idiopathic cervical dystonia patients and 41 control subjects (12 normal subjects, 6 patients with isolated head tremor, 4 with chorea, 6 with tics, 4 with head ptosis due to myasthenia or amyotrophic lateral sclerosis, 7 with orthopedic/rheumatologic neck diseases, and 2 with ocular torticollis). The best combination of sensitivity and specificity was observed considering all the items except for an item related to capability to voluntarily suppress spasms (sensitivity: 96.1%; specificity: 81%).

CONCLUSIONS

An accurate diagnosis of cervical dystonia can be achieved if, in addition to the core motor features, we also consider some clinical features related to dystonia mimics that should be absent in dystonia.

Health-related quality of life of daily-life-affected benign essential blepharospasm: Multi-center observational study

PURPOSE

To compare Thais' health-related quality of life (HRQOL) and severity grading, efficacy and safety in daily-life-affected benign essential blepharospasm (BEB) patients at baseline and after Botulinum toxin type A (BTX-A) treatment.

DESIGN

Prospective-observational study.

PARTICIPANTS

BEB patients with Jankovic rating scale (JRS) at least 3 in both severity and frequency graded from 14 institutes nationwide were included from August 2020 to June 2021.

METHODS

Demographic data, HRQOL evaluated by the Thai version of EQ-5D-5L and NEI-VFQ-25 questionnaires, and severity grading score evaluated by Jankovic rating scale (JRS) at baseline, 1, and 3 months after the treatment were collected. The impact of the BTX-A injections and their complications were recorded.

RESULTS

184 daily-life-affected BEB patients were enrolled; 159 patients (86.4%) had complete data with a mean age of 61.40±10.09 years. About 88.05% were female, and 10.1% were newly diagnosed. Most of the patients had bilateral involvement (96.9%) and 12.6% had history of BEB-related accident. After BTX-A treatment, HRQOL improved significantly in 4 dimensions of EQ-5D-5L, except self-care. The EQ_VAS (mean±SD) was 64.54±19.27, 75.13±15.37, 73.8±15.85 (p<0.001) and EQ-5D-5L utility score was 0.748±0.23, 0.824±0.19 and 0.807±0.19 at baseline, 1, 3 months after treatment, respectively. From NEI-VFQ-25, HRQOL also improved in all dimensions, except eye pain. The JRS improved in all patients. Self-reported minor adverse events were 22.6%, which mostly resolved within the first month.

CONCLUSION

Daily-life-affected BEB impacted HRQOL in most dimensions from both generic and visual-specific questionnaires. BTX-A treatment not only decreased disease severity, but also improved quality of life.

Relevance of Fluorodopa PET Scan in Dopamine Responsive Dystonia and Juvenile Parkinsonism: A Systematic Review

BACKGROUND

Dopamine Responsive Dystonia (DRD) and Juvenile Parkinsonism (JP) are two diseases commonly presenting with parkinsonian symptoms in young patients. Current clinical guidelines offer a diagnostic approach based on molecular analysis. However, developing countries have limitations in terms of accessibility to these tests. We aimed to assess the utility of imaging equipment, usually more available worldwide, to help diagnose and improve patients' quality of life with these diseases.

METHODS

We performed a systematic literature review in English using the preferred reporting items for systematic reviews and meta-analyses (PRISMA) and meta-analysis of observational studies in epidemiology (MOOSE) protocols. We only used human clinical trials about dopamine responsive dystonia and juvenile parkinsonism patients in which a fluorodopa (FD) positron emission tomography (PET) scan was performed to identify its use in these diseases.

RESULTS

We included six studies that fulfilled our criteria. We found a clear pattern of decreased uptake in the putamen and caudate nucleus in JP cases. At the same time, the results in DRD were comparable to normal subjects, with only a slightly decreased marker uptake in the previously mentioned regions by the FD PET scan.

CONCLUSIONS

We found a distinctive pattern for each of these diseases. Identifying these findings with FD PET scans can shorten the delay in making a definitive diagnosis when genetic testing is unavailable, a common scenario in developing countries.

Motor and psychiatric features in idiopathic blepharospasm: A data-driven cluster analysis

INTRODUCTION

Idiopathic blepharospasm is a clinically heterogeneous dystonia also characterized by non motor symptoms.

METHODS

We used a k-means cluster analysis to assess 188 patients with idiopathic blepharospasm in order to identify relatively homogeneous subpopulations of patients, using a set of motor and psychiatric variables to generate the cluster solution.

RESULTS

Blepharospasm patients reached higher scores on scales assessing depressive- and anxiety-related disorders than healthy/disease controls. Cluster analysis suggested the existence of three groups of patients that differed by type of spasms, overall motor severity, and presence/severity of psychiatric problems. The greater severity of motor symptoms was observed in Group 1, the least severity in Group 3, while the severity of blepharospasm in Group 2 was between that observed in Groups 1 and 3. The three motor subtypes also differed by psychiatric features: the lowest severity of psychiatric symptoms was observed in the group with least severe motor symptoms (group 3), while the highest psychiatric severity scores were observed in group 2 that carried intermediate motor severity rather than in the group with more severe motor symptoms (group 1). The three groups did not differ by disease duration, age of onset, sex or other clinical features.

CONCLUSIONS

The present study suggests that blepharospasm patients may be classified in different subtypes according to the type of spasms, overall motor severity and presence/severity of depressive symptoms and anxiety.

Diagnosis and classification of blepharospasm: Recommendations based on empirical evidence

BACKGROUND

Blepharospasm is one of the most common subtypes of dystonia, and often spreads to other body regions. Despite published guidelines, the approach to diagnosis and classification of affected body regions varies among clinicians.

OBJECTIVE

To delineate the clinical features used by movement disorder specialists in the diagnosis and classification of blepharospasm according to body regions affected, and to develop recommendations for a more consistent approach.

METHODS

Cross-sectional data for subjects diagnosed with all types of isolated dystonia were acquired from the Dystonia Coalition, an international, multicenter collaborative research network. Data were evaluated to determine how examinations recorded by movement disorder specialists were used to classify blepharospasm as focal, segmental, or multifocal.

RESULTS

Among all 3222 participants with isolated dystonia, 210 (6.5%) had a diagnosis of focal blepharospasm. Among these 210 participants, 34 (16.2%) had dystonia outside of upper face region. Factors such as dystonia severity across different body regions and number of body regions affected influenced the classification of blepharospasm as focal, segmental, or multifocal.

CONCLUSIONS

Although focal blepharospasm is the second most common type of dystonia, a high percentage of individuals given this diagnosis had dystonia outside of the eye/upper face region. These findings are not consistent with existing guidelines for the diagnosis and classification of focal blepharospasm, and point to the need for more specific guidelines for more consistent application of existing recommendations for diagnosis and classification.

A Clinical Approach to Focal Dystonias

Dystonia is a hyperkinetic movement disorder (HMD), characterised by sustained or intermittent involuntary muscle contractions resulting in abnormal postures and/or movements [1]. Although primary dystonia has an estimated prevalence of 16 per 100,000 [2], the diagnosis may be delayed, due to its clinical heterogeneity, the lack of objective biomarkers and the potential for pseudodystonic conditions to mimic it [1,3]. We provide an overview of the classification and common subtypes of focal dystonia, focusing on the clinical phenomenology and diagnosis.

The impact of the reclusion on patients with blepharospasm during the COVID19 pandemic

Background

Blepharospasm (BS) is a focal dystonia that can be treated successfully with Botulinum toxin (BoNT). During the reclusion due to the Covid 19 pandemic many patients missed the scheduled treatment.

Objectives

Aim of the study is to evaluate Level of Disability (LoD) related to BS during the lockdown period.

Methods

LoD was assessed by an adapted version of Blepharospasm Disability Index (4iBSDI) during reclusion (T1), and three months after the first injection following the lock down phase (T2). 4iBSDI scores were compared between T1 and T2, a correlation between the change of LoD in the two periods (t-delta) and patients’ clinical data was analyzed.

Results

LoD was not modified between the two periods in most of the patients and it was reduced at T1 in almost one third of the participants. No correlation between t-delta and clinical data was found.

Conclusions

LoD did not increase during the lock down period in most of BS patients although BoNT treatment was suspended. Environmental and psychosocial factors may contribute to determine the LoD due to BS.