Pallidal deep brain stimulation in the treatment of Meige syndrome

Outcome of pallidal deep brain stimulation for treating isolated orofacial dystonia

BACKGROUND

Isolated orofacial dystonia is a rare segmental neurological disorder that affects the eye, mouth, face, and jaws. Current literature on pallidal surgery for orofacial dystonia is limited to case reports and small-scale studies. This study was to investigate clinical outcomes of deep brain stimulation (DBS) of the globus pallidus internus (GPi) in patients with isolated orofacial dystonia.

METHODS

Thirty-six patients who underwent GPi DBS at Incheon St. Mary's Hospital, The Catholic University of Korea, between 2014 and 2019 were included in this study. Burke-Fahn-Marsden Dystonia Rating Scale, Unified Dystonia Rating Scale, and Global Dystonia Severity Rating Scale were retrospectively retrieved for analysis before surgery, at 6-month follow-up as short-term outcome, and at follow-up over 1 year (12 months to 69 months) as long-term results.

RESULTS

Mean total BFMDRS-M scores at the three time points (baseline, 6 months, and over 1 year follow-up) were 11.6 ± 4.9, 6.1 ± 5.2 (50.3 ± 29.9% improvement, p < 0.05), and 4.3 ± 4.2 (65.0 ± 24.2% improvement, p < 0.05), respectively. In terms of UDRS and GDS, improvement rates were 45.1% (p < 0.001) and 47.7% (p < 0.001) at 6 months, and 63.8% (p < 0.001) and 65.7% (p < 0.001) at over 1 year after surgery, respectively.

CONCLUSIONS

Bilateral GPi DBS in isolated orofacial dystonia can be effective if conservative treatment option fails. Its benefit is not only observed in a short term, but also maintained in a long-term follow-up.

Movement disorders of the mouth: a review of the common phenomenologies

Movement disorders of the mouth encompass a spectrum of hyperactive movements involving the muscles of the orofacial complex. They are rare conditions and are described in the literature primarily in case reports originating from neurologists, psychiatrists, and the dental community. The focus of this review is to provide a phenomenological description of different oral motor disorders including oromandibular dystonia, orofacial dyskinesia and orolingual tremor, and to offer management strategies for optimal treatment based on the current literature. A literature search of full text studies using PubMed/Medline and Cochrane library combined with a manual search of the reference lists was conducted until June 2021. Results from this search included meta-analyses, systematic reviews, reviews, clinical studies, case series, and case reports published by neurologists, psychiatrists, dentists and oral and maxillofacial surgeons. Data garnered from these sources were used to provide an overview of most commonly encountered movement disorders of the mouth, aiding physicians in recognizing these rare conditions and in initiating appropriate therapy.

Bilateral pallidal DBS for blepharospasm: A case report and review of the literature

Background:

Deep brain stimulation (DBS) of the globus pallidus internus (GPi) in the treatment of craniocervical dystonia often requires an extended period of stimulation parameter manipulations.

Case Description:

We present a patient suffering from debilitating blepharospasm treated with bilateral DBS of the GPi alongside 7 years of stimulation parameter manipulations and a literature review of comparable patients.

Conclusion:

Our literature review suggests that a patient’s specific dystonic symptoms can guide stimulation parameter manipulations. Further research regarding trends in stimulation parameters being used in the field for different dystonic symptoms may expedite the stimulation parameter manipulation process.

Blepharospasm, Oromandibular Dystonia, and Meige Syndrome: Clinical and Genetic Update

Meige syndrome (MS) is cranial dystonia characterized by the combination of upper and lower cranial involvement and including binocular eyelid spasms (blepharospasm; BSP) and involuntary movements of the jaw muscles (oromandibular dystonia; OMD). The etiology and pathogenesis of this disorder of the extrapyramidal system are not well-understood. Neurologic and ophthalmic examinations often reveal no abnormalities, making diagnosis difficult and often resulting in misdiagnosis. A small proportion of patients have a family history of the disease, but to date no causative genes have been identified to date and no cure is available, although botulinum toxin A therapy effectively mitigates the symptoms and deep brain stimulation is gaining increasing attention as a viable alternative treatment option. Here we review the history and progress of research on MS, BSP, and OMD, as well as the etiology, pathology, diagnosis, and treatment.

Deep brain stimulation for Meige syndrome: a meta-analysis with individual patient data

BACKGROUND

Deep brain stimulation (DBS) is an effective intervention for Meige syndrome, a type of dystonia characterized by blepharospasm, facial, and oromandibular dystonia. This individual patient-level data meta-analysis was to identify the potential outcome predictors, compare the stimulation targets and summarize the efficacy of DBS for Meige syndrome.

METHODS

Three electronic databases (PubMed, Web of Science and Embase) were searched with no publication data restriction to identify studies regarding DBS for Meige syndrome. The primary outcome was the improvement in BFMDRS-M score. Pearson's correlation coefficients and a stepwise multivariate regression analysis were used to identify the potential prognostic factors.

RESULTS

Twenty-three studies (115 patients, 94 with pallidal stimulation and 21 with subthalamic stimulation) were eligible. Patients showed significant improvement in Burke-Fahn-Marsden Dystonia Rating Scale movement (BFMDRS-M) (21.5 ± 11.0 vs 8.6 ± 6.9, P < 0.001) and disability (BFMDRS-D) (6.4 ± 5.1 vs 2.9 ± 2.4, P < 0.001) scores at the last follow-up visit (31.9 ± 30.7 months), compared with scores at baseline. Preoperative BFMDRS-M and BFMDRS-D scores were positively correlated with the relative changes in BFMDRS-M score at the last follow-up visit. On the stepwise multivariate regression, only the preoperative BFMDRS remained significant in the best predictive model.

CONCLUSIONS

Based on the existing evidence, pallidal/subthalamic stimulation is an effective therapy for even the refractory Meige syndrome. Higher preoperative scores probably indicate larger improvement. Stimulation targets or other clinical factors do not constitute the outcome predictive factors.

Bilateral deep brain stimulation of the subthalamic nucleus in primary Meige syndrome

OBJECTIVE

Subthalamic nucleus deep brain stimulation has been shown to be effective in reducing symptoms of primary Meige syndrome. However, assessments of its efficacy and safety have been limited to several case reports and small studies.

METHODS

The authors performed a retrospective study to assess the efficacy and safety of bilateral subthalamic nucleus stimulation in 15 patients with primary Meige syndrome who responded poorly to medical treatments or botulinum toxin injections. Using the movement and disability subscores of the Burke-Fahn-Marsden Dystonia Rating Scale, the authors evaluated the severity of patients’ dystonia and related before surgery and at final follow-up during neurostimulation. The movement scale was assessed based on preoperative and postoperative video documentation by an independent rater who was unaware of each patient’s neurostimulation status. Quality of life was assessed with the Medical Outcomes Study 36-Item Short-Form General Health Survey.

RESULTS

The dystonia movement subscores in 14 consecutive patients improved from 19.3 ± 7.6 (mean ± standard deviation) before surgery to 5.5 ± 4.5 at final follow-up (28.5 ± 16.5 months), with a mean improvement of 74% (p < 0.05). The disability subscore improved from 15.6 ± 4.9 before surgery to 6.1 ± 3.5 at final follow-up (p < 0.05). In addition, the postoperative SF-36 scores increased markedly over those at baseline. The authors also found that bilateral stimulation of the subthalamic nucleus immediately improved patient symptoms after stimulation and required lower stimulation parameters than those needed for pallidal deep brain stimulation for primary Meige syndrome. Four adverse events occurred in 3 patients; all of these events resolved without permanent sequelae.

CONCLUSIONS

These findings provide further evidence to support the long-term efficacy and safety of subthalamic nucleus stimulation as an alternative treatment for patients with medically intractable Meige syndrome.

Long-term clinical outcome of bilateral pallidal stimulation for intractable craniocervical dystonia (Meige syndrome). Report of 6 patients

BACKGROUND

The aim of the present study was to report the short-term as well long-term results of bilateral pallidal stimulation in 6 consecutive patients for severe debilitating craniocervical dystonia (Meige syndrome) using Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS).

METHODS

We evaluated 6 consecutive patients with the diagnosis of intractable long-standing craniocervical dystonia. The formal objective assessment included the motor and disability BFMDRS scores. The BFMDRS assessment was performed before and after it roughly annually up to 60months when bilateral pallidal stimulation was switched on and compared to baseline BFMDRS scores. We present short-term (3months postoperatively) follow-up as well long-term (from 6 to 60months) results. Baseline BFMDRS scores and subsequent follow-up BFMDRS scores were compared with the use of a Wilcoxon signed-rank test for matched pairs. A two-tailed probability level of 5% (p<0.05) was considered significant.

RESULTS

Bilateral GPi DBS improved the BFMDRS total movement score by 65% at short-term follow-up and by 53% at long-term follow-up when compared to baseline scores. Subscores for eyes at short-term follow-up were reduced by 78%, for mouth by 58%, and for speech/swallowing by 49%. This improvements for individual subscores were maintained at long-term follow-up and were as follows for eyes by 67%, mouth by 50% and speech/swallowing by 39%. The BFMDRS disability score was reduced by 48% at short-term follow-up and by 55% at long-term follow-up when compared to baseline scores.

CONCLUSION

Our results showed that bilateral GPi DBS in craniocervical dystonia is effective and safe. Phasic dystonic movements like blepharospasm or oromandibular dystonia responded very fast and favorable to pallidal stimulation reducing disabilities.

Bilateral pallidotomy for Meige syndrome

Meige syndrome (MS) is usually described as a combination of blepharospasm with oromandibular dystonia. There are a large number of case reports of deep brain stimulation (DBS) of the globus pallidus internus (GPI) for MS and only one report of unilateral pallidotomy (PT). We report the first case of staged bilateral PT for treatment of a patient with MS using intraoperative high-frequency stimulation in order to predict and prevent postoperative deficit. There was a significant improvement of the Burk-Fahn-Marsden dystonia rating scale from 26 to 3. There were no adverse postoperative neurological and neuropsychological events.

Blepharospasm 40 years later

Forty years ago, C.D. Marsden proposed that blepharospasm should be considered a form of adult-onset focal dystonia. In the present paper, we provide a comprehensive overview of the findings regarding blepharospasm reported in the past 40 years. Although prolonged spasms of the orbicularis oculi muscles remain the clinical hallmark of blepharospasm, patients with blepharospasm may be characterized by various types of involuntary activation of periocular muscles. In addition to motor features, blepharospasm patients may also have nonmotor manifestations, including psychiatric, mild cognitive, and sensory disturbances. The various motor and nonmotor symptoms are not present in all patients, suggesting that blepharospasm is phenomenologically a heterogeneous condition. This emphasizes the need for tools for severity assessment that take into account both motor and nonmotor manifestations. The cause of blepharospasm remains elusive, but several lines of evidence indicate that blepharospasm is a multifactorial condition in which one, or several, as yet unknown genes together with epigenetic and environmental factors combine to reach the threshold of the disease. Although blepharospasm was originally believed to be solely a basal ganglia disorder, neurophysiological and neuroimaging evidence point to anatomical and functional involvement of several brain regions. The contribution of multiple areas has led to the hypothesis that blepharospasm should be considered as a network disorder, and this might reflect the varying occurrence of motor and nonmotor manifestations in blepharospasm patients. Despite advances in the aetiology and pathophysiology, treatment remains symptomatic. © 2017 International Parkinson and Movement Disorder Society.

Blepharospasm: Update on Epidemiology, Clinical Aspects, and Pathophysiology

Blepharospasm (BSP) is a rather distressing form of focal dystonia. Although many aspects of its pathophysiological mechanisms are already known, we lack fundamental evidence on etiology, prevention, and treatment. To advance in our knowledge, we need to review what is already known in various aspects of the disorder and use these bases to find future lines of interest. Some of the signs observed in BSP are cause, while others are consequence of the disorder. Non-motor symptoms and signs may be a cue for understanding better the disease. Various cerebral sites have been shown to be functionally abnormal in BSP, including the basal ganglia, the cortex, and the cerebellum. However, we still do not know if the dysfunction or structural change affecting these brain regions is cause or consequence of BSP. Further advances in neurophysiology and neuroimaging may eventually clarify the pathophysiological mechanisms implicated. In this manuscript, we aim to update what is known regarding epidemiology, clinical aspects, and pathophysiology of the disorder and speculate on the directions of research worth pursuing in the near future.

Globus pallidus interna deep brain stimulation in a patient with medically intractable meige syndrome

Medical therapies in patients with Meige syndrome, including botulinum toxin injection, have been limited because of incomplete response or adverse side effects. We evaluated a patient with Meige syndrome who was successfully treated with deep brain stimulation (DBS) in the globus pallidus interna (GPi). This case report and other previous reports suggest that bilateral GPi DBS may be an effective treatment for medically refractory Meige syndrome, without significant adverse effects.

Diffusion tensor imaging in blepharospasm and blepharospasm-oromandibular dystonia

Patterns of white matter (WM) abnormalities and correlation with clinical features in patients with blepharospasm (BSP) and patients with blepharospasm-oromandibular dystonia (BOM) remain unknown. Using voxel-based analysis, diffusion behaviors of WM including fractional anisotropy (FA), mean diffusivity (MD) and eigenvalues were compared between 20 BSP patients vs. 11 healthy controls (HCs) and 11 patients with BOM vs. 11 HCs. Correlation analyses were performed to assess possible association between diffusion behaviors of significantly different areas and clinical measures. Compared with HCs, BSP patients showed significant FA reductions in the left anterior lobe of cerebellum. Significant increases of MD and radial diffusivity (RD) were detected in right lentiform nucleus and thalamus. Significantly decreased FA in the right precuneus of parietal lobe, increased MD in the right lentiform nucleus and insula, and increased axial diffusivity in the right insula were observed in BOM patients. The FA values in the WM of left cerebellum negatively correlated with disease severity in BSP patients measured by JRS (r = -0.655, p = 0.002). The FA values in the right parietal WM negatively correlated with disease duration in BOM patients (r = -0.745, p = 0.008). Both BSP and BOM are related to microstructural abnormalities of WM in the basal ganglia. WM changes outside the basal ganglia may present trait features that are specific for individual dystonia phenotype. The correlation between FA abnormalities and symptom severity suggests that DTI parameters might be of clinical value in assessing and following disability in BSP patients.

Glucose hypermetabolism in the thalamus of patients with drug-induced blepharospasm

We examined the difference in cerebral function alterations between drug-induced blepharospasm patients and essential blepharospasm (EB) patients by using positron emission tomography with (18)F-fluorodeoxyglucose. Cerebral glucose metabolism was examined in 21 patients with drug-induced blepharospasm (5 men and 16 women; mean age, 53.1 [range, 29-78] years), 21 essential EB patients (5 men and 16 women; mean age, 53.0 [range, 33-72] years) and 24 healthy subjects (6 men and 18 women; mean age, 57.9 [range, 22-78] years) with long-term history of benzodiazepines use (drug healthy subjects). Drug-induced blepharospasm patients developed symptoms while taking benzodiazepines or thienodiazepines. Sixty-three normal volunteers (15 men and 48 women; mean age, 53.6 [range, 20-70] years) were examined as controls. Differences between the patient groups and control group were examined by statistical parametric mapping. Additionally, we defined regions of interests on both sides of the thalamus, caudate nucleus, anterior putamen, posterior putamen and primary somatosensory area. The differences between groups were tested using two-sample t-tests with Bonferroni correction for multiple comparisons. Cerebral glucose hypermetabolism on both side of the thalamus was detected in drug-induced blepharospasm, EB patients and drug healthy subjects by statistical parametric mapping. In the analysis of regions of interest, glucose metabolism in both sides of the thalamus in the drug-induced blepharospasm group was significantly lower than that in the EB group. Moreover, we observed glucose hypermetabolism in the anterior and posterior putamen bilaterally in EB group but not in drug-induced blepharospasm group and drug healthy subjects. Long-term regimens of benzodiazepines or thienodiazepines may cause down-regulation of benzodiazepine receptors in the brain. We suggest that the functional brain alteration in drug-induced blepharospasm patients is similar to that in EB patients, and that alteration of the GABAergic system might be related to the pathology of both blepharospasm types.

Deep brain stimulation for dystonia

The few controlled studies that have been carried out have shown that bilateral internal globus pallidum stimulation is a safe and long-term effective treatment for hyperkinetic disorders. However, most recent published data on deep brain stimulation (DBS) for dystonia, applied to different targets and patients, are still mainly from uncontrolled case reports (especially for secondary dystonia). This precludes clear determination of the efficacy of this procedure and the choice of the 'good' target for the 'good' patient. We performed a literature analysis on DBS for dystonia according to the expected outcome. We separated those with good evidence of favourable outcome from those with less predictable outcome. In the former group, we review the main results for primary dystonia (generalised/focal) and highlight recent data on myoclonus-dystonia and tardive dystonia (as they share, with primary dystonia, a marked beneficial effect from pallidal stimulation with good risk/benefit ratio). In the latter group, poor or variable results have been obtained for secondary dystonia (with a focus on heredodegenerative and metabolic disorders). From this overview, the main results and limits for each subgroup of patients that may help in the selection of dystonic patients who will benefit from DBS are discussed.

Deep brain stimulation for dystonia

The few reported controlled studies show that bilateral stimulation of the globus pallidus interna (GPi) is a safe and effective long-term treatment for hyperkinetic disorders. However, the recently published data on deep brain stimulation (DBS) applied to different targets or patients (especially those with secondary dystonia) are mainly uncontrolled case reports, precluding a clear determination of its efficacy, and providing little guidance as to the choice of a "good" target in a "good" patient. This chapter reviews the literature on DBS in primary dystonia, paying particular attention to the risk:benefit ratio in focal and segmental dystonias (cervical dystonia, cranial dystonia) and to the predictive factors for a good outcome. The chapter also highlights recent data on the marked benefits of the technique in myoclonus dystonia (in which pallidal, as opposed to thalamic, stimulation is more effective) and in tardive dystonia-dyskinesia. Although, the decision to treat appears relatively straightforward in patients with primary dystonia, myoclonus-dystonia, and tardive dystonia who have a normal findings on magnetic resonance imaging and normal cognitive function, there are still no reliable tools to help predict the timescale of postoperative benefit. This chapter provides a comprehensive analysis of the use of the treatment in various types of secondary dystonia, with little to moderate benefit in most cases, based on single cases or small series. Beyond the reduction in the severity of dystonia, the global motor and functional outcome is difficult to determine owing to the paucity of adequate evaluation tools. Because of the large interpatient variability, different targets may be effective depending on the symptoms in each individual.

Meige syndrome relieved by bilateral pallidal stimulation with cycling mode: case report

BACKGROUND AND IMPORTANCE

Deep brain stimulation (DBS) of the bilateral globus pallidus internus (GPi) has been used effectively to treat dystonia. We report a patient with severe Meige syndrome who received bilateral GPi DBS with good improvement in symptoms during the first 24-month stimulation therapy. To decrease energy consumption and to prolong battery life, the stimulation parameters of the replaced programmable pulse generator were adjusted to the cyclic mode and the stimulator was turned off during nighttime sleep. The patient achieved similar good treatment effect with extended battery life in the following years.

CLINICAL PRESENTATION

A 66-year-old woman with a 3-year history of severe cranial-cervical dystonia received stereotaxic surgery for bilateral GPi DBS therapy. The Burke-Fahn-Marsden dystonia score improved from 32 to 7.5. The effect lasted up to 24 months after therapy when the battery ran out of life. After careful evaluation, we adjusted the stimulation parameters of the second implantable pulse generator to the cyclic stimulation mode and programmed the stimulator to turn off automatically during nighttime sleep. The patient showed persistent good effect 36 months after starting use of the second implantable pulse generator.

CONCLUSION

To treat dystonic symptoms effectively, stimulation parameters with higher energy consumption are usually required. For reducing the discomfort of repeated battery replacement within a short time and decreasing energy consumption in implantable pulse generator, cyclic mode stimulation could be considered in dystonic patients receiving bilateral GPi DBS.

Five-year follow-up of 10 patients treated with globus pallidus internus deep brain stimulation for segmental or multisegmental dystonia

INTRODUCTION

Globus pallidus internus (GPi) deep brain stimulation (DBS) represents a validated, effective, and safe treatment for patients affected by generalized dystonia resistant to conservative treatment. Segmental and multisegmental dystonia have more recently been proposed as further indications for GPi DBS despite the lack of long-term homogenous follow-up. Here we present an original and detailed long-term follow-up (5 years) of a homogeneous population of 11 patients affected by segmental or multisegmental dystonia.

MATERIALS AND METHODS

Ten patients underwent bilateral GPi DBS electrode implantations under a Leksell stereotactic guide, with intraoperative neurophysiological monitoring. The follow-ups at 1, 3 and 5 years were collected using video-BFMDRS for motor and disability scores. The statistical analysis of the results is provided.

RESULTS

We reported a statistically significant improvement in motor and disability overall scores until 5 years after treatment. At the last follow-up, even the single motor subitems were statistically improved.

DISCUSSION

We observed a continuous and statistically significant improvement in all of the motor subitems and in the overall disability score until the 3-year follow-up. These results did not improve any further but they appeared steady at the last follow-up. We also report a significant improvement in the cranial-cervical subitems.

CONCLUSIONS

GPi DBS should definitely be considered a safe and effective treatment also for segmental and multisegmental dystonia even in cases of relevant or prevalent cranial-cervical involvement.

Convergent mechanisms in etiologically-diverse dystonias

INTRODUCTION

Dystonia is a neurological disorder associated with twisting motions and abnormal postures, which compromise normal movements and can be both painful and debilitating. It can affect a single body part (focal), several contiguous regions (segmental), or the entire body (generalized), and can arise as a result of numerous causes, both genetic and acquired. Despite the diversity of causes and manifestations, shared clinical features suggest that common mechanisms of pathogenesis may underlie many dystonias.

AREAS COVERED

Shared themes in etiologically-diverse dystonias exist at several biological levels. At the cellular level, abnormalities in the dopaminergic system, mitochondrial function and calcium regulation are often present. At the anatomical level, the basal ganglia and the cerebellum are frequently implicated. Global CNS dysfunction, specifically aberrant neuronal plasticity, inhibition and sensorimotor integration, are also observed in a number of dystonias. Using clinical data and data from animal models, this article seeks to highlight shared pathways that may be critical in understanding mechanisms and identifying novel therapeutic strategies in dystonia.

EXPERT OPINION

Identifying shared features of pathogenesis can provide insight into the biological processes that underlie etiologically diverse dystonias, and can suggest novel targets for therapeutic intervention that may be effective in a broad group of affected individuals.

Deep brain stimulation: current and future clinical applications

Deep brain stimulation (DBS) has developed during the past 20 years as a remarkable treatment option for several different disorders. Advances in technology and surgical techniques have essentially replaced ablative procedures for most of these conditions. Stimulation of the ventralis intermedius nucleus of the thalamus has clearly been shown to markedly improve tremor control in patients with essential tremor and tremor related to Parkinson disease. Symptoms of bradykinesia, tremor, gait disturbance, and rigidity can be significantly improved in patients with Parkinson disease. Because of these improvements, a decrease in medication can be instrumental in reducing the disabling features of dyskinesias in such patients. Primary dystonia has been shown to respond well to DBS of the globus pallidus internus. The success of these procedures has led to application of these techniques to multiple other debilitating conditions such as neuropsychiatric disorders, intractable pain, epilepsy, camptocormia, headache, restless legs syndrome, and Alzheimer disease. The literature analysis was performed using a MEDLINE search from 1980 through 2010 with the term deep brain stimulation, and several double-blind and larger case series were chosen for inclusion in this review. The exact mechanism of DBS is not fully understood. This review summarizes many of the current and potential future clinical applications of this technology.

Effectiveness of unilateral pallidotomy for meige syndrome confirmed by motion analysis

BACKGROUND

We report the case of a 64-year-old woman with bilateral manifestation of Meige syndrome (MS) successfully treated with left-side unilateral ventroposterolateral pallidotomy.

METHODS

Symptoms were evaluated according to the Burke-Fahn-Marsden dystonia rating scale. Head tremor, blepharospasm and orofacial dyskinesia were measured with an infrared, video-based, computerized, real-time passive marker-based analyzer of motions (RTPAM).

RESULTS

The Burke-Fahn-Marsden score showed a 90.2% reduction (from 25.5 to 2.5) at 6 months, and an 88.2% long-lasting benefit (to 3.0) at the 3-year follow-up with good bilateral control of the blepharospasm and orofacial movements. The RTPAM showed a substantial regression of acceleration for all markers, and abolishment of the 4.8-Hz head tremor. The correlation between symmetrical markers, and between markers within the right and left sides, was significantly decreased.

CONCLUSIONS

Pallidotomy with staged procedure is recommended for the treatment of MS in patients on whom deep brain stimulation could not be performed. In case of good bilateral benefits from the unilateral procedure, contralateral surgery is not needed. The RTPAM is a useful tool for the mapping of facial involuntary movements.

Long-term clinical outcome in meige syndrome treated with internal pallidum deep brain stimulation

Deep brain stimulation of the globus pallidus internus (GPi DBS) is effective in the treatment of primary segmental and generalized dystonia. Although limb, neck, or truncal dystonia are markedly improved, orofacial dystonia is ameliorated to a lesser extent. Nevertheless, several case reports and small cohort studies have described favorable short-term results of GPi DBS in patients with severe Meige syndrome. Here, we extend this preliminary experience by reporting long-term outcome in a multicenter case series, following 12 patients (6 women, 6 men) with Meige syndrome for up to 78 months after bilateral GPi DBS. We retrospectively assessed dystonia severity based on preoperative and postoperative video documentation. Mean age of patients at surgery was 64.5 ± 4.4 years, and mean disease duration 8.3 ± 4.4 years. Dystonia severity as assessed by the Burke-Fahn-Marsden Dystonia Rating Scale showed a mean improvement of 45% at short-term follow-up (4.4 ± 1.5 months; P < 0.001) and of 53% at long-term follow-up (38.8 ± 21.7 months; P < 0.001). Subscores for eyes were improved by 38% (P = 0.004) and 47% (P < 0.001), for mouth by 50% (P < 0.001) and 56% (P < 0.001), and for speech/swallowing by 44% (P = 0.058) and 64% (P = 0.004). Mean improvements were 25% (P = 0.006) and 38% (P < 0.001) on the Blepharospasm Movement Scale and 44% (P < 0.001) and 49% (P < 0.001) on the Abnormal Involuntary Movement Scale. This series, which is the first to demonstrate a long-term follow-up in a large number of patients, shows that GPi DBS is a safe and highly effective therapy for Meige syndrome. The benefit is preserved for up to 6 years.

Adult-onset dystonia

Dystonia is defined as involuntary sustained muscle contractions producing twisting or squeezing movements and abnormal postures. The movements can be stereotyped and repetitive and they may vary in speed from rapid to slow; sustained contractions can result in fixed postures. Dystonic disorders are classified into primary and secondary forms. Several types of adult-onset primary dystonia have been identified but all share the characteristic that dystonia (including tremor) is the sole neurologic feature. The forms most commonly seen in neurological practice include cranial dystonia (blepharospasm, oromandibular and lingual dystonia and spasmodic dysphonia), cervical dystonia (also known as spasmodic torticollis) and writer's cramp. These are the disorders that benefit most from botulinum toxin injections. A general characteristic of dystonia is that the movements or postures may occur in relation to specific voluntary actions by the involved muscle groups (such as in writer's cramp). Dystonic contractions may occur in one body segment with movement of another (overflow dystonia). With progression, dystonia often becomes present at rest. Dystonic movements typically worsen with anxiety, heightened emotions, and fatigue, decrease with relaxation, and disappear during sleep. There may be diurnal fluctuations in the dystonia, which manifest as little or no involuntary movement in the morning followed by severe disabling dystonia in the afternoon and evening. Morning improvement (or honeymoon) is seen with several types of dystonia. Patients often discover maneuvers that reduce the dystonia and which involve sensory stimuli such as touching the chin lightly in cervical dystonia. These maneuvers are known as sensory tricks, or gestes antagonistes. This chapter focuses on adult-onset focal dystonias including cranial dystonia, cervical dystonia, and writer's cramp. The chapter begins with a review of the epidemiology of focal dystonias, followed by discussions of each major type of focal dystonia, covering clinical phenomenology, differential genetics, and diagnosis. The chapter concludes with discussions of the pathophysiology, the few pathological cases published of adult-onset focal dystonia and management options, and a a brief look at the future.

Low-voltage bilateral pallidal stimulation for severe meige syndrome in a patient with primary segmental dystonia: case report

BACKGROUND AND IMPORTANCE

Meige syndrome (MS) is an adult-onset segmental dystonia characterized by the combination of upper and lower cranial involvement. Its treatment is challenging and the use of oral medication or of botulinum neurotoxin treatment is not decisive. Deep brain stimulation of the globus pallidus internum (GPi DBS) has been used occasionally in severe cases.

CLINICAL PRESENTATION

We report the long-term efficacy of low-voltage chronic bilateral GPi DBS in a patient with segmental dystonia featuring severe MS and cervical brachial involvement. The patient received a bilateral ventroposterolateral GPi implant. Postoperative 3-dimensional reconstruction allowed checking of the definitive position of the electrode and contacts within the targeted nucleus. Following implant, the patient received bilateral low-voltage stimulation, consisting in amplitude of 1.3 V with a pulse width of 90 microseconds and a frequency of 130 Hz, yielding a current of 23 microA. Clinical follow-up for 38 months showed a progressive and sustained improvement of dystonia with unchanged electrical settings throughout the observation period. The patient again undertook normal life activities.

CONCLUSION

Bilateral low-voltage GPi stimulation allowed efficient control of MS symptoms and the associated brachial cervical dystonia.

Deep brain stimulation for dystonia: patient selection and outcomes

In a literature survey, 341 patients with primary and 109 with secondary dystonias treated with deep brain stimulation (DBS) of the internal segment of the globus pallidus (GPi) were identified. In general, the outcomes for primary dystonias were more favourable compared to the secondary forms. For some secondary dystonias--like tardive dystonia, myoclonus-dystonia (M-D), NBIA (PANK2), the outcome was very good. Only for the primary generalized dystonias, the efficacy of GPi-DBS has been confirmed in randomised controlled trials. Predictors of outcome are the experience and dedication of the stereotactic team, the selection of patients--the diagnosis and pre-operative screening--and the quality of the post-operative care. Predictors of negative outcome are long duration of the disease--with contractures or scoliosis--and concomitant symptoms like spasticity and cerebellar dysfunction. More studies are required to establish the role of GPi-DBS in the treatment of secondary dystonias.

Long-term follow-up of deep brain stimulation for Meige syndrome

OBJECT

Meige syndrome is characterized by blepharospasm, cervical dystonia, and facial oromandibular dystonia. The medical treatment of this condition is largely unsuccessful over time and is a major source of decreased quality of life in those patients suffering from this disease. Recent advances in the application of deep brain stimulation (DBS) surgery techniques for many disorders have prompted several recent reports of DBS for medically refractory cases of Meige syndrome. While the etiology for this disorder is unknown, it is considered by many investigators to be a form of idiopathic torsion dystonia. Pallidal stimulation is widely considered to be effective for dystonia.

METHODS

The authors report the long-term results of bilateral globus pallidus internus (GPi) or subthalamic nucleus (STN) stimulation in 3 patients with Meige syndrome and 1 patient with Parkinson disease and associated craniofacial dystonia treated at their center.

RESULTS

Initial 12-month and long-term follow-up Burke-Fahn-Marsden scores were substantially improved in all 4 patients compared with preoperative scores.

CONCLUSIONS

Bilateral GPi DBS may be an effective and safe treatment for medically refractory Meige syndrome. The results are comparable with those reported in the literature. Sustained and long-term improvement in symptoms does appear to be reproducible across reports. The authors' patient with Parkinson disease and associated craniofacial dystonia syndrome undergoing bilateral STN DBS noted immediate and sustained improvement in his symptoms. Further study is required, but these results, along with the other reports, suggest that bilateral GPi DBS is an effective treatment for medically refractory Meige syndrome.

Orbicularis oculi myo-osseous fixation: a new treatment for benign essential blepharospasm and blepharospasm associated with diffuse facial dystonia (meige syndrome)

BACKGROUND AND OBJECTIVE

This article describes a novel surgical procedure, myo-osseous fixation, as an adjunct therapy for patients with reduced or poor response to repeated botulinum toxin injections for essential blepharospasm and Meige syndrome.

PATIENTS AND METHODS

The small-incision, rapidly healing, rapidly performed technique uses self-drilling titanium screws tightly engaged with a compression wrench. The screws fixate the periorbital orbicularis oculi muscle to bone, creating mechanical resistance to outer portions of the orbicularis muscle involved in debilitating involuntary contractions.

RESULTS

Eleven of the treated 12 patients experienced immediate improvement in function. Each responding patient noted enhanced effect of subsequent botulinum toxin injections at previously ineffective doses. The benefit was substantial and sustained for 6 months in 9 of 12 patients. Decreased brow depression during forced closure, forced frown, and brow elevation at rest was apparent in all patients postoperatively. Although the brow elevation effect was reduced after 6 months, reduced brow depression during forced closure still was easily demonstrated in most patients. Complications included a nodular bump over the brow, more commonly found when large titanium screws were used, transient headache, and easily removed dislodged screw.

CONCLUSION

Initial data suggest that this procedure appears safe, well tolerated, and useful in the treatment of patients with essential blepharospasm and Meige syndrome responding poorly to botulinum toxin therapy.

Dystonia: a surgeon's perspective

Surgery for dystonia has a history stretching back for centuries including myotomy and other procedures on the musculoskeletal system. In the last century lesional procedures, mainly involving the pallidum became popular. More recently, with the advent of deep brain stimulation, bilateral medial pallidal stimulation has become commonplace. This review describes the issues with patient selection, technical aspects of implantation and effects as well as complications of the technique. Some of the rarer types of dystonia that have also been treated with DBS are also described.

Meige's syndrome: A cranial dystonia treated with bilateral pallidal deep brain stimulation

BACKGROUND

Meige's syndrome is a rare form of segmental dystonia characterized by blepharospasm and oromandibular dystonia. Medical treatment including botulinum toxin injections usually present disappointing results. The experience on Deep Brain Stimulation (DBS) in the treatment of Meige's syndrome and other segmental dystonias is still limited. At the moment, only a few cases of pallidal DBS have been reported to improve this rare form of dystonia.

CASE DESCRIPTION

We report on a case of a woman with a 7-year history of Meige's syndrome, which rendered her functionally blind. The treatment with botulinum toxin injections failed to improve her symptoms, whereas stereotactic bilateral DBS of the pallidum led to a dramatic clinical improvement. Clinical assessment using the Burke-Fahn-Mardsen Dystonia Rating Scale (BFMDRS) in a double-blind manner, showed an improvement of 70% in the Movement score and 93.33% in the Disability score (84% reduction of the total score) on the 3 and 6 month follow-up.

CONCLUSIONS

Stereotactic pallidal DBS might be considered as a potential treatment in the management of Meige's syndrome.

A family with a hereditary form of torsion dystonia from northern Sweden treated with bilateral pallidal deep brain stimulation

To evaluate pallidal DBS in a non-DYT1 form of hereditary dystonia. We present the results of pallidal DBS in a family with non-DYT1 dystonia where DYT5 to 17 was excluded. The dystonia is following an autosomal dominant pattern. Ten members had definite dystonia and five had dystonia with minor symptoms. Four patients received bilateral pallidal DBS. Mean age was 47 years. The patients were evaluated before surgery, and "on" stimulation after a mean of 2.5 years (range 1-3) using the Burke-Fahn-Marsden scale (BFM). Mean BFM score decreased by 79 % on stimulation, from 42.5 +/- 24 to 9 +/- 6.5 at the last evaluation. Cervical involvement improved by 89%. The 2 patients with oromandibular dystonia and blepharospasm demonstrated a reduction of 95% regarding these symptoms. The present study confirms the effectiveness of pallidal DBS in a new family with hereditary primary segmental and generalized dystonia.

Selected lid problems in neurologic practice

Ptosis is a common clinical finding. The many causes of ptosis include involutional (aging), myopathic, neuropathic, congenital, infectious, tumorous, traumatic, and inflammatory processes. This article reviews recent literature on some causes of ptosis and other lid conditions.

Meige syndrome: what's in a name?

Frequently, blepharospasm is associated with involuntary movements of the platysma, lower face and masticatory muscles. Similarly, masticatory dystonia may occur in isolation or in combination with dystonia of other cranial and cervical muscles. The non-possessive and possessive forms of Meige and Brueghel syndromes have been variably and imprecisely ascribed to various anatomical variations of craniocervical dystonia. Herein, the origin of eponymic terms as applied to craniocervical dystonia is reviewed as support for proposed elimination of these eponyms from clinical usage. Although the term "segmental craniocervical dystonia" more accurately captures the combination of blepharospasm and dystonia of other head and neck muscles, delineation of craniocervical subphenotypes is essential for etiological/genetic and treatment studies. To conclude, the clinical features, epidemiology, pathophysiology and therapeutic management of segmental craniocervical dystonia are examined with a particular focus on "blepharospasm-plus" subphenotypes.