Meige syndrome: neuropathology of a case

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.

Efficacy and Safety of Long-Term Therapy with Type A Botulinum Toxin in Patients with Blepharospasm

Blepharospasm (BPS) is one of the most frequent types of facial dystonia and, at the same time, one of the most disabling, being able to trigger functional blindness if not treated. Our aim with this work was to evaluate the efficacy and safety of long-term onabotulinum A toxin (BAT) treatment in a cohort of patients with BPS. The retrospective study was conducted on consecutive patients with BPS treated with subcutaneous BAT. The selection of muscles and dose was made based on each patient's needs. The clinical and demographic characteristics, number of sessions, dose, duration and effectiveness of treatment, and adverse events were analysed. 130 patients were included in the study. The median (95% confidence interval) length of follow-up was 14 (13-15.6) years with an average of 20.5 sessions (range from 10 to 57). Regarding the efficacy of the treatment, 114 (87.7%) experienced satisfactory results with functional and aesthetics recovery. Patient evaluation of global response suggested a clear improvement without adverse events in 72 (55.4%) patients. Adverse events developed at least once during the treatment in 39% of patients, with transient ptosis and haematoma the most common reported both by physician and patient. The results of our study suggest that botulin toxin A is a safe and effective long-term treatment for blepharospasm with mild, transient and well-tolerated side effects when they appear.

Multimodal Quantitative MRI Reveals No Evidence for Tissue Pathology in Idiopathic Cervical Dystonia

Background: While in symptomatic forms of dystonia cerebral pathology is by definition present, it is unclear so far whether disease is associated with microstructural cerebral changes in idiopathic dystonia. Previous quantitative MRI (qMRI) studies assessing cerebral tissue composition in idiopathic dystonia revealed conflicting results.

Objective: Using multimodal qMRI, the presented study aimed to investigate alterations in different cerebral microstructural compartments associated with idiopathic cervical dystonia in vivo.

Methods: Mapping of T₁, T₂, T2*, and proton density (PD) was performed in 17 patients with idiopathic cervical dystonia and 29 matched healthy control subjects. Statistical comparisons of the parametric maps between groups were conducted for various regions of interest (ROI), including major basal ganglia nuclei, the thalamus, white matter, and the cerebellum, and voxel-wise for the whole brain.

Results: Neither whole brain voxel-wise statistics nor ROI-based analyses revealed significant group differences for any qMRI parameter under investigation.

Conclusions: The negative findings of this qMRI study argue against the presence of overt microstructural tissue change in patients with idiopathic cervical dystonia. The results seem to support a common view that idiopathic cervical dystonia might primarily resemble a functional network disease.

Neuropathology of Dystonia

Background

Dystonia is characterized by sustained or intermittent muscle contractions resulting in abnormal, often repetitive, movements, postures, or both. Neuropathologic research has been essential in understanding the etiology and disease progression of other movement disorders, including Parkinson’s disease and cerebellar ataxias. In the field of dystonia, however, research is stymied by the paucity of post-mortem tissue available and the phenotypic heterogeneity found in those with dystonia.

Methods

A PubMed search was conducted using the term “neuropathology of dystonia”. The resulting list of references was limited to English-language human neuropathology articles. A total of 20 publications were retrieved and reviewed.

Results

Historically, based on study of acquired forms of dystonia, lesions of the putamen and globus pallidus have been identified as causing dystonia. After the identification of genetic causes of dystonia and the study of limited tissue available from those cases, as well as findings from cases of isolated focal and segmental dystonia, there is evidence that brainstem cholinergic neurons and specific cell populations within the cerebellum also play a role in the pathophysiology of dystonia.

Discussion

Based on limited available brain tissue, there is evidence that the pathophysiology of dystonia may involve a combination of dysfunction within neurons of the brainstem, cerebellum, putamen, and globus pallidus. In order to gain a better understanding of the pathophysiology of dystonia, a prospective, quantitative study in well-phenotyped subjects with different types of genetic and isolated dystonia is required.

A novel therapeutic agent, sodium oxybate, improves dystonic symptoms via reduced network-wide activity

Oral medications for the treatment of dystonia are not established. Currently, symptoms of focal dystonia are managed with botulinum toxin injections into the affected muscles. However, the injection effects are short-lived and not beneficial for all patients. We recently reported significant clinical improvement of symptoms with novel investigational oral drug, sodium oxybate, in patients with the alcohol-responsive form of laryngeal focal dystonia. Understanding the mechanism of action of this promising oral agent holds a strong potential for the development of a scientific rationale for its use in dystonia. Therefore, to determine the neural markers of sodium oxybate effects, which may underlie dystonic symptom improvement, we examined brain activity during symptomatic speech production before and after drug intake in patients with laryngeal dystonia and compared to healthy subjects. We found that sodium oxybate significantly attenuated hyperfunctional activity of cerebellar, thalamic and primary/secondary sensorimotor cortical regions. Drug-induced symptom improvement was correlated with decreased-to-normal levels of activity in the right cerebellum. These findings suggest that sodium oxybate shows direct modulatory effects on disorder pathophysiology by acting upon abnormal neural activity within the dystonic network.

Current Opinions and Areas of Consensus on the Role of the Cerebellum in Dystonia

A role for the cerebellum in causing ataxia, a disorder characterized by uncoordinated movement, is widely accepted. Recent work has suggested that alterations in activity, connectivity, and structure of the cerebellum are also associated with dystonia, a neurological disorder characterized by abnormal and sustained muscle contractions often leading to abnormal maintained postures. In this manuscript, the authors discuss their views on how the cerebellum may play a role in dystonia. The following topics are discussed: The relationships between neuronal/network dysfunctions and motor abnormalities in rodent models of dystonia. Data about brain structure, cerebellar metabolism, cerebellar connections, and noninvasive cerebellar stimulation that support (or not) a role for the cerebellum in human dystonia. Connections between the cerebellum and motor cortical and sub-cortical structures that could support a role for the cerebellum in dystonia. Overall points of consensus include: Neuronal dysfunction originating in the cerebellum can drive dystonic movements in rodent model systems. Imaging and neurophysiological studies in humans suggest that the cerebellum plays a role in the pathophysiology of dystonia, but do not provide conclusive evidence that the cerebellum is the primary or sole neuroanatomical site of origin.

Reduced Number of Pigmented Neurons in the Substantia Nigra of Dystonia Patients? Findings from Extensive Neuropathologic, Immunohistochemistry, and Quantitative Analyses

Background

Dystonias (Dys) represent the third most common movement disorder after essential tremor (ET) and Parkinson's disease (PD). While some pathogenetic mechanisms and genetic causes of Dys have been identified, little is known about their neuropathologic features. Previous neuropathologic studies have reported generically defined neuronal loss in various cerebral regions of Dys brains, mostly in the basal ganglia (BG), and specifically in the substantia nigra (SN). Enlarged pigmented neurons in the SN of Dys patients with and without specific genetic mutations (e.g., GAG deletions in DYT1 dystonia) have also been described. Whether or not Dys brains are associated with decreased numbers or other morphometric changes of specific neuronal types is unknown and has never been addressed with quantitative methodologies.

Methods

Quantitative immunohistochemistry protocols were used to estimate neuronal counts and volumes of nigral pigmented neurons in 13 SN of Dys patients and 13 SN of age-matched control subjects (C).

Results

We observed a significant reduction (∼20%) of pigmented neurons in the SN of Dys compared to C (p<0.01). Neither significant volumetric changes nor evident neurodegenerative signs were observed in the remaining pool of nigral pigmented neurons in Dys brains. These novel quantitative findings were confirmed after exclusion of possible co-occurring SN pathologies including Lewy pathology, tau-neurofibrillary tangles, β-amyloid deposits, ubiquitin (ubiq), and phosphorylated-TAR DNA-binding protein 43 (pTDP43)-positive inclusions.

Discussion

A reduced number of nigral pigmented neurons in the absence of evident neurodegenerative signs in Dys brains could indicate previously unconsidered pathogenetic mechanisms of Dys such as neurodevelopmental defects in the SN.

Rapid-onset dystonia-parkinsonism associated with the I758S mutation of the ATP1A3 gene: a neuropathologic and neuroanatomical study of four siblings

Rapid-onset dystonia-parkinsonism (RDP) is a movement disorder associated with mutations in the ATP1A3 gene. Signs and symptoms of RDP commonly occur in adolescence or early adulthood and can be triggered by physical or psychological stress. Mutations in ATP1A3 are also associated with alternating hemiplegia of childhood (AHC). The neuropathologic substrate of these conditions is unknown. The central nervous system of four siblings, three affected by RDP and one asymptomatic, all carrying the I758S mutation in the ATP1A3 gene, was analyzed. This neuropathologic study is the first carried out in ATP1A3 mutation carriers, whether affected by RDP or AHC. Symptoms began in the third decade of life for two subjects and in the fifth for another. The present investigation aimed at identifying, in mutation carriers, anatomical areas potentially affected and contributing to RDP pathogenesis. Comorbid conditions, including cerebrovascular disease and Alzheimer disease, were evident in all subjects. We evaluated areas that may be relevant to RDP separately from those affected by the comorbid conditions. Anatomical areas identified as potential targets of I758S mutation were globus pallidus, subthalamic nucleus, red nucleus, inferior olivary nucleus, cerebellar Purkinje and granule cell layers, and dentate nucleus. Involvement of subcortical white matter tracts was also evident. Furthermore, in the spinal cord, a loss of dorsal column fibers was noted. This study has identified RDP-associated pathology in neuronal populations, which are part of complex motor and sensory loops. Their involvement would cause an interruption of cerebral and cerebellar connections which are essential for maintenance of motor control.

Mouse models of neurodevelopmental disease of the basal ganglia and associated circuits

This chapter focuses on neurodevelopmental diseases that are tightly linked to abnormal function of the striatum and connected structures. We begin with an overview of three representative diseases in which striatal dysfunction plays a key role--Tourette syndrome and obsessive-compulsive disorder, Rett's syndrome, and primary dystonia. These diseases highlight distinct etiologies that disrupt striatal integrity and function during development, and showcase the varied clinical manifestations of striatal dysfunction. We then review striatal organization and function, including evidence for striatal roles in online motor control/action selection, reinforcement learning, habit formation, and action sequencing. A key barrier to progress has been the relative lack of animal models of these diseases, though recently there has been considerable progress. We review these efforts, including their relative merits providing insight into disease pathogenesis, disease symptomatology, and basal ganglia function.

Primary dystonia: moribund or viable

With increasing understanding of dystonia genetic etiologies and pathophysiology there has been renewed scrutiny and reappraisal of dystonia classification schemes and nomenclature. One important category that includes both clinical and etiologic criteria is primary dystonia. This editorialized review discusses the impact of recent findings on primary dystonia criteria and argues that it remains useful in clinical and research practice. © 2013 Movement Disorder Society.

Neuropathological diagnostic considerations in hyperkinetic movement disorders

Neuropathology of hyperkinetic movement disorders can be very challenging. This paper starts with basic functional anatomy of the basal ganglia in order to appreciate that focal lesions like for instance tumor or infarction can cause hyperkinetic movement disorders like (hemi)ballism. The neuropathology of different causes of chorea (amongst others Huntington’s disease, neuroacanthosis, and HLD-2) and dystonia (DYT1, PD, and Dopa-Responsive Dystonia) are described. Besides the functional anatomy of the basal ganglia a wider anatomical network view is provided. This forms the basis for the overview of the neuropathology of different forms of tremor.

Cerebellar pathology of a dual clinical diagnosis: patients with essential tremor and dystonia

BACKGROUND

Clinical studies have implicated the cerebellum in the pathogenesis of essential tremor (ET), and recent postmortem studies have identified structural changes in the ET cerebellum. While the basal ganglia have traditionally been implicated in dystonia, cerebellar involvement has been suggested as well, and a recent study showed Purkinje cell (PC) loss. We conducted a detailed postmortem examination of the brain in four individuals with clinical diagnoses of ET and dystonia, and hypothesized that pathological changes in the cerebellum would be greater in these four ET cases than in published ET cases without dystonia.

METHODS

After a complete neuropathological assessment, a standard parasagittal neocerebellar tissue block was harvested in each brain. One 7-µm thick section was stained with luxol fast blue/hematoxylin and eosin, and one section with the Bielschowsky method. We quantified PCs, torpedoes, heterotopic PCs, PC dendritic swellings, and basket cell changes.

RESULTS

Two ET+dystonia cases had more microscopic changes in the cerebellum than published ET cases; the other two cases had similar changes to published ET cases.

DISCUSSION

This is the first report that uses human autopsy tissue to study patients with both ET and dystonia. The findings were heterogeneous. Additional studies, with larger samples, are needed.

Update on the pathology of dystonia

Dystonia is a clinical syndrome with sustained muscle contraction, twisting, and abnormal postures. A number of different genetic forms have been defined, but most cases are sporadic in nature and of uncertain cause. Relatively few cases of dystonia have been studied pathologically. In primary dystonias, where dystonia is the main symptom, most reports describe little or no detectable neuropathology, although changes in brainstem neurons have been described in some cases. Secondary dystonias are associated with degenerative or destructive diseases of the nervous system; the pathology may be located in the basal ganglia, but in some cases the primary pathological changes are found in the cerebellum or cerebellar outflow pathways, suggesting that both regions may be involved in the pathogenesis of dystonic symptoms. Overall the number of well-documented pathological cases available for study is few, and there is an urgent need for additional postmortem studies. This article is part of a Special Issue entitled "Advances in dystonia".

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.

Actin and Diseases of the Nervous System

Abnormal regulation of the actin cytoskeleton results in several pathological conditions affecting primarily the nervous system. Those of genetic origin arise during development, but others manifest later in life. Actin regulation is also affected profoundly by environmental factors that can have sustained consequences for the nervous system. Those consequences follow from the fact that the actin cytoskeleton is essential for a multitude of cell biological functions ranging from neuronal migration in cortical development and dendritic spine formation to NMDA receptor activity in learning and alcoholism. Improper regulation of actin, causing aggregation, can contribute to the neurodegeneration of amyloidopathies, such as Down's syndrome and Alzheimer's disease. Much progress has been made in understanding the molecular basis of these diseases.

Review and update of involuntary facial movement disorders presenting in the ophthalmological setting

We review the existing literature on the involuntary facial movement disorders-benign essential blepharospasm, apraxia of eyelid opening, hemifacial spasm, and aberrant facial nerve regeneration. The etiology of idiopathic blepharospasm, a disorder of the central nervous system, and hemifacial spasm, a condition involving the facial nerve of the peripheral nervous system, is markedly different. We discuss established methods of managing patients and highlight new approaches.

Brainstem pathology in spasmodic dysphonia

Spasmodic dysphonia (SD) is a primary focal dystonia of unknown pathophysiology, characterized by involuntary spasms in the laryngeal muscles during speech production. We examined two rare cases of postmortem brainstem tissue from SD patients compared to four controls. In the SD patients, small clusters of inflammation were found in the reticular formation surrounding solitary tract, spinal trigeminal, and ambigual nuclei, inferior olive, and pyramids. Mild neuronal degeneration and depigmentation were observed in the substantia nigra and locus coeruleus. No abnormal protein accumulations and no demyelination or axonal degeneration were found. These neuropathological findings may provide insights into the pathophysiology of SD.

Meige's syndrome and hemichorea associated with hyperthyroidism

Movement disorders are known to be associated with hyperthyroidism. However, the association of Meige's syndrome and hemichorea with hyperthyroidism has not been reported. We describe a young Chinese woman with hyperthyroidism, who presented with a unique combination of Meige's syndrome and hemichorea in the left limbs. Both neurologic manifestations were preceded by symptoms of hyperthyroidism, and resolved following treatment with methimazole for hyperthyroidism. Nevertheless, the neurologic symptoms recurred when she stopped taking methimazole, but abated when she returned to a euthyroid state after additional treatment with methimazole. The evolution of her clinical course indicated that the involuntary movements were in association with hyperthyroidism. This case is the first report of Meige's syndrome and hemichorea in a patient with hyperthyroidism, which raises the likelihood that hyperthyroidism may be a cause of Meige's syndrome and hemichorea. Furthermore, it emphasizes the need for greater attention to thyroid function in those afflicted with involuntary movements in order to optimize clinical management.

Focal white matter changes in spasmodic dysphonia: a combined diffusion tensor imaging and neuropathological study

Spasmodic dysphonia is a neurological disorder characterized by involuntary spasms in the laryngeal muscles during speech production. Although the clinical symptoms are well characterized, the pathophysiology of this voice disorder is unknown. We describe here, for the first time to our knowledge, disorder-specific brain abnormalities in these patients as determined by a combined approach of diffusion tensor imaging (DTI) and postmortem histopathology. We used DTI to identify brain changes and to target those brain regions for neuropathological examination. DTI showed right-sided decrease of fractional anisotropy in the genu of the internal capsule and bilateral increase of overall water diffusivity in the white matter along the corticobulbar/corticospinal tract in 20 spasmodic dysphonia patients compared to 20 healthy subjects. In addition, water diffusivity was bilaterally increased in the lentiform nucleus, ventral thalamus and cerebellar white and grey matter in the patients. These brain changes were substantiated with focal histopathological abnormalities presented as a loss of axonal density and myelin content in the right genu of the internal capsule and clusters of mineral depositions, containing calcium, phosphorus and iron, in the parenchyma and vessel walls of the posterior limb of the internal capsule, putamen, globus pallidus and cerebellum in the postmortem brain tissue from one patient compared to three controls. The specificity of these brain abnormalities is confirmed by their localization, limited only to the corticobulbar/corticospinal tract and its main input/output structures. We also found positive correlation between the diffusivity changes and clinical symptoms of spasmodic dysphonia (r = 0.509, P = 0.037). These brain abnormalities may alter the central control of voluntary voice production and, therefore, may underlie the pathophysiology of this disorder.

Jaw-opening dystonia (Brueghel's syndrome) associated with cavum septi pellucidi and Verga's ventricle - a case report

Jaw-opening dystonia (oromandibular dystonia with jaw-opening; Brueghel's syndrome) is a rare condition, and only a limited number of cases have been reported in the literature. However, many patients may remain undiscovered or misdiagnosed, like a patient described previously. A case (40-year-old man) of jaw-opening dystonia (oromandibular dystonia with jaw-opening; Brueghel's syndrome) is reported. In this case, brain anomalies, cavum septi pellucidi and Verga's ventricle, were observed on magnetic resonance imaging of the brain. This case and a review of the literature indicate the presence of organic factors in the etiology of Brueghel's syndrome. The etiological relationship of brain anomalies in Bruegel's syndrome is discussed.

Aggregation of actin and cofilin in identical twins with juvenile-onset dystonia

The neuropathology of the primary dystonias is not well understood. We examined brains from identical twins with DYT1-negative, dopa-unresponsive dystonia. The twins exhibited mild developmental delays until age 12 years when they began developing rapidly progressive generalized dystonia. Genetic, metabolic, and imaging studies ruled out known causes of dystonia. Cognition was subnormal but stable until the last few years. Death occurred at ages 21 and 22 years. The brains were macroscopically unremarkable. Microscopic examination showed unusual glial fibrillary acidic protein-immunoreactive astrocytes in multiple regions and iron accumulation in pallidal and nigral neurons. However, the most striking findings were 1) eosinophilic, rod-like cytoplasmic inclusions in neocortical and thalamic neurons that were actin depolymerizing factor/cofilin-immunoreactive but only rarely actin-positive; and 2) abundant eosinophilic spherical structures in the striatum that were strongly actin- and actin depolymerizing factor/cofilin-positive. Electron microscopy suggested that these structures represent degenerating neurons and processes; the accumulating filaments had the same dimensions as actin microfilaments. To our knowledge, aggregation of actin has not been reported previously as the predominant feature in any neurodegenerative disease. Thus, our findings may shed light on a novel neuropathological change associated with dystonia that may represent a new degenerative mechanism involving actin, a ubiquitous constituent of the cytoskeletal system.

Severe generalized dystonia due to primary putaminal degeneration: case report and review of the literature

Putaminal lesions of a variety of etiologies may cause secondary dystonia. We report on a case of primary putaminal degeneration as a cause of severe childhood-onset generalized dystonia and review the literature of the pathology of dystonia. A 44-year-old patient with severe generalized childhood-onset dystonia and macrocephaly underwent neurological evaluation and neuropathological examination. Neurological examination was normal apart from dystonia and signs referable to prior cryothalamotomy. Workup for metabolic and genetic causes of dystonia was negative. Neuroimaging showed severe bilateral putaminal degeneration, which subsequently correlated with the neuropathological findings of gliosis, spongiform degeneration, and cavitation. The substantia nigra pars compacta contained a normal number of neurons but decreased tyrosine hydroxylase immunoreactivity. There were no histopathological markers of other metabolic or degenerative diseases.

Immunohistochemical localization and distribution of torsinA in normal human and rat brain

Dystonia is a disease of basal ganglia function, the pathophysiology of which is poorly understood. Primary torsion dystonia is one of the most severe types of inherited dystonia and can be transmitted in an autosomal dominant manner. Recently, one mutation causing this disorder was localized to a gene on chromosome 9q34, designated DYT1, which encodes for a novel protein termed torsinA. The role of this protein in cellular function, in either normal or dystonic individuals is not known. We have developed a polyclonal antibody to torsinA and report its localization and distribution in normal human and rat brain. We demonstrate that torsinA is widely expressed in brain and peripheral tissues. Immunohistochemical studies of normal human and rat brain reveal the presence of torsinA in the dopaminergic neurons of the substantia nigra pars compacta (SNc), in addition to many other regions, including neocortex, hippocampus, and cerebellum. Labeling is restricted to neurons, as shown by double-immunofluorescence microscopy, and is present in both nuclei and cytoplasm. An ATP-binding property for torsinA has been suggested by its homology to ATP-binding proteins; this was confirmed by enrichment of torsinA in ATP-agarose affinity-purified fractions from tissue homogenates. An understanding of the role of torsinA in cellular function and the impact of the mutation (deletion of a glutamic acid at residue 303) is likely to provide insights into the etiopathogenesis of primary dystonia.

Increased activation of frontal areas during arm movement in idiopathic torsion dystonia

Most positron emission tomography (PET) studies of regional cerebral function in idiopathic torsion dystonia (ITD) have failed to show abnormalities, but there have been few studies of the changes in regional cerebral blood flow (rCBF) that occur during movement in dystonia. Using PET, we have studied six patients with familial generalized ITD both at rest and while moving a joystick with the right hand. The patterns of CBF change obtained were compared with those in six age-matched control subjects. In the dystonia group, free selection of movement was associated with relative increases in rCBF above that observed in control subjects in the left premotor area, the supplementary motor area (SMA), the anterior cingulate cortex, and the left dorsolateral prefrontal area. Subcortical increases were observed within the cerebellum and the putamen. There was a relative decrease in flow through the contralateral primary sensorimotor cortex. These findings contrast with those reported in patients with Parkinson's disease undertaking the same task in which the activity in the SMA and putamen was decreased. We suggest that arm dystonia in ITD is associated with overactivity of the premotor areas, including the SMA, and that this results from release of the thalamus from the normal inhibitory influence of the globus pallidus internal segment. Other abnormalities of basal ganglia control of brain stem centers may be involved in axial dystonia.

Pathological diagnostic criteria for dementia associated with cortical Lewy bodies: review and proposal for a descriptive approach

In recent years dementia histologically characterised by the presence of cortical Lewy bodies has been increasingly recognised. There is now need for a scheme for an internationally acceptable scheme for pathological diagnosis and classification so that clinical, pathological and molecular features of disease can be correlated. Recent observations made by different groups in large patient series have used slightly different pathological criteria resulting in at least seven different diagnostic terms. In some patients the only cortical pathology is the presence of Lewy bodies, while in the majority of patients there are coexisting pathological changes which either overlap with those seen in Alzheimer's disease (AD). Cortical Lewy bodies can also be present in patients who do not have any obvious cognitive abnormality. A problem with equating studies from different groups is that different criteria have been used to define AD, so that establishing the relevance of cortical Lewy bodies themselves to cognitive decline and separating this from the contribution which may be related to the AD pathology is problematic. The lesions which appear to be of most relevance to potential cognitive decline in DLB are cortical Lewy bodies, Lewy-related neurites, senile plaques, neurofibrillary tangles, neuronal and synaptic loss, spongiform change, and cortical cholinergic deficits. It is possible to operationally classify patients with cognitive decline and cortical Lewy bodies into three main groups, Cortical Lewy body disease, Cortical Lewy body disease with plaques, and Cortical Lewy body disease with plaques and tangles. There are frequent cases which overlap these groups making operational classification difficult in practice. A descriptive classification, in which the severity of different pathological changes is rated, is easy to use in practice. As new molecular risk factors for AD or DLB are revealed they will need to be related to morphological and clinical features. A descriptive diagnostic assessment for DLB will facilitate such studies and makes no judgements as to what these relationships will be.

Dystonia and dyskinesia

Dystonia is defined as a syndrome of sustained muscle contractions, frequently causing twisting and repetitive movements, or abnormal postures. Tardive dyskinesia (TD), estimated to occur in 30% of patients treated with neuroleptics, encompasses a broad spectrum of hyperkinesias associated with exposure to these drugs. Dystonia is one of the most common expressions of tardive dyskinesia. This article aims to provide an overview of classification, phenomenology, epidemiology, genetics, pathophysiology, neuropsychologic aspects, and treatment of these two conditions.

Mosaic pattern of gliosis in the neostriatum of a North American man with craniocervical dystonia and parkinsonism

We present the case of a 51-year-old patient with a 31-year history of psychiatric symptoms, craniocervical dystonia, bulbar dysfunction, and parkinsonism. His dystonic movements included blepharospasm, jaw opening and lingual dystonia, and spasmodic retrocollis. Psychiatric symptoms included psychosis and depression, with onset years before the movement disorder. After his death by aspiration, examination of his brain revealed abnormalities limited to the neostriatum. Staining of brain sections, including Holzer, glial fibrillary acidic protein, and immunohistochemical stain for calbindin D28k, revealed the presence of a mosaic pattern of gliosis with neuronal loss (sparing large neurons) within this region. The islands of tissue between stands of gliosis had a normal appearance. This patient represents only the fourth case (and first North American born) with a mosaic pattern of gliosis in the neostriatum. The clinical and pathologic features were similar in all four cases except that our patient was the first with prominent psychiatric symptoms and a more stable, less progressive course. Mosaicism has been described in the X-linked Filipino disorder Lubag. Occurrence in non-Filipino patients, such as ours, suggest that either Lubag can develop in non-Filipino families or that mosaicism is a nonspecific pathologic finding in some patients with idiopathic dystonia. Finally, our case reports the notion that craniocervical dystonia may result from neostriatal dysfunction.

Saccadic eye movements in idiopathic blepharospasm

Visually guided saccades, memory-contingent saccades, and antisaccades were studied with an infra-red reflection technique in 12 patients with idiopathic blepharospasm and in controls. Latencies of the three kinds of saccades were prolonged. Peak velocities and gains did not differ. Our results indicate an initiation defect in the saccadic system, which may be localized in the caudate nucleus.

Orofacial dystonia and rest tremor in a patient with normal brain pathology

We report a patient with cranial dystonia who also had rest tremor of one arm and who developed drug-induced parkinsonism on treatment. The patient's brain was normal on autopsy. We also review the findings in the few reported cases of cranial dystonia with pathology.

A case of bilateral alternating hemifacial spasms

We report a 24-year old woman who developed bilateral hemifacial spasm alternating from one side to the other. The spasms followed a left peripheral facial palsy 2 years previously. This unusual type of bilateral hemifacial spasm was possibly due to lesions of multiple sclerosis in the brainstem.

Severe generalised dystonia associated with a mosaic pattern of striatal gliosis

A mosaic pattern of striatal pathology is described in a male who developed severe generalised dystonia from the age of 10 years, and died at the age of 18 years. There was no family history of dystonia, and extensive investigations during his life failed to identify a cause for the dystonia. The caudate nucleus and putamen showed a network of cell loss and gliosis surrounding islands of preserved striatum. Dorsal parts showed confluent gliosis, and ventral parts were spared. The pattern suggested a correlation with patch-matrix organisation, but there was no correlation with the distribution of calbindin immunoreactive cells, which are present in the matrix of the classical striosome-matrix organisation. The pathological findings were unlike those in status marmoratus, perinatal hypoxia-ischaemia, Huntington's disease, and neuroacanthocytosis, but similar to those reported in a 44-year-old man with predominantly cranial dystonia.

Ocular movements in essential blepharospasm

In essential blepharospasm histopathologic and electrophysiologic evidence supports the existence of lesions in proximity to brainstem nuclei controlling ocular movements. We studied horizontal ocular movements in eight patients who had been treated previously with surgery or botulinum toxin injection to control essential blepharospasm (mean age, 58 years) and compared these with seven control subjects who did not have blepharospasm (mean age, 68 years). We examined fixation stability, saccades, the vestibulo-ocular reflex, visual enhancement and suppression of the vestibulo-ocular reflex, optokinetic nystagmus, and pursuit by using digitally sampled, direct current electro-oculography. Patients with blepharospasm exhibited no ocular movement abnormalities. Since quantitative aspects of ocular movements are sensitive to nonspecific brainstem lesions, the absence of abnormal ocular movements suggests that the lesion in blepharospasm is specifically limited to neurons regulating the facial muscles.

Saccadic eye movements in essential blepharospasm

To provide evidence of an organic pathology for essential (idiopathic) blepharospasm, reflex saccadic eye movements in response to randomly stepped visual targets were assessed in seven affected patients and seven age-matched controls using the magnetic scleral search coil technique. The results indicate a significant prolongation in latency and a reduction in gain of horizontal saccades, and an increase in latency and reduction of peak velocity of large downward saccades. These findings suggest an organic component to the aetiology of blepharospasm, the pathology of which also appears to involve the oculomotor system. The pattern of the oculomotor disorder does not allow specific localisation but is consistent with the underlying pathology being localised in the basal ganglia.

Dyskinesia in the elderly presenting as respiratory disorder

Two elderly women suffering from dyskinesia affecting the respiratory muscles are described. The diagnosis was initially missed in both cases, and thought to be anxiety syndrome in one patient, and chronic obstructive airways disease in the other. Drug therapy further increased the severity of the dyskinetic movements which greatly improved when it was discontinued. Dyskinesia should be considered as the cause of respiratory disorder in old age, especially when this develops slowly in patients with movement disorders and a history of taking antidopaminergic drugs.