Delayed onset mixed involuntary movements after thalamic stroke: clinical, radiological and pathophysiological findings

Objective clinical registration of tremor, bradykinesia, and rigidity during awake stereotactic neurosurgery: a scoping review

Tremor, bradykinesia, and rigidity are incapacitating motor symptoms that can be suppressed with stereotactic neurosurgical treatment like deep brain stimulation (DBS) and ablative surgery (e.g., thalamotomy, pallidotomy). Traditionally, clinicians rely on clinical rating scales for intraoperative evaluation of these motor symptoms during awake stereotactic neurosurgery. However, these clinical scales have a relatively high inter-rater variability and rely on experienced raters. Therefore, objective registration (e.g., using movement sensors) is a reasonable extension for intraoperative assessment of tremor, bradykinesia, and rigidity. The main goal of this scoping review is to provide an overview of electronic motor measurements during awake stereotactic neurosurgery. The protocol was based on the PRISMA extension for scoping reviews. After a systematic database search (PubMed, Embase, and Web of Science), articles were screened for relevance. Hundred-and-three articles were subject to detailed screening. Key clinical and technical information was extracted. The inclusion criteria encompassed use of electronic motor measurements during stereotactic neurosurgery performed under local anesthesia. Twenty-three articles were included. These studies had various objectives, including correlating sensor-based outcome measures to clinical scores, identifying optimal DBS electrode positions, and translating clinical assessments to objective assessments. The studies were highly heterogeneous in device choice, sensor location, measurement protocol, design, outcome measures, and data analysis. This review shows that intraoperative quantification of motor symptoms is still limited by variable signal analysis techniques and lacking standardized measurement protocols. However, electronic motor measurements can complement visual evaluations and provide objective confirmation of correct placement of the DBS electrode and/or lesioning. On the long term, this might benefit patient outcomes and provide reliable outcome measures in scientific research.

Unilateral Myoclonus as an initial manifestation in Moyamoya disease with asymmetric vasculature

Movement disorders have been identified as a rare early manifestation of the Moyamoya disease. Herein, we present a case of a 34-year-old man with a genetically confirmed Moyamoya disease who showed unilateral myoclonus as an initial manifestation. Neuroimaging studies showed prominent asymmetrically developed Moyamoya disease on the right hemisphere with near-complete loss of normal vessels while the left hemisphere was adjunctively fed with extension of posterior cerebral artery: uneven progression of vasculature. ^99mTc-hexamethylpropylene amine oxime single-photon emission computed tomography demonstrated impaired vascular reserve. Electroencephalography showed occasional sharp waves on right temporal area. The phenomenon of this patient could be explained in the context of excitable cortex and hypoactive subcortical substrate that might imply putative contradictory neurobiology in Moyamoya disease.

Dystonic posturing with athetoid movements in stroke without thalamic lesion

Complex hyperkinetic movement disorders are a rare complication of stroke, frequently involving posterolateral contralateral thalamic lesions. One of the proposed mechanisms for these presentations is proprioceptive impairment, hence not involving deregulation of the basal ganglia-thalamocortical circuits. We report a patient who presented with dystonic posturing and athetoid movements with onset 2 years after right frontoparietotemporal stroke. Brain MRI showed no thalamic lesion. Based on the phenomenology, a diagnosis of pseudochoreoathetosis was proposed. To our knowledge, this is the first case report of poststroke pseudochoreoathetosis without thalamic involvement.

DDOST-CDG: Clinical and molecular characterization of a third patient with a milder and a predominantly movement disorder phenotype

Congenital disorders of glycosylation (CDG) are a group of heterogeneous inherited metabolic disorders affecting posttranslational protein modification. DDOST-CDG, caused by biallelic pathogenic variants in DDOST which encodes dolichyl-diphospho-oligosaccharide-protein glycosyltransferase, a subunit of N-glycosylation oligosaccharyltransferase (OST) complex, is an ultra-rare condition that has been described in two patients only. The main clinical features in the two reported patients include profound developmental delay, failure to thrive, and hypotonia. In addition, both patients had abnormal transferrin glycosylation. Here, we report an 18-year-old male who presented with moderate developmental delay, progressive opsoclonus, myoclonus, ataxia, tremor, and dystonia. Biochemical studies by carbohydrate deficient transferrin analysis showed a type I CDG pattern. Exome sequencing identified compound heterozygous variants in DDOST: a maternally inherited variant, c.1142dupT (p.Leu381Phefs*11), and a paternally inherited variant, c.661 T > C (p.Ser221Pro). Plasma N-glycan profiling showed mildly increased small high mannose glycans including Man0-5 GlcNAc2, a pattern consistent with what was previously reported in DDOST-CDG or defects in other subunits of OST complex. Western blot analysis on patient's fibroblasts revealed decreased expression of DDOST and reduced intracellular N-glycosylation, as evident by the biomarkers ICAM-1 and LAMP2. Our study highlights the clinical variability, expands the clinical and biochemical phenotypes, and describes new genotype, which all are essential for diagnosing and managing patients with DDOST-CDG.

Pseudochoreoathetosis secondary to progressive spondylotic cervical myelopathy

Pseudochoreoathetosis is a rare movement disorder associated with loss of proprioception. Culprit lesions may occur at any point between the cerebral cortex and the peripheral nerve. Seldom is the underlying cause reversible or prone to improvement. An elderly man presented to our tertiary centre with choreoathetoid movements secondary to spondylotic subaxial cervical myelopathy. His myelopathy fulminated and he was emergently treated with posterior decompressive neurosurgery. Unexpectedly, his choreoathetoid movements improved significantly post-operatively. There are a multitude of reports of pseudochoreoathetosis secondary to lesions of various aetiologies; however, few have reported this disorder secondary to cervical spondylosis. To our knowledge, there is only one other report in the medical literature. Herein, we report a second case, for the purposes of raising awareness of this disorder, and to highlight relevant clinical pearls for clinicians who encounter this rare pathology.

Post-stroke palatal tremor as a clinical predictor of dysphagia and its neuroanatomical correlates in patients with midbrain and pontine lesions

The precise associations between dysphagia and palatal tremor (PT) remain unknown. We aimed to identify the association between PT and dysphagia among patients with midbrain/pontine stroke, compare the characteristics of dysphagia between patients with PT (PT + dysphagia) and without PT (PT- dysphagia), and verify neuroanatomical predictors of PT + dysphagia in this patient population. This retrospective observational study enrolled 40 patients (34 males, 6 females; mean age: 95% confidence interval [CI], 56.6 ± 14.6 years) with first-ever midbrain or pontine stroke exhibiting brain stem lesions admitted to the stroke unit of a single rehabilitation hospital between January 2010 and April 2020. Main outcome measures included dysphagia and aspiration rates and videofluoroscopic swallowing study findings. Lesion localization was stratified according to established vascular territories. Associations between PT and dysphagia and lesion location according to PT and dysphagia were analyzed. Dysphagia and aspiration rates were greater among patients with PT than among those without PT (95% CI, p = 0.030 and p = 0.017, respectively). The proportion of patients exhibiting oral stage impairment (95% CI, p = 0.007) was greater in the PT + dysphagia group than in the PT- dysphagia group. The posterolateral portion of the midbrain and pons (95% CI, p = 0.001 and p < 0.001, respectively) were the lesions more often involved in the PT + dysphagia group. Patients with PT following midbrain/pontine stroke more frequently present with dysphagia than those without PT. Thus, they should be carefully examined for PT and delayed dysphagia, including oral stage impairment, if initial brain images show posterolateral midbrain and pons lesions.

Post-stroke Movement Disorders: Clinical Spectrum, Pathogenesis, and Management

Involuntary movements develop after 1-4% of strokes and they have been reported in patients with ischemic and hemorrhagic strokes affecting the basal ganglia, thalamus, and/or their connections. Hemichorea-hemiballism is the most common movement disorder following a stroke in adults while dystonia is most common in children. Tremor, myoclonus, asterixis, stereotypies, and vascular parkinsonism are other movement disorders seen following stroke. Some of them occur immediately after acute stroke, some can develop later, and others may have delayed onset progressive course. Proposed pathophysiological mechanisms include neuronal plasticity, functional diaschisis, and age-related differences in brain metabolism. There are no guidelines regarding the management of post-stroke movement disorders, mainly because of their heterogeneity.

Thalamic versus midbrain tremor; two distinct types of Holmes' Tremor: a review of 17 cases

INTRODUCTION

Holmes Tremor (HT) is a unique and debilitating movement disorder. It usually results from lesions of the midbrain and its connection but can also result from posterior thalamic injury. Clinical examination can help lesion localization between these two areas. We studied the clinical features and their radiological correlations to distinguish midbrain HT (HT-m) from thalamic HT (HT-t).

METHODS

Retrospective review of 17 patients with a HT-type presentation was conducted. Tremor characteristics, associated clinical signs and radiological findings were studied.

RESULTS

Eleven patients had a myorythmic rest tremor, large amplitude proximal tremor with goal-directed worsening, with or without mild distal dystonic posturing, representing HT-m. Six patients had slow, large amplitude proximal tremors and distal choreathetoid movements, significant proximal/distal dystonic posturing, associated with proprioceptive sensory loss, representing HT-t. Haemorrhagic lesions were the predominant cause of HT-m; whereas, ischaemia was more commonly associated with HT-t.

CONCLUSION

When assessing patients with HT, attentiveness to the presence of associated signs in the affected limb, such as a proprioceptive sensory deficits and additional movement disorders, can aid lesion localisation, which can have implications for management.

Impact of early intervention with onabotulinumtoxinA treatment in adult patients with post-stroke lower limb spasticity: results from the double-blind, placebo-controlled, phase 3 REFLEX study

The aim of this study in patients with post-stroke lower limb spasticity (PSLLS) was to evaluate the relationship between time of onabotulinumtoxinA treatment relative to stroke and efficacy outcomes. This was a phase 3, international, multicenter, randomized, 12-week, double-blind study, followed by a repeated treatment, open-label extension. Patients were aged 18–85 years with PSLLS (Modified Ashworth Scale [MAS] ≥ 3) of the ankle with the most recent stroke occurring ≥ 3 months before screening. Patients (double-blind phase) were randomized (n = 468) to onabotulinumtoxinA 300–400 U (300 U, mandatory ankle muscles (gastrocnemius, soleus, tibialis posterior); and ≤ 100 U, optional lower limb muscles (flexor digitorum longus, flexor hallucis longus, flexor digitorum brevis, extensor hallucis, and rectus femoris]) or placebo. Primary endpoint: MAS change from baseline (average score of weeks 4 and 6). Secondary endpoints: physician-assessed Clinical Global Impression of Change (CGI) average score of weeks 4 and 6 and physician-assessed Goal Attainment Scale (GAS; active and passive, weeks 8 and 12). When stratified by time since stroke (≤ 24 months, n = 153; > 24 months, n = 315, post hoc), patients treated ≤ 24 months post-stroke experienced greater improvements from baseline versus placebo in MAS (− 0.31 vs − 0.17), CGI (0.49 vs 0.12), and passive GAS scores (week 12, 0.37 vs 0.26). A ≥  − 1-point improvement in active (week 12; p = 0.04) and passive (week 8; p = 0.02) GAS scores versus placebo was achieved by more patients treated ≤ 24 months post-stroke; in patients treated > 24 months post-stroke, improvements were only observed in active scores (week 8; p = 0.04). OnabotulinumtoxinA 300–400 U was well tolerated, with no new safety findings.

A data-driven framework for selecting and validating digital health metrics: use-case in neurological sensorimotor impairments

Digital health metrics promise to advance the understanding of impaired body functions, for example in neurological disorders. However, their clinical integration is challenged by an insufficient validation of the many existing and often abstract metrics. Here, we propose a data-driven framework to select and validate a clinically relevant core set of digital health metrics extracted from a technology-aided assessment. As an exemplary use-case, the framework is applied to the Virtual Peg Insertion Test (VPIT), a technology-aided assessment of upper limb sensorimotor impairments. The framework builds on a use-case-specific pathophysiological motivation of metrics, models demographic confounds, and evaluates the most important clinimetric properties (discriminant validity, structural validity, reliability, measurement error, learning effects). Applied to 77 metrics of the VPIT collected from 120 neurologically intact and 89 affected individuals, the framework allowed selecting 10 clinically relevant core metrics. These assessed the severity of multiple sensorimotor impairments in a valid, reliable, and informative manner. These metrics provided added clinical value by detecting impairments in neurological subjects that did not show any deficits according to conventional scales, and by covering sensorimotor impairments of the arm and hand with a single assessment. The proposed framework provides a transparent, step-by-step selection procedure based on clinically relevant evidence. This creates an interesting alternative to established selection algorithms that optimize mathematical loss functions and are not always intuitive to retrace. This could help addressing the insufficient clinical integration of digital health metrics. For the VPIT, it allowed establishing validated core metrics, paving the way for their integration into neurorehabilitation trials.

Poststroke Parkinsonism associates with an increased mortality risk in patients

Background

To determine whether poststroke Parkinsonism (PSP) increases mortality risk in poststroke patients by using Taiwan National Health Insurance Research Database (NHIRD).

Methods

We analyzed NHIRD data of ≥40-year-old patients diagnosed as having stroke [International Classification of Disease, Ninth Revision, Clinical Modification (ICD-9-CM) codes 430-438] between 2000 and 2013. Poststroke patients were divided into those with subsequent PSP (ICD-9-CM codes 332, 332.0, and 332.1) and without PSP (non-Parkinsonism, PSN) cohorts, all compared with a sex-, age-, comorbidity-, and index date-matched comparison cohort. We calculated adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) of all-cause mortality risk in these cohorts after adjustments for age, sex, and comorbidities.

Results

PSP was noted in 11.87% (1,644/13,846) of poststroke patients. In the PSN, PSP, and comparison cohorts, mortality incidence rates were 69.1, 124.9, and 38.8 per 1,000 person-years, respectively. Compared with the comparison cohort, the mortality risks in patients aged 40 to 64, 65 to 74, and ≥75 years were respectively 2.21-, 1.91-, and 1.86-fold higher mortality risks in the PSN cohort and 4.57-, 2.84-, and 2.27-fold higher mortality risks in the PSP cohort. Male sex further increased mortality risk in poststroke patients with PSP.

Conclusions

Long-term all-cause mortality risk is increased by 1.39 times in poststroke patients with PSP than in those without. Our findings depict vital information in incidence and risk of PSP. Those would aid clinicians and the government to improve future poststroke care.

Pseudodystonia: A new perspective on an old phenomenon

Pseudodystonia represents a wide range of conditions that mimic dystonia, including disorders of the peripheral nervous system, spinal cord, brainstem, thalamus, cortex and non-neurological conditions such as musculoskeletal diseases. Here, we propose a definition of pseudodystonia and suggest a classification based on underlying pathophysiological mechanisms. We describe phenomenology of different forms of pseudodystonia and point to distinctions between dystonia and pseudodystonia as well as challenging issues that may arise in clinical practice. The term pseudodystonia can be used to describe abnormal postures, repetitive movements or both, in which results of clinical, imaging, laboratory or electrophysiological investigations provide definite explanation of symptoms which is not compatible with dystonia. Pseudodystonia can be classified into non-neurological disorders of the musculoskeletal system, disorders of sensory pathways, disorders of motor pathways and compensatory postures in other neurological diseases. Presence of associated neurological findings in the affected body part is the key towards diagnosis of pseudodystonia. Additional supporting features are the presence of fixed postures, the absence of sensory trick, acute mode of onset and severe pain. Worsening on eye closure, traditionally considered typical for pseudodystonia, is not always present and can also appear in dystonia. It is challenging to separate dystonia and pseudodystonia in patients with thalamic lesions or corticobasal syndrome, where abnormal postures coexist with sensory loss. Many cases of pseudodystonia are treatable. Therefore, it is essential to consider pseudodystonia in a differential diagnosis of abnormal postures until a detailed neurological examination rules it out.

Post-Thalamic Stroke Movement Disorders: A Systematic Review

BACKGROUND

After a stroke, movement disorders are rare manifestations mainly affecting the deep structures of the brain like the basal ganglia (44%) and thalamus (37%), although there have been case studies of movement disorders in strokes affecting the cerebral cortex also.

SUMMARY

This review aims to delineate the various movement disorders seen in association with thalamic strokes and tries to identify the location of the nuclei affected in each of the described movement disorders. Cases were identified through a search of PubMed database using different search terms related to post-thalamic stroke movement disorders and a secondary search of references of identified articles. We reviewed 2,520 research articles and only 86 papers met the inclusion criteria. Cases were included if they met criteria for post-thalamic stroke movement disorders. Case-cohort studies were also reviewed and will be discussed further. Key Messages: The most common post-stroke abnormal movement disorder reported in our review was dystonia followed by hemiataxia. There was a higher association between ischaemic stroke and movement disorder. Acute onset movement disorders were more common than delayed. The posterolateral thalamus was most commonly involved in post-thalamic stroke movement disorders.

Post-stroke Movement Disorders: The Clinical, Neuroanatomic, and Demographic Portrait of 284 Published Cases

PURPOSE

Abnormal movements are a relatively uncommon complication of strokes. Besides the known correlation between stroke location and certain movement disorders, there remain uncertainties about the collective effects of age and stroke mechanism on phenomenology, onset latency, and outcome of abnormal movements.

MATERIALS AND METHODS

We systematically reviewed all published cases and case series with adequate clinical-imaging correlations. A total of 284 cases were analyzed to evaluate the distribution of different movement disorders and their association with important cofactors.

RESULTS

Posterolateral thalamus was the most common region affected (22.5%) and dystonia the most commonly reported movement disorder (23.2%). The most common disorders were parkinsonism (17.4%) and chorea (17.4%) after ischemic strokes and dystonia (45.5%) and tremor (19.7%) after hemorrhagic strokes. Strokes in the caudate and putamen were complicated by dystonia in one third of the cases; strokes in the globus pallidus were followed by parkinsonism in nearly 40%. Chorea was the earliest poststroke movement disorder, appearing within hours, whereas dystonia and tremor manifested several months after stroke. Hemorrhagic strokes were responsible for most delayed-onset movement disorders (>6 months) and were particularly overrepresented among younger individuals affected by dystonia.

CONCLUSIONS

This evidence-mapping portrait of poststroke movement disorders will require validation or correction based on a prospective epidemiologic study. We hypothesize that selective network vulnerability and resilience may explain the differences observed in movement phenomenology and outcomes after stroke.

Consensus Statement on the classification of tremors. from the task force on tremor of the International Parkinson and Movement Disorder Society

BACKGROUND

Consensus criteria for classifying tremor disorders were published by the International Parkinson and Movement Disorder Society in 1998. Subsequent advances with regard to essential tremor, tremor associated with dystonia, and other monosymptomatic and indeterminate tremors make a significant revision necessary.

OBJECTIVES

Convene an international panel of experienced investigators to review the definition and classification of tremor.

METHODS

Computerized MEDLINE searches in January 2013 and 2015 were conducted using a combination of text words and MeSH terms: "tremor", "tremor disorders", "essential tremor", "dystonic tremor", and "classification" limited to human studies. Agreement was obtained using consensus development methodology during four in-person meetings, two teleconferences, and numerous manuscript reviews.

RESULTS

Tremor is defined as an involuntary, rhythmic, oscillatory movement of a body part and is classified along two axes: Axis 1-clinical characteristics, including historical features (age at onset, family history, and temporal evolution), tremor characteristics (body distribution, activation condition), associated signs (systemic, neurological), and laboratory tests (electrophysiology, imaging); and Axis 2-etiology (acquired, genetic, or idiopathic). Tremor syndromes, consisting of either isolated tremor or tremor combined with other clinical features, are defined within Axis 1. This classification scheme retains the currently accepted tremor syndromes, including essential tremor, and provides a framework for defining new syndromes.

CONCLUSIONS

This approach should be particularly useful in elucidating isolated tremor syndromes and syndromes consisting of tremor and other signs of uncertain significance. Consistently defined Axis 1 syndromes are needed to facilitate the elucidation of specific etiologies in Axis 2. © 2017 International Parkinson and Movement Disorder Society.

Pathological ponto-cerebello-thalamo-cortical activations in primary orthostatic tremor during lying and stance

Primary orthostatic tremor is a rare neurological disease characterized mainly by a high frequency tremor of the legs while standing. The aim of this study was to identify the common core structures of the oscillatory circuit in orthostatic tremor and how it is modulated by changes of body position. Ten patients with orthostatic tremor and 10 healthy age-matched control subjects underwent a standardized neurological and neuro-ophthalmological examination including electromyographic and posturographic recordings. Task-dependent changes of cerebral glucose metabolism during lying and standing were measured in all subjects by sequential ¹⁸F-fluorodeoxyglucose-positron emission tomography on separate days. Results were compared between groups and conditions. All the orthostatic tremor patients, but no control subject, showed the characteristic 13-18 Hz tremor in coherent muscles during standing, which ceased in the supine position. While lying, patients had a significantly increased regional cerebral glucose metabolism in the pontine tegmentum, the posterior cerebellum (including the dentate nuclei), the ventral intermediate and ventral posterolateral nucleus of the thalamus, and the primary motor cortex bilaterally compared to controls. Similar glucose metabolism changes occurred with clinical manifestation of the tremor during standing. The glucose metabolism was relatively decreased in mesiofrontal cortical areas (i.e. the medial prefrontal cortex, supplementary motor area and anterior cingulate cortex) and the bilateral anterior insula in orthostatic tremor patients while lying and standing. The mesiofrontal hypometabolism correlated with increased body sway in posturography. This study confirms and further elucidates ponto-cerebello-thalamo-primary motor cortical activations underlying primary orthostatic tremor, which presented consistently in a group of patients. Compared to other tremor disorders one characteristic feature in orthostatic tremor seems to be the involvement of the pontine tegmentum in the pathophysiology of tremor generation. High frequency oscillatory properties of pontine tegmental neurons have been reported in pathological oscillatory eye movements. It is remarkable that the characteristic activation and deactivation pattern in orthostatic tremor is already present in the supine position without tremor presentation. Multilevel changes of neuronal excitability during upright stance may trigger activation of the orthostatic tremor network. Based on the functional imaging data described in this study, it is hypothesized that a mesiofrontal deactivation is another characteristic feature of orthostatic tremor and plays a pivotal role in development of postural unsteadiness during prolonged standing.

Cerebral Venous Thrombosis in the Superior Sagittal Sinus as a Rare Cause of a Paroxysmal Kinetic Tremor

Cerebral venous thrombosis (CVT) has a broad spectrum of clinical presentation compared to arterial etiology. Seizure is one of the common symptoms and is more frequent than in other stroke types. Hence, transient neurological symptoms in CVT patients are usually due to epileptic seizures, while transient repetitive movement disorder is extremely rare except as a complication of epilepsy. We report a case of CVT in the superior sagittal sinus with a 1-year history of paroxysmal kinetic tremor without evident epilepsy.

Functional Neuroimaging in Stroke Recovery and Neurorehabilitation: Conceptual Issues and Perspectives

Background

In stroke, functional neuroimaging has become a potent diagnostic tool; opened new insights into the pathophysiology of ischaemic damage in the human brain; and made possible the assessment of functional–structural relationships in postlesion recovery.

Summary of review

Here, we give a critical account on the potential and limitation of functional neuroimaging and discuss concepts related to the use of neuroimaging for exploring the neurobiological and neuroanatomical mechanisms of poststroke recovery and neurorehabilitation. We identify and provide evidence for five hypotheses that functional neuroimaging can provide new insights into: adaptation occurs at the level of functional brain systems; the brain–behaviour relationship varies with recovery and over time; functional neuroimaging can improve our ability to predict recovery and select individuals for rehabilitation; mechanisms of recovery reflect different pathophysiological phases; and brain adaptation may be modulated by experience and specific rehabilitation. The significance and application of this new evidence is discussed, and recommendations made for investigations in the field.

Conclusion

Functional neuroimaging is an important tool to explore the mechanisms underlying brain plasticity and, thereby, to guide clinical research in neurorehabilitation.

Movement Disorders Following Cerebrovascular Lesions: Etiology, Treatment Options and Prognosis

Post-stroke movement disorders are uncommon, but comprise an important part of secondary movement disorders. These exert variable and heterogeneous clinical courses according to the stroke lesion and its temporal relationships. Moreover, the predominant stroke symptoms hinder a proper diagnosis in clinical practice. This article describes the etiology, treatment options and prognosis of post-stroke movement disorders.

Movement Disorders Following Cerebrovascular Lesions in Cerebellar Circuits

Cerebellar circuitry is important to controlling and modifying motor activity. It conducts the coordination and correction of errors in muscle contractions during active movements. Therefore, cerebrovascular lesions of the cerebellum or its pathways can cause diverse movement disorders, such as action tremor, Holmes’ tremor, palatal tremor, asterixis, and dystonia. The pathophysiology of abnormal movements after stroke remains poorly understood. However, due to the current advances in functional neuroimaging, it has recently been described as changes in functional brain networks. This review describes the clinical features and pathophysiological mechanisms in different types of movement disorders following cerebrovascular lesions in the cerebellar circuits.

Movement Disorders Following Cerebrovascular Lesion in the Basal Ganglia Circuit

Movement disorders are primarily associated with the basal ganglia and the thalamus; therefore, movement disorders are more frequently manifest after stroke compared with neurological injuries associated with other structures of the brain. Overall clinical features, such as types of movement disorder, the time of onset and prognosis, are similar with movement disorders after stroke in other structures. Dystonia and chorea are commonly occurring post-stroke movement disorders in basal ganglia circuit, and these disorders rarely present with tremor. Rarer movement disorders, including tic, restless leg syndrome, and blepharospasm, can also develop following a stroke. Although the precise mechanisms underlying the pathogenesis of these conditions have not been fully characterized, disruptions in the crosstalk between the inhibitory and excitatory circuits resulting from vascular insult are proposed to be the underlying cause. The GABA (gamma-aminobutyric acid)ergic and dopaminergic systems play key roles in post-stroke movement disorders. This review summarizes movement disorders induced by basal ganglia and thalamic stroke according to the anatomical regions in which they manifest.

Post-stroke dyskinesias

Strokes, whether ischemic or hemorrhagic, are among the most common causes of secondary movement disorders in elderly patients. Stroke-related (vascular) movement disorders, however, are uncommon complications of this relatively common disease. The spectrum of post-stroke movement disorders is broad and includes both hypo- and hyperkinetic syndromes. Post-stroke dyskinesias are involuntary hyperkinetic movements arising from cerebrovascular insults and often present with mixed phenotypes of hyperkinesia which can sometimes be difficult to classify. Nevertheless, identification of the most relevant motor phenotype, whenever possible, allows for a more specific phenomenological categorization of the dyskinesia and thus helps guide its treatment. Fortunately, post-stroke dyskinesias are usually self-limiting and resolve within 6 to 12 months of onset, but a short-term pharmacotherapy might sometimes be required for symptom control. Functional neurosurgical interventions targeting the motor thalamus or globus pallidus interna might be considered for patients with severe, disabling, and persistent dyskinesias (arbitrarily defined as duration longer than 12 months).

A rare case of movement disorder in Intensive Care Unit

Hemichorea-hemiballismus syndrome (HCHB represents a peculiar form of hyperkinetic movement disorder with varying degrees of chorea and/or ballistic movements on one side of body. The patients are conscious of their environment but unable to control the movements. HCHB is a rare occurrence in acute stroke patients. Patients with sub-cortical strokes are more prone to develop movement disorders than with cortical stroke. We report one such interesting case here posing difficulties in management and intensive care of the patient. The patient remained refractory to all the drugs described in literature, and adequate control of the hyperkinetic movements could be achieved only with continuous intravenous sedation.

Multiple variant type thalamic infarcts: pure and combined types

BACKGROUND AND PURPOSE

Variant topographic patterns of thalamic infarction with distinct manifestations have been classified into three territories: anteromedian, central, and posterolateral. The purpose of this study was to determine clinical, etiological, and radiological features of multiple variant thalamic infarcts.

METHODS

We reviewed 8400 patients with a first clinical stroke included in the Ege Stroke Registry between 2000 and 2013. Among 80 patients with an acute multiple thalamic infarcts confirmed by MRI, we selected all patients with lesions outside the classical territories and studied their clinical, etiological, and radiological features.

RESULTS

Among 8400 patients with first-ever stroke in our registry, 21 patients (26% of all multiple thalamic infarcts) showed infarction outside the classical territories, allowing us to delineate three variant distributions; (i) unilateral multiple variant infarcts [seven patients (9%) in the anteromedian, central, and posterolateral territories] presented with predominantly decreased vigilance (66% with right lesions, 75% with left lesions), cognitive impairment including amnesia (71%), aphasia (57%) in left-sided or bilateral lesions, and executive dysfunction (43%). The most frequent stroke mechanism was cardioembolism (43%). (ii) Bilateral multiple variant infarcts [five patients (6%)], with lesions on the variant territories of the thalamus, resulting in a variety of neurological and neuropsychological signs, consciousness disturbances (80%), sensory-motor deficits (80%). Cardioembolism (60%) was the most frequent etiology. (iii) Combined multiple variant and classical infarcts [nine patients (11%)], characterized by hemihypesthesia (89%) as the most frequent manifestation, followed by hemiataxia (78%), and cognitive deficits. Cardioembolism (56%) and large-artery disease of the vertebrobasilar system (33%) were the main stroke mechanisms.

CONCLUSIONS

We described multiple variant topographic patterns of thalamic infarction with distinct manifestations and etiologies. We thought that multiple variant infarcts are the result of variation in thalamic arterial supply or reflect a source of embolism.

The anatomical basis of dystonia: current view using neuroimaging

This review will consider the knowledge that neuroimaging studies have provided to the understanding of the anatomy of dystonia. Major advances have occurred in the use of neuroimaging for dystonia in the past 2 decades. At present, the most developed imaging approaches include whole-brain or region-specific studies of structural or diffusion changes, functional imaging using fMRI or positron emission tomography (PET), and metabolic imaging using fluorodeoxyglucose PET. These techniques have provided evidence that regions other than the basal ganglia are involved in dystonia. In particular, there is increasing evidence that primary dystonia can be viewed as a circuit disorder, involving the basal ganglia-thalamo-cortical and cerebello-thalamo-cortical pathways. This suggests that a better understanding of the dysfunction in each region in the network and their interactions are important topics to address. Current views of interpretation of imaging data as cause or consequence of dystonia, and the postmortem correlates of imaging data are presented. The application of imaging as a tool to monitor therapy and its use as an outcome measure will be discussed. © 2013 Movement Disorder Society.

Dystonia as a network disorder: what is the role of the cerebellum?

The dystonias are a group of disorders defined by sustained or intermittent muscle contractions that result in involuntary posturing or repetitive movements. There are many different clinical manifestations and causes. Although they traditionally have been ascribed to dysfunction of the basal ganglia, recent evidence has suggested dysfunction may originate from other regions, particularly the cerebellum. This recent evidence has led to an emerging view that dystonia is a network disorder that involves multiple brain regions. The new network model for the pathogenesis of dystonia has raised many questions, particularly regarding the role of the cerebellum. For example, if dystonia may arise from cerebellar dysfunction, then why are there no cerebellar signs in dystonia? Why are focal cerebellar lesions or degenerative cerebellar disorders more commonly associated with ataxia rather than dystonia? Why is dystonia more commonly associated with basal ganglia lesions rather than cerebellar lesions? Can answers obtained from animals be extrapolated to humans? Is there any evidence that the cerebellum is not involved? Finally, what is the practical value of this new model of pathogenesis for the neuroscientist and clinician? This article explores potential answers to these questions.

Secondary blepharospasm associated with structural lesions of the brain

BACKGROUND

Blepharospasm is a form of focal dystonia that manifests as repetitive involuntary closure of the eyes. The pathogenesis of blepharospasm and the neuroanatomic substrates involved are not fully understood. Dysfunction of the basal ganglia traditionally is presumed to be the main cause of most forms of dystonia, but a growing body of evidence suggests that a network of additional cortical and subcortical structures may be involved.

METHODS

The medical records of 1114 patients with blepharospasm seen over past 10 years at Emory University were reviewed to identify potentially contributing brain lesions. A systematic review of the published literature was also conducted to identify potentially contributing brain lesions.

RESULTS

Among patients with blepharospasm at Emory University, 18 had focal lesions on imaging studies available for review. The literature review revealed 25 articles describing 30 additional cases of blepharospasm associated with focal lesions. Among all 48 cases, lesions were found in multiple regions including the thalamus (n=12), lower brainstem (n=11), basal ganglia (n=9), cerebellum (n=9), midbrain (n=7), and cortex (n=1).

CONCLUSIONS

These data in combination with functional imaging studies of primary blepharospasm support a model in which a network of different regions plays a role in the pathogenesis of blepharospasm.

Movement disorders in cerebrovascular disease

Movement disorders can occur as primary (idiopathic) or genetic disease, as a manifestation of an underlying neurodegenerative disorder, or secondary to a wide range of neurological or systemic diseases. Cerebrovascular diseases represent up to 22% of secondary movement disorders, and involuntary movements develop after 1-4% of strokes. Post-stroke movement disorders can manifest in parkinsonism or a wide range of hyperkinetic movement disorders including chorea, ballism, athetosis, dystonia, tremor, myoclonus, stereotypies, and akathisia. Some of these disorders occur immediately after acute stroke, whereas others can develop later, and yet others represent delayed-onset progressive movement disorders. These movement disorders have been encountered in patients with ischaemic and haemorrhagic strokes, subarachnoid haemorrhage, cerebrovascular malformations, and dural arteriovenous fistula affecting the basal ganglia, their connections, or both.

Dual treatment of hemichorea-hemiballismus syndrome with tetrabenazine and chemodenervation

BACKGROUND

Hemichorea-hemiballismus involves unilateral involuntary flailing movements and random jerking movements involving proximal or distal muscles. We describe a case of hemichorea-hemiballismus with dystonia after stroke. Treatment with tetrabenazine and chemodenervation produced beneficial responses. Effective treatment of both hemichorea-hemiballismus and dystonia due to stroke has not been reported.

CASE REPORT

A 65-year-old male developed left hemichorea-hemiballismus and dystonia after a right hemisphere stroke. He underwent initial treatment with neuroleptics and anticonvulsants without improvement. Subsequent treatment with tetrabenazine improved the hemichorea-hemiballismus and chemodenervation reduced the dystonia.

DISCUSSION

Hemichorea-hemiballismus associated with dystonia can be improved with both tetrabenazine and chemodenervation.

Pure hemi-chorea resulting from an acute phase of contralateral thalamic lacunar infarction: a case report

Background

Thalamic lesions give rise to a variety of clinical syndromes such as pure sensory stroke, ataxic hemiparesis, and rarely involuntary movements including chorea. Generally and classically, lacunar infarction in the subthalamic nucleus has been regarded as the lesion mainly responsible for hemi-chorea and hemi-ballismus, on the basis of previous anatomical studies.

Case Presentation

This report describes the case of an 81-year-old man who developed sudden-onset pure hemi-chorea in the right limbs resulting from an acute phase of left thalamic lacunar infarction detected on a diffusion-weighted image (DWI) in an MRI study. The patient had no other neurological symptoms such as ataxic hemiparesis and sensory disturbance. A single-photon emission computed tomography (SPECT) study using the ^99mTc-ECD Patlak plot method demonstrated significant perfusional asymmetry between the right and left thalami (p = 0.0035), consistent with the left thalamic lesion on DWI.

Conclusion

It is speculated that this perfusional asymmetry, in particular the hypoperfusion in the left thalamus, detected by SPECT might play the most important role in the contralateral pure hemi-chorea as a rare neurological manifestation in this case.

Post-stroke Movement Disorders: Clinical Manifestations and Pharmacological Management

Involuntary abnormal movements have been reported after ischaemic and haemorrhagic stroke. Post stroke movement disorders can appear as acute or delayed sequel. At the moment, for many of these disorders the knowledge of pharmacological treatment is still inadequate. Dopaminergic and GABAergic systems may be mainly involved in post-stroke movement disorders. This article provides a review on drugs commonly used in post-stroke movement disorders, given that some post-stroke movement disorders have shown a partial benefit with pharmacological approach.

The phenomenology of parkinsonian tremor

The definition of Parkinsonian tremor covers all different forms occurring in Parkinson's disease. The most common form is rest tremor, labelled as typical Parkinsonian tremor. Other variants cover also postural and action tremors. Data support the notion that suppression of rest tremor may be more specific for PD tremors. Several differential diagnoses like rest tremor in ET, dystonic tremor, psychogenic tremor and Holmes' tremor may be misinterpreted as PD-tremor. Tests and clinical clues to separate them are presented.

Movement disorders after stroke in adults: a review

Background

Movement disorders occur in association with stroke and may have important clinical implications.

Methods

We reviewed the medical literature regarding the clinical phenomenology, prevalence, localization and etiologic implications, and treatments for movement disorders occurring after stroke in adult patients.

Results

Movement disorders occur uncommonly after stroke and include both hyperkinetic and parkinsonian conditions. They can occur at the time of stroke or appear as a later manifestation. Stroke lesions are typically due to small vessel cerebrovascular disease in the middle or posterior cerebral artery territory, vessels supplying the basal ganglia. Hemorrhagic lesions are more likely to induce hyperkinetic movements. Movement disorders in the setting of stroke tend to resolve spontaneously over time. Medical and surgical therapies are available to treat the movement problems.

Discussion

Movement disorders after stroke can be helpful in localizing lesions after stroke, determining the etiology of stroke, may need to be a target for therapy and may importantly influence long term outcome.

Milestones in tremor research

Tremor is one of the most frequent movement disorders and covers a wide spectrum of entities summarized in the 1998 consensus statement of the Movement Disorder Society. Essential tremor and Parkinson tremor are most common and are also the most thoroughly studied. Major progress has occurred in the clinical semiology, neuroimaging, epidemiology, and pathophysiology of tremors. Pathology and genetic research are rapidly growing fields of study. Recently described tremor entities include orthostatic tremor, dystonic tremor, cortical tremor, and thalamic tremor. Treatment research methodology has improved substantially, but few double-blind controlled trials have been published. Deep brain stimulation is the most effective treatment for most tremors but is reserved for advanced cases.

Atypical presentations of acute cerebrovascular syndromes

Correct diagnosis of acute stroke is of paramount importance to clinicians to enable selection of correct treatments and to ensure prevention of acute complications, including recurrent stroke. Timely diagnosis can be difficult in some cases because patients with acute stroke can present with atypical or uncommon symptoms that suggest another cause altogether. Publications on these patients suggest that the following strategies could help to reduce misdiagnosis. First, clinicians should suspect stroke in any patient with abrupt onset of neurological symptoms. Second, clinicians should be aware that some patients will initially present with various uncommon and atypical stroke symptoms. Third, a complete and systematic neurological examination should be routinely done in patients presenting with acute neurological symptoms because this might shed light on the true nature of the problem. Finally, clinicians should be aware that even with the most sophisticated neuroimaging tests, stroke might be missed in the early hours after the event.