Stereotypy after cerebellar infarction

Cilostazol attenuated prenatal valproic acid-induced behavioural and biochemical deficits in a rat model of autism spectrum disorder

OBJECTIVES

Autism spectrum disorder (ASD) is categorized as a neurodevelopmental disorder, presenting with a variety of aetiological and phenotypical features. Inhibiting the enzyme phosphodiesterase-3 (PDE3) with cilostazol is known to produce beneficial effects in several brain disorders. The pharmacological outcome of cilostazol administration was investigated in prenatal valproic acid (VPA)-induced ASD deficits in albino Wistar rats.

METHODS

Cilostazol was administered in two doses (30/60 mg/kg) to male rats born of females administered with VPA on gestational day 12. Behavioural assays on locomotion (open field), social interaction, repetitive behaviour (y-maze) and anxiety (elevated plus maze) were performed in all groups. Further, biochemical assessments of markers associated with neuronal function (BDNF, pCREB), inflammation (TNF-α, IL-6, IL-10) and oxidative stress were carried out in frontal cortex, hippocampus, striatum and cerebellum.

KEY FINDINGS

The cilostazol regimen, attenuated prenatal VPA exposure associated hyperlocomotion, social interaction deficits, repetitive behavior, and anxiety. Further, biochemical markers such as BDNF, pCREB, IL-10 and GSH were found to be significantly increased contrary to markers such as TNF-α, IL-6 and TBARS in the assessed brain regions.

CONCLUSIONS

Cilostazol rectified core behavioural traits while producing significant changes to biochemistry in the brain, suggesting benefits of cilostazol administration in experimental models of ASD.

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.

The neural circuitry of restricted repetitive behavior: Magnetic resonance imaging in neurodevelopmental disorders and animal models

Restricted, repetitive behaviors (RRBs) are patterns of behavior that exhibit little variation in form and have no obvious function. RRBs although transdiagonstic are a particularly prominent feature of certain neurodevelopmental disorders, yet relatively little is known about the neural circuitry of RRBs. Past work in this area has focused on isolated brain regions and neurotransmitter systems, but implementing a neural circuit approach has the potential to greatly improve understanding of RRBs. Magnetic resonance imaging (MRI) is well-suited to studying the structural and functional connectivity of the nervous system, and is a highly translational research tool. In this review, we synthesize MRI research from both neurodevelopmental disorders and relevant animal models that informs the neural circuitry of RRB. Together, these studies implicate distributed neural circuits between the cortex, basal ganglia, and cerebellum. Despite progress in neuroimaging of RRB, there are many opportunities for conceptual and methodological improvement. We conclude by suggesting future directions for MRI research in RRB, and how such studies can benefit from complementary approaches in neuroscience.

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.

Punding following posterior cerebral artery infarction: a case report and literature review

INTRODUCTION

Punding is a complex stereotyped behavior, characterized by excessiveness, non-goal orientation, and repetitiveness. It is mostly associated with Parkinson's disease, and very few cases in non-Parkinson's disease have been reported. We report a case of punding associated with supratentorial ischemic stroke.

CASE PRESENTATION

We present a 70-year-old man with left posterior cerebral artery infarction with quetiapine-induced punding manifesting as repetitive unidirectional body turning. Remission of punding behavior ensued after cessation of quetiapine and administration of clonazepam.

CONCLUSION

This case describes the clinical course of quetiapine-induced punding in a patient with left posterior cerebral artery infarction. It suggests clonazepam may serve as a treatment option for poststroke punding.

Adult-onset stereotypical motor behaviors

Stereotypies have been defined as non-goal-directed movement patterns repeated continuously for a period of time in the same form and on multiple occasions, and which are typically distractible. Stereotypical motor behaviors are a common clinical feature of a variety of neurological conditions that affect cortical and subcortical functions, including autism, tardive dyskinesia, excessive dopaminergic treatment of Parkinson's disease and frontotemporal dementia. The main differential diagnosis of stereotypies includes tic disorders, motor mannerisms, compulsion and habit. The pathophysiology of stereotypies may involve the corticostriatal pathways, especially the orbitofrontal and anterior cingulated cortices. Because antipsychotics have long been used to manage stereotypical behaviours in mental retardation, stereotypies that present in isolation tend not to warrant pharmacological intervention, as the benefit-to-risk ratio is not great enough.

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.