Functional brain networks in movement disorders

Abstract

Purpose of review Different neuroimaging techniques have been used to identify disease-specific functional brain networks in Parkinson’s disease, atypical parkinsonian syndromes, and other movement disorders. This review highlights recent advances in network imaging and its clinical applications in movement disorders. Recent findings Positron emission tomography and functional MRI studies have revealed distinct, abnormal metabolic brain networks and altered interregional connectivity in Parkinson’s disease and related movement disorders. Network-level functional changes have been found to correlate with disease severity and progression. Moreover, network-based categorization algorithms are proving useful in enhancing the accuracy of clinical diagnosis in patients with early symptoms and in providing objective evidence of treatment response. Summary Although in most movement disorders the predominant histopathology involves the basal ganglia, including the substantia nigra, functional changes in relevant neural circuits are not limited to these structures. The current advances in functional brain imaging have contributed to a better pathophysiological understanding of movement disorders as complex alterations of widespread functional brain networks. The promising findings from recent studies may help to establish new and reliable biomarkers to monitor disease progression and treatment effects in future clinical trials.

Increased interhemispheric resting-state functional connectivity in paroxysmal kinesigenic dyskinesia: A resting-state fMRI study

“…These previous studies suggested regional abnormalities in the basal gangliathalamo-cortical circuitry in PKD, yet are limited to regional alterations, unable to manifest the functional connectivity related to this circuitry. Nowadays movement disorders have been viewed as circuitry disorders which are not confined to localized structure or functional abnormalities [18]. Robust disease and symptom specific functional networks have been identified in movement disorders using different paradigms [19,20].…”

Multifocal Myoclonus after Stroke and Rehabilitation - A Case Report

“…This patient presented with multifocal myoclonus occurring immediately following a right ACA territory stroke which had not been reported before [1]. The presence of multifocal involuntary movement following unilateral brain infarct may be explained by the recent advances in functional brain imaging which suggests that although the histopathological hallmark of movement disorders is located in the basal ganglia, they can be caused by alterations within functional whole brain networks rather than localized neurodegeneration [9].…”

Are the neuromotor disabilities of bilirubin-induced neurologic dysfunction disorders related to the cerebellum and its connections?

“…Movement disorders, however, are increasingly recognized to arise from abnormalities of neuronal circuitry rather than localized, circumscribed lesions [42]. The cerebellum has extensive bidirectional circuitry projections to an array of brainstem nuclei and the cerebral cortex that modulate and refine motor activities [43e45].…”

“…Indeed, investigators speculate that a "non-optimally wired brain" [9], i.e., a brain with aberrant connectivity, may be the pathologic substrate of BIND [9,13]. Anatomical and functional connectivity using advanced neuroimaging techniques have identified specific alterations in functional brain networks in other brain disorders [42] and as a function of sex [67] and age [68]. These techniques may be able to identify some of the cerebellar and striatal pathways that are presumed to be altered in kernicterus and BIND patients.…”