%0 Journal Article
%T The Mechanisms of Movement Control and Time Estimation in Cervical Dystonia Patients
%A Pavel Filip
%A Ovidiu V. Lungu
%A Daniel J. Shaw
%A Tomas Kasparek
%A Martin Bare£¿
%J Neural Plasticity
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/908741
%X Traditionally, the pathophysiology of cervical dystonia has been regarded mainly in relation to neurochemical abnormities in the basal ganglia. Recently, however, substantial evidence has emerged for cerebellar involvement. While the absence of neurological ¡°cerebellar signs¡± in most dystonia patients may be considered at least provoking, there are more subtle indications of cerebellar dysfunction in complex, demanding tasks. Specifically, given the role of the cerebellum in the neural representation of time, in the millisecond range, dysfunction to this structure is considered to be of greater importance than dysfunction of the basal ganglia. In the current study, we investigated the performance of cervical dystonia patients on a computer task known to engage the cerebellum, namely, the interception of a moving target with changing parameters (speed, acceleration, and angle) with a simple response (pushing a button). The cervical dystonia patients achieved significantly worse results than a sample of healthy controls. Our results suggest that the cervical dystonia patients are impaired at integrating incoming visual information with motor responses during the prediction of upcoming actions, an impairment we interpret as evidence of cerebellar dysfunction. 1. Introduction Cervical dystonia, the most frequent adult focal dystonia, is a syndrome characterized by involuntary twisting movements of the head, leading ultimately to temporary or constant abnormal postures interfering with voluntary movement [1, 2]. Despite over a century of research since its first description in the literature [3], the pathophysiology of this disease still remains elusive. Aberrant activity in the basal ganglia has been noted repeatedly as the main cause of the sustained cocontraction of opposing agonist and antagonist muscles [2, 4, 5]. Recently, however, the cerebellum¡ªfirst noted in dystonia pathophysiology over 25 years ago [6]¡ªhas received considerable attention [7¨C9]. Neurophysiological [10] and neuroimaging studies [11], showing increase in gray matter density in cerebellum [12], abnormal cerebellar activation in various tasks [13¨C15], and increased glucose metabolism in cerebellum [16, 17], clearly demonstrate its involvement in dystonia. Furthermore, an elegant review of 25 secondary cervical dystonia cases connects the pathophysiology of cervical dystonia primarily with cerebellar lesions [18]. For a long time the cerebellum has been associated exclusively with motor functions. Increasingly, though, the cerebellum is implicated in a wide spectrum of different process
%U http://www.hindawi.com/journals/np/2013/908741/