title: Implied functional crossed cerebello-cerebral diaschisis and interhemispheric compensation during hand grasping more than 20 years after unilateral cerebellar injury in early childhood.
abstract: BACKGROUND
  Crossed cerebello-cerebral diaschisis (CCCD) conventionally refers to decreased resting cerebral activity caused by injury to the contralateral cerebellum. We investigated whether functional activation of a contralesional cerebral cortical region controlling a specific task is reduced during task performance in a patient with a unilateral cerebellar lesion. We also examined functional compensation by the corresponding ipsilesional cerebral cortex. It was hypothesized that dysfunction of the primary sensorimotor cortex (SM1) contralateral to the cerebellar lesion would be detected together with a compensatory increase in neural activity of the ipsilesional SM1. To test these possibilities, we conducted non-invasive functional neuroimaging techniques for bilateral SM1 during hand grasping, a task known to activate predominantly the SM1 contralateral to the grasping hand. Activity in SM1 during hand grasping was measured electrophysiologically by magnetoencephalography and hemodynamically by near-infrared spectroscopy in an adult with mild right hemiataxia associated with a large injury of the right cerebellum due to resection of a tumor in early childhood.
  
  
  RESULTS
  During left hand grasping, increased neural activity was detected predominantly in the right SM1, the typical developmental pattern. In contrast, neural activity increased in the bilateral SM1 with slight right-side dominance during right (ataxic) hand grasping.
  
  
  CONCLUSIONS
  This study reported a case that implied functional CCCD and compensatory neural activity in the SM1 during performance of a simple hand motor task in an adult with unilateral cerebellar injury and mild hemiataxia 24 years prior to the study without rehabilitative interventions. This suggests that unilateral cerebellar injuries in early childhood may result in persistent functional abnormalities in the cerebrum into adulthood. Therapeutic treatments that target functional CCCD and interhemispheric compensation might be effective for treating ataxia due to unilateral cerebellar damage.
authors.affiliation: Department of Clinical Neuroscience and Psychiatry, Osaka University Graduate School of Medicine, D3 2-2 Yamadaoka, Suita, Osaka 565-0871 Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Nakahachi
authors.affiliation: Department of Clinical Neuroscience and Psychiatry, Osaka University Graduate School of Medicine, D3 2-2 Yamadaoka, Suita, Osaka 565-0871 Japan.
authors.forename: Ryouhei
authors.identifier: 0000-0002-4245-0953
authors.initials: R
authors.lastname: Ishii
authors.affiliation: Laboratory of Cognitive and Computational Neuroscience, Center for Biomedical Technology, Madrid Complutense University and Madrid Polytechnic University, Campus Montegancedo, 28223 Pozuelo de Alarcón, Madrid Spain.
authors.forename: Leonides
authors.initials: L
authors.lastname: Canuet
authors.affiliation: Department of Clinical Neuroscience and Psychiatry, Osaka University Graduate School of Medicine, D3 2-2 Yamadaoka, Suita, Osaka 565-0871 Japan.
authors.forename: Masao
authors.initials: M
authors.lastname: Iwase
keywords: Brain injuries; Cerebellar ataxia; Cerebellum; Magnetoencephalography; Near-infrared spectroscopy; Sensorimotor cortex