Motor extinction in distinct reference frames: A double dissociation

Issue title: Primary Progressive Aphasia and Post-Stroke Aphasia: Some Complementary Insights into Brain-Behavior Relationships/Hemispatial Neglect and Related Disorders

Article type: Research Article

Authors: Heidler-Gary, Jennifer | Pawlak, Mikolaj^; | Herskovits, Edward H | Newhart, Melissa | Davis, Cameron | Trupe, Lydia A. | Hillis, Argye E^{; ;}

Affiliations: Departments of Neurology, Johns Hopkins University, School of Medicine, Baltimore, MD, USA | Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA | Department of Neurology and Cerebrovascular Disorders, Poznan University of Medical Sciences, Poznan, Poland | Physical Medicine and Rehabilitation, Johns Hopkins University, School of Medicine, Baltimore, MD, USA | Department of Cognitive Science, Johns Hopkins University, Baltimore, MD, USA

Note: [] Corresponding author: Argye E. Hillis, MD, Meyer 6-113, Johns Hopkins Hospital, Baltimore, MD 21287, USA. Tel.: +1 410 614 2381; Fax: +1 410 955 0672; E-mail: [email protected]

Abstract: Objective: Test the hypothesis that right hemisphere stroke can cause extinction of left hand movements or movements of either hand held in left space, when both are used simultaneously, possibly depending on lesion site. Methods: 93 non-hemiplegic patients with acute right hemisphere stroke were tested for motor extinction by pressing a counter rapidly for one minute with the right hand, left hand, or both simultaneously with their hands held at their sides, or crossed over midline. Results: We identified two distinct types of motor extinction in separate patients; 20 patients extinguished left hand movements held in left or right space (left canonical body extinction); the most significantly associated voxel cluster of ischemic tissue was in the right temporal white matter. Seven patients extinguished either hand held in left space (left space extinction), and the most significantly associated voxel cluster of ischemic tissue was in right parietal white matter. Conclusions: There was a double dissociation between left canonical body extinction and left space motor extinction. Left canonical body extinction seems to be associated with more dorsal (parietal) ischemia, and left canonical body extinction seems to be associated with more ventral (temporal) ischemia.

Keywords: Extinction, left body, left space, bimanual motor

DOI: 10.3233/BEN-2012-110254

Journal: Behavioural Neurology, vol. 26, no. 1-2, pp. 111-119, 2013