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Behavioural Neurology
Volume 26 (2013), Issue 1-2, Pages 131-138
http://dx.doi.org/10.3233/BEN-2012-110235

Disentangling the Neuroanatomical Correlates of Perseveration from Unilateral Spatial Neglect

Jonathan T. Kleinman,1,4 Jeffery C. DuBois,1 Melissa Newhart,1 and Argye E. Hillis1,2,3

1Departments of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
2Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, MD, USA
3Department of Cognitive Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
4Stanford University School of Medicine, Stanford, CA, USA

Received 26 March 2012; Accepted 26 March 2012

Copyright © 2013 Hindawi Publishing Corporation and the authors. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Perseverative behavior, manifest as re-cancelling or re-visiting targets, is distinct from spatial neglect. Perseveration is thought to reflect frontal or parietal lobe dysfunction, but the neuroanatomical correlates remain poorly defined and the interplay between neglect and perseveration is incompletely understood. We enrolled 87 consecutive patients with diffusion-weighted, perfusion-weighted imaging, and spatial neglect testing within 24 hours of right hemisphere ischemic stroke. The degrees of spatial neglect and perseveration were analyzed. Perseveration was apparent in 46% (40/87) of the patients; 28% (24/87) showed perseveration only; 18% (16/87) showed both perseveration and neglect; and 3% (3/87) showed neglect only. Perseverative behaviors occur in an inverted “U” shape: little neglect was associated with few perseverations; moderate neglect with high perseverations; and in severe neglect targets may not enter consciousness and perseverative responses decrease. Brodmann areas of dysfunction, and the caudate and putament, were assessed and volumetrically measured. In this study, the caudate and putamen were not associated with perseveration. After controlling for neglect, and volume of dysfunctional tissue, only Brodmann area 46 was associated with perseveration. Our results further support the notion that perseveration and neglect are distinct entities; while they often co-occur, acute dorsolateral prefrontal cortex ischemia is associated with perseveration specifically.