Detection and mapping of hippocampal abnormalities in autism

Nicolson, Rob; DeVito, Timothy J.; Vidal, Christine N.; Sui, Yihong; Hayashi, Kiralee M.; Drost, Dick J.; Williamson, Peter C.; Rajakumar, Nagalingam; Toga, Arthur W.; Thompson, Paul M.

doi:10.1016/j.pscychresns.2006.02.005

« Previous Next »Psychiatry Research: Neuroimaging
Volume 148, Issue 1 , Pages 11-21, 22 November 2006

Detection and mapping of hippocampal abnormalities in autism

Rob Nicolson
- Department of Psychiatry, The University of Western Ontario, London, Ontario, Canada
- Corresponding author. London Health Sciences Centre, 800 Commissioners Road East, E2-601, London, Ontario, Canada N6C-2V5. Tel.: +1 519 685 8427; fax: +1 519 685 8595.
Timothy J. DeVito
- Department of Medical Biophysics, The University of Western Ontario, London, Ontario, Canada
Christine N. Vidal
- Laboratory of Neuro Imaging, Department of Neurology, UCLA School of Medicine, Los Angeles, CA, United States
Yihong Sui
- Laboratory of Neuro Imaging, Department of Neurology, UCLA School of Medicine, Los Angeles, CA, United States
Kiralee M. Hayashi
- Laboratory of Neuro Imaging, Department of Neurology, UCLA School of Medicine, Los Angeles, CA, United States
Dick J. Drost
- Department of Medical Biophysics, The University of Western Ontario, London, Ontario, Canada
Peter C. Williamson
- Department of Psychiatry, The University of Western Ontario, London, Ontario, Canada
Nagalingam Rajakumar
- Department of Psychiatry, The University of Western Ontario, London, Ontario, Canada
Arthur W. Toga
- Laboratory of Neuro Imaging, Department of Neurology, UCLA School of Medicine, Los Angeles, CA, United States
Paul M. Thompson
- Laboratory of Neuro Imaging, Department of Neurology, UCLA School of Medicine, Los Angeles, CA, United States

Received 7 September 2005; received in revised form 2 February 2006; accepted 13 February 2006.

Abstract

Brain imaging studies of the hippocampus in autism have yielded inconsistent results. In this study, a computational mapping strategy was used to examine the three-dimensional profile of hippocampal abnormalities in autism. Twenty-one males with autism (age: 9.5±3.3 years) and 24 male controls (age: 10.3±2.4 years) underwent a volumetric magnetic resonance imaging scan at 3 Tesla. The hippocampus was delineated, using an anatomical protocol, and hippocampal volumes were compared between the two groups. Hippocampal traces were also converted into three-dimensional parametric surface meshes, and statistical brain maps were created to visualize morphological differences in the shape and thickness of the hippocampus between groups. Parametric surface meshes and shape analysis revealed subtle differences between patients and controls, particularly in the right posterior hippocampus. These deficits were significant even though the groups did not differ significantly with traditional measures of hippocampal volume. These results suggest that autism may be associated with subtle regional reductions in the size of the hippocampus. The increased statistical and spatial power of computational mapping methods provided the ability to detect these differences, which were not found with traditional volumetric methods.