Grey matter changes in motor conversion disorder
- Selma Aybek1,2,
- Timothy R J Nicholson1,
- Bogdan Draganski2,3,4,
- Eileen Daly5,
- Declan G Murphy5,
- Anthony S David1,
- Richard A Kanaan1
- 1Section of Cognitive Neuropsychiatry, Institute of Psychiatry, King's College London, London, UK
- 2Laboratoire de Recherche en Neuroimagerie (LREN), Département des Neurosciences Cliniques, CHUV, Lausanne, Switzerland
- 3Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
- 4Mind Brain Institute, Charité and Humboldt University, Berlin, Germany
- 5Department of Forensic and Neurodevelopmental Sciences, Institute of Psychiatry, King's College London, London, UK
- Correspondence to Dr Selma Aybek, Section of Cognitive Neuropsychiatry, Institute of Psychiatry, PO68, Denmark Hill, SE5 8AF London, UK;
- Received 20 September 2012
- Revised 7 November 2012
- Accepted 14 November 2012
- Published Online First 12 December 2012
Objective To detect anatomical differences in areas related to motor processing between patients with motor conversion disorder (CD) and controls.
Methods T1-weighted 3T brain MRI data of 15 patients suffering from motor CD (nine with hemiparesis and six with paraparesis) and 25 age- and gender-matched healthy volunteers were compared using voxel-based morphometry (VBM) and voxel-based cortical thickness (VBCT) analysis.
Results We report significant cortical thickness (VBCT) increases in the bilateral premotor cortex of hemiparetic patients relative to controls and a trend towards increased grey matter volume (VBM) in the same region. Regression analyses showed a non-significant positive correlation between cortical thickness changes and symptom severity as well as illness duration in CD patients.
Conclusions Cortical thickness increases in premotor cortical areas of patients with hemiparetic CD provide evidence for altered brain structure in a condition with presumed normal brain anatomy. These may either represent premorbid vulnerability or a plasticity phenomenon related to the disease with the trends towards correlations with clinical variables supporting the latter.