Temporal Lobe Changes in Early, Untreated Parkinson’s Disease W.R. Wayne Martin, MD, 1 * Marguerite Wieler, MSc, 1 Myrlene Gee, PhD, 2 and Richard Camicioli, MD 1 1 Division of Neurology, University of Alberta, Edmonton, Alberta, Canada 2 Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada Abstract: The purpose of this study was to determine if focal cortical abnormalities may occur in early Parkinson’s disease (PD). We studied 26 untreated patients with early PD and 14 healthy control subjects, with cognitive screening and mag- netic resonance imaging (MRI). Voxel-based morphometry was used to assess for the presence of localized cortical grey matter (GM) and/or subcortical white matter (WM) changes. Patient and control groups showed no differences in age or gender distribution. Females had a greater GM% than males (P 5 0.001). Comparison of patients and controls revealed no difference in local GM volumes. In PD, however, there was decreased WM volume in the anterior right fusiform gyrus and superior temporal gyrus. There were no correla- tions between the California Verbal Learning Test long delay free recall, Judgment of Line Orientation, Trail Making A or B and either the GM or WM localized volumes. These results suggest that right anterior temporal lobe changes occur in untreated patients with PD. The earliest changes may occur in subcortical white matter rather than temporal cortex. Ó 2009 Movement Disorder Society Key words: Parkinson’s disease; magnetic resonance imaging; temporal lobe Parkinson’s disease (PD) is characterized classically by motor impairment, but it is becoming increasingly clear that nonmotor issues are also an important com- ponent of the syndrome. One aspect of nonmotor impairment is the cognitive dysfunction that occurs in some individuals, particularly with advanced disease. Dementia is not an uncommon feature of PD, occur- ring with an estimated prevalence of about 30%. 1 The underlying pathophysiology of cognitive changes is uncertain, but is thought to involve limbic and neocort- ical changes as well as dysfunction of nondopaminer- gic neurotransmitter systems such as the cholinergic system. 2 Impaired cognition is less of a problem in early PD, although there is evidence that heterogeneous cognitive dysfunction may be present even at the time of PD diagnosis in some individuals. 3 Previous studies have also suggested that hippocampal atrophy may occur in older patients with PD before the development of dementia. 4 The present study was undertaken in untreated patients with early PD to determine whether focal cortical abnormalities may be present in early disease before the initiation of medical treatment. We utilized voxel-based morphometry (VBM) 5,6 to determine whether localized cortical grey matter (GM) and/or subcortical white matter (WM) volume may differ in these patients when compared with healthy control subjects. METHODS Subjects Twenty-six patients with early PD were recruited from the University of Alberta/Capital Health Move- ment Disorders Clinic and compared with 14 control subjects who were healthy and free of neurological and psychiatric disease. All control subjects and 25 of 26 patients were right handed. Control subjects were recruited from patients’ friends and spouses and from the general university community. All patients fulfilled standard criteria for a clinical diagnosis of PD 7 and none were treated with levodopa, dopamine agonists or Potential conflict of interest: None reported. *Correspondence to: W.R. Wayne Martin, Movement Disorders Clinic, Glenrose Rehabilitation Hospital, 10230—111 Ave., Edmon- ton, AB, Canada T5G 0B7. E-mail: wayne.martin@ualberta.ca Received 3 June 2008; Revised 15 February 2009; Accepted 27 May 2009 Published online 15 July 2009 in Wiley InterScience (www. interscience.wiley.com). DOI: 10.1002/mds.22680 1949 Movement Disorders Vol. 24, No. 13, 2009, pp. 1949–1954 Ó 2009 Movement Disorder Society