Clinical Study Brain flexibility and balance and gait performances mark morphological and metabolic abnormalities in the elderly Douraied Ben Salem a, * , Paul M. Walker b , Serge Aho c , Be ´atrice Tavernier d , Maurice Giroud e , Christophe Tzourio f , Fre ´de ´ric Ricolfi a , Franc ßois Brunotte b a Neuroradiology, Dijon University Hospital, 3 rue du Faubourg Raines, 21033 Dijon Cedex, France b Imaging Group, LE2I UMR CNRS 5158, Dijon, France c Epidemiology Unit, Dijon University Hospital, Dijon, France d Dijon 3-City Center, Dijon, France e Neurology, CEP, EA4184, Dijon University Hospital, Dijon, France f INSERM, Paris, France Received 5 September 2007; accepted 3 January 2008 Abstract Although previous studies have found that cerebral white matter hyperintensities are associated with balance–gait disorders, no pro- ton magnetic resonance spectroscopy data at the plane of the basal ganglia have been published. We investigated a possible relationship between balance performance and brain metabolite ratios or structural MRI measurements. We also included neuropsychological tests to determine whether such tests are related to structural or metabolic findings. All 80 participants were taken from the cohort of the Three- City study (Dijon–Bordeaux–Montpellier, France). The ratios of N-acetyl-aspartate to creatine (NAA/Cr) and choline to creatine (Cho/Cr) were calculated in the basal ganglia, thalami and insular cortex. We used univariate regression to identify which variables pre- dicted changes in NAA/Cr and Cho/Cr, and completed the analysis with a multiple linear or logistic regression. After the multivariate analysis including hypertension, age, balance–gait, sex, white matter lesions, brain atrophy and body mass index, only balance–gait per- formance remained statistically significant for NAA/Cr (p = 0.01) and for deep white-matter lesions (p = 0.02). The Trail-Making Test is independently associated with brain atrophy and periventricular white-matter hyperintensities. Neuronal and axonal integrity at the plane of the basal ganglia is associated with balance and gait in the elderly, whereas brain flexibility is associated with structural MRI brain abnormalities. Ó 2008 Elsevier Ltd. All rights reserved. Keywords: Depression; Elderly; Gait; MRI; Proton magnetic resonance spectroscopy ( 1 H-MRS); Trail-Making Test 1. Introduction Rabbit et al. 1 demonstrated a relationship between bal- ance and cognitive performance in healthy elderly individ- uals, and suggested that balance clearly reflects general physiological fitness, and therefore neurophysiological integrity. Cognitive ability and control of balance and gait are impaired in the elderly when severe white matter lesions are detected on MRI. 2 However, most studies on balance and gait problems in old age have focused on the impact of cerebral white matter hyperintensities, 3,4 whereas few have discussed the abnormalities of grey matter structures at the plane of the basal ganglia. 5 Focal disruption of white matter fibers is a commonly cited mechanism that leads to disequilibrium, 6,7 but the direct consequences of this dis- connection on the striatum and thalami have not been demonstrated in balance gait impairment. Interruption of afferent and efferent connections between the cortex and subcortical nuclei may lead to functional diaschisis 8,9 with reduction of the neuronal input to the subcortical grey 0967-5868/$ - see front matter Ó 2008 Elsevier Ltd. All rights reserved. doi:10.1016/j.jocn.2008.01.010 * Corresponding author. Tel.: +33 380 293 744; fax: +33 380 293 866. E-mail address: douraied.bensalem@chu-dijon.fr (D. Ben Salem). www.elsevier.com/locate/jocn Available online at www.sciencedirect.com Journal of Clinical Neuroscience 15 (2008) 1360–1365