White matter imaging correlates of early cognitive impairment detected by the MoCA after TIA and minor stroke

Background and Purpose Among screening tools for cognitive impairment in large cohorts, the Montreal Cognitive assessment (MoCA) appears to be more sensitive to early cognitive impairment than the Mini-Mental State Examination (MMSE), particularly after transient ischemic attack (TIA) or minor stroke. We reasoned that if MoCA-detected early cognitive impairment is pathologically significant, then it should be specifically associated with the presence of white matter hyperintensities (WMH) and reduced fractional anisotropy (FA) on MRI. Methods Consecutive eligible patients with TIA or minor stroke (Oxford Vascular Study) underwent MRI and cognitive assessment. We correlated MoCA and MMSE scores with WMH and FA, then specifically studied patients with low MoCA and normal MMSE. Results Among 400 patients, MoCA and MMSE scores were significantly correlated (all p Conclusions In patients with TIA or minor stroke, early cognitive impairment detected with the MoCA but not with the MMSE was independently associated with white matter damage on MRI, particularly reduced FA.