Abnormalities of magnetic resonance spectroscopy and diffusion tensor imaging are correlated with executive dysfunction in patients with ischemic leukoaraiosis

Abnormal diffusion tensor imaging (DTI) results have been observed in the periventricular white matter in patients with ischemic leukoaraiosis (ILA). However, the underlying pathological changes and their relationship to cognitive impairments are obscure. In addition, damage in the thalamus, an important structure in the executive function network, has been suggested in ILA, but is poorly understood. Twenty patients with ILA and 20 healthy volunteers with similar ages and educational histories underwent DTI, magnetic resonance spectroscopy (MRS) and a neuropsychological assessment. In patients with ILA, we observed an increased mean diffusivity (MD) and decreased levels of N-acetylaspartate (NAA)/creatine (Cr) in the anterior and posterior periventricular region and the thalamus, as well as decreased fractional anisotropy (FA) in the anterior and posterior periventricular regions. MD and NAA/Cr levels in the anterior and posterior periventricular white matter and NAA/Cr levels in the thalamus were correlated with executive function. DTI and MRS abnormalities were consistent with axonal and/or neuronal loss and dysfunction in the anterior and posterior periventricular white matter and the thalamus. This study demonstrates that DTI and MRS techniques can be used to investigate pathological changes in the anterior and posterior periventricular white matter and the thalamus; these changes may be correlated with executive functional changes in patients with ILA.