ABSTRACT
<p><b>OBJECTIVE</b>To investigate the correlation between the diffusion anisotropy of the white matter fibers and the cognitive function in patients with leukoaraiosis (LA).</p><p><b>METHODS</b>Thirty-one LA patients were enrolled in this study, including 13 with grade LA-1 (mild), 12 with grade LA-2 (moderate) and 6 with grade LA-3 (severe) condition. The control group consisted of 18 subjects who were free of obvious clinical symptoms or had only mild dizziness and headache but with negative history for neural system diseases and in the absence of cognitive dysfunction, brain trauma, positive signs in neurological examinations, or abnormities in MRI examination. The Mini-mental State Examination (MMSE) was applied to evaluate the patients' cognitive function. The LA patients underwent examination with diffusion tensor MR imaging (DTI), and the FA and MD values in the normal-appearing white matter (NAWM) were measured.</p><p><b>RESULTS</b>The cognitive function of the LA patients tended to decline with the decrease of the MMSE scores, and their scores for time orientation, place orientation and calculation were significantly lower than those of the control group (P<0.05). No significant difference was found in memory, language and comprehensive abilities between the LA and control groups. In LA-1, LA-2 and total LA cases, the FA value in the NAWM was positively, and the MD value inversely, correlated to the cognitive function with correlation coefficients ranging from 0.5 to 0.8 (P<0.05).</p><p><b>CONCLUSION</b>The DTI parameters of NAWM region are correlated to the cognitive function of LA patients. DTI is far more sensitive than MRI in evaluating cognitive dysfunction in LA patients.</p>
Subject(s)
Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Anisotropy , Case-Control Studies , Cognition Disorders , Diagnosis , Diffusion Magnetic Resonance Imaging , Methods , Leukoaraiosis , Pathology , Neuropsychological TestsABSTRACT
<p><b>OBJECTIVE</b>To investigate the correlation between cerebral white matter fraction anisotropy (FA) in normal human adults using the diffusion tensor magnetic resonance (MR) imaging (DTI).</p><p><b>METHODS</b>Forty-five adults with normal cerebral white matter MRI findings in 3 age groups (n=15), namely 25 approximately 35 years (young), 45 approximately 55 years (middle-aged) and 65 years or above (elderly), underwent conventional MRI and diffusion tensor MR imaging. FA was measured in different regions of interest (ROIs) including the genu and splenium of the corpus callosum, posterior limb and anterior limb of the internal capsule, centrum semiovale, frontal white matter, thalamus and head of the caudate nucleus.</p><p><b>RESULTS</b>The FA values of the corresponding regions were similar between the left and right hemispheres. The FA value in the genu of the corpus callosum, centrum semiovale and the frontal white matter decreased with age, showing significant differences between the 3 age groups (P<0.05). The FA value in the splenium of the corpus callosum decreased significantly with age, with significant differences between the elderly and young groups and between the elderly and middle-aged groups (P<0.05). The values in the posterior limb and anterior limb of the internal capsule also decreased significantly with age as shown by comparison between the elderly and young groups (P<0.05). No significant difference was found in the FA value of the thalamus and head of the caudate nucleus between the three groups (P>0.05).</p><p><b>CONCLUSION</b>The FA values decrease with age, especially in the genu of corpus callosum, centrum semiovale and frontal white matter. The patient's age and age-related white matter degradation must be considered in DTI-based diagnosis of cerebral diseases.</p>