Objective To investigate the changing characteristics of the fractional anisotropy (FA) in cerebral peduncles and its relation with motor evoked potential (MEP) after acute cerebral infarction and to clear the clinical sigiificance of the low limit value of the FA in cerebral peduncles. Methods The low limit value of the FA in normal cerebral peduncles was determined based on mean - 1. 64 standard deviation. The patients with acute cerebral infarction (n = 58) were divided into MEP positive group and MEP negative group according to the absence and presence of MEP, in which the patients in the MEP positive group were redivided into the FA in cerebral peduncles ＜ the low limit value and≥ the low limit value groups according to the FA in cerebral peduncles on the affected sides. Results The low limit value of the FA in normal cerebral peduncles was 0. 36. There was significant difference in the FA in cerebral peduncles on the affected sides between the MEP negtive and MEP positive groups. The MEP negative group was the lowest (P=0. 000). The FA in cerebral peduncles on the affected sides in the positive group was significantly lower than that on the unaffected sides (P=0. 000), and the latency on the affected sides was longer than that on the normal sides (P=0. 000). The FA in cerebral peduncles on the affected sides was negatively correlated with the MEP latency (r=-0.332,P=0. 042). The MEP latency in the FA＜the low limit value group was significantly longer than that in the FA ≥ low limit value group (P=0. 002). There were no significant differences in the FA in cerebral peduncles on the normal sides and the MEP latency among an groups. The detection rate of the FA in cerebral peduncle＜0. 36 on the affected sides was the highest (50%). Conclusions In the evaluation of the prognosis of the patients, the changes of the FA in cerebral peduncles on the affected sides in patients with acute cerebral infarction had correlation,consistency, and complementarity with MEP.The detection rate of the low limit value of the FA in normal cerebral peduncles was the highest in the MEP negative patients. When the FA in cerebral peduncles was＜0.36 on the affected sides, particularly when MET was negative, it might predict that the prognosis was poor.

OBJECTIVETo investigate the relationship between fractional anisotropy (FA) and somatosensory evoked potentials (SEP) in the postcentral gyrus subcortex in patients with acute infarction of the posterior limb of the internal capsule.

METHODSThirty-one patients with acute infarction of the posterior limb of the internal capsule underwent diffusion tensor imaging to obtain the FA values of the subcortical region of the postcentral gyrus with manual placement of the regions of interest (ROI). SEP and the sensory functions of the patients were examined and graded.

RESULTSIn each SEP grade group, the FA values of the subcortical region of the postcentral gyrus were significantly decreased on the diseased side compared to those of the normal side (P<0.05). The FA values of the diseased side differed significantly between patients with different SEP grades (P<0.05), and increased SEP abnormalities were associated with lowered FA values. The sensory function of the patients was positively correlated to the grade of SEP (r=0.520, P<0.05).

CONCLUSIONFor patients with acute infarction of the posterior limb of the internal capsule, the changes of FA in the postcentral gyrus subcortex on the diseased side are correlated and complementary to SEP in evaluating the prognosis.

Aged ; Anisotropy ; Brain Infarction ; pathology ; physiopathology ; Brain Mapping ; Diffusion Magnetic Resonance Imaging ; Evoked Potentials, Somatosensory ; Female ; Humans ; Internal Capsule ; pathology ; Male ; Middle Aged