| Background:Evidences from animal experiments and autopsy have demonstrated that secondary degeneration, such as damage of nerve fiber and loss of nerve cells had been detected far away from the original area after a focal cerebral infarction, and the area has the connection of nerve fibre but difference of blood supply. With the development of magnetic resonance imaging (MRI), diffusion tensor imaging (DTI), a new technology of imaging and post-processing, which derive from the diffusion weighted imaging (DWI), has the advantage of detection in examining changes of tissue microstructure in brain, and it is a favorable means of detect secondary degeneration in the region remote from primary lesion after a focal cerebral infarction. At present, study of DTI has demonstrated that secondary degeneration in pyramidal tract following a focal cerebral infarction has been detected, the sign of fractional anisotropy (FA) imaging became weaker with time, in the meantime, FA values were significantly lower. The study indicated that DTI could in two forms of imaging and data to describe the characteristics of secondary degeneration after a focal cerebral infarction. Lentiform nucleus is one of the basal ganglia, and there ere widely fiber contact with cerebral hemispheres. Whether can causes the secondary degeneration of lentiform nucleus after a focal corona radiate cerebral infarction is a worthy of exploring. Using DTI to prospectively observe the diffusion changes of lentiform nucleus after a focal corona radiate infarction, and survey the influence of the neurological recovery process within the patients, may find its characteristic and significant.Objective:Using DTI to prospective detect the process of secondary degeneration of lentiform nucleus after a focal corona radiate infarction, and explore the relationship between the procession and the recovery of neurological.Methods:Eighteen inpatients with acute infarction at unilateral corona radiata were included continuously as the experimental group, and the patients’ diagnosis were accord with the standard of WHO. Eighteen age and gender matched healthy volunteers underwent DTI once served as control group. DTI was conducted in the week1(4±2d), week4(30±2d) and week12(90±2) after the onset of stroke, during which NIHSS(National Institutes of Health Stroke Scale), FM(Fugl-Meyer score) and BI(Barthel Index) were measured to assess the prognosis as well as activities of daily living ability of those patients. Meanwhile, Unified Parkinson’s Disease Rating Scale (UPDRS) Part III subscales was measured to evaluate the severity of patients who appeared similar symptoms of Parkinson’s disease. By measuring the values of MD (mean diffusivity) and FA, the DTI data respectively from2voxel-ROI(region of interest) in ipsilateral infarction and contralateral lentiform nucleus were analyzed after the whole study. Paired t-test was used between the DTI data of patients and controls. Repeated measures ANOVA was used to analysis the DTI parameters obtained at w1, w4, and w12, and to compare the DTI data from each time we used least significance difference test. In order to reveal the relation between the secondary degeneration and the recovery of neurological, we use Pearson product-moment correlation coefficient to analysis the DTI data and neurological score.Results:MD of ipsilateral lentiform nuclear significant increased from week1((0.85±0.03),week4(0.96±0.03)to week12(1.02±0.02)(P<0.01), while FA showed no significant change (P>0.05). MD and FA values changes in contralateral lentiform nucleus far away from infarct lesion show no statistical significance. The increase percentage of ipsilateral MD may related to the reduce percentage of NIHSS (r=-0.694, P<0.01) and increase percentage of FM (r=0.489, P>0.05), and positively correlated with changes of BI (r=0.662, P<0.05). Compared with patients without Parkinson-like symptoms, MD values of ipsilateral lentiform nucleus increased by18%(P<0.01) in3cases with similar Parkinson symptoms. And this rise of MD(r=0.886, P<0.05) positively correlated with the severity of Parkinson-like symptoms.Conclusion:A focal corona radiate infarct can cause degeneration of lentiform neuleus, which would get gradually worsened with time and hinder the process of neurological function recovery, and may also involved in the process of vascular parkinsonism(VP). |
