Clinical Features, Risk Factors, and Early Prognosis for Wallerian Degeneration in the Descending Pyramidal Tract after Acute Cerebral Infarction

Background: Wallerian degeneration(WD) occurs in the descending pyramidal tract (DPT) after cerebral infarction commonly, but studies of its degree evaluation, influencing factors and effects on nervous function are still limited. Objectives: The purpose of this study was to describe these findings and estimate their clinical significance. Methods: In total, 133 patients confirmed acute cerebral infarction and restricted diffusion in the DPT of the cerebral peduncle by MRI scans. These cases were retrospectively reviewed. We describe their clinical characteristics and analyze influence factors of WD, including the timespan from symptom onset to MRI and TOAST classification. Their NIHSS scores at admission and first 7 days NIHSS improvement rate after admission were also analyzed. Results: These patients were divided into three groups by timespan <= 7 days(n = 45),7-14 days(n = 70) and >14 days(n = 18). The mean WD degree (%)of these three groups was 44.41 +/- 22.51,52.35 +/- 22.61and 44.31 +/- 19.35,respectively(p = 0.122).According to the TOAST classification, the mean WD degree(%) of the cardioembolism group (n = 28, 62.80 +/- 25.12) was significantly different from both the large-artery atherosclerosis group(n = 73,45.08 +/- 20.03,p = 0.000) and the small-vessel occlusion group (n = 23,39.68 +/- 16.95,p = 0.000). The mean NIHSS score upon admission of the WD degree <= 50% group(n = 82,8.17 +/- 5.87) was different from that of the >50% group (n = 51,11.31 +/- 7.00)(p = 0.006). However, the mean 7 days NIHSS improvement rate(%) of the WD degree <= 50% group(n = 79,11.83 +/- 23.76)and >50% group (n = 50,13.40 +/- 27.88) was not significantly different(p = 0.733). Conclusions: Early WD in ischemic stroke patients has a correlation with serious baseline functional defects. Therefore, we should give close attention to imaging change, especially in those with cardioembolism.