RESUMO
Objective To determine the effect of local mild hypothermia on patients with acute cerebral infarction and ascertain its optimal therapeutic window. Methods According to the time receiving treatment, 114 patients with acute cerebral infarction were divided into group A (≤6 h), group B (6-24 h) and group C (≥ 24 h). Then, each group was subdivided into 2 groups at random: treatment group (A1, B1, C1) and control group (A2, B2, C2). Patients in the control group were subjected to such conventional therapy as anti-platelet aggregation. Patients in the treatment group were treated with local mild hypothermia (33-35 ℃ body-core temperature) for 48 h besides conventional therapy. Clinical outcomes were assessed by the National institutes of health stroke scale (NIHSS) on admission and 7, 14,30 d after treatment. Furthermore, we detected the serum level of nitrogen monoxidum (NO) and superoxide dismutasc (SOD) on admission, and 7 and 14 d after treatment. Results Compared with the control group, treatment group enjoyed significantly decreased scores of NIHSS 7, 14 and 30 d after treatment and significantly decreased level of NO 7 and 14 d after treatment (P＜0.05), but obviously increased SOD vitality 7 and 14 d after treatment (P＜0.05). No significant differences in terms of NIHSS scores, level of NO and SOD vitality were noted between group C1 and group C2 at each time point (P＞0.05). Group Al and group B1 had obviously lower scores of NIHSS than group C1 on the 7th, 14th and 30th d of treatment, and had significantly lower level of NO and obviously increased SOD vitality as compared with group C1 on the 7th and 14th d of treatment (P＜ 0.05), and group A1 enjoyed its advantage.Conclusion Early local mild hypothermia therapy can improve neurological function in patients with acute cerebral infarction. The mild hypothermia induced within 6 h may be optimal therapeutic window;mild hypothermia induced at 6-24 h is less effective and that above 24 h is non-effective.