An Physiological Survey on the Mechanism of Delirium in the Elderly

我们采用单盲对照研究，对老年人术后谵妄患者连续14天静脉给予强睡眠-清醒节律调节剂维生素B_<12>（甲钴胺）和安慰剂进行治疗，并从生物节律方面评价其作用机制。在甲钴胺组（n=10）中，从开始给药到谵妄缓解的时间明显短于安慰剂组（n=10）。在给药后第3 ~ 7天，甲钴胺组谵妄评分量表（DRS）积分总和低于安慰剂组。甲钴胺组的DRS症状项如情绪不稳定、情绪昼夜变化、睡眠-觉醒节律障碍和幻觉存在的时间明显短于安慰剂组。在分析睡眠的日分布时，甲钴胺组在第3天至第9天白天睡眠时间与夜间睡眠时间的比例明显较小。此外，甲钴胺组术后谵妄缓解前2 ~ 3天的嗜睡症状均得到抑制。从临床症状的病程与睡眠-觉醒节律的关系以及甲钴胺素的疗效来看，怀疑老年患者术后谵妄是昼夜节律障碍所致。此外，甲基钴胺素被认为可以增加夜间睡眠和/或提高白天的警觉性，从而稳定睡眠-清醒节奏。

We made a single blind controlled study on the treatment of postoperative delirium in the elderly with intravenous administration of Vitamin B_<12> (methylcobalamin), a strong regulator of sleep - awake rhythm and placebo for 14 consecutive days, and assessed the mechanism of the disorder from the aspect of biological rhythm. In the group administered with methylcobalamin (n=10), periods from the start of the administration to the remission of delirium were significantly shorter than the group with placebo (n=10). From 3rd day to 7th day after the initiation of the administration, sum of the points of delirium rating scale (DRS) were lower in the group with methylcobalamin compared with the group with placebo. The periods, in which the symptom items of DRS such as emotional instabilty, diurnal varition of the mood, disorder of sleep - awake rhythm and hallucination existed, were significantly shorter in the group with methylcobalamin than the group with placebo. When analyzing the diurnal distribution of sleep, daytime sleep to night time sleep ratio were significantly smaller from 3rd day to 9th day in the group with methylcobalamin. In addition to that, hypersomnolence which existed in two or three days period befor the remission of postoperative delirium were suppressed in the group with methylcobalamin.Judging from the relation between the course of clinical symptoms and sleep-awake rhythm as well as the efficacy of methylcobalamin, postoperative delirium in the elderly was suspected to occur as a result of the circadian rhythm disorder. And also, methylcobalamin was thought to increase nocturnal sleep and/ or enhance the alertness in the daytime leading to stabilize sleep - awake rhythm.