Department of Internal Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
Clin Toxicol (Phila). 2011 Jul;49(6):464-70. doi: 10.3109/15563650.2011.591400. Epub 2011 Aug 2.
Following acute organophosphate exposure, morphological changes in certain regions of the brain have been reported to develop within a few hours and involve neuronal degeneration. Single photon emission computed tomography (SPECT) has been used to determine changes in the regional cerebral blood flow and attempts have been made to correlate these changes with long-term neurological sequelae.
The aim of the study was to determine changes in the regional cerebral blood flow by 99mTc-ECD SPECT following acute organophosphate poisoning and to correlate these defects with abnormalities in neurocognitive testing carried out during admission and at 3 months post exposure, in order to determine whether any changes in the cerebral blood flow could help in predicting future development of neurocognitive deficit.
Twenty-eight patients with acute organophosphorous poisoning were included in the study. The inclusion criteria were a history of ingestion or accidental exposure, clinical features of cholinergic crises, and low serum acetylcholinesterase (AChE). Twenty age- and sex-matched patients from a previous study were used as controls for the neurocognitive tests. There were no controls for SPECT.
Of the 28 patients studied, 27 had abnormalities in the regional cerebral blood flow on SPECT with men having significantly higher abnormalities than women (p < 0.05). The right side of the brain had more defects than the left, with the occipital lobes being the most commonly involved. Of seven neurocognitive function tests carried out on patients who had regional cerebral blood flow defects during admission, abnormalities were observed in six tests. In 18 of 26 patients who could be tested at 3 months post exposure, improvement was observed in Trail B and Visual retention tests. However, others tests remained significantly abnormal.
We conclude that a single episode of clinically significant organophosphate intoxication can lead to persistent residual neurocognitive deficits. Detection of regional cerebral blood flow defects on 99mTc-ECD SPECT can possibly help in predicting long-term deficits in neurocognitive functions in such patients.
急性有机磷中毒后，数小时内报告某些脑区出现形态学改变，涉及神经元变性。单光子发射计算机断层扫描（SPECT）已用于确定局部脑血流的变化，并尝试将这些变化与长期神经后遗症相关联。
本研究旨在通过 99mTc-ECD SPECT 确定急性有机磷中毒后局部脑血流的变化，并将这些缺陷与入院期间和暴露后 3 个月进行的神经认知测试中的异常相关联，以确定脑血流的任何变化是否有助于预测未来神经认知缺陷的发展。
28 例急性有机磷中毒患者纳入本研究。纳入标准为摄入或意外暴露史、胆碱能危象的临床特征和血清乙酰胆碱酯酶（AChE）低。20 名年龄和性别匹配的患者来自之前的一项研究，作为神经认知测试的对照组。SPECT 没有对照组。
在研究的 28 例患者中，27 例 SPECT 显示局部脑血流异常，男性异常明显高于女性（p < 0.05）。右脑比左脑有更多的缺陷，枕叶是最常受累的部位。在入院时有局部脑血流缺陷的七项神经认知功能测试中，有六项测试异常。在 18 例可在暴露后 3 个月进行测试的 26 例患者中，Trail B 和视觉保留测试有改善。然而，其他测试仍然明显异常。
我们的结论是，单次临床显著有机磷中毒可导致持续的残留神经认知缺陷。99mTc-ECD SPECT 检测局部脑血流缺陷可能有助于预测此类患者的长期神经认知功能缺陷。
