Tak Ali Zeynal Abidin, Dayan Erdal, Bulut Hacı Taner
Department of Neurology, Adiyaman University Faculty of Medicine, Siteler Mahallesi, Atatürk Bulvarı, No. 411, Adiyaman, Turkey.
Department of Neurology, Mardin State Hospital, Vali Ozan Caddesi Nur Mahallesi, Artuklu, Mardin, Turkey.
Acta Neurol Belg. 2018 Jun;118(2):289-296. doi: 10.1007/s13760-018-0912-1. Epub 2018 Apr 16.
Vitamin B12 plays an important role in the mechanisms which are responsible for myelinization in the central nervous system. It can particularly lead to hematological and neuropsychiatric symptoms when serum levels fall due to insufficient intake with diet or absorption problems. The purpose of this study was to show the cognitive effects in vitamin B12 deficiency cases that have not reached clinical symptom level using neuropsychological tests, and to show possible cerebral neuronal damage using diffusion tensor imaging (DTI) method. A total of 62 asymptomatic vitamin B12 deficiency patients and 40 healthy subjects were included in the study and both groups were subjected to Standardized Mini-Mental State Examination, Montreal Cognitive Assessment Test, Rey Auditory Verbal Learning Test, forward and backward digit span (WMS-R forward and backward), Visual Reproduction Subtest (WMS-III), Category Fluency Test, Trail Making (Trail A-B) (21) and Similarities (BENZ) tests. DTI examinations were performed on both groups. Patient group was determined to get lower scores in all neuropsychological tests compared to control group. In DTI examination, a significant decrease in FA values of bilateral hippocampus and a prominent increase in apparent diffusion coefficient (ADC) values were determined in the patient group compared to control group. In this study, it was determined that there was microstructural damage in the brain in the presence of vitamin B12 deficiency even in the asymptomatic period, and the patients revealed cognitive decline. In accordance with this result, early treatment of the easily diagnosed and treated vitamin B12 deficiency may prevent possible irreversible damage in the future.
维生素B12在中枢神经系统髓鞘形成机制中发挥着重要作用。当由于饮食摄入不足或吸收问题导致血清水平下降时，它尤其会引发血液学和神经精神症状。本研究的目的是通过神经心理学测试来显示尚未达到临床症状水平的维生素B12缺乏病例的认知影响，并使用扩散张量成像（DTI）方法显示可能存在的脑神经元损伤。共有62例无症状维生素B12缺乏患者和40名健康受试者纳入本研究，两组均接受标准化简易精神状态检查、蒙特利尔认知评估测试、雷伊听觉词语学习测试、顺背和倒背数字广度（韦氏记忆量表修订版顺背和倒背）、视觉再现分测验（韦氏记忆量表第三版）、类别流畅性测试、连线测验（A-B）以及相似性测试（本茨）。对两组均进行了DTI检查。与对照组相比，患者组在所有神经心理学测试中的得分均较低。在DTI检查中，与对照组相比，患者组双侧海马的FA值显著降低，表观扩散系数（ADC）值显著升高。在本研究中，确定即使在无症状期，维生素B12缺乏时大脑也存在微观结构损伤，且患者出现认知能力下降。根据这一结果，对易于诊断和治疗的维生素B12缺乏进行早期治疗，可能会预防未来可能出现的不可逆损伤。
