应用28通道近红外光谱分析恢复过程中老年期抑郁症患者前额叶的激活特征

Prefrontal lobe function in remitted geriatric depression:A study by using 28-channel near-infrared spectroscopy

目的:认知功能障碍是老年期抑郁症的可逆性症状,试验以认知功能研究为突破口,采用28通道的近红外光谱技术分析处于恢复过程中的老年期抑郁症患者在执行词语流畅性测验时前额叶的激活特点,探讨老年期抑郁症的发病机制。方法:①分组:患者组为2006-03/12首都医科大学附属北京安定医院收治的12例处于恢复过程中的老年期抑郁症患者,入组时符合DSM-4有关重度和中度抑郁发作或复发的标准诊断,首次发病年龄≥60岁,均服用SSRIs类抗抑郁药物治疗。对照组为12例性别、年龄和教育程度与患者组相匹配的健康志愿者。所有受试者排除脑器质性病变。②试验方法:所有受试者接受近红外光谱测查,在28通道的CW5(TechEn Inc.American)NIRS系统上完成。通过近红外光谱系统监测被试者在执行词语流畅性测验任务过程中,前额叶氧合血红蛋白和脱氧血红蛋白浓度的变化,从而反映前额叶认知任务相关的激活效应。采用组块设计的词语流畅性测验作为认知激活任务,任务范式包括词语重复任务和词语流畅性任务两种试验。结果:24例受试者均进入结果分析。①在健康老年人和处于恢复过程中的老年期抑郁症患者,词语流畅性测验能够激活双侧前额叶,未发现半球单侧化激活效应。②处于恢复过程中的老年期抑郁症患者在词语流畅性测验任务过程中,左侧前额叶激活效应较对照组减弱。③尽管在健康老年人和处于恢复过程中的老年期抑郁症患者,近红外光谱显示了不同的激活模式,但词语流畅性测验的成绩不存在显著性的组间差异(P>0.05)。结论:处于恢复过程中的老年期抑郁症患者存在词语流畅性测验相关的功能性左侧前额叶功能减退,微血管功能失调和多巴胺系统异常也许在老年期抑郁症的病理生理学机制中起重要作用。

AIM： Cognitive disturbance is a reversible symptom of old patients with depressive disorder. Using a 26-channel near-infrared spectroscopy （NIRS） to study the effect of verbal fluency task （VFT） on the prefrontal lobe activation in remitted geriatric depressive patients, further research the etiopathogenesis of geriatric depression. METHODS： ①Totally 12 patients with remitted geriatric depressive disorder were enrolled from Beijing Anding Hospital, Capital Medical University from March to December 2006 as patient group. At the time of being selected, these patients were diagnosed according to the DSM-4 criteria about the moderate or severe depressive episode or relapse. The age at onset of the first depressive episode in these patients was at least 60 years. All of them were medicated with a selective serotonin reuptake inhibitor. Twelve health volunteers with matched sex, age and education as patient group were selected as control group. None of them had a history of cerebral organic lesions. ②A 26-channel near-infrared spectroscopy （NIRS） imaging system was employed to monitor the concentration changes of Oxy-Hb and Deoxy-Hb in the bilateral prefrontal cortex of all subjects during cognitive tasks. It could reflect prefrontal cognition-dependent activation. A block designed verbal fluency task （VFT） was used as cognitive tasks. Tasks contained word repetition and word fluency. RESULTS： Totally 24 testees were involved in the result analysis. ①The performance of the VFT lead to activation in prefrontal brain areas of the patients with remitted geriatric depressive disorder and the healthy old people, but failed to find lateralized activation. ②Activation of the left prefrontal cortex during the VFT was significantly less in patients as compared with controls. ③The task performances of the VFT were not significantly different between the two groups although activation patterns were distinct respectively （P 〉 0.05）. CONCLUSION： There is the VFT-relative functional left hypofrontality in remitted geriatric depressive patients. Microvascular dysregulation and the dysfunction of dopamine in the prefrontal cortex may play important roles in the pathophysiology of elderly geriatric depression.