Relative glucose metabolic rate higher in white matter in patients with schizophrenia
Relative glucose metabolic rate higher in white matter in patients with schizophrenia
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DOI：
10.1176/appi.ajp.164.7.1072
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发表时间：
2007-07-01
影响因子：
17.7
通讯作者：
Hof, Patrick R.
中科院分区：
文献类型：
--
作者：
Buchsbaum, Monte S.;Buchsbaum, Bradley R.;Hof, Patrick R.
目的：越来越多的证据表明精神分裂症患者额叶、纹状体、颞叶和小脑均存在环路异常，提示应研究连接这些区域的白质的代谢活动。方法：作者对170例受试者进行了[F-18]氟脱氧葡萄糖正电子发射断层扫描(PET)和匹配的T1加权磁共振成像(MRI)。受试者为103名正常志愿者和67名未服药的精神分裂症(N=61)或分裂情感障碍(N=6)患者。结果：与正常志愿者相比，患者额叶白质、胼胝体、上纵束、白质核心等部位的相对代谢率较高。白质活动的增加在大白质束的中心最为明显，特别是大脑的额部和内囊。白质升高似乎与灰质/白质脑比例的变化、全脑代谢率偏差或患者过度的头部运动并不完全相关，但在没有绝对血糖测定的情况下，不能排除这一点。患者在额叶、颞叶、尾状核、扣带回和丘脑背内侧核的相对糖代谢也明显低于正常志愿者，这与早期的研究结果一致。结论：在未用药的精神分裂症患者与正常志愿者相比，精神分裂症患者脑白质的相对代谢增加，灰质的相对代谢减少。脑回路效率低下，白质缺陷导致能量需求增加，白质损伤，轴突堆积密度改变，这些都是与精神分裂症相关的发现白质代谢相对增加的可能解释。
Objective: There is increasing evidence demonstrating that circuits involving the frontal lobe, striatum, temporal lobe, and cerebellum are abnormal in individuals with schizophrenia, which suggests that metabolic activity in the white matter connecting these areas should be investigated.Method- The authors obtained [F-18]fluorodeoxyglucose(FDG) positron emission tomography (PET) and matching T1-weighted magnetic resonance imaging (MRI) on 170 subjects. Participants were 103 normal volunteers and 67 unmedicated patients with schizophrenia (N=61) or schizoaffective disorder (N=6). The images were coregistered and warped to standard space for significance probability mapping.Results: Compared with normal volunteers, patients showed higher relative metabolic rates in the frontal white matter, corpus callosum, superior longitudinal fasciculus, and white matter core of the temporal lobe. Elevated activity in white matter was most pronounced in the center of large white matter tracts, especially the frontal parts of the brain and the internal capsule. The white matter elevation did not appear to be entirely related to changes in gray matter/white matter brain proportions, whole brain metabolic rate bias, or excess head motion in patients, but this cannot be ruled out without absolute glucose determinations. Patients also showed significantly lower relative glucose metabolism in the frontal and temporal lobes, caudate nucleus, cingulate gyrus, and mediodorsal nucleus of the thalamus relative to normal volunteers, which is consistent with earlier studies.Conclusions: In comparisons of unmedicated schizophrenia patients with normal volunteers, relative metabolic increases are apparent in white matter in patients with schizophrenia as well as decreases in gray matter. Inefficiency in brain circuitry, defects in white matter leading to enhanced energy need, white matter damage, and alterations in axon packing density are among the possible explanations for these schizophrenia-related findings of relatively increased metabolism in white matter.