Silverman Daniel H S, Truong Co T, Kim Shanna K, Chang Carol Y, Chen Wei, Kowell Arthur P, Cummings Jeffrey L, Czernin Johannes, Small Gary W, Phelps Michael E
Department of Molecular and Medical Pharmacology, University of California, Los Angeles, School of Medicine, Los Angeles, CA, USA.
Mol Genet Metab. 2003 Nov;80(3):350-5. doi: 10.1016/S1096-7192(03)00139-2.
It is difficult to accurately forecast the clinical course of many patients presenting with mild cognitive problems. The utility in prognostic evaluation of various parameters of brain structure and function that can now be noninvasively measured remains to be clearly defined. The present work examined the value of regional cerebral metabolism, assessed with positron emission tomography (PET) and [(18)F]fluoro-2-deoxyglucose, in this context. PET scans of 167 patients (mean Mini-Mental State Examination (MMSE)=24 of 30 possible points) were classified as being positive or negative for evidence of progressive dementia. Results of scans were compared to patients' subsequent clinical course in general and in particular, to their changes in MMSE scores, for up to 10 years following PET. Data were further stratified according to the predictions of referring physicians based upon clinical assessments that had been performed up until the time of PET. Among those patients for whom a progressive dementing course had been predicted by PET criteria (but not those who were predicted by PET criteria to remain stable) a significant decline in general cognitive performance and MMSE scores occurred in the period following PET. Among those patients predicted by clinical criteria to have a progressive dementing illness, 94% of those with positive PET scans did suffer a progressive decline, while only 25% of those with negative scans progressed (relative risk 3.8). Similarly, among those patients who had been predicted by clinical criteria to remain cognitively stable, 74% of those with positive PET scans nevertheless suffered progressive decline, compared with 4% of those with negative PET scans (relative risk 18.4). These data indicate that evaluation of brain metabolism by PET in appropriately selected patients may improve the accuracy of clinical prognostic assessment.
准确预测许多存在轻度认知问题患者的临床病程具有一定难度。目前可通过非侵入性测量的各种脑结构和功能参数在预后评估中的效用仍有待明确界定。在这种背景下，本研究探讨了用正电子发射断层扫描（PET）和[（18）F]氟脱氧葡萄糖评估的局部脑代谢的价值。对167例患者（简易精神状态检查表（MMSE）平均得分为30分制中的24分）进行PET扫描，根据是否有进行性痴呆的证据将扫描结果分为阳性或阴性。将扫描结果与患者随后的总体临床病程进行比较，特别是与PET扫描后长达10年的MMSE评分变化进行比较。根据转诊医生在PET检查之前基于临床评估所做出的预测对数据进行进一步分层。在那些根据PET标准预测会出现进行性痴呆病程的患者中（但不包括那些根据PET标准预测病情稳定的患者），PET扫描后总体认知能力和MMSE评分出现了显著下降。在那些根据临床标准预测患有进行性痴呆疾病的患者中，PET扫描阳性的患者中有94%确实出现了进行性衰退，而PET扫描阴性的患者中只有25%病情进展（相对风险为3.8）。同样，在那些根据临床标准预测认知功能保持稳定的患者中，PET扫描阳性的患者中有74%出现了进行性衰退，而PET扫描阴性的患者中这一比例为4%（相对风险为18.4）。这些数据表明，对适当选择的患者进行PET脑代谢评估可能会提高临床预后评估的准确性。
