Watanabe Y, Hashikawa K, Moriwaki H, Oku N, Seike Y, Kodaka R, Ono J, Uehara T, Kusuoka H, Nishimura T
Department of Radiology, National Toneyama Hospital, Osaka University Medical School, Suita, Japan.
J Nucl Med. 1998 Jun;39(6):961-4.
We investigated the alterations in regional cerebral blood flow (rCBF) in mitochondrial encephalomyopathy (MEM), using [123I]N-isopropyl-p-iodoamphetamine (IMP) or 99mTc-hexamethyl propyleneamine oxime SPECT in 10 MEM patients.
Four of the patients had MEM with lactic acidosis and strokelike episodes (MELAS), 2 had Kearns-Sayre syndrome (KSS), 1 had myoclonic epilepsy with ragged red fibers (MERRF) and 3 had cytochrome C oxidase deficiency (CCOD). Cerebral perfusion reserve was obtained from 6 patients (3 MELAS, 1 MERRF, 1 KSS, 1 CCOD) for a comparative analysis using the split-dose 123I-IMP SPECT method before and after the injection of acetazolamide.
All patients with MELAS showed focal hypoperfusion in the parietal and/or occipital lobes. Follow-up studies (3 MELAS patients) revealed extension or improvement in the abnormal perfusion. The hypoperfused lesions were correlated with abnormal CT/MRI findings. Perfusion was normal in 1 MERRF, 2 KSS and 3 CCOD patients, whereas CT/MRI findings in 1 MERRF, 1 KSS and 1 CCOD patient were abnormal. The cerebral perfusion reserve in 3 MELAS patients was decreased significantly compared with that in patients with other types of MEM (MELAS 7.4%, other MEM 33.8%; p < 0.05).
The rCBF was altered specifically in patients with MELAS, suggesting that brain perfusion SPECT will be useful in diagnosing and assessing such patients. The decreased cerebral perfusion reserve in patients with MELAS may represent an important feature of the pathogenesis of the strokelike episodes. The SPECT findings of patients with other types of MEM (MERRF, KSS and CCOD) were normal.
我们使用[123I]N-异丙基-p-碘安非他明（IMP）或99mTc-六甲基丙烯胺肟单光子发射计算机断层扫描（SPECT）对10例线粒体脑肌病（MEM）患者的局部脑血流量（rCBF）变化进行了研究。
4例患者患有伴乳酸性酸中毒和类卒中发作的MEM（MELAS），2例患有凯-塞尔综合征（KSS），1例患有肌阵挛性癫痫伴破碎红纤维（MERRF），3例患有细胞色素C氧化酶缺乏症（CCOD）。对6例患者（3例MELAS、1例MERRF、1例KSS、1例CCOD）使用分剂量123I-IMP SPECT方法在注射乙酰唑胺前后获取脑灌注储备，以进行对比分析。
所有MELAS患者均显示顶叶和/或枕叶局灶性灌注不足。随访研究（3例MELAS患者）显示异常灌注有扩展或改善。灌注不足的病灶与CT/MRI异常表现相关。1例MERRF、2例KSS和3例CCOD患者的灌注正常，而1例MERRF、1例KSS和1例CCOD患者的CT/MRI表现异常。3例MELAS患者的脑灌注储备与其他类型MEM患者相比显著降低（MELAS为7.4%，其他MEM为33.8%；p<0.05）。
MELAS患者的rCBF有特异性改变，提示脑灌注SPECT对诊断和评估此类患者有用。MELAS患者脑灌注储备降低可能是类卒中发作发病机制的一个重要特征。其他类型MEM（MERRF、KSS和CCOD）患者的SPECT表现正常。
