Neurology Service, Epilepsy Unit, Hospital Universitari de Bellvitge-IDIBELL, Universitat de Barcelona, L'Hospitalet de Llobregat, Barcelona, Spain; Neurology Department, Hospital de Viladecans, Viladecans, Barcelona, Spain.
Image Diagnostic Institute (IDI), Nuclear Medicine Department, PET Unit, Hospital de Bellvitge, Universitat de Barcelona, L'Hospitalet de Llobregat, Barcelona, Spain.
Epilepsy Behav. 2019 Dec;101(Pt B):106544. doi: 10.1016/j.yebeh.2019.106544. Epub 2019 Nov 18.
The diagnosis of nonconvulsive status epilepticus (NCSE) can pose a challenge. Electroencephalogram (EEG) patterns can be difficult to interpret, and the absence of an EEG correlate does not rule out the diagnosis of NCSE. In this setting, neuroimaging tools to help in the diagnosis are crucial. Our aim was to evaluate the role of 99mTc-hexamethyl propyleneamine oxime (HMPAO) single photon emission computed tomography (SPECT) and quantitative HMPAO-SPECT (QtSPECT) in patients with clinical suspicion of NCSE, and to evaluate their value in the final diagnosis of NCSE.
We recruited consecutive patients admitted in our center with suspicion of NCSE, and selected those who underwent an HMPAO-SPECT. All patients were admitted to the neurology ward and underwent an EEG. We divided the patients into those who were finally with diagnosed NCSE (NCSE-p) and those who were not (non-NCSE) according to the Salzburg Diagnostic EEG criteria. Sensitivity and specificity of the diagnostic tools were calculated. The SPECTs were acquired in a Skylight SPECT (Philips Healthcare, Amsterdam). The injections were done during the clinical episode suspected of being an NCSE. The HMPAO-SPECT was analyzed by two experts and was also quantified. All data were normalized to the SPM SPECT template. We used an external healthy normal database to obtain a Z-score map for each individual versus the normal database. The Z-score maximum (Z) was extracted from each region of the AAL atlas as was the percentage of voxels with a Z-score higher than 2.5 (N(%)). A logistic regression combining the Z, N(%), and the effect of patient age was fitted to predict the final NCSE diagnosis. A receiver operator characteristic (ROC) curve and the area under the curve (AUC) were obtained to evaluate the classification performance.
We included 55 patients, 21 of them women (38.9%), with a median age of 62.1 years old (range 25-84). Thirty-six patients were with diagnosed NCSE (62.9%). Initial EEG had a sensitivity of 61.1% and a specificity of 89%. Most of the patients were critically ill with diagnostic difficulties, and it could be one of the main reasons to find low sensitivity of the Salzburg diagnostic EEG criteria. The Z and N(%) were significantly higher in NCSE-p than in non-NCSE (p = 0.005 and p < 0.001, respectively). The HMPAO-SPECT qualitative analysis had a sensitivity of 80.5% and specificity of 89.5% while QtSPECT had a sensitivity of 82% and specificity of 81%.
Both 99mTc-HMPAO-SPECT and QtSPECT can be useful in the diagnosis of NCSE. This article is part of the Special Issue "Proceedings of the 7th London-Innsbruck Colloquium on Status Epilepticus and Acute Seizures".
非惊厥性癫痫持续状态（NCSE）的诊断具有挑战性。脑电图（EEG）模式可能难以解读，并且没有 EEG 相关性并不能排除 NCSE 的诊断。在这种情况下，有助于诊断的神经影像学工具至关重要。我们的目的是评估 99mTc-六甲基丙烯胺肟（HMPAO）单光子发射计算机断层扫描（SPECT）和定量 HMPAO-SPECT（QtSPECT）在临床怀疑 NCSE 的患者中的作用，并评估它们在 NCSE 的最终诊断中的价值。
我们连续招募了怀疑患有 NCSE 的中心入院患者，并选择了接受 HMPAO-SPECT 的患者。所有患者均被收入神经内科病房并进行 EEG 检查。我们根据萨尔茨堡诊断 EEG 标准将患者分为最终诊断为 NCSE 的患者（NCSE-p）和未诊断为 NCSE 的患者（非-NCSE）。计算诊断工具的灵敏度和特异性。SPECT 是在 Skylight SPECT（飞利浦医疗保健，阿姆斯特丹）上获得的。注射是在疑似 NCSE 的临床发作期间进行的。HMPAO-SPECT 由两位专家进行分析，并进行定量分析。所有数据均归一化为 SPM SPECT 模板。我们使用外部健康正常数据库为每个个体获得相对于正常数据库的 Z 分数图。从 AAL 图谱的每个区域提取 Z 分数最大值（Z），以及 Z 分数高于 2.5 的体素百分比（N（%））。对 Z、N（%）和患者年龄的影响进行逻辑回归拟合，以预测最终的 NCSE 诊断。获得接收器操作特性（ROC）曲线和曲线下面积（AUC），以评估分类性能。
我们纳入了 55 名患者，其中 21 名女性（38.9%），中位年龄为 62.1 岁（范围 25-84 岁）。36 名患者被诊断为 NCSE（62.9%）。初始 EEG 的灵敏度为 61.1%，特异性为 89%。大多数患者病情危急，诊断困难，这可能是 Salzburg 诊断 EEG 标准灵敏度低的主要原因之一。NCSE-p 中的 Z 和 N（%）明显高于非-NCSE（p=0.005 和 p<0.001）。HMPAO-SPECT 定性分析的灵敏度为 80.5%，特异性为 89.5%，而 QtSPECT 的灵敏度为 82%，特异性为 81%。
99mTc-HMPAO-SPECT 和 QtSPECT 均可用于 NCSE 的诊断。本文是“第七届伦敦-因斯布鲁克癫痫持续状态和急性发作研讨会论文集”特刊的一部分。
