Barrington S F, Koutroumanidis M, Agathonikou A, Marsden P K, Binnie C D, Polkey C E, Maisey M N, Panayiotopoulos C P
The Guys and St Thomas' Clinical PET Centre, London, UK.
Epilepsia. 1998 Jul;39(7):753-66. doi: 10.1111/j.1528-1157.1998.tb01162.x.
EEG is widely used during positron emission tomography (PET) to confirm the interictal state of the patient and assist in scan interpretation when a seizure occurs. Ictal scans usually reflect mixed interictal-ictal-postictal metabolic activity as seizures are brief in comparison to the 30-min uptake period of the tracer. We wished to determine whether routine EEG is justified and if seizures commonly affect the diagnostic information of the PET scan.
We examined the PET scans of 6 of 236 outpatients with intractable epilepsy with clinical and electrical evidence of a seizure during tracer uptake. We performed semi-quantitative analysis in 2 patients who had "ictal" and control interictal scans.
Patients with single seizures lasting 23 s to 4 min [four complex partial seizures (CPS) and one absence seizure (AS)] had focal hypometabolism concordant with results of other investigations. One patient with complex partial status had irregular cortical uptake and focal hypometabolism, but the site of the ictal focus could not be confirmed.
In this group of patients, seizures occurred infrequently during tracer uptake. The interpretation of the PET scan when single seizures occurred did not appear to be influenced by the continuous scalp EEG (CSEEG) recordings. The value of routine CSEEG in outpatients treated with medication should be reappraised, with potential cost savings. In rare circumstances in which a true ictal study occurs (complex partial status, epilepsia partialis continua, and repetitive CPS), PET scanning may be inconclusive and repeat interictal scanning should be pursued.
在正电子发射断层扫描（PET）期间广泛使用脑电图（EEG）来确认患者的发作间期状态，并在癫痫发作时协助扫描解读。发作期扫描通常反映发作间期 - 发作期 - 发作后期的混合代谢活动，因为与示踪剂30分钟的摄取期相比，癫痫发作很短暂。我们希望确定常规EEG是否合理，以及癫痫发作是否通常会影响PET扫描的诊断信息。
我们检查了236例难治性癫痫门诊患者中的6例患者的PET扫描，这些患者在示踪剂摄取期间有临床和电生理证据表明发生了癫痫发作。我们对2例进行了“发作期”和对照发作间期扫描的患者进行了半定量分析。
单次发作持续23秒至4分钟的患者[4例复杂部分性发作（CPS）和1例失神发作（AS）]有局灶性代谢减低，与其他检查结果一致。1例复杂部分性癫痫持续状态患者有不规则的皮质摄取和局灶性代谢减低，但发作期病灶部位无法确定。
在这组患者中，示踪剂摄取期间癫痫发作很少见。单次发作时PET扫描的解读似乎不受连续头皮脑电图（CSEEG）记录的影响。对于接受药物治疗的门诊患者，常规CSEEG的价值应重新评估，可能会节省成本。在罕见的真正发作期研究情况（复杂部分性癫痫持续状态、部分性癫痫持续状态和重复性CPS）下，PET扫描可能无定论，应进行重复发作间期扫描。
