Kanemura H, Sano F, Sugita K, Aihara M
Department of Pediatrics, Faculty of Medicine, University of Yamanashi, Yamanashi, Japan.
Neuropediatrics. 2011 Oct;42(5):200-3. doi: 10.1055/s-0031-1291222. Epub 2011 Oct 20.
Petit mal absence has been reported with 3-Hz generalized spike-and-wave discharges induced by secondary bilateral synchrony. Absence seizure may be present in patients with frontal lobe epilepsy. The thalamic rhythmogenic mechanisms responsible for spike-and-wave discharges have been investigated, providing a better understanding of the underlying anatomico-physiological mechanisms. We report the thalamocortical coupling in a patient with frontal absence by performing synchronous ictal single photon emission computed tomography (SPECT) analysis. Ictal SPECT revealed thalamic hyperperfusion combined with ipsilateral frontal cortical hyperperfusion in the patient. Moreover, lateral indexes of cerebral blood flow in the frontal region and thalamus were higher than those from non-epileptic control subjects. Thalamocortical coupling was thus revealed by ictal SPECT. Frontal absences should be considered as a secondarily generalized epilepsy syndrome originating from the frontal regions. The thalamus may play a crucial role as a pacemaker of rhythmic electroencephalographic activities such as secondary bilateral synchronous discharges in patients with frontal absences.
失神小发作曾被报道与继发双侧同步化所诱发的3赫兹广泛性棘慢复合波放电有关。额叶癫痫患者可能会出现失神发作。对负责棘慢复合波放电的丘脑节律发生机制进行了研究，从而对潜在的解剖生理机制有了更好的理解。我们通过进行同步发作期单光子发射计算机断层扫描（SPECT）分析，报告了一名额叶失神患者的丘脑皮质耦合情况。发作期SPECT显示该患者丘脑血流灌注增加，同时同侧额叶皮质血流灌注也增加。此外，额叶区域和丘脑的脑血流侧向指数高于非癫痫对照受试者。因此，发作期SPECT揭示了丘脑皮质耦合。额叶失神应被视为起源于额叶区域的继发性全身性癫痫综合征。丘脑可能作为节律性脑电图活动的起搏器发挥关键作用，如额叶失神患者的继发双侧同步放电。
