癲癇発作時脳波の研究

緒言

　脳波がテンカン診断に果す役割りについては誰しも異論のないところであるがテンカンの脳波所見といつても主として非発作時の脳波所見であつて，テンカン発作中の脳波変化に関してはさほど業績は多くなく，また各研究者間に必ずしも意見の一致がみられていない様である。

　これは通常の脳波描記に際して，自然発作の起ることは極めて少ないこと，又発作が起つた場合にはartifactsの混入が記録を信頼し難いものとするからである。誘発発作の際も同様である。これ等が発作時脳波変化に関する業績が少ない理由であつて，わずかにGibbs^17），Penfield, Jasper^42），Gastaut^{19），20）}，Ajmone-Marsan^1）等^{11），41），49），61），62）66），71），72）}少数の報告をかぞえるにすぎない。

　EEG changes of epilepsy during the ictal period are well known, as compared to those inthe interictal period.

　The most annoying impediment in tracing ofseizure patterns is muscle movement artifacts, whether the seizure is spontaneous or induced. The author has applied a synthetic curare-likedrug (S. C. C.), which practically does not modify the EEG, to eliminate muscle movementartifacts.

　Most of the seizures studied were induced byintravenous drip infusion of pentylenetetrazol (Pentazol) with the speed of 1mg/kg/30sec, thetotal doses being 500mg to 1,000mg.

　By means of curarization, all ictal EEG manifestations could be recorded from the start to theend.

　A group of 31 patients (6 female and 25 male), ranging in age from 11 to 48, were studied.They were classified as grand mal-4, psychomotor seizure-19, other focal seizure-6, andpetit mal-2.

　The results are as follows.

　1) The application of curarization for the study of seizure patterns is clinically useful procedure.

　2) Grand mal is characterized by rhythmicspikes, predominantly in the neocortex.

　3) Ictal automatism is characterized by rhythmic spikes in the hippocampal formation, amygdala, and the temporal pole and by slow wavesin the neocortex.

　4) Dreamy state seizure is characterized byrhythmic spikes in the lateral temporal cortex.

　5) The seizure patterns of petit mal are 3c/sspike-and-wave in all leads, predominantly inthe frontal leads, as reported hitherto.

　In order to analyse the seizure patterns, animal (cat) experiments were performed on 13abult cats.

　Spiking foci were established, utilizing penicillin suspension (30×10⁴units/cc). Cortical epileptiform lesions were made by using 3mm cotton ball, soaked in penicillin suspension. Subcortical lesions were made by injecting a smallquantity of penicillin suspension (0.05cc), utilizing a needle (diameter 0.7~0.8mm), which wasleft as an electrode.

　Pentazol activation was carried out by intraperitoneal injection.

　The correlation between the induced seizuresof men and animals was discussed.

　1) The induced ictal EEG patterns of cats,of which spiking foci were produced in the mesencephalic reticular formation, were resembling.to human grand mal EEG patterns.

　2) The induced ictal EEG patterns of cats, of which spiking foci were produced in the hippocampal formation and the cortex, were similar to psychomotor seizure (ital automatism)and focal convulsive seizure respectively.

　These facts present a strong suggestion as tothe pathophysiological mechanism of these seizures.