ヒト焦点性テンカンに対する単一神経細胞活動記録を中心とする分析

UNITARY ANALYSIS OF THE CORTICAL FOCI AND THEIR SURROUNDS IN THE HUMAN EPILEPSY

はじめに

　脳波上のテンカン性発射波と皮質細胞活動との関係は，1939年Adrian　＆　Moruzzi^1）により始めて論じられて以来，多数の報告がある。然しそれらは実験的テンカンによる研究であり，ヒトのテンカンと同一とはみなせない。

　ヒトテンカン脳の単一細胞活動記録の試みは，1955年Ward　＆　Thomas^18）により始めて報告され，次いで1967年Rayport　＆　Waller^16）により報告されているが，彼らのデータは必ずしも十分とはいえず，皮質脳波との相関などの分析はほとんどなされていない。

The extracellular unit recording was performed at and arround the epileptic foci of the two cases during operation.

One is 23 year old male with left occipital focal epilepsy and the other is 37 year old male with focus in the right post-central gyrus.

Analysis is made with special reference to the correlation between the surface epileptic events and their surroundings.

Summary

1) In the focus, we found many epileptic neurons which fire with the surface paroxysmal activity (positive neurons). But its firing is not definitely time locked with the paroxysmal activity, but it is scattered arrond the peak of the E. E. G. spikes.

2) We found the difference of the unit firing pattern between the focus and its surrounding area. At the focus almost all neurons fire with paroxy-smal activity, but in the surrounding area the population of positive neurons decreases. As to the activity of the positive neuron itself, it is higher in the focus than in the surrounding area as indicated by the firing index (the degree of cor-relation of individual neuronal activity).

3) We can not find any negative neuron (its fir-ing stops during paroxysmal events) in the sur-rounding area. We can not verify the "Surround Inhibition" proposed by D. A. Prince in 1967.

4) We observed the unit firing during total course of seizure induced by metrazol injection (100 mg).

5) We found the unit which showes the long lasting firing in the rising phase of the 6 wave burst in the surrounding area.