定位的脳手術における微小電極記録

Micro-electrode Recordings in Stereotactic Functional Neurosurgery

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・淡蒼球内節（GPi）は高頻度で持続発火する神経活動を特徴とし，後腹側領域では感覚運動関連応答が記録できる．

・視床下核（STN）には不規則な発火を特徴とする神経細胞が密に存在し，背外側領域では感覚運動関連応答が記録できる．

・視床中間腹側核（Vim核）の外側領域では振戦に同期する神経活動を高率に認め，感覚運動関連応答を有する．

・GPi，STN，Vim核の感覚運動領域にはそれぞれ身体部位局在がある．

　Accurate targeting to the sensorimotor territory of the globus pallidus internus （GPi）, the subthalamic nucleus （STN）, and the thalamic ventral intermediate nucleus （Vim） is crucial for the stereotactic neurosurgery of lesioning or implantation of a deep brain stimulation electrode. Intra-operative micro-electrode recording can aid in the localization of these structures. Neurons in the GPi are characterized by high-frequency tonic discharge. The STN has a high density of neurons that show irregular discharge. The majority of neurons in the sensorimotor territory of the GPi and STN exhibit neuronal responses to passive manipulation or active movement of the limbs and orofacial parts, and they are somatotopically arranged. Neurons responding to movements of the legs, arms, and face were found along the dorsal-ventral axis in the posterolateral GPi and along the medial-lateral axis in the posterolateral STN. Similarly, in the lateral part of the thalamic Vim nucleus, most neurons exhibit kinesthetic responses that show well-organized somatotopic arrangement, with the leg on the dorsolateral side, arm on the medioventral side, and face on the more medial side. Some Vim neurons have rhythmic bursting discharges synchronous with limb tremor. These electrophysiological findings allow us to achieve better surgical results.