著者

Takamitsu YAMAMOTO Yoichi KATAYAMA Toshiki OBUCHI Kazutaka KOBAYASHI Hideki OSHIMA Chikashi FUKAYA

出版者

社団法人 日本脳神経外科学会

雑誌

Neurologia medico-chirurgica (ISSN:04708105)

巻号頁・発行日

vol.52, no.7, pp.475-481, 2012 (Released:2012-07-25)

参考文献数

32

被引用文献数

3 29

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Minimally conscious state (MCS) is characterized by inconsistent but clearly discernible behavioral evidence of consciousness, and can be distinguished from coma and the vegetative state (VS). Ten MCS patients were evaluated neurologically and electrophysiologically over 3 months after the onset of brain injury, and were treated by spinal cord stimulation (SCS). A flexible four-contact, cylinder electrode was inserted into the epidural space of the cervical vertebrae, and placed at the C2-C4 levels. Stimulation was applied for 5 minutes every 30 minutes during the daytime at an intensity that produced motor twitches of the upper extremities. We used 5 Hz for SCS, considering that the induced muscle twitches can be a useful functional neurorehabilitation for MCS patients. Eight of the 10 MCS patients satisfied the electrophysiological inclusion criteria, which we proposed on the basis of the results of deep brain stimulation for the treatment of patients in the VS. Seven patients recovered from MCS following SCS therapy, and were able to carry out functional interactive communication and/or demonstrate the functional use of two different objects. Cervical SCS increased cerebral blood flow (CBF) diffusely in the brain, and CBF increased by 22.2% during the stimulation period compared with CBF before stimulation in MCS patients (p < 0.0001, paired t-test). Five-Hz cervical SCS could increase CBF and induce muscle twitches of the upper extremities. This SCS therapy method may be suitable for treating MCS.

著者

Hideki OSHIMA Yoichi KATAYAMA

出版者

社団法人 日本脳神経外科学会

雑誌

Neurologia medico-chirurgica (ISSN:04708105)

巻号頁・発行日

vol.50, no.9, pp.845-852, 2010 (Released:2010-09-25)

参考文献数

50

被引用文献数

4 12 6

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The theoretical basis of some deep brain stimulation (DBS) trials undertaken in the early years was the phenomenon of “brain stimulation reward (BSR),” which was first identified in rats. The animals appeared to be rewarded by pleasure caused by the stimulation of certain brain regions (reward system), such as the septal area. “Self-stimulation” experiments, in which rats were allowed to stimulate their own brain by pressing a freely accessible lever, they quickly learned lever pressing and sometimes continued to stimulate until they exhausted themselves. BSR was also observed with DBS of the septal area in humans. DBS trials in later years were undertaken on other theoretical bases, but unexpected BSR was sometimes induced by stimulation of some areas, such as the locus coeruleus complex. When BSR was induced, the subjects experienced feelings that were described as “cheerful,” “alert,” “good,” “well-being,” “comfort,” “relaxation,” “joy,” or “satisfaction.” Since the DBS procedure is equivalent to a “self-stimulation” experiment, they could become “addicted to the stimulation itself” or “compulsive about the stimulation,” and stimulate themselves “for the entire day,” “at maximum amplitude” and, in some instances, “into convulsions.” DBS of the reward system has recently been applied to alleviate anhedonia in patients with refractory major depression. Although this approach appears promising, there remains a difficult problem: who can adjust their feelings and reward-oriented behavior within the normal range? With a self-stimulation procedure, the BSR may become uncontrollable. To develop DBS to the level of a standard therapy for mental disorders, we need to discuss “Who has the right to control the mental condition?” and “Who makes decisions” on “How much control is appropriate?” in daily life.