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Biomedical subjects

A Kotani

Publications and source records attributed to A Kotani.

At least 73 records · Page 4Linked to original sources
PubMed1977

[Modulating mechanism of the dorsal column stimulation for pain relief (author's transl)].

The neural mechanism of the modulating effects of spinal cord stimulation upon intractable pain was studied in cats under local anaesthesia. The electrical activity at the centre median nucleus of the thalamus (CEM), which responded to noxious stimuli and was inhibited by nitrous oxide inhalation, was recorded as an indicator of the degree of pain sensation. The suppressed effect upon the evoked potential responding to sciatic stimulation (1 Hz) was recorded during and after train stimulation of various parts of the spinal cord by means of silver ball bipolar electrode. Whenever inhibitory modulating effect upon CEM response was observed by spinal cord stimulation, the bilateral dorsal tractotomy cranial, caudal or both to the stimulating point in order to examine the influence upon the CEM potential. The results are as follows: 1) The CEM evoked potential responding to sciatic stimulation is inhibited by about 30-45% of its amplitude by dorsal column stimulation. This effect corresponds to the inhibitory effect by 75% N2O gas inhalation. Upon dorsal column stimulation, the intraspinal electrical activity is found in the central gray matter the antero-lateral quandrants of the spinal cord as well as the dorsal column. 2) Following lateral or anterior column stimulation as well as dorsal column stimulation, the CEM evoked potential responding to sciatic stimulation is inhibited by about 50% of its amplitude. 3) Following bilateral dorsal tractotomy cranial, caudal or both to the stimulating point, the CEM evoked potentials responding to sciatic stimulation are inhibited by dorsal column stimulation. According to the experimental results, it may be concluded that the inhibitory modulating mechanism by dorsal column stimulation for pain relief is not only mediated through the dorsal column, but also through other ascending spinal pathways.

Animals↗
PubMed1975

[Treatment for traumatic aneurysm of the cerebral artery--identification between deteriorating type and spontaneously disappearing type (author's transl)].

Thirty five cases of traumatic aneurysm of the cortical cerebral artery were reviewed in the literatures cited in the references. Five cases of them healed spontaneously without operative treatment (disappearing type), the other cases underwent direct operation of aneurysm, in spite of high operative moltality or mobility (deteriorating type). Recently four cases of traumatic aneurysm of the cortical cerebral artery were treated in our clinic. Three cases which had the aneurysm in the pericallosal artery (1 case) and middle cerebral artery (2 cases) respectively underwent radical operation for treatment as progressively deteriorating type and fourth case which had the aneurysm in the peripheral part of the frontopolar artery was treated by medication as the spontaneously disappearing type until the aneurysm disappeared on the angiogram. According to the review of literatures, it is the most important for the treatment of tramatic aneurysm to know whether disappearing type or deteriorating type, because deteriorating type had bad prognosis without radical operation and the prognosis of disappearing type was excellent without operation. Analysing the clinical signs and angiographical findings of the all cases, the authors found out some specific characteristics of the spontaneously disappearing type. are (1) The aneurysm is found in the relativery late post traumatic stage except for cases caused by penetrating wound, (2) The irregular shape, uneven opacity of the aneurysm without clear neck connecting with pearent artery on angiography, (3) Shape and size of the aneurysm in follow up angiogram (two weeks or more) became smaller, (4) Around of aneurysm, there are not any kind of intracranical hemetoma. According to these results, differential diagnosis between spontaneously disappearing type and deteriorating type was done in the author's four cases and the three cases of deteriorating type were relieved by radical operation without any postoperative disability and one case of spontaneously disappearing type was treated by medical treatment until disappear of aneurysm. It is concluded that traumatic aneurysm of the cortical cerebral artery is relative rare and it is important to know whether deteriorating type or spontaneously disappearing type in order to get excellent results.

Adolescent↗