1993 Fiscal Year Final Research Report Summary
Study of transcranial magnetic responses
| Project/Area Number |
04671089
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
Ophthalmology
|
|---|
| Research Institution | Kawasaki Medical School |
|---|
Principal Investigator |
KAWASHIMA Sachio Kawasaki Medical School, Dept.of Medicine, lecture, 医学部, 講師 (80177675)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
FUKAI Sakuko 川崎医療福祉大学, 医療技術学部, 教授 (50238432)
KIMURA Hisashi 川崎医科大学, 医学部, 助教授 (70169936)
TABUCHI Akio 川崎医科大学, 医学部, 教授 (90122431)
|
|---|
| Project Period (FY) |
1992 – 1993
|
| Keywords | Transcranial magnetic stimulation / Safety / Electropysiological study / Pathological study / Saccadic eye movement / pupil reaction / Cervical sympathetic nerve |
|---|
| Research Abstract |
We investigated changes in background elctroencephaographic activity and visual evoked potential before, during and after transcranial magnetic stimulation in 10 healthy human volunteers. There were no significant differences in the power specrtum and topographical distribution of the background electroencephalographic activity or the major components in pattern reversal visual evoked potential between pre- and post transcranial magnetic stimulation. We also evaluated the long-term safety of these procedures in white rabbits that received transcranial magnetic stimulation over 5000 times (100 times per day) with a maximal intensity, (100%, 1.9T). No psychophysical or neurological deficits were observed after the transcranial magnetic stimulation. After the stimulation, the animals were sacrificed for the preparation of a histopathological study. There was no evidence of pathological change in the occipital cortex, subcortical visual pathway, thalamus, hypocampus, basal ganglions, brain stem, cerebellum, optic nerve or retina as compared with a normal control. The transcranial magnetic stimulation was considered as safe for short and middle term periods Ten normal human volunteers received transcranial magnetic stimulation with a maximal intensity of 1.9T to Brodmann area 8. Saccadic eye movement was suppressed when the transcranial magnetic stimulation was applied 100 msec prior to the onset of eye movement, but pursuit eye movement not changed. Area 8 was considered as a region where saccadic eye movement was programed. Pupil size was observed after the magnetic stimulation of maximal intensity of 1.9T was applied to the posterior cervical region near the seventh vertebra in 10 normal human volunteers. The pupillary dilatation rate extended to 14.0(〕SY.+-.〔)4.5%, and the onset latency was measured as 1.5(〕SY.+-.〔)0.49 second after the magnetic stimulation. The duration of mydriasis was 3.08(〕SY.+-.〔)1.84 seconds. It was speculated that mydriasis was evoked by the
|
