The Clinical Study Of Cerebral Evoked Magnetic Fields In Acute Cerebral Infarction By Magnetoencephalgraphy

In recent years, there are a obvious increasing in the rate of incidence and sequelae of acute cerebral infarction in our country. With the development of neuroscience, the mortality is under the control. But the rate of sequelse is still high. which affect the quality of living of the patients badly and consume much social care resource and wealth. The progress of medical imageology us measure the focus accurately now. But we can't measure the injury of cerebral function directly and objectively.which impede the advance of the study on cerebral remedy mechanism and is harmful to select the most effective therapy. The cerebral activities are always accompanied by cerebral electromagnetic activities which contain a great deal of message of cerebral function and the cerebral magnetic signal can transfer through the skull without being interfered. But it is difficult to be detected for its signal is too faint and the noise is too intense. super-conducting quantum interfere device(SQUID) that was invented in 1970s brought human being the strong power to detect the cerebral magnetic signal clearly, which made Magnetoencephalography(MEG) can apply to clinic indeed. With the reform from single-channelbiomagnetometer to mutil-channel device, there was a great improvement in the speed and precision of MEG.The merging of the technologies of MEG and magnetic source imaging(MRI) resulted in a new medical imaging method-MSI(magnetic source imaging, MSI).It is a non-invasive examining technique on cerebral function with high temporal resolution and spatial resolution and location capacity in anatomic tomography. We measured somatosensory evoked magnetic fields and auditory evoked magnetic fields of healthy objects and patients of acute cerebral infarction by 306-channels magnetoencephalgraphy. The objective is to study the MSI of somatosensory evoked magnetic fields(SEFs)and auditory evoked magnetic fields(AEFs) of acute cerebral infarction patients and to assess the injury to cerebral function. There are two part in this paper, which is(1) The clinical study of somatosensory evoked magnetic fields in patients with acute cerebral infarction by magnetoencephalgraphy;(2) The clinical study of auditory evoked magnetic fields in patients with acute cerebral infarction by magnetoencephalgraphy. The results are as follows:1 The clinical study of somatosensory evoked magnetic fields in patients with acute cerebral infarction by magnetoencephalgraphyObjective: To study somatosensory evoked magnetic fields in patients with acute cerebral infarction bymagnetoencephalgraphy(MEG). Methods:Somatosensory evoked magnetic fields (SEFs) were recorded from 15 acute cerebral infarction patients by a 306-channel whole-head MEG made by 4D Neuroimaging company(U.S.A) and 16 healthy volunteers were examined as control group. All subjects were imaginged by 1.5Tesla MR made by GE(U.S.A).Electric stimulation were given to all the subjects' left and right wrist median nerve. The interstimulus intervals (ISI) was 0.5s. The MSI of primary somatosensory cortex was gotten by superimposing MEG data on MRI. The peak of SEFs were estimated by equivalent current dipole(ECD). Results:M20,M35 and M60 (M20,M35 and M60 are the somatosensory evoked responses about 20ms,35ms and 60ms respectively after the somatosensory stimuli)were the most elemental components of SEFs. Their ECDs were located in the hand area of the primary somatosensory cortex. Several abnormity were presented in the patients group, that is: The interhemispheric difference of the M20 positions was more evident In patients group (P<0.01); The strength of ECD was smaller in affected hemisphere(P<0.01); The peak latency of M20 responses was longer than control group(P<0.01). 2 The clinical study of auditory evoked magnetic fields in patients with acute cerebral infarction by magnetoencephalgraphyObjective:To study auditory evoked magnetic fields in patients with acute cerebal infarction bymagnetoencephalgraphy(MEG). Methods: Auditory evoked magnetic...