Adult guinea pigs with normal Preyer’s reflexes were used in this experiment and were di-vided into 3 groups according to the intensity of noise and exposure time.Auditory brainstemevoked response was recorded before...Adult guinea pigs with normal Preyer’s reflexes were used in this experiment and were di-vided into 3 groups according to the intensity of noise and exposure time.Auditory brainstemevoked response was recorded before and after exposure to noise.Clicks were presented monaurallyat a rate of high (50Hz) as well as low (10Hz).The superior olive and inferior colliculus were ob-served under an electron microscope after the guinea pigs were exposured to 110dB noise for30min.The average shift of wave Ⅳ amplitude-intensity function curve was more than that ofwave Ⅰ after exposure to intensive noise.The difference value of wave \ latency from low(10Hz) to high (50Hz) stimulus click rate decreased and was negatively correlated with the exposuretime.Ⅰ-Ⅴ,Ⅲ-Ⅴ and Ⅳ-Ⅴ interpeak latencies were shorter after exposure to noise.Themitochondria and neurilemma swelling were found in the superior olive and inferior colliculus afterexposure,Some mechanisms of the changes of auditory center were discussed in this paper.展开更多
Background Neurophysiologic monitoring during surgery is to prevent permanent neurological injury resulting from surgical manipulation. To improve the accuracy and sensitivity of intraoperative neuromonitoring, combin...Background Neurophysiologic monitoring during surgery is to prevent permanent neurological injury resulting from surgical manipulation. To improve the accuracy and sensitivity of intraoperative neuromonitoring, combined monitoring of transcranial electrical stimulation motor evoked potentials （TES-MEPs）, somatosensory evoked potentials （SSEPs） and brainstem auditory evoked potentials （BAEPs） was attempted in microsurgery for lesions adjacent to the brainstem and intracranial aneurysms. Methods Monitoring of combined TES-MEPs with SSEPs was attempted in 68 consecutive patients with lesions adjacent to the brainstem as well as intracranial aneurysms. Among them, 31 patients （31 operations, 28 of posterior cranial fossa tumors, 3 of posterior circulation aneurysms） were also subjected to monitoring of BAEPs. The correlation of monitoring results and clinical outcome was studied prospectively. Results Combined monitoring of evoked potentials （EPs） was done in 64 （94.1%） of the 68 patients. MEPs monitoring was impossible for 4 patients （5.9%）. No complication was observed during the combined monitoring in all the patients. In 45 （66.2%） of the 68 patients, EPs were stable, and they were neurologically intact. Motor dysfunction was detected by MEPs in 8 patients, SSEPs in 5, and BAEPs in 4, respectively. Conclusions A close relationship exists between postoperative motor function and the results of TES-MEPs monitoring TES-MEPs are superior to SSEPs and BAEPs in detecting motor dysfunction, but combined EPs serve as a safe, effective and invasive method for intraoperative monitoring of the function of the motor nervous system. Monitoring of combined EPs during microsurgery for lesions adjacent to the brainstem and intracranial aneurysms may detect potentially hazardous maneuvers and improve the safety of subsequent procedures.展开更多
文摘Adult guinea pigs with normal Preyer’s reflexes were used in this experiment and were di-vided into 3 groups according to the intensity of noise and exposure time.Auditory brainstemevoked response was recorded before and after exposure to noise.Clicks were presented monaurallyat a rate of high (50Hz) as well as low (10Hz).The superior olive and inferior colliculus were ob-served under an electron microscope after the guinea pigs were exposured to 110dB noise for30min.The average shift of wave Ⅳ amplitude-intensity function curve was more than that ofwave Ⅰ after exposure to intensive noise.The difference value of wave \ latency from low(10Hz) to high (50Hz) stimulus click rate decreased and was negatively correlated with the exposuretime.Ⅰ-Ⅴ,Ⅲ-Ⅴ and Ⅳ-Ⅴ interpeak latencies were shorter after exposure to noise.Themitochondria and neurilemma swelling were found in the superior olive and inferior colliculus afterexposure,Some mechanisms of the changes of auditory center were discussed in this paper.
文摘Background Neurophysiologic monitoring during surgery is to prevent permanent neurological injury resulting from surgical manipulation. To improve the accuracy and sensitivity of intraoperative neuromonitoring, combined monitoring of transcranial electrical stimulation motor evoked potentials （TES-MEPs）, somatosensory evoked potentials （SSEPs） and brainstem auditory evoked potentials （BAEPs） was attempted in microsurgery for lesions adjacent to the brainstem and intracranial aneurysms. Methods Monitoring of combined TES-MEPs with SSEPs was attempted in 68 consecutive patients with lesions adjacent to the brainstem as well as intracranial aneurysms. Among them, 31 patients （31 operations, 28 of posterior cranial fossa tumors, 3 of posterior circulation aneurysms） were also subjected to monitoring of BAEPs. The correlation of monitoring results and clinical outcome was studied prospectively. Results Combined monitoring of evoked potentials （EPs） was done in 64 （94.1%） of the 68 patients. MEPs monitoring was impossible for 4 patients （5.9%）. No complication was observed during the combined monitoring in all the patients. In 45 （66.2%） of the 68 patients, EPs were stable, and they were neurologically intact. Motor dysfunction was detected by MEPs in 8 patients, SSEPs in 5, and BAEPs in 4, respectively. Conclusions A close relationship exists between postoperative motor function and the results of TES-MEPs monitoring TES-MEPs are superior to SSEPs and BAEPs in detecting motor dysfunction, but combined EPs serve as a safe, effective and invasive method for intraoperative monitoring of the function of the motor nervous system. Monitoring of combined EPs during microsurgery for lesions adjacent to the brainstem and intracranial aneurysms may detect potentially hazardous maneuvers and improve the safety of subsequent procedures.
