[Anesthesia in magnetic resonance tomography]. / Provedenie anestezii pri magnitno-rezonansnoi tomografii.

Sixty patients were anesthesized for MRI. Intravenous and/or intramuscular anesthesia with ketamine, diazepam, pipolphen (promethazine) was supplemented by aminazine (chlorpromazine) or tisercin for adult patients. Spontaneous respiration was maintained, which helped avoid problems with endotracheal intubation and assisted ventilation. The method is safe, economic, and its side effects are negligible. Main features of MRI and specific anesthesiological problems associated with this method are discussed.

[Monitoring of eye movements in surgery of the brain stem and parastem structures]. / Monitoring dvizhenii glaz pri khirurgicheskikh vmeshatel'stvakh na stvole mozga i parastvolovykh strukturakh.

Intraoperative electrooculograms (EOG) of 44 patients with bulky formations in the posterior cranial fossa demonstrated a good correlation of the sum of EOG waves caused by mechanical stimulation (aspiration, retraction, etc.) and the sum of complexes of EOG waves, on one hand, and the outcome, on other, in patients with brain stem involvement and less so in those with involvement of the cerebellum. The method is not informative for predicting the status of stem structures in surgery on the pontocerebellar angle. Stimulation of cerebral tissue caused by electrocoagulation cannot be recognized by EOG because it is associated with electric artefacts.

[Monitoring of short latent evoked potentials during brain stem surgery]. / Monitoring korotkolatentnykh vyzvannykh potentsialov vo vremia operatsii na stvole golovnogo mozga.

The studies were carried out in 33 patients with intrastem volumetric tumors. In 6 patients the monitoring was impossible because of technological problems. Somatosensory evoked potentials (SSEP) were recorded in 10 and acoustic stem evoked potentials (ASEP) in 18 out of 27 patients and the findings correlated to changes in the neurological status on day 1 postoperation. In 3 out of 9 patients operated on in a sitting posture SSEP monitoring during the main stage of the operation became impossible because the response disappeared due to an air layer above the parietal cortex. Transitory or constant changes in SSEP at the stage of tumor removal were detected in 5 patients. In 9 patients intraoperative changes in ASEP were recorded. False-positive results of ASEP monitoring were obtained in 4 cases. In 2 cases a discrepancy between intraoperative changes of SSEP and the postoperative neurologic deficit were detected. The authors discuss the technological and methodological problems of intraoperative monitoring of evoked potentials and approaches to solution of these problems.