Introduction to Electroencephalography

This chapter presents an introduction to electroencephalography, a non-invasive electrophysiological monitoring method to record electrical activity of the brain. It discusses waveforms in the electroencephalogram (EEG), and EEG changes with general anaesthesia. It covers EEG neurobiology, effects of different drugs (e.g., opioids, NMDA blockers, GABAergic intravenous induction agents, hydrocarbon-based volatile anaesthetic drugs), EEG changes as a function of patients’ age, and the titration of anaesthesia. It also covers special concepts in anaesthetic monitoring, including power spectrum, spectral edge frequency, spectrogram, cross frequency coupling and coherence, proprietary pEEG indices, EEG measures of connectivity, and artefacts. Finally, it discusses future directions within the specialty.

Effects of rivastigmine and memantine alone and in combination on learning and memory in rats with scopolamine-induced amnesia

Background: Cholinesterase inhibitors and glutamate blockers are commonly used for the treatment of cognitive impairment in Alzheimer’s disease. The aim was to evaluate the effects of rivastigmine and memantine alone or in combination in rats with scopolamine-impaired memory. Method: 5 groups of rats were used: control, scopolamine (model), model with rivastigmine, model with memantine, and model with both drugs. Active avoidance test was performed and the number of conditioned responses, unconditioned responses and intertrial crossing were recorded. Passive avoidance tests step-through with criteria latency of reaction 180 s in the light chamber and step-down with criteria latency of reaction 60 s on the platform were done. Results: Control rats learned the task and kept it on memory tests. Scopolamine treated rats failed to perform it. The rivastigmine, memantine and its combination groups showed increased CRs during learning and memory retention tests. In both passive avoidance tests an increased latency of reaction was observed in the drug treated groups. Conclusion: The combination of both drugs rivastigmine and memantine is more effective than the use of the single drug in cognitive impaired rats. Cholinesterase inhibitors and NMDA blockers may be combined in the treatment of different kind of dementias.