SUMMARY Background. Quantitative electroencephalography (qEEG) analysis incorporating the use of normative or reference database comparison has developed from being primarily a research tool into an increasingly widely used method for clinical neurophysiological evaluation. Method. A survey of several of the most widely used qEEG databases as well as issues surrounding the construction and use of these databases is presented, comparing and contrasting the various features of these databases, followed by a discussion of critical issues in this developing technology. Results. This review considers the concept of normalcy, norming of qEEG features, and validation of clinical findings. Technical issues such as methods for recording and analysis, filter use, broad bands versus single Hz finer frequency resolution, the number of variables relative to the number of cases, and the problem of multiple statistical testing are addressed. The importance of the recording electrode and montage reformatting for normativ...

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Use of Databases in QEEG Evaluation

Evoked potential monitoring is a standard examination method in neurological intensive therapy units. Previously, multimodality observation was only possible in follow-up examinations. First experience with a new bed-side system continuously monitoring 12 neurophysiological and clinical parameters is reported. It consists of a personal computer and various stimulation units. EEG activity, median nerve somatosensory evoked potentials (SEPs) and brainstem auditory evoked potentials (BAEPs) are recorded. Additionally, EEG spectral band power, heart rate, heart rate variability, intracranial presure, body temperature, expiratory PCO2, blood pressure and transcutaneously measured oxygenation can be monitored. This paper reports on 4 exemplary cases of the 33 patients we have monitored to date, illustrating the principles and main advantages of the system. The system was developed to support the observation of ICU patients as well as to aid therapeutic decisions. It supports the clinical determination of brain death by specifying the deterioration of various neurological systems.

Continuous multivariable monitoring in neurological intensive care patients--preliminary reports on four cases.

The purpose of this study was to investigate brain bioelectrical activity during hyperbaric oxygenation by continuous and simultaneous monitoring of electroenccphalographic and bimodal (auditory, somatosensory) evoked potentials. Multivariable recordings (electroencephalogram, brainstem auditory evoked potentials, early somatosensory evoked potentials, heart rate, heart rate variability, and transcutaneous partial pressure of oxygen) were measured with a new technique in 12 healthy male volunteers 26 to 52 years old (mean ± SD, 35.9 ± 9.5 years). Recordings were obtained while the subjects breathed (1) air at normal atmospheric pressure, (2) 100% oxygen at normal atmospheric pressure, (3) air at 2 atm (10 meters sea water [msw]), and (4) 100% oxygen at 2 atm (10 msw). Spontaneous brain electrical activity, somatosensory evoked potentials, and heart rate variability were not significantly affected during hyperbaric oxygenation, whereas the heart rate showed a significant decrease (pairedt test,P < 0.05). Alterations in brainstem auditory evoked potentials were seen under hyperbaric conditions and did not reach statistical significance (increase of the I-V interpeak latency by pairedt test;P < 0.2). All subjects showed insignificant increases in dominant alpha frequency and decreases in delta frequency under hyperbaric situations.

Electroencephalographic and evoked potential monitoring in the hyperbaric environment

The activation of neuronal structures and systems in the brain is accompanied by changes of the electrical potentials recorded from the scalp. Evoked potentials (EP) can be used to study brain functions in the intensive care unit and the operating room, in addition to spontaneous cerebral electrical activity (electroencephalography, EEG) [1-5].

Present and Future Trends in Multimodal Cerebral Monitoring in Anesthesia and Intensive Care

Brain Function Monitoring: A New Method for Simultaneous Recording and Processing of EEG-Powerspectra and Brainstem Potentials (BAEP) - Hirnfunktionsüberwachung: Eine neue Methode zur simultanen Registrierung und Verarbeitung von EEG-Leistungsspektren und Hirnstammpotentialen

ERD(Event-Related-Desynchronization)-Mapping — ein neues Verfahren für die funktioneile Hirndiagnostik - ERD(Event-Related-Desynchronization)-Mapping - a New Method for Functional Diagnosis of the Brain

Die vorliegende Arbeit beschreibt ein Gerät, welches den Bedingungen bei wissenschaftlichen -und klinischen Untersuchungen evozierter Potentiale besonders Rechnung trägt. Neben periodischen Impulsfolgen stehen auch solche mit zeitlich statistischer Verteilung zur Verfügung. Die Reizimpulse können strömoder spannungskonstant appliziert werden. Bei größeren Artefakten im EEG erfolgt für die Dauer der Störung automatisch eine Blockierung der Reizimpulse, ebenso kann die Auslösung vom Überoder Unterschreiten des a-Anteiles im EEG abhängig gemacht werden. Die Arbeit .umfaßt eine Beschreibung des Gerätes, Besprechung der Baugruppen und wesentlicher Schaltungsteile sowie die Angabe technischer Daten.

S. Schuy

Papers

Brain Function Monitoring: A New Method for Simultaneous Recording and Processing of EEG-Powerspectra and Brainstem Potentials (BAEP) - Hirnfunktionsüberwachung: Eine neue Methode zur simultanen Registrierung und Verarbeitung von EEG-Leistungsspektren und Hirnstammpotentialen

ERD(Event-Related-Desynchronization)-Mapping — ein neues Verfahren für die funktioneile Hirndiagnostik - ERD(Event-Related-Desynchronization)-Mapping - a New Method for Functional Diagnosis of the Brain

Elektrischer Stimulator mit statistischen und periodischen Reizimpulsfolgen und automatischer Blockierung bei störendem EEG-Verlauf

[Recording and evaluation of electrophysiological parameters from engine drivers during real driving situations (author's transl)].

A computerized model of cerebrovascular circulation