PubMed · 15442433
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
P PUECH, H FISCHGOLD. 1950-07-22. [Electroencephalography; introduction].. https://pubmed.ncbi.nlm.nih.gov/15442433/
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
OBJECTIVE: The EEG provides an objective staging of hepatic encephalopathy (HE), but its interpretation may be biased by inter-observer variability. This study aims at comparing an entirely automatic EEG classification of HE based on an artificial neural network-expert system procedure (ANNES) with visual and spectral analysis based EEG classifications. METHODS: Two hundred and thirty-eight consecutive cirrhotic patients underwent closed-eye EEG. They were followed up for up to one-year to detect bouts of overt HE and death. The EEG was classified by ANNES, qualitative visual reading, main basic rhythm frequency and spectral analysis. The classifications were assessed on the basis of: (i) match with liver function, (ii) prognostic value and (iii) repeatability. RESULTS: All classifications were found to be related to the severity of liver failure, with cognitive findings and a history of previous bouts of HE. All of them had prognostic value on the occurrence of overt HE and on survival. The ANNES based classification was more repeatable than the qualitative visual one, and had the advantage of detecting low power EEG, but its efficiency in analyzing low-grade alterations was questionable. CONCLUSIONS: An entirely automatic - ANNES based - EEG classification of HE can improve the repeatability of EEG assessment, but further improvement of the device is required to classify mild alterations. SIGNIFICANCE: The ANNES based EEG grading of HE needs further improvements to be recommended in clinical practice, but it is already sufficient for detecting normal and clearly altered EEG tracings.
RATIONALE: There is a growing psychopharmacological literature on the use of Acute Tryptophan Depletion (ATD) for experimental modulation of the serotonergic system. To date, no systematic review has been undertaken assessing the neurophysiological effects following this acute central 5-HT manipulation. MATERIALS AND METHODS: A comprehensive MEDLINE, EMBASE, PsycINFO search was performed for reports on neural substrates of Acute Tryptophan Depletion in healthy individuals and in clinical population. RESULTS: Twenty-eight placebo-controlled studies were included in the review. Although tryptophan depletion reduced plasma serotonin levels in all studies, significant effects on mood were only observed in studies with recovered depressed patients. In functional neuroimaging studies ATD was consistently found to modulate cortical activity in prefrontal areas implicated in mnemonic and executive functions and in orbitofrontal, cingulate, and subcortical regions associated with emotional processing. Electrophysiological studies indicated that ATD has a significant effect on both "selective" and "involuntary" attention. CONCLUSIONS: The combination of ATD with modern brain imaging techniques allows the investigation of the neurophysiological effects of reduced 5-HT synthesis on global brain activity, executive functions, memory, attention, and affect.
Explore the source record for details and available documents.