Biomagnetism from the neuropsychiatric viewpoint--principles of recent developments in diagnostic procedure

The following survey is intended to demonstrate and discuss some principle problems of biomagnetism and the application in clinical fields. The development of special technical parameters especially by the SQUID method is initiating new possibilities of research and completing the neurobiologically determinated basis and conditions of neuropsychiatric disorders. The Magnetoencephalography (MEG) will be represent an important role of a new functional diagnostic method.     

Electromagnetic articulography: use of alternating magnetic fields for tracking movements of multiple points inside and outside the vocal tract

The purpose of this paper is to present a new electromagnetic device which uses alternating magnetic fields for tracking movements of multiple points inside and outside the vocal tract. It is biologically safe, noninvasive, it does not interfere with speech movements, allows for multiple recording in the same subject, and for easy collection of large amounts of data. It is especially suitable for evaluation of patients with speech motor impairments.     

Automatic detection of transient potentials in the EEG

A classifier based on the linear regression model was developed to automatically detect sharp transients in EEG, matching the definition of spikes and sharp waves accepted by IFSECN. Practical applications proved the accuracy of the method which succeeded in detecting 84% of sharp transients previously found by an experienced electronencephalographer. Computerized search for sharp transients in EEG records will be particularly useful in long term EEG records obtained from epileptic patients.     

Status of perfusion scintigraphy in the diagnostic strategy in cerebrovascular disorders and space-occupying lesions

The results of an evaluation of the perfusion scintigraphy findings of 350 hospitalised neurological patients and 55 more strictly selected neurosurgical patients with cerebrovascular complaints, revealed an accuraty of 83%, a sensitivity of 89%, and a specificity of 83%. The selection of the patients had no influence on the results as a whole. Compared with contrast-medium angiography, incorrect diagnosis must be expected in 17% of the cases. This includes erroneous negative findings in 10% of the cases. Grounds for misinterpretations are suggested, and the biological and methodological limitations of the method are set forth.     

Neurochemical knowledge in electroconvulsive therapy (ECT)

The paper is concerned with an attempt to generalize and categorize current hypotheses on the biochemical basis of ECT. The hypotheses are critically evaluated with respect to the relevance of their experimental fundamentals. Thus, certain hypotheses are valid only in a qualified sense. Particular interest is focussed on those conceptions which try to correlate ECT-induced changes in synaptic receptor sensitivities (up-/down-regulation) with super- resp. subsensitivity hypotheses of psychoses. In this connection, noradrenergic and opioid systems on the one hand, and the axis hypothalamus-hypophysis on the other hand seem to play a dominant role.     

Principles of computer-assisted classification in psychiatry

The use of computer based diagnostic decision and artificial intelligence are discussed in relation to the problems of validity and reliability of psychiatric diagnoses. The authors suggest a definition of a computer aided classificator as an existent decision system for an automatically analysis of findings.     

Psychometric detection of depressive mood conditions

An investigation into the diagnostic value of psychometric methods for the diagnosis of depressive states involved five psychometric questionnaires, one concentration test procedure, and one problem-solving approach to register cognitive processes. The data obtained for 80 depressive patients of varied aetiology were compared with those of sample of 80 neurotics without depressive aberration. Even univariate comparisons revealed statistically significant differences between the two samples. Multivariate methods (factor analysis, discriminative analysis) yielded more differentiated information. The "Scale for depression depth measurements" was found to be of particular diagnostic relevance; it was standardized for the time being.