CERAD und NOSGER: Der prädiktive Wert dieser Verfahren in der Demenzdiagnostik einer Schweizer gerontopsychiatrischen Patientenpopulation

Zusammenfassung: Hintergrund: Die CERAD-Batterie (Consortium to Establish a Registry for Alzheimer's Disease) ist ein gängiges Screeninginstrument in der Diagnostik der Alzheimer-Demenz. Dem NOSGER (Nurses Observation' Scale for Geriatric Patients), eigentlich entwickelt, um Verhaltensauffälligkeiten im Alltag zu erfassen, scheint bei der Alzheimer-Demenz auch eine diagnostische Bedeutung zuzukommen. Material und Methode: In einer retrospektiven Studie mit 400 Patienten unserer Klinik, die bei unterschiedlichen psychiatrischen Erkrankungen kognitive Störungen aufwiesen, haben wir CERAD und NOSGER mittels logistischer Berechnung in uni- und multivariaten Modellen auf ihren prädiktiven Wert für die Diagnose Demenz untersucht. Ergebnisse: Im univariaten Modell waren alle CERAD-Subtests signifikante Prädiktoren für Demenz. Das beste multivariate Modell umfasste die Subtests "Verbale Flüssigkeit", "Wortliste Abrufen", "Konstruktive Praxie Abrufen" und MMS (Mini-Mental Status). Der NOSGER zeigte keinen prädiktiven diagnostischen Wert. Schlussfolgerung: Innerhalb einer gerontopsychiatrischen Population grenzt der CERAD Demenzpatienten von nicht dementen mit hoher Vorhersagewahrscheinlichkeit ab, während der NOSGER keinen prädiktiven Wert für die Diagnose Demenz aufweis

EEG power and coherence in children with educational problems

SUMMARY: SUMMARY This study deals with the quantitative EEG (QEEG) of children attending schools for the mentally retarded and learning disabled. Questions are in which way do the EEGs of these children differ from normal development and whether deviations are restricted to a subgroup of children. The topographic distribution of EEG power is of particular interest. Based on a sample of n = 158 normal children, age-standardized values of absolute power (delta, theta, alpha 1, alpha 2, beta 1, beta 2 at F4, F3, C4, C3, CZ, PZ, O2, O1) and of coherence are computed for all children. The topographic distribution is assessed by analysis of variance (ANOVA) and by a principal component approach. The EEG of children with educational problems differs substantially from normal development in the slow bands and differs less in the fast bands. Deviations affect a subgroup of children, mainly children attending a school for the mentally retarded. Topographic distribution is an important factor in all bands. Coherence analysis leads to rather weak results that lack a clear interpretation. The QEEG is useful for understanding neurophysiological development in children with educational problems as a group more than individually. Parameters of topographic distribution provide strong additional information to power itself

Correction of muscle artefacts in the EEG power spectrum

OBJECTIVE: To provide a method for correcting muscle artefacts in fast band power at EEG derivations. METHODS: We define an indicator of surface EMG as power in the band 51.0-69.0 Hz ('muscle power'). This indicator is used to approximately eliminate the contribution of muscle activity on fast band power via a regression model. RESULTS: (1) Patients show a larger proportion of muscle activity in fast band power. (2) There is a clear topographic pattern, frontal-temporal derivations being most susceptible to EMG artefacts. (3) The contribution of surface EMG can be drastically reduced by the proposed correction method. (4) Without correction, results for fast bands can be biased when e.g. comparing control and patient groups and the proposed correction method by and large eliminates this bias. CONCLUSIONS: It is advisable to correct the quantitative EEG reflecting fast activity for the extent of EMG artefacts. SIGNIFICANCE: To render the quantitative EEG more valid as an indicator of cerebral activity

Alzheimer disease versus mixed dementias: An EEG perspective

To examine differences between patients with AD (n=54) and mixed (vascular Alzheimer) dementia (n=24), and controls (n=66), with respect to clinic, neuropsychology, neuroradiology and quantitative EEG (QEEG). METHODS: We used CAMDEX, CT and QEEG. RESULTS: Patients with mixed dementia had more subcortical lesions. Increased slow frequency EEG power was observed in mixed dementia compared to AD, whereas the level of high frequency power was nearly normal in mixed dementia, but decreased in pure AD. Topography of slow band power was unaltered in both groups, but was changed for fast bands. The Hachinski score and neuropsychological tests showed small differences between mixed dementia and pure AD. CONCLUSION: Neuroimaging and QEEG made a greater differential diagnostic contribution than clinical symptoms and neuropsychology. An alteration of slow frequency power with nearly normal high frequency power in mixed dementia may reflect subcortical pathology, whereas cortical pathology in pure AD may relate to decreased fast frequency power. With vascular pathology, less AD pathology is needed for a similar severity of dementia. SIGNIFICANCE: In dementia of the Alzheimer type a vascular component is often found - especially at an older age. The quantitative EEG can contribute to a better understanding of the interaction of the two components

Unrecognised long-lasting tramadol-induced delirium in two elderly patients. A case report

We present the cases of two elderly patients with intermittent long-term tramadol intake against chronic back pain. Over a period of more than two years they experienced fluctuating confusional states and cognitive deficits, reversible only after discontinuation of tramadol. According to the DSM IV-criteria, an unrecognised recurrent tramadol-induced delirium can be diagnosed in both cases. Although tramadol may represent a well established safe therapy for chronic non-malignant pain in the elderly, these cases demonstrate that it should be applied with caution even in healthy subjects

Rivastigmine effects on EEG spectra and three-dimensional LORETA functional imaging in Alzheimer’s disease

OBJECTIVE: The objective of the study is to investigate the electrocortical and the global cognitive effects of 3 months rivastigmine medication in a group of mild to moderate Alzheimer's disease patients. MATERIALS AND METHODS: Multichannel EEG and cognitive performances measured with the Mini Mental State Examination in a group of 16 patients with mild to moderate Alzheimer's Disease were collected before and 3 months after the onset of rivastigmine medication. RESULTS: Spectral analysis of the EEG data showed a significant power decrease in the delta and theta frequency bands during rivastigmine medication, i.e., a shift of the power spectrum towards 'normalization'. Three-dimensional low resolution electromagnetic tomography (LORETA) functional imaging localized rivastigmine effects in a network that includes left fronto-parietal regions, posterior cingulate cortex, bilateral parahippocampal regions, and the hippocampus. Moreover, a correlation analysis between differences in the cognitive performances during the two recordings and LORETA-computed intracortical activity showed, in the alpha1 frequency band, better cognitive performance with increased cortical activity in the left insula. CONCLUSION: The results point to a 'normalization' of the EEG power spectrum due to medication, and the intracortical localization of these effects showed an increase of cortical activity in frontal, parietal, and temporal regions that are well-known to be affected in Alzheimer's disease. The topographic convergence of the present results with the memory network proposed by Vincent et al. (J. Neurophysiol. 96:3517-3531, 2006) leads to the speculation that in our group of patients, rivastigmine specifically activates brain regions that are involved in memory functions, notably a key symptom in this degenerative disease

Correlation between disease severity and brain electric LORETA tomography in Alzheimer's disease

The present data support the hypothesis of an asymmetrical progression of the Alzheimer's disease