K. Maurer

Dementia of the alzheimer type: Effects on the spontaneous EEG described by dipole sources

The present study on brain electrical activity in healthy subjects (n = 35) and patients suffering from dementia of the Alzheimer type (DAT; n = 35) used Fast Fourier Transformation-dipole approximation to quantify differences between the two groups. DAT patients showed a shift of alpha and beta activity toward frontal brain regions. The amount of this shift correlated with the degree of dementia. The relative distribution of magnitude of activity between the frequency bands differed between DAT patients and control subjects. DAT patients had higher magnitudes in the slow frequency range, correlating with the severity of dementia, and lower ones in the alpha and beta range compared with findings in age-matched control subjects.

Amplitudes of auditory P300 in remitted and residual schizophrenics : correlations with clinical features

The parameters of auditory P300 were studied with reference-independent methods in a group of 18 remitted and residual schizophrenics, and in 18 age- and sex-matched controls. In the schizophrenic group, significant inverse correlations were found between P300 amplitudes and level of psychopathology assessed with the Scale for Assessment of Negative Symptoms and with the Brief Psychiatric Rating Scale. Clinical variables regarding social functioning and adaptation, assessed with the Schedule for Affective Disorders and Schizophrenia, and with axis V of DSM-III-R, correlated significantly with low amplitudes. The scalp locations of the maxima and minima of the P300 potentials had the tendency to be dislocated to the right in schizophrenics compared with controls. The results indicate low P300 amplitudes to be associated with pervasive cognitive impairment. Future studies will determine whether low P300 amplitudes have prognostic validity for course and outcome of schizophrenic disorders.

Topography of the quantitative electroencephalogram in dementia of the Alzheimer type : relation to severity of dementia

Conventional electroencephalographic (EEG) frequency bands and peak frequency were investigated in patients with probable dementia of the Alzheimer type (DAT). Measures of EEG topography and activity were also related to the severity of dementia, as assessed by neuropsychological tests. EEG activity measured in conventional frequency bands proved to be the most sensitive parameter for the quantitative differentiation of DAT, whereas the topography of peak frequency was the better qualitative discriminator between healthy subjects and DAT patients.

Differences in P300 amplitudes and topography between cycloid psychosis and schizophrenia in Leonhard's classification

In a polydiagnostic approach, we investigated the parameters of auditory P300 in a group of 18 remitted schizophrenics and in 18 age‐ and sex‐matched controls. All patients fulfilled the criteria of schizophrenic disorder according to DSM‐III‐R. Applying Leonhards classification, patients were to be subdivided into 7 cycloid psychosis and 11 Leonhards schizophrenics. Patients with cycloid psychosis fulfilled the operational criteria of Brockington et al. We found significantly lower P300 amplitudes in the group of Leonhards schizophrenics than in controls and in cycloid psychosis, whereas no difference could be shown between patients with cycloid psychosis and controls. Both the maxima and the minima of the P300 field map were dislocated significantly to the right in the group of Leonhards schizophrenics but not in cycloid psychosis.

Integrity of the blood-CSF barrier in dementia of Alzheimer type: CSF/serum ratios of albumin and IgG

SummarySerum and cerebrospinal fluid (CSF) from 25 patients with dementia of Alzheimer type (DAT) and 25 controls were assayed for concentrations of albumin and IgG. The severity of dementia was rated with the Mini Mental State Examination. The CSF/serum ratio for albumin and IgG as well as the IgG index were used to evaluate blood-CSF barrier function in the respective groups. The control group was matched for age, sex and the indirect alcohol parameters, mean corpuscular volume and gamma-glutamyltranspeptidase. There were no signs of dysfunction of the blood-CSF barrier for proteins or signs of local synthesis of IgG in the central nervous system (CNS) of the demented patients. The permeability of the blood-CSF barrier appeared to be unrelated to dementia severity. The data do not support the hypothesis that a pathological leakage through the blood-CSF barrier facilitates the entry of extraneuronal proteins to the CNS, which might contribute to the pathophysiological process in DAT.

Alzheimer's disease : epidemiology, neuropathology, neurochemistry, and clinics

Some philosophical aspects of Alzheimers discovery: an American perspective.- The aging brain and its disorders.- Epidemiology of Alzheimers disease.- Descriptive and analytic epidemiology of Alzheimers disease.- A proposed classification of familial Alzheimers disease based on analysis of 32 multigeneration pedigrees.- Morphology of Alzheimers disease and related disorders.- Morphology of white matter, subcortical, dementia in Alzheimers disease.- Morphology of the cerebral cortex in relation to Alzheimers dementia.- Quantitative investigations of presenile and senile changes of the human entorhinal region.- Neuronal plasticity of the septo-hippocampal pathway in patients suffering from dementia of Alzheimer type.- Morphology of neurofibrillary tangles and senile plaques.- An in vitro model for the study of the neurofibrillary degeneration of the Alzheimer type.- Molecular and cellular changes associated with neurofibrillary tangles and senile plaques.- Brain abnormalities in aged monkeys: a model sharing features with Alzheimers disease.- Aged dogs: an animal model to study beta-protein amyloidogenesis.- Immunocytochemical and ultrastructural pathology of nerve cells in Alzheimers disease and related disorders.- Choline-acetyltransferase immunoreactivity in the hippocampal formation of control subjects and patients with Alzheimers disease.- Calbindin immunoreactive _eurons in Alzheimer-type dementia.- Lactate production and glycolytic enzymes in sporadic and familial Alzheimers disease.- Impairment of cerebral glucose metabolism parallels learning and memory dysfunctions after intracerebral streptozotocin.- Choline levels, the regulation of acetylcholine and phosphatidylcholine synthesis, and Alzheimers disease.- Acetylcholine synthesis and membrane phospholipids.- Hippocampal and cardiovascular effects of muscarinic agents.- Cholinergie and monoaminergic neuromediator systems in DAT. Neuropathological and neurochemical findings.- Alterations in catecholamine neurons in the locus coeruleus in dementias of Alzheimers and Parkinsons disease.- Tyrosine hydroxylase, tryptophan hydroxylase, biopterin and neopterin in the brains and biopterin and neopterin in sera from patients with Alzheimers disease.- Postreceptorial enhancement of neurotransmission for the treatment of cognitive disorders.- Excitatory dicarboxylic amino acid and pyramidal neurone neurotransmission of the cerebral cortex in Alzheimers disease.- The sequence within the two polyadenylation sites of the A4 amyloid peptide precursor stimulates the translation.- Alzheimer-like changes of cortical amino acid transmitters in elderly Downs syndrome.- Characteristics of learning deficit induced by ibotenic acid lesion of the frontal cortex in rats.- Memory loss by glutamate antagonists: an animal model of Alzheimers disease?.- Convulsant properties of methylxanthines, potential cognitive enhancers in dementia syndromes.- Neurodegenerative diseases: CSF amines, lactate and clinical findings.- Somatostatin-like immunoreactivity and neurotransmitter metabolites in the cerebrospinal fluid of patients with senile dementia of Alzheimer type and Parkinsons disease.- Nerve growth factor in serum of patients with dementia (Alzheimer type).- Neuroendocrine dysfunction in early-onset Alzheimers disease.- Urinary excretion of salsolinol enantiomers and 1,2-dehydrosalsolinol in patients with degenerative dementia.- Alzheimers disease - one, two or several?.- Diagnostic criteria of Alzheimers disease.- Clinical diagnosis of Alzheimers disease: DSM-III-R, ICD-10 - what else?.- Clinical aspects and terminology of dementing syndromes.- Symptoms of depression in the course of multi-infarct dementia and dementia of Alzheimers type.- Cognitive deterioration and dementia outcome in depression: the search for prognostic factors.- Diagnostic significance of language evaluation in early stages of Alzheimers disease.- The Alzheimer patient in the family context: how to help the family to cope.- Towards a clinically specific profile of severe senile primary degenerative dementia of the Alzheimer type (PDDAT).- Sequential clinical approach to differential diagnosis of dementia.- Do old patients with Downs syndrome develop premature brain atrophy?.- Results of EEG brain mapping and neuroimaging methods in Senile Dementia of Alzheimers Typ (SDAT) and Vascular Dementia (VD).- Regulation of EEG delta activity by the cholinergic nucleus basalis.- EEG- and cognitive changes in Alzheimers disease - a correlative follow-up study.- Decreased hippocampal metabolic rate in patients with SDAT assessed by positron emission tomography during olfactory memory task.- PET criteria for diagnosis of Alzheimers disease and other dementias.- Oxygen metabolism in the degenerative dementias.- Positron emission tomography for differential diagnosis of dementia: a case of familial dementia.- Comparison between cerebral glucose metabolism and late evoked potentials in patients with Alzheimers disease.- High resolution regional cerebral blood flow measurements in Alzheimers disease and other dementia disorders.- Single photon emission computed tomography (SPECT) in Picks disease: two case reports.- In vivo studies of hippocampal atrophy in Alzheimers disease.- Outline for the evaluation of nootropic drugs.- Drug treatment of dementia.- Cognitive enhancing properties of antagonist ?-carbolines: new insights into clinical research on the treatment of dementias?.- Long term treatment of SDAT patients with pyritinol.- Listed in Current Contents.

Stage-dependent reductions of regional cerebral blood flow measured by HMPAO-SPECT in dementia of Alzheimer type

In the present study, we used HMPAO-SPECT to examine the rCBF patterns in two subgroups (moderately and severely demented) of patients with DAT. Temporoparietal and frontal cerebral blood flow were compared between the two patient groups

Topography of the maximum of the amplitude of EEG frequency bands in dementia of the Alzheimer type

The localization of the maxima of activity of 36 patients with dementia of the Alzheimer type and 36 age-matched controls was calculated after Fourier transformation of EEG data in six frequency bands (4 Hz steps between 1 and 24 Hz). Patients were divided into three groups of severity (BCRS mean < 3,9, 4.0-4.9, and > 4.9). Significant differences were found in the beta frequency band. In the distribution of the maxima of the activity, the maxima of patients were located more frontally than the maxima of controls. The alterations were staged dependent. The beta activity in EEG is said to be correlated with cognitive processes; the correlation between cognitive decline and decreasing beta activity in dementia of the Alzheimer type might support this assumption. Differences in the location of the maxima between patients and controls might allow for differentiation between both groups.

Staging in dementia of the alzheimer type: Topography of electrical brain activity reflects the severity of the disease

In dementia of the Alzheimer type (DAT), electrical brain activity shows increases in delta and theta frequencies as well as a diminution of beta frequency. Two groups of 10 patients, each suffering from DAT, were compared with 10 healthy aged controls with respect to topogaphy of beta activity

A comparison of gEEG and HMPAO-SPECT in relation to the clinical severity of Alzheimer’s disease

Electroencephalographical studies have disclosed correlations between topographical features of Fast Fourier Transformation maps and the severity of Alzheimer’s disease (DAT). The object of the present study was to explore the relations of HMPAO-SPECT and quantitative EEG (gEEG) with the severity of dementia. Twenty-three patients were included in the study. Spectral and topographical EEG parameters were compared with global and regional cerebral blood flow, and with psychometric measures of clinical serverity. None of the regions of interest of the SPECT scans were significantly correlated with clinical severity. Low values in delta- and theta-bands, however, were related to high scores on the Mini-Mental-State examination (P < 0.01), whereas the Syndrom-Kurz test correlated inversely with the power values in the alpha and beta band. The global decrease in cerebral blood flow (CBF) was associated with a shift on the topographical alpha-centroids in the posterior direction (P < 0.01). In previous studies correlations between CBF and clinical severity were weak, indicating a high interindividual variance, or interactions with concomitant vascular lesions. Whereas SPECT is a well-established tool for the diagnosis of dementia, the present study indicates qEEG as a potential marker for the staging of the cognitive decline in DAT.