Relation of the Electroencephalogram to Intellectual Function in Senescence

Obrist, Walter D.; Busse, Ewald W.; Eisdorfer, Carl; Kleemeier, Robert W.

doi:10.1093/geronj/17.2.197

Cited by 65 publications

(34 citation statements)

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“…The effects of scopolamine on EEG and neuropsycho logical status are qualitatively congruent with the modifi cations these parameters are described to undergo in organic brain syndrome and dementia or during aging [Gordon, 1968;Hughes and Cayaffa, 1977;Obrist et al, 1962Obrist et al, , 1966Roubicek, 1977;Gerson et al, 1976;Bartus et al, 1982;Corkin et al, 1982;Coben et al, 1985;Penitila et al, 1985; for general reviews, Obrist, 1976;Corkin et al, 1982], In spite of the methodological problems rel ative to the issue and the differences among study reports [Obrist, 1976;Coben et al, 1985], this similarity seems even more to support the cholinergic hypothesis concern ing geriatric conditions and dementia [Bartus et al, 1982], To assimilate the acute administration of scopol amine to a dementia model nevertheless requires the ful fillment of criteria which exceed those of the similarity of change; noncholinergic receptor-neurotransmitter sys tems are potentially sensitive to scopolamine [Krnjevic, 1974;Brimblecombe, 1974;Birdsall et al, 1978Birdsall et al, , 1979, and the concurrence of other neurotransmitter-specified systems [Davis et al, 1980;Roberts et al, 1985] and/or other factors [Scheibel and Wecksler, 1986] is conceiv ably relevant in brain aging and dementia. Despite these general limitations, acute administration of scopolamine can be instrumental in pharmaco-EEG studies by provid ing standard drug effects which can be counterbalanced by putative cholinergic compounds.…”

Section: Discussionmentioning

confidence: 84%

Effects of Scopolamine (0.25–0.75 mg i.m.) on the Quantitative EEG and the Neuropsychological Status of Healthy Volunteers

Sannita

Maggi

Rosadini³

1987

Neuropsychobiology

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There has been clinical and experimental evidence that cholinergic compounds and precursors of choline are potentially useful in the treatment of dementia. Anticholinergic compounds have also been proposed as a possible acute model for pharmaco-EEG studies focussed on CNS aging. Single doses of scopolamine (0.25–0.75 mg i.m.) and a matching placebo were administered to 8 young healthy volunteers. Quantitative EEG recordings and neuropsychological testing were performed in baseline conditions prior to and 30, 90 and 120 min after drug administration. Scopolamine induced a dose-related increase of relative power in low- and high-frequency components and a decrease in the range 8.0–13.5 Hz and in total signal power. These modifications were found to be limited to the posterior scalp electrode derivations and were observed from the 90-min control onwards. Concomitantly, there was a significant impairment in the subjects’ response to neuropsychological testing after the administration of 0.50 and 0.75 mg of scopolamine. At a dose of 0.75 mg, volunteers complained about subjective symptoms which were definitely unpleasant. The effects of this dose on the EEG and the neuropsychological status did not differ significantly from those observed after a dose of 0.50 mg. As regards dose and tolerance, 0.50 mg of scopolamine administered intramuscularly appears to be a suitable dose for pharmaco-EEG studies.

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Section: Discussionmentioning

confidence: 84%

Effects of Scopolamine (0.25–0.75 mg i.m.) on the Quantitative EEG and the Neuropsychological Status of Healthy Volunteers

Sannita

Maggi

Rosadini³

1987

Neuropsychobiology

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“…In elderly subjects, a slowing of the alpha frequency has been shown [39]. Increase in delta activity with age has been correlated with impairment of memory function and with reduced acetylcholinesterase activity in CSF [40].…”

Section: Discussionmentioning

confidence: 95%

“…Increase in delta activity with age has been correlated with impairment of memory function and with reduced acetylcholinesterase activity in CSF [40]. EEG recordings from patients with Alzheimer's disease show a high percentage of abnormalities [39,41,42]. In a longitudinal study of Alzheimer patients, relative delta and theta power increased and alpha and beta power decreased [43].…”

Section: Discussionmentioning

confidence: 99%

Intracerebroventricular Infusion of Nerve Growth Factor in Three Patients with Alzheimer’s Disease

Jönhagen

Nordberg

Amberla

et al. 1998

Dement Geriatr Cogn Disord

423

217

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Nerve growth factor (NGF) is important for the survival and maintenance of central cholinergic neurons, a signalling system impaired in Alzheimer’s disease. We have treated 3 patients with Alzheimer’s disease with a total of 6.6 mg NGF administered continuously into the lateral cerebral ventricle for 3 months in the first 2 patients and a total of 0.55 mg for 3 shorter periods in the third patient. The patients were extensively evaluated with clinical, neuropsychological, neurophysiological and neuroradiological techniques. Three months after the NGF treatment ended, a significant increase in nicotine binding was found in several brain areas in the first 2 patients and in the hippocampus in the third patient as studied by positron emission tomography. A clear cognitive amelioration could not be demonstrated, although a few neuropsychology tests showed slight improvements. The amount of slow-wave cortical activity as studied by electroencephalography was reduced in the first 2 patients. Two negative side effects occurred with NGF treatment: first, a dull, constant back pain was observed in all 3 patients, which in 1 patient was aggravated by axial loading resulting in sharp, shooting pain of short duration. When stopping the NGF infusion, the pain disappeared within a couple of days. Reducing the dose of NGF lessened the pain. Secondly, a marked weight reduction during the infusion with a clear weight gain after ending the infusion was seen in the first 2 patients. We conclude from this limited trial that, while long-term intracerebroventricular NGF administration may cause certain potentially beneficial effects, the intraventricular route of administration is also associated with negative side effects that appear to outweigh the positive effects of the present protocol. Alternative routes of administration, and/or lower doses of NGF, perhaps combined with low doses of other neurotrophic factors, may shift this balance in favor of positive effects.

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“…conventionally interpreted, shows a high per centage of abnormalities in DAT [35][36][37][38][39]. Most of these studies also showed a correlation between the degree of EEG abnormality and the severity of dementia.…”

Section: Eeg In Dementia Of Alzheim Er Typementioning

confidence: 99%

Electroencephalography as a Diagnostic Tool in Dementia

Rosén

1997

Dement Geriatr Cogn Disord

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Clinical electroencephalography is a relatively simple and inexpensive diagnostic tool with a high sensitivity for diffuse organic encephalopathy of various aetiologies but with a rather low specificity for the type of diagnosis. The highest sensitivity is shown in DAT and Parkinson dementia, and in these conditions the degree of EEG abnormality is correlated with the disease severity. Quantification of EEG makes these correlations more reliable and provides a method for monitoring therapeutic effects. Dementias with predominantly frontal pathology show much less EEG abnormality, and in these conditions the EEG is often normal despite obvious clinical dementia. Also, alcohol dementias often show normal EEG patterns. At an early stage of clinical evaluation, EEG may be useful in the discrimination of organic dementia from pseudodementia, because EEG is usually normal in depression, confusion, agitation and other psychiatric conditions. In pseudodementia due to intoxication with sedatives the EEG is usually dominated by diffuse β activity. At the stage of differential diagnosis of an organic brain disorder, EEG cannot reliably discriminate between encephalopathies secondary to hydrocephalus, AIDS, cerebrovascular disease, B12 deficiency and primary degenerative diseases such as DAT. More specific EEG patterns are seen in acute cerebrovascular lesions, metabolic encephalopathies, i.e. of hepatic origin, Creutzfeldt-Jakob disease, herpes encephalitis, and nonconvulsive status epilepticus as possible causes of a rapidly deteriorating mental and neurological condition. Repeated EEG recordings over time would add significantly to the diagnostic information. New techniques such as topographical brain mapping, analysis of the EEG during REM sleep, coherence analysis of the EEG activity, and the combination of quantified EEG techniques with evoked potentials and event-related potentials will presumably add to the sensitivity as well as the specificity of the electrophysiological methods in the diagnosis of dementia.

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Relation of the Electroencephalogram to Intellectual Function in Senescence

Cited by 65 publications

References 0 publications

Effects of Scopolamine (0.25–0.75 mg i.m.) on the Quantitative EEG and the Neuropsychological Status of Healthy Volunteers

Effects of Scopolamine (0.25–0.75 mg i.m.) on the Quantitative EEG and the Neuropsychological Status of Healthy Volunteers

Intracerebroventricular Infusion of Nerve Growth Factor in Three Patients with Alzheimer’s Disease

Electroencephalography as a Diagnostic Tool in Dementia

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