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P208 Changes in regional EEG-power spectra during imagination of pleasant and unpleasant autobiographic life events
Poster Session: EEG and EEG Related Techniques Epilepsy
322
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12 months control no statistical difference was seen in group comparison even though 27 patients depicted improvement and 38 deterioration of their EEG with respect to disappearance or appearance of EP. 4. If the EEG was completely normal 16 of 18 patients became seizure-free. 5. If EP were seen outside the site of surgery only 7 of 15 patients became seizure-free. In conclusion, the scalp-derived EEG after surgery for epilepsy is a significant predictor of seizure-outcome.
CHANGES IN REGIONAL EEG-POWERSPECTRA DURING IMAGINATIONOF PLEASANT AND UNPLEASANT AUTOBIOGRAPHIC LIFE EVENTS K. Bollow, U. Engel, K. Ernst, W. Gierow, G. Irmisch, T. Polak, C. Rehn, G. Richter, J. Richter, D. Schltifke. Universiti~tRostock, Zentrumfiir
136 mild to moderate demented patients and 30 age-matched healthy controls (aged between 50 and 95 years) underwent several psychopathological ratings and objective neurophysiological measurements during mental load. A strong correlation was found between median absolute theta-power at rest and MMS (r = -0.41, p < 0.001), more pronounced during cognitive tests (r = 0.55, p < 0.00001). Most prominent theta-power increases were measured during Figure-Detection-Test at left frontal (F7) regions: 147% in the demented patients, 241% in the controls. The more demented a patient is, the less is his capability to generate any more theta power during cognitive test performance. And this theta-power increase seems to be a sensitive neurometric tool for early diagnosis
~1-~
Nervenheilkunde, KlinikJ~r Psychiatrie, Germany This study presents first results of a research project on the complexity of depressivity supported by the Deutsche Forschungsgemeinschaft (Er 225/1 ). We investigated as an preliminary course 10 patients with depressive symptoms and 10 voluntary healthy controls in an experimental session, where all subjects were asked to imagine to their individual previously collected autobiographic life situation (script induced imagination technique). Each imagination trial consists of three phases: intention (instructed relaxation), vocal script presentation and quiet imagination. During the imagination sequence we recorded the EEG from 19 standard electrode positions with eyes closed. The EEG activity of each electrode was calculated as power spectra of five 2 s epochs in the separate phases in bands theta (3.5-7.5 Hz), alpha (8-12.5) and beta (13-30). We found specifically different patterns in all band activities for depressed patients and healthy controls in both situations by means of laterally distinct activation. Our findings are compared to facial muscle activity during the imagination sequence and discussed with results from literature.
EEG REACTIVITY,NEUROPSYCHOLOGYAND MULTMNFARCT DEMENTIA J. Partanen, H. Soininen, E.L. Helkala, M. K6n6nen, R. Kilpelainen.
University Hospital of Kuopio, Finland We performed conventional and spectral analysis of EEG in 17 patients with multi-infarct dementia (MID). All patients were also evaluated with a neuropsychological test battery comprising visual, praxie, verbal and memory functions and Mini-Mental status test. The variables of background EEG with eyes closed (amplitude of alpha, beta, theta and delta activity; mean frequency) did not correlate with neuropsycbological test scores. However, the eyes closed (EO)/eyes open (EO) amplitude ratios of alpha activity showed significant correlations with several neuropsyehologieal variables. Alpha rhythm seems to reflect a non-functional stage of a cortical area and desynchronization reflects cortical activation. A vascular damage of the brain causes functional impairment which is reflected in the neuropsychological performance as well as in the functional reactivity of the brain, measured with the alpha EC/EO ratio. The present study points out the superiority of a functional EEG variable, alpha EC/EO ratio, as to correlations with neuropsychological test scores, compared to the background EEG variables in MID. We conclude that the dynamic EC/EO alpha ratio variable is more sensitive in the assessment of brain dysfunction in MID than the background EEG variables and we think that EEG measures of brain reactivity should be applied in patients with suspected vascular lesions of the brain.
•
QUANTITATIVEEEG AND PSYCHOMETRY SIMULTANEOUSLYPERFORMED IN DEMENTED PATIENTS
R. Schellenberg, A. Todorova-Rudolph, W. Dimpfel. Pro Science Priv.
Res. Institute, 35440Linden, Germany Psychopathological rating scales like Mini-Mental-State (MMS) examination are common methods for practical examination of the mental state in dementia. Difficulties do exist in diagnosing the very early stages of dementia. Due to the reduced functional capacity of the deteriorated brain we have choosen both, quantitative EEG (qEEG) and psychometric tests for studying of functional changes in dementia.
QUANTITATIVEEEG (QEEG) IN CHILDREN: COMPARISON OF TWO ACTIVATIONMETHODS
T. Sand, M. Bjcrgaas. Trondheim University Hospital, Trondheim, Norway In QEEG studies it may be of major importance to avoid drowsiness and other state fluctuations. In the present study we compared the effects of two activation methods on QEEG variables. Thirty-one healthy children (15 boys, 16 girls, mean age 12.5 years, range 8-15 years) were studied. Five minutes of EEG was recorded and 45-60 seconds of relative artefact-free EEG was selected for each condition. The conditions were: 1) Relaxed with eyes closed, eye-opening for 5 seconds every 90 seconds, and eye-opening on signs of EEG-drowsiness. 2) Relaxed with eyes closed listening to a fairy tale. analysis was performed and relative amplitudes in the delta, theta, and alpha bands were computed for F3, F4, T3, T4, T5, T6, C3, C4, P3, P4, 01, and 02 electrodes with common average reference. A paired Student's t-test was used. Small but significant mean reduction of relative theta amplitudes were found during the listening task at T4 (p < 0.02), T5, T6, and 01 (p < 0.005). Relative delta activity decreased on T5 (p < 0.02) while mean relative alpha amplitude was slightly reduced during listening at T3 (p < 0.01). No changes in parieto-occipital relative alpha amplitudes were found however. The results imply that a simple story-listening task may affect (mainly temporal) theta activity. This effect may not be due to suppression of drowsiness, however, because the temporal lobe hearing areas also will be specifically activated during a listening task. ~-~
INFLUENCE OF PROPENTOFYLLINE ON EEG-POWER IN PRIMARY-DEGENERATIVEAND VASCULAR DEMENTIA
R. Mielke, B. Szelies, J. Kessler, W.D. Heiss. Max-Planck lnstitutfiir Neurologische Forschung, D-50931 KOln, Germany Propentofylline (HWA 285, Hoechst AG) is a novel compound that blocks reuptake of adenosine by neurons and glia cells, and inhibits phosphodiesterases of cyclic adenosine monophosphate. The pharmacological profile of propentofylline includes neuroprotective and blood flow improving properties. In a double-blind, placebo-controlled trial in thirty patients with vascular dementia (VD) according to DSM-III-R criteria and thirty patients with Alzheimer's disease according to NINCDS-ADRDA criteria, we analyzed the effects of propentofylline on EEG-power. Propentofylline was given three times a day as one tablet ~i 300 mg. EEG was recorded under resting conditions with eyes closed using an online 19-channel EEG system (Brain Atlas llI, Biologic) according to the 10-20 system. EEG data were collected with linked mastoid reference and sampled at a rate of 128 Hz. After visual inspection and rejection of EEG segments with artifacts or subvigilance at least 15 artifact-free 2-second periods were selected for fast Fourier transformation (FFT). Frequency band power was calculated for delta, theta alpha and beta. In the VD-group significant treatment effects were seen in relative theta power (increase in the placebo-group; p < 0.05), while in AD we observed an influence on relative beta power (decrease in the placebo-group; p < 0.05). Thus, propentofylline may slow down the occurrence of lower band frequencies in the course of primary degenerative and vascular dementia.
322
-
12 months control no statistical difference was seen in group comparison even though 27 patients depicted improvement and 38 deterioration of their EEG with respect to disappearance or appearance of EP. 4. If the EEG was completely normal 16 of 18 patients became seizure-free. 5. If EP were seen outside the site of surgery only 7 of 15 patients became seizure-free. In conclusion, the scalp-derived EEG after surgery for epilepsy is a significant predictor of seizure-outcome.
CHANGES IN REGIONAL EEG-POWERSPECTRA DURING IMAGINATIONOF PLEASANT AND UNPLEASANT AUTOBIOGRAPHIC LIFE EVENTS K. Bollow, U. Engel, K. Ernst, W. Gierow, G. Irmisch, T. Polak, C. Rehn, G. Richter, J. Richter, D. Schltifke. Universiti~tRostock, Zentrumfiir
136 mild to moderate demented patients and 30 age-matched healthy controls (aged between 50 and 95 years) underwent several psychopathological ratings and objective neurophysiological measurements during mental load. A strong correlation was found between median absolute theta-power at rest and MMS (r = -0.41, p < 0.001), more pronounced during cognitive tests (r = 0.55, p < 0.00001). Most prominent theta-power increases were measured during Figure-Detection-Test at left frontal (F7) regions: 147% in the demented patients, 241% in the controls. The more demented a patient is, the less is his capability to generate any more theta power during cognitive test performance. And this theta-power increase seems to be a sensitive neurometric tool for early diagnosis
~1-~
Nervenheilkunde, KlinikJ~r Psychiatrie, Germany This study presents first results of a research project on the complexity of depressivity supported by the Deutsche Forschungsgemeinschaft (Er 225/1 ). We investigated as an preliminary course 10 patients with depressive symptoms and 10 voluntary healthy controls in an experimental session, where all subjects were asked to imagine to their individual previously collected autobiographic life situation (script induced imagination technique). Each imagination trial consists of three phases: intention (instructed relaxation), vocal script presentation and quiet imagination. During the imagination sequence we recorded the EEG from 19 standard electrode positions with eyes closed. The EEG activity of each electrode was calculated as power spectra of five 2 s epochs in the separate phases in bands theta (3.5-7.5 Hz), alpha (8-12.5) and beta (13-30). We found specifically different patterns in all band activities for depressed patients and healthy controls in both situations by means of laterally distinct activation. Our findings are compared to facial muscle activity during the imagination sequence and discussed with results from literature.
EEG REACTIVITY,NEUROPSYCHOLOGYAND MULTMNFARCT DEMENTIA J. Partanen, H. Soininen, E.L. Helkala, M. K6n6nen, R. Kilpelainen.
University Hospital of Kuopio, Finland We performed conventional and spectral analysis of EEG in 17 patients with multi-infarct dementia (MID). All patients were also evaluated with a neuropsychological test battery comprising visual, praxie, verbal and memory functions and Mini-Mental status test. The variables of background EEG with eyes closed (amplitude of alpha, beta, theta and delta activity; mean frequency) did not correlate with neuropsycbological test scores. However, the eyes closed (EO)/eyes open (EO) amplitude ratios of alpha activity showed significant correlations with several neuropsyehologieal variables. Alpha rhythm seems to reflect a non-functional stage of a cortical area and desynchronization reflects cortical activation. A vascular damage of the brain causes functional impairment which is reflected in the neuropsychological performance as well as in the functional reactivity of the brain, measured with the alpha EC/EO ratio. The present study points out the superiority of a functional EEG variable, alpha EC/EO ratio, as to correlations with neuropsychological test scores, compared to the background EEG variables in MID. We conclude that the dynamic EC/EO alpha ratio variable is more sensitive in the assessment of brain dysfunction in MID than the background EEG variables and we think that EEG measures of brain reactivity should be applied in patients with suspected vascular lesions of the brain.
•
QUANTITATIVEEEG AND PSYCHOMETRY SIMULTANEOUSLYPERFORMED IN DEMENTED PATIENTS
R. Schellenberg, A. Todorova-Rudolph, W. Dimpfel. Pro Science Priv.
Res. Institute, 35440Linden, Germany Psychopathological rating scales like Mini-Mental-State (MMS) examination are common methods for practical examination of the mental state in dementia. Difficulties do exist in diagnosing the very early stages of dementia. Due to the reduced functional capacity of the deteriorated brain we have choosen both, quantitative EEG (qEEG) and psychometric tests for studying of functional changes in dementia.
QUANTITATIVEEEG (QEEG) IN CHILDREN: COMPARISON OF TWO ACTIVATIONMETHODS
T. Sand, M. Bjcrgaas. Trondheim University Hospital, Trondheim, Norway In QEEG studies it may be of major importance to avoid drowsiness and other state fluctuations. In the present study we compared the effects of two activation methods on QEEG variables. Thirty-one healthy children (15 boys, 16 girls, mean age 12.5 years, range 8-15 years) were studied. Five minutes of EEG was recorded and 45-60 seconds of relative artefact-free EEG was selected for each condition. The conditions were: 1) Relaxed with eyes closed, eye-opening for 5 seconds every 90 seconds, and eye-opening on signs of EEG-drowsiness. 2) Relaxed with eyes closed listening to a fairy tale. analysis was performed and relative amplitudes in the delta, theta, and alpha bands were computed for F3, F4, T3, T4, T5, T6, C3, C4, P3, P4, 01, and 02 electrodes with common average reference. A paired Student's t-test was used. Small but significant mean reduction of relative theta amplitudes were found during the listening task at T4 (p < 0.02), T5, T6, and 01 (p < 0.005). Relative delta activity decreased on T5 (p < 0.02) while mean relative alpha amplitude was slightly reduced during listening at T3 (p < 0.01). No changes in parieto-occipital relative alpha amplitudes were found however. The results imply that a simple story-listening task may affect (mainly temporal) theta activity. This effect may not be due to suppression of drowsiness, however, because the temporal lobe hearing areas also will be specifically activated during a listening task. ~-~
INFLUENCE OF PROPENTOFYLLINE ON EEG-POWER IN PRIMARY-DEGENERATIVEAND VASCULAR DEMENTIA
R. Mielke, B. Szelies, J. Kessler, W.D. Heiss. Max-Planck lnstitutfiir Neurologische Forschung, D-50931 KOln, Germany Propentofylline (HWA 285, Hoechst AG) is a novel compound that blocks reuptake of adenosine by neurons and glia cells, and inhibits phosphodiesterases of cyclic adenosine monophosphate. The pharmacological profile of propentofylline includes neuroprotective and blood flow improving properties. In a double-blind, placebo-controlled trial in thirty patients with vascular dementia (VD) according to DSM-III-R criteria and thirty patients with Alzheimer's disease according to NINCDS-ADRDA criteria, we analyzed the effects of propentofylline on EEG-power. Propentofylline was given three times a day as one tablet ~i 300 mg. EEG was recorded under resting conditions with eyes closed using an online 19-channel EEG system (Brain Atlas llI, Biologic) according to the 10-20 system. EEG data were collected with linked mastoid reference and sampled at a rate of 128 Hz. After visual inspection and rejection of EEG segments with artifacts or subvigilance at least 15 artifact-free 2-second periods were selected for fast Fourier transformation (FFT). Frequency band power was calculated for delta, theta alpha and beta. In the VD-group significant treatment effects were seen in relative theta power (increase in the placebo-group; p < 0.05), while in AD we observed an influence on relative beta power (decrease in the placebo-group; p < 0.05). Thus, propentofylline may slow down the occurrence of lower band frequencies in the course of primary degenerative and vascular dementia.