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Biomedical subjects

F A Struve

Publications and source records attributed to F A Struve.

At least 37 records · Page 2Linked to original sources
PubMed1995

Topographic quantitative EEG measures of alpha and theta power changes during caffeine withdrawal: preliminary findings from normal subjects.

Neurophysiological consequences of withdrawal from caffeine are poorly understood. In particular, quantitative studies of EEG changes that may occur during the period of caffeine abstinence in caffeine dependent individuals have not been reported. In this pilot study, 13 physically- and psychiatrically-normal caffeine users were asked to abstain from caffeine for a period of 4 days. Quantitative EEGs were obtained prior to stopping caffeine and on Days 1, 2, and 4 of the caffeine abstinence period. Results indicated that significant increases in alpha and theta absolute power accompany the caffeine withdrawal process with return to the pre-abstinent EEG levels when caffeine usage is resumed. The implications of these findings are discussed with special reference to the possible need to control for the variable of caffeine usage in quantitative EEG studies of other phenomena.

Adolescent↗
PubMed1994

Habituation and motion sickness.

The vestibular, cerebellar, and reticular systems are central in importance, in motion sickness and habituation, to the effects of motion. Nuclear medicine single photon emission computed tomography (SPECT) studies of cerebral blood flow and power spectral electroencephalographic recordings during motion sickness were used to determine alterations in the central nervous system. The rotating chair with and without visual stimulation was used to study the rate of habituation and the effect of antimotion sickness medications on this rate. An increase of theta waves over the frontal cortex indicated a decreased activation of the higher centers during motion sickness. Motion sickness also produces an increase of blood flow in the central cerebellum that has connections to the reticular system. This increase in cerebellar activity is relayed to the reticular system whereby neural recruitment builds up to trigger the vomiting center, producing motion sickness. Habituation may be a conditioned compensatory activation of the reticular neurons that prevents this disruption of normal activation. The rate of habituation when motion sickness was prevented by scopolamine was slowed, indicating that, if the central nervous system is not challenged by disruption of normal activation, it does not produce the compensatory reactions that result in habituation.

Adult↗
PubMed1994

Brainstem auditory response (BAER) in polydrug abuse.

Based on preliminary data suggesting that polydrug abuser subjects may have delayed wave V BAER latencies, we contrasted BAER latency and amplitude measures between a group of polydrug users and six different comparison groups of subjects drawn from our laboratory files. A series of analyses showed that BAER latencies were, in fact, prolonged for psychiatric polydrug users as compared with groups of medically screened and unscreened normals not using drugs and normals using marijuana only. However, further analyses which compared polydrug abusers with nondrug users or marijuana-only users drawn from a psychiatric patient population failed to confirm these differences, thus suggesting that psychiatric status was more important than polydrug abuse in producing BAER alterations. Furthermore, subsidiary analyses using wave I latency as statistical covariate suggested that wave V latency prolongations could, under certain circumstances, be epiphenomena or reflections of earlier wave I alterations.

Acoustic Stimulation↗
PubMed1994

Persistent topographic quantitative EEG sequelae of chronic marihuana use: a replication study and initial discriminant function analysis.

In a previous pilot study using psychiatric patients we reported that daily marihuana users had significant elevations of (1) Absolute Alpha Power, (2) Relative Alpha Power, and (3) Interhemispheric Alpha Coherence over both frontal and frontal-central areas when contrasted with subjects who did not use marihuana. We referred to this phenomenon as Hyperfrontality of Alpha. The study presented here is a successful replication of our previous findings using new samples of subjects and identical methods. Post hoc analyses based on the combined sample from both studies suggest that variables of psychiatric diagnoses and medication did not bias our results. In addition, a discriminant function analysis using quantitative EEG variables as candidate predictors generated a 95% correct THC user versus nonuser classification accuracy which received a successful jackknife replication.

Adult↗
PubMed1989

Topographic mapping of quantitative EEG variables in chronic heavy marihuana users: empirical findings with psychiatric patients.

EEG studies of marihuana use dating back to 1945 were reviewed. The earlier studies depended upon visual analysis of the tracing, and while some minor frequency and amplitude variations occurred in some subjects, there was no consistent THC induced change noticeable across subjects. Quantitative EEG studies of acute exposure to THC came later and produced reliable findings of a placebo controlled dose dependent THC induced increase in relative power of alpha, combined with decreased alpha frequency and a reduction of beta activity. These findings were reported for data collected from central-occipital derivations only. In our present investigation, we report that chronic heavy THC users have EEGs characterized by (1) increased absolute power of all frequencies over all cortical areas (2) hyperfrontality of elevated relative and absolute power and coherence values of alpha activity, and (3) a decrease in relative power of all non-alpha frequencies. Methodological issues were discussed and some suggestions were made for continuing research in this area.

Adult↗
PubMed1987

MMPI correlates of a controversial EEG pattern among adolescent psychiatric patients.

Relative to adult MMPI studies, few investigations address adolescent correlates of the MMPI. A particularly neglected area of potential importance has been the relationship between adolescent MMPI profiles and electroencephalographic (EEG) disturbances. This study examined EEG recordings, MMPI results, and psychiatric diagnosis of 99 (49 male; 50 female) psychiatrically hospitalized adolescents. Because there was a high incidence of 14 and 6 per second positive spike EEG patterns among males, one-way analyses of variance (ANOVAs) were employed to compare MMPI results for 31 males with normal EEG patterns and 17 males with 14 and 6 per second positive spiking. The 14 and 6 per second positive spike EEG signal was related to significantly higher MMPI T score elevations on Hs, PD, and MF. The results are discussed in terms of their implications for both EEG and MMPI interpretations.

Adolescent↗
PubMed1987

Lithium-specific pathological electroencephalographic changes: a successful replication of earlier investigative results.

In three independent comparisons, patients treated with lithium carbonate (either alone or in combination with other agents) were contrasted with both medication free and other psychotropic medicated patients, in terms of the prevalence of abnormal generalized slowing and paroxysmal diffuse delta activity in the clinical EEG. In all samples, abnormal EEG changes occurred in from 30.3 to 39.4% of lithium treated patients as contrasted with from only 1.5 to 4.6% of medication free controls. In all comparisons, the prevalence of abnormal EEGs was significantly higher for lithium treated patients than for patients free of medication or those treated with other psychotropic agents. EEG changes are reversible with discontinuance of lithium, and their role in suggesting potential early neurotoxicity is discussed.

Adolescent↗
PubMed1987

Clinical electroencephalographic variables suggesting extrapyramidal side effect risk.

Previous work has suggested that paroxysmal EEG dysrhythmias in psychiatric patients may be associated with an increased incidence of such diverse side effects as dyskinetic movements, extrapyramidal symptoms, iatrogenic seizures, and somatic/affective effects of oral contraceptives. The new analyses presented here extend these observations by using a large sample of 375 neuroleptically treated psychiatric patients with independently secured awake and asleep admission EEG studies. Those patients with minor paroxysmal EEG dysrhythmias are much more likely than normal EEG patients to receive anti-EPS medication during their treatment program. Furthermore, using data obtained from direct examination for EPS signs, neuroleptically treated patients with paroxysmal dysrhythmias as contrasted with those with normal EEGs, display statistically significant increases in EPS symptoms regardless of whether or not they are receiving concurrent anti-EPS medication at the time of examination. Prediction of side effect risk for the individual patient is not permitted by the strengths of associations reported for grouped data. However, it is suggested that future studies concerned with pharmacological side effect development in humans might benefit from stratification of samples by presence or absence of major and/or minor paroxysmal EEG patterns.

Adolescent↗
PubMed1985

Possible potentiation of suicide risk in patients with EEG dysrhythmias taking oral contraceptives: a speculative empirical note.

In a study of 160 female psychiatric patients aged 14 to 48, the possibility that increased suicide risk may be associated with combined paroxysmal EEG dysrhythmia and recent oral contraceptive use is offered for speculative heuristic purpose. The retrospective cross-sectional method with limited samples does not permit firm conclusions or generalization beyond these data. Additional support of these empirical associations by further study could be pragmatically valuable in helping to identify an important clinical subgroup of high potential suicide risk.

Adolescent↗
PubMed1983

Cognitive dysfunction and tardive dyskinesia.

From a prospective study of tardive dyskinesia (TD), psychiatric patients with neuroleptically-induced "persistent" TD were contrasted with controls on a neuropsychological measure of abstracting ability. A significant association is demonstrated between impaired cognitive performance and TD, even when the neuropsychological measure was obtained in advance of TD onset.

Aged↗