Biomedical subjects

L Rausch

Publications and source records attributed to L Rausch.

At least 19 recordsLinked to original sources

PubMed2005

Prediction of longitudinal cognitive decline in normal elderly with subjective complaints using electrophysiological imaging.

An extensive literature reports changes in quantitative electroencephalogram (QEEG) with aging and a relationship between magnitude of changes and degree of clinical deterioration in progressive dementia. Longitudinal studies have demonstrated QEEG differences between mild cognitively impaired (MCI) elderly who go on to decline and those who do not. This study focuses on normal elderly with subjective cognitive complaints to assess the utility of QEEG in predicting future decline within 7 years. Forty-four normal elderly received extensive clinical, neurocognitive and QEEG examinations at baseline. All study subjects (N = 44) had only subjective complaints but no objective evidence of cognitive deficit (evaluated using the Global Deterioration Scale [GDS] score, GDS stage = 2) at baseline and were re-evaluated during 7-9 year follow-up. Baseline QEEGs of Decliners differed significantly (p < 0.0001, by MANOVA) from Non-Decliners, characterized by increases in theta power, slowing of mean frequency, and changes in covariance among regions, especially on the right hemisphere. Using logistic regression, an R2 of 0.93 (p < 0.001) was obtained between baseline QEEG features and probability of future decline, with an overall predictive accuracy of 90%. These data indicate high sensitivity and specificity for baseline QEEG as a differential predictor of future cognitive state in normal, subjectively impaired elderly.

Aged↗

PubMed2004

The Patient State Index as an indicator of the level of hypnosis under general anaesthesia.

BACKGROUND: This retrospective study describes the performance of the Patient State Index (PSI), under standard clinical practice conditions. The PSI is comprised of quantitative features of the EEG (QEEG) that display clear differences between hypnotic states, but consistency across anaesthetic agents within the state. METHODS: The PSI was constructed from a systematic investigation of a database containing QEEG extracted from the analyses of continuous 19 channel EEG recordings obtained in 176 surgical patients. Induction was accomplished with etomidate, propofol, or thiopental. Anaesthesia was maintained by isoflurane, desflurane, or sevoflurane, total i.v. anaesthesia using propofol, or nitrous oxide/narcotics. It was hypothesized that a multivariate algorithm based on such measures of brain state, would vary significantly with changes in hypnotic state. RESULTS: Highly significant differences were found between mean PSI values obtained during the different anaesthetic states selected for study. The relationship between level of awareness and PSI value at different stages of anaesthetic delivery was also evaluated. Regression analysis for prediction of arousal level using PSI was found to be highly significant for the combination of all anaesthetics, and for the individual anaesthetics. CONCLUSIONS: The PSI, based upon derived features of brain electrical activity in the anterior/posterior dimension, significantly co-varies with changes in state under general anaesthesia and can significantly predict the level of arousal in varying stages of anaesthetic delivery.

Adolescent↗

PubMed1996

Cardiac rhythm effects of .125-Hz paced breathing through a resistive load: implications for paced breathing therapy and the polyvagal theory.

This study examined the psychophysiological effects of slow-paced breathing while subjects breathed through external respiratory resistive loads. Twenty-four normal volunteers completed four 5-min trials of paced breathing (.125 Hz) through an inspiratory resistive wire mesh screen (0 to 25 cm H2O/L/s). Each trial was followed by a 5-min rest trial. There was evidence for hyperventilation and/or fatigue during paced breathing. Also, respiratory sinus arrhythmia (RSA) was elevated in the first minute of paced breathing, and then declined toward baseline. Heart period decreased during paced breathing trials, and fell significantly below baseline during rest periods. These data suggest decreased vagus nerve activity and/or sympathetic activation, following an initial increase in parasympathetic activity during paced breathing. They are not consistent with the use of .125-Hz paced breathing as a relaxation technique, particularly during respiratory resistive stress. Finally, although RSA and average heart period changed synchronously within paced breathing and rest conditions, they diverged in comparisons between pacing and rest. This dissociation suggests that different mechanisms mediate these two cardiac parameters. These data are consistent with Porges' theory that vagal influences on tonic heart rate are mediated by the combined effect of vagal projections from both the nucleus ambiguus and the dorsal motor nucleus, while RSA is mediated only through the nucleus ambiguus alone.

Adolescent↗

PubMed1994

Relaxation and music therapies for asthma among patients prestabilized on asthma medication.

One hundred six asthmatic subjects were medically prestabilized, then assigned to eight sessions of progressive relaxation, music, or a waiting-list. Seventy-two subjects completed treatment, of which 37 were evaluated in the laboratory with measures of forced expiratory flow. Relaxation-group subjects reported feeling the most deeply relaxed and produced the greatest improvement in forced expiratory flow during the last presession assessment period. All groups evidenced decreases in asthma symptoms. All groups showed decreases in pulmonary function immediately after relaxation sessions. None of the changes in pulmonary function reached levels that are accepted in drug trials to be of clinical significance, and the therapeutic changes occurred only in the situation where training was rendered. Listening to music produced greater decreases in peaks of tension than progressive relaxation, and it produced greater compliance with relaxation practice, but it did not produce any specific therapeutic effects on asthma.

Adolescent↗

PubMed1994

The effects of atropine on respiratory sinus arrhythmia in asthma.

Heart rate is rhythmically related to respiratory rate, in a phenomenon known as respiratory sinus arrhythmia (RSA). Amplitude of RSA has been found to be an accurate noninvasive measure of vagal tone in the normal population. The purpose of this study was to examine the relationship between RSA and cardiac vagal tone among asthmatics, a group which has been described as having elevated RSA. This was accomplished by examining the effects of atropine on RSA in asthmatics, and comparing the results to those obtained elsewhere among normal subjects. Atropine at a dose of 1 mg/75 kg body weight was administered to 18 asthmatics, and produced decreases in RSA, equivalent to those previously found among normal subjects. The results suggest that the relationship between cardiac vagal tone and RSA is unaffected by the presence of asthma.

Adolescent↗

PubMed1994

Effects of aerosol ipratropium bromide on cardiac vagal tone.

Thirty-one adult asthmatic subjects, aged 18 to 40 years, were administered both ipratropium bromide and placebo, in two sessions, held at least 2 days apart, in balanced order. Pulmonary function, heart period (milliseconds between heart beats), and respiratory sinus arrhythmia (a measure of cardiac vagal tone) were assessed before drug administration and 45 min thereafter. Ipratropium bromide had no significant effect on cardiac vagal tone, while it did produce improvement in pulmonary function.

Administration, Inhalation↗

PubMed1993

The Asthma Symptom Profile: a psychophysically based scale for assessment of asthma symptoms.

The Asthma Symptom Profile (ASP) assesses phasic changes in three dimensions of asthma symptoms: intensity, unpleasantness, and quality of sensations. Quantification data on verbal descriptors were gathered from 46 adult asthmatics for each of these scales, using bimodality scaling: i.e., with numerical estimates and drawing lines varying length. Close agreement was obtained between these two modalities. The ASP was analyzed before and after a bronchodilator in 44 asthmatics using ipratropium bromide (IB). Forty of these subjects were also tested in a placebo condition. Although ASP changes produced by IB were no greater than those produced by the placebo, correlations with changes in spirometry variables were significant. There were no significant differences in correlations with line drawings vs. numerical ratings. The ASP appears to be useful measure of phasic changes in asthma symptoms. Asthmatics with mild airway obstruction do not appear to be able to discriminate small changes in airway function.

Adolescent↗

PubMed1987

Parasitic infections in Yakima Indians.

Two hundred and five Yakima Indians (age range: one to 66 years) were examined for parasitic infections, and various environmental exposures to infection. A questionnaire was completed by each participant and an anal swab, blood specimens and a single faecal sample were obtained. Eight of 181 swabs (4.4%) contained eggs of Enterobius vermicularis. Of 89 faecal specimens submitted, 12 (13.5%) and 1 (1.1%) respectively contained Giardia lamblia and Cryptosporidium. Sera were screened for antibodies to Toxocara canis, Echinococcus granulosus and Toxoplasma gondii, utilizing enzyme immunoassay, indirect haemagglutination (IHA) and indirect fluorescent antibody tests respectively. Toxocara seroprevalence was 31% (38/123). Seven of 39 (18%) sera were reactive to E. granulosus antigen in the IHA test, but none was positive for arc 5 antigen in the double immunodiffusion test. The seroprevalence of T. gondii was 20% (23/114).

Adolescent↗

PubMed1985

[Radiation protection in mammography].

According to the generally held view, objections in terms of radiation hygiene are less important in individually indicated mammographic investigations. Radiation protection in mammography is restricted to the carcinogenic side effect of radiation exposure in mass screening of asymptomatic women. A dose-proportional carcinogenic side effect independent of the dose distribution in time is also to be assumed in the small dose range. The International Radiation Protection Commission therefore requires a cost-benefit analysis to including costs for all mass X-ray examinations. It is indispensable to consider each age group separately in order to arrive at a rational and medically acceptable result. Cost/benefit analyses integrated over all age groups obscure important decision indicators with their positive results throughout. In a differentiated consideration, one arrives at a minimum age of entry for participation of asymptomatic women in regular mass screening. This depends on the dose requirement of the system used. The available recommendations tend to be restrictive in the case of relatively high dose requirement, and can be interpreted more extensively in the case of lower dose requirement. Inclusion of younger age groups with very low incidence which is possible in terms of risk criteria after a major lowering of the dose requirement leads to a low specific benefit and high specific costs, i.e. to a poor cost/benefit relation. Objections to the cost/benefit analyses undertaken could be shown to be based on the neglect of an age-differentiated consideration, one-sided selection of material, selective interpretation of the literature, inadmissible generalizations, the highlighting of relatively implausible assumptions, fundamental errors and argumentations colored by professional interest.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗

PubMed1982