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Biomedical subjects

E Pauli

Publications and source records attributed to E Pauli.

At least 19 recordsLinked to original sources
PubMed2001

Qualitative and quantitative olfactometric evaluation of different concentrations of ethanol peppermint oil solutions.

Selection of an adequate placebo is a major problem in clinical trials of Euminz(R) (10% peppermint oil/ethanol) which is used topically for the treatment of tension-type headache. This randomized, controlled, double-blind, cross-over study was performed to investigate whether there are qualitative differences between 10%, 1%, 0.5%, 0.1%, and 0% peppermint oil. Forty-one healthy subjects participated (age range 21-28 years); they rated both intensity, and hedonic tone of the stimuli. Verbal descriptions were combined to multiple response sets (MRS). In addition, the trigeminal impact of odorants was determined. Intensity ratings and MRS "menthol like" and "alcohol/solvent" changed with stimulus concentration. However, intensity had no significant effect on hedonics, trigeminal impact, or the number of descriptive items used. When MRS "menthol like" and "alcohol/solvent" were analysed after being weighted with intensity ratings, changes in relation to stimulus concentration were lost. Thus, the differences between the five concentrations of peppermint oil were--to their largest part--due to changes in stimulus intensity. Considering the large day-to-day variability of olfactory sensitivity the present data support the hypothesis that the odour quality of 10% peppermint oil cannot be discriminated from the odour of 0.1%, 0.5%, or 1% peppermint oil when tested on separate days.

Adult↗
PubMed2001

[Diagnostic imaging in refractory temporal lobe epilepsy. A comparison of MR volumetry and multivoxel-MR-spectroscopy for assessment of postoperative prognosis].

While the importance of magnetic resonance (MR) spectroscopy, volumetry, and T2-relaxometry for preoperative localization has already been verified, the question arises as to what extent the individual techniques are useful for assessing postoperative prognosis with respect to seizures and neuropsychological outcome. In a prospective comparative study, 26 patients were examined preoperatively with a 1.5 T whole-body scanner. The MR spectroscopy was taken by high resolution 1 H proton spectroscopy, the volumetry with MP rage technique. The postoperative outcome was laid down using Engel's classification. Our results show that the metabolic changes can be divided into three groups using MR spectroscopy: unilateral, slightly bilateral, and severely bilateral to contralateral. In case of bilateral changes, the severity of metabolic changes in the nonoperated, contralateral side was decisive for postoperative outcome. The results from volumetry did not correlate with postoperative outcome.

Adult↗
PubMed2001

Magnetic resonance spectroscopy and histopathological findings in temporal lobe epilepsy.

PURPOSE: In some patients with temporal lobe epilepsy, histopathological evaluation of resected brain tissue after surgical treatment may reveal several features indicative of discrete cortical malformations. We sought to determine whether these histopathological features were accompanied by hippocampal changes detectable preoperatively by proton magnetic resonance (MR) spectroscopy and to evaluate their relationship with postoperative outcome. METHODS: In 25 consecutive temporal lobe epilepsy patients who were scheduled for surgical treatment, MR spectroscopy was performed, and resected brain tissue was analyzed histopathologically for the presence of discrete cortical malformations (e.g., microdysgenesis). Outcome was assessed in all patients with an average postoperative period of 26 months. RESULTS: In 13 patients, we found subtle, histopathologically detectable signs of cortical malformation: 6 of them with concomitant hippocampal sclerosis (dual pathology) and 7 without. The latter subgroup had a worse surgical outcome and showed enhanced bilateral and/or contralateral pathological changes in the hippocampal formation when investigated by MR spectroscopy. CONCLUSIONS: These data suggest that by showing contralaterally or bilaterally abnormal spectra, MR spectroscopy might be able to indicate pathological changes in subtle developmental disorders that are possibly more widespread over the brain. This observation may improve noninvasive diagnosis in presurgical evaluation and the neurobiological understanding of cortical malformations in pharmacoresistant temporal lobe epilepsy.

Adult↗
PubMed2000

[MRI spectroscopy, T2 relaxometry, and postoperative prognosis in cryptogenic temporal lobe epilepsy].

The preoperative localization of pharmaco-resistant focal epilepsies before surgery and the prognosis concerning seizure outcome are both of importance. In addition to conventional MRI diagnostics for the detection of small epileptogenic lesions, proton magnetic resonance spectroscopic imaging (HMR spectroscopy) can be useful for assessing the bilaterality of pathological changes in cryptogenic temporal lobe epilepsies. The technique and findings of HMR spectroscopy are reported in patients with cryptogenic temporal lobe epilepsies. The findings indicate that chemical shift imaging (CSI) investigations of the ipsilateral and contralateral hemispheres provide important information for the prediction of seizure outcome after epilepsy surgery.

Adult↗
PubMed2000

[Temporal lobe epilepsy: effect of focus side on the autonomic regulation of heart rate?].

Epileptic activity can modulate reactions of the autonomic nervous system. Although there is some evidence of a differential left/right hemispheric influence on the cardiovascular system, diverse investigations have shown controversial results. In our study, complex partial seizures of patients with temporal lobe epilepsy were recorded using subdural electrodes, thus providing reliable information on the focus side. We analyzed the preictal and ictal heart rates of 27 patients, 16 revealing right and 11 revealing left temporal foci. During the seizures, both groups showed a significant increase in heart rate. Preictal tachycardia was only significant in the right focus group, whereas no significant change in heart rates could be detected in the left focus group. Our results confirm a right hemispheric lateralization of sympathetic cardiac control.

Adult↗
PubMed2000

Multicenter investigation of 1,036 subjects using a standardized method for the assessment of olfactory function combining tests of odor identification, odor discrimination, and olfactory thresholds.

"Sniffin' Sticks" is a test of nasal chemosensory performance that is based on penlike odor-dispensing devices. It is comprised of three tests of olfactory function: tests for odor threshold, discrimination and identification. Previous work has already established its test-retest reliability and validity in comparison to established measures of olfactory sensitivity. The results of this test are presented as a composite TDI score--i.e., the sum of results obtained for threshold, discrimination and identification measures. The present multicenter investigation aimed at providing normative values in relation to different age groups. To this end, 966 patients were investigated in 11 centers. An additional study tried to establish values for the identification of anosmic patients, with 70 anosmics investigated in five specialized centers where the presence of anosmia was confirmed by means of olfactory evoked potentials. For healthy subjects, the TDI score at the 10th percentile was 24.5 in subjects younger than 15 years, 30.3 for ages from 16 to 35 years, 28.8 for ages from 36 to 55 years and 27.5 for subjects older than 55 years. While these data can be used to estimate individual olfactory abilities in relation to a subject's age, hyposmia was defined as the 10th percentile score of 16- to 35-year-old subjects. Our latter study revealed that none of 70 anosmics reached a TDI score higher than 15. This score of 15 is regarded as the cut-off value for functional anosmia. These results provide the basis for the routine clinical evaluation of patients with olfactory disorders using "Sniffin' Sticks."

Adolescent↗
PubMed2000

Maculo-papillary branch retinal artery occlusions following the Wada test.

BACKGROUND: The Wada test induces short-term anesthesia of one hemisphere by injection of sodium amytal into an internal carotid artery. It is an important presurgical diagnostic tool in epileptic patients. PATIENT: A 22-year-old man with idiopathic epilepsy noticed a shadow in the central visual field of his right eye immediately following a Wada test of the right hemisphere. RESULTS: The patient presented with an occlusion of two small branch retinal arteries and corresponding defects in his visual field. Fluorescence angiography revealed small dense hyperfluorescent spots within the occluded retinal vessels. CONCLUSION: Branch retinal artery occlusions are a possible complication of the Wada test, possibly induced by undissolved contrast medium or sodium amytal.

Adult↗
PubMed2000

Magnetoencephalography in extratemporal epilepsy.

Epilepsy surgery candidates with extratemporal foci represent a particular diagnostic and therapeutic challenge, because of anatomic and functional features of the pertaining areas. In the last decade, novel developments in the field of electrophysiological techniques have offered new approaches to detailed localization of specific epileptic discharges as well as eloquent regions. Magnetoencephalography, in combination with neuroimaging data and simultaneously recorded EEG, yields promising results to clarify centers of epileptic activity and their relationship to structural abnormalites and functionally significant areas. Examples are given to illustrate the range of applications of this method as a contribution to routine presurgical evaluation.

Adolescent↗
PubMed2000

Chemical shift imaging spectroscopy and memory function in temporal lobe epilepsy.

PURPOSE: Hippocampal neuron loss and associated memory deficits are characteristic of intractable temporal lobe epilepsy (TLE). Proton chemical shift imaging (CSI) spectroscopy is a sensitive tool for detecting neuronal loss. The aim of this study was to investigate the correlation between memory functions and results provided by CSI spectroscopy of the hippocampal structures. METHODS: Ten patients with cryptogenic TLE participated. The study protocol involved both the acquisition of high-spatial-resolution CSI spectroscopy and neuropsychological evaluation, including memory testing and intracarotid sodium amytal test (IAT). The analysis of the CSI data was based on normative data obtained in 30 healthy volunteers. Memory functions were represented by verbal, visual, and general memory indices. RESULTS: A significant correlation was found between CSI spectroscopy of the hippocampal formation and the verbal memory indices for the dominant hemisphere. In addition, there was a significant correspondence of the qualitative judgment "hippocampal pathology indicated by CSI spectroscopy" and both "material specific memory deficit" and "memory deficit in the IAT." CONCLUSIONS: Our results demonstrate that CSI spectroscopy of the hippocampal structures is strongly related to lateralized memory deficits in patients with TLE. This suggests that CSI spectroscopy may be useful in the prediction of postoperative outcome in respect of seizure control and memory.

Adult↗
PubMed1998

Olfactory function in acute rhinitis.

This study was performed to investigate the effects of the common cold on olfactory function, which was assessed using chemosensory event-related potentials (CSERP, in response to both olfactory [H2S] and trigeminal [CO2] stimuli) and psychophysical measures (intensity ratings, odor discrimination, butanol threshold); nasal volume was assessed by means of acoustic rhinometry. The investigation was performed in 36 subjects (18 women, 18 men). After onset of the rhinitis (day 0) measurements were performed on days 2, 4, 6 and 35. The cold produced a decrease of the volume of the anterior nasal cavity accompanied by an increase of mucus secretion, an increase of olfactory thresholds, a decrease of intensity ratings and a decrease of N1 CSERP amplitudes to olfactory and trigeminal stimuli. When mucus secretion of the contralateral nasal cavity was controlled with oxymetazoline, N1 amplitudes to olfactory stimuli were still affected by the cold as indicated by the significant increase of amplitudes as subjects recovered; this phenomenenon was not found for responses to trigeminal stimuli. This indicates that the common cold has a small effect on olfactory function which may be independent of nasal congestion.

Acute Disease↗
PubMed1998

Effects of the nasal decongestant oxymetazoline on human olfactory and intranasal trigeminal function in acute rhinitis.

OBJECTIVE: The placebo-controlled, randomized, double-blind study was performed to investigate dose-related effects of oxymetazoline on olfactory function during the course of the spontaneously occurring cold. METHODS: Drug effects were assessed using olfactory/ trigeminal event-related potentials (ERPs) and psychophysical measures (intensity ratings, odor discrimination, butanol threshold); nasal volume was monitored by means of acoustic rhinometry. The investigation was performed in 36 subjects (mean age 24.6 years). The subjects were assigned to treatment groups A, B or C (three groups with 12 subjects each; six women and six men per group). All the subjects received placebo on the left side; on the right side, group A subjects received placebo and group B and C subjects received 0.25 mg x ml(-1) and 0.5 mg x ml(-1) oxymetazoline, respectively. After onset of the rhinitis (day 0) measurements were performed on days 2, 4, 6 and 35. RESULTS: Oxymetazoline clearly produced an increase in nasal volume. However, during the 2-h observation period, effects produced by the two dosages were not significantly different. Despite the increase in nasal volume, oxymetazoline produced only an increase of the overall intensity of H2S stimuli; it had no systematic effect on other measures of olfactory or trigeminal function. In addition, after all the subjects had recovered from the cold, oxymetazoline had no significant main effect on olfactory/trigeminally mediated sensations. CONCLUSIONS: Oxymetazoline appeared to have neither negative nor major positive effects on intranasal chemosensory function. It is hypothesized that oxymetazoline needs to be applied locally to the area of the olfactory cleft in order to significantly improve olfaction during the course of the common cold.

Acute Disease↗
PubMed1998

Chemosensory event-related potentials change with age.

The study examined age-related changes in the perception of olfactory and trigeminal chemical stimuli using chemosensory event-related potentials (CSERP). Three groups of healthy volunteers, each comprised of 8 men and 8 women, were tested (age ranges 15-34, 35-54, and 55-74 years). Subjects underwent extensive psychological testing focusing on impairments of memory and attention. In addition, odor identification and discrimination ability was evaluated, as well as detection threshold sensitivity for two odorants. Odor discrimination scores exhibited a significant age-related decrease. Significant age-related changes were also observed for CSERP N1P2 and P2 amplitudes, and for the N1 peak latency. The age-related decrease of CSERP amplitudes appeared to follow a different time course for responses to trigeminal and olfactory stimulants.

Adolescent↗
PubMed1998

Clonidine and methohexital-induced epileptic magnetoencephalographic discharges in patients with focal epilepsies.

PURPOSE: During presurgical evaluation, 14 patients with medically intractable focal epilepsies underwent magnetoencephalographic (MEG) recordings for focus localization. To increase the number of epileptic discharges required for MEG analysis, we administered methohexital (MHT), a short-acting barbiturate known to provoke epileptic activity. We also investigated the spike-provoking properties of clonidine in comparison with MHT. METHODS: Patients were briefly anesthetized with intravenously administered MHT after being premedicated orally with clonidine. Numbers and locations of epileptic MEG discharges were assessed after clonidine premedication as well as during MHT anesthesia. Results were compared with baseline MEG recordings. RESULTS: MHT increased the frequency of focal epileptic discharges in 8 of 13 patients ( of the 14 patients did not receive MHT after premedication with clonidine). Premedication with clonidine also increased focal epileptic discharges in 9 of 14 patients. The numbers of epileptic signals and numbers of spikes contributing to MEG source localizations were significantly increased in MEG recordings under both treatment conditions (clonidine premedication and MHT anesthesia) as compared with baseline MEG recordings. CONCLUSIONS: Our results confirmed the selective proconvulsive effects of MHT on the epileptic focus, as previously suggested by EEG and electrocorticographic (ECoG) investigations. However, our present data establish for the first time that clonidine increases epileptic activity in patients with seizure disorders and indicate that clonidine is suitable as an activating agent for localization of epileptogenic foci by MEG. This effect of clonidine on specific epileptic activity also indicates that specific care must be taken when clonidine is used as an antihypertensive drug in patients with seizure disorders.

Adult↗
PubMed1998

Clonidine- and methohexital-induced epileptiform discharges detected by magnetoencephalography (MEG) in patients with localization-related epilepsies.

PURPOSE: During presurgical evaluation, 14 patients with medically intractable focal epilepsies underwent magnetoencephalographic (MEG) recordings to localize the epileptogenic focus. To increase the number of epileptiform discharges required for MEG analysis, methohexital a short-acting barbiturate that is known to activate epileptiform activity, was used. Additionally, we investigated the spike-provoking properties of clonidine in comparison to methohexital. METHODS: After oral premedication with clonidine, short-lasting anesthesia was provided by intravenously administered methohexital. The number and location of epileptiform MEG discharges were assessed after clonidine premedication and during methohexital anesthesia. Results were compared with baseline MEG recordings. RESULTS: Methohexital increased the frequency of focal epileptiform discharges in eight of 13 patients (one of the 14 patients did not receive methohexital after premedication with clonidine). Additionally, premedication with clonidine was found to increase focal epileptiform discharges in nine of 14 patients. When compared with baseline MEG recordings, recordings after treatment with both clonidine premedication and methohexital anesthesia showed a significant increase in the total number of epileptiform signals and the number of spikes contributing to MEG source localizations. CONCLUSIONS: This study confirms the selective proconvulsant effects of methohexital on the epileptogenic focus as suggested previously by EEG and electrocorticogram (ECoG) investigations. Additionally, our data establish for the first time that clonidine increases epileptiform activity in patients with seizure disorders. These results indicate that clonidine is suited as an activating agent for the localization of epileptogenic foci by means of MEG. This effect of clonidine on specific epileptic activity also indicates that clonidine should be used with caution as an antihypertensive drug in patients with seizure disorders.

Adult↗
PubMed1998

Responses to nasal irritation obtained from the human nasal mucosa.

Responses to chemical irritation can be obtained from the human respiratory mucosa in response to stimulation with gaseous CO2; these negative mucosal potentials (NMPs) are thought to be summated receptor potentials from chemosensitive nociceptors. The present study aimed to investigate the relation of this response to both stimulus concentration and perceived intensity. A total of 29 healthy volunteers participated. Maximum negative amplitudes occurred 1.1 s after stimulus onset. The negativity exhibited a higher coefficient of correlation to intensity estimates of the painful sensations (r = .65) than to the stimulus concentration (r = .46); it appeared at the same time when the subjects' tracking of the painful sensations reached its maximum amplitude. These findings suggest that the NMP is suited for the investigation of peripheral nociceptive events in man.

Adult↗