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J Zeithofer

Publications and source records attributed to J Zeithofer.

3 recordsLinked to original sources
PubMed1995

Technetium-99m-HMPAO SPECT imaging of cerebral blood flow during REM sleep in narcoleptics.

UNLABELLED: This study was performed to demonstrate global and regional cerebral blood flow (rCBF) changes during rapid eye movement (REM) sleep in six patients with narcolepsy using SPECT and 99mTc-HMPAO. METHODS: Global and hemispheric HMPAO uptake as well as regional (RI) and asymmetry indices were estimated and compared between polysomnographically verified sleep onset (SO)REM and wakefulness. RESULTS: The estimated global HMPAO uptake did not differ between the two conditions indicating a similar overall cortical activity. During (SO)REM sleep, hemispheric HMPAO uptake as well as calculated RI, especially in the supratemporal plane, were significantly higher on the right side than contralateral. This indicates an initially right-sided cerebral activation and a special involvement of the right, nondominant hemisphere during dreaming which is responsible for visual-spatial perceptions. Furthermore, increased RI in superior parietal regions during sleep were evident and were explained by an activation of associative areas. In thalamic regions, decreased RI were found during sleep, which may reflect thalamic dysfunction. CONCLUSION: A definite assignment of these CBF alterations to (SO)REM sleep might be problematic because of unstable boundaries between sleep stages in narcolepsy. On the other hand, specificity of such CBF changes for narcolepsy requires further study.

Adolescent↗
PubMed1987

[Acute effect of prostigmin on lung function and breathing of patients with myasthenia gravis at rest and following ergometric exercise].

The acute effects of a single intravenous Prostigmin injection (0.5 mg) on lung function and gas exchange during rest and bicycle ergometry were measured in 26 patients with myasthenia gravis. The mean age of the patients was 44.6 +/- 17.6 years and the mean duration of myasthenia gravis 5.4 +/- 6.3 years. Lung function parameters obtained from 15 patients showed a normal total lung capacity with an increase in functional residual capacity and residual volume, while vital capacity was diminished. While the application of Prostigmin showed no acute effects on these lung volumes, there was a significant increase in airway resistance, even into the pathologic range. Data obtained during spiro-ergometry concerning gas exchange, circulation and muscle metabolism correspond to those expected from healthy individuals; application of Prostigmin did only influence the heart rate, which can be explained by parasympathomimetic activity. We conclude that dyspnoea in patients with myasthenia gravis need not necessarily be a symptom of the illness itself but can also be caused by therapy; in the latter case bronchodilatators are required.

Adult↗