[Clinical aspects and therapy of neuralgia and vertebrogenic pains in the clinic and practice of an otorhinolaryngologist].
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Biomedical subjects
Publications and source records attributed to D Riemann.
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Disinhibition of rapid eye movement (REM) sleep (e.g. shortening of REM latency, heightened REM density) is frequently encountered in patients with a major depressive disorder (MDD). Administration of cholinomimetics prior to or during sleep leads to a more pronounced advance of REM sleep in depressed patients compared to healthy controls and patients with other psychiatric disorders. The present study tested whether the cholinergic REM induction test (CRIT) with 1.5 mg RS 86 (an orally acting muscarinic agonist) differentiates patients with MDD (n = 40) from those with schizophrenia (n = 43) and healthy controls (n = 36). The most pronounced shortening of REM latency after cholinergic stimulation occurred in patients with MDD. However, a significant number of patients with schizophrenia also displayed short REM latencies (REM latency < 25 minutes) under placebo conditions and after cholinergic stimulation. REM density measures more clearly differentiated patients with MDD from those with schizophrenia. It is concluded that a subgroup of patients suffering from schizophrenia displays signs of a muscarinic receptor supersensitivity.
The fast but short-lasting improvement of depressive symptoms by sleep deprivation (SD) in about 60% of patients with a major depressive disorder is well established, but the mechanisms of action are still not clear. Recent studies suggest that changes in non rapid eye movement (NREM) sleep, especially in slow wave activity (SWA), could be associated with the therapeutic outcome of SD. In the current study, spectral analysis of NREM sleep EEG directly prior to SD was performed to determine if automatically derived sleep parameters predict SD response. Sixteen pair matched and drug free patients with a major depressive disorder, 8 SD responders and 8 non-responders (response criterion: 50% reduction on the 6-item HAMD score), were included. Average EEG spectral power was calculated for the whole night before SD and for single NREM episodes. While whole-night averages of spectral power did not differ significantly between subgroups, SD responders showed a steady decrease of SWA across successive NREM episodes, whereas in non-responders an increase from the first to the second episode was observed. The different distribution of SWA was significantly expressed in the delta sleep ratio (quotient of SWA in the first to the second NREM episode). In conclusion, a high delta sleep ratio is a positive predictor for SD response. Referred to psycho- and pharmacotherapeutic results it is hypothesized that low and high values of the delta sleep ratio characterize subgroups of depressed patients with different neurobiological alterations, which could be relevant for further scientific and therapeutic approaches.
Pseudodementia as a common trait in elderly depressives presents a major problem in gerontopsychiatry, especially for the differential diagnosis between Old-Age Depression (OAD) and Dementia of the Alzheimer Type (DAT). The present polysomnographic study examined parameters of sleep continuity, sleep architecture, and REM sleep to differentiate DAT from OAD. The investigation was based on the theoretical framework of the cholinergic-aminergic imbalance model of depression, the cholinergic deficit hypothesis of Alzheimer's disease and the reciprocal interaction model of Non-REM/REM sleep regulation, according to which REM sleep parameters should have high discriminative value to differentiate OAD and DAT. We investigated 35 DAT patients, 39 OAD patients and 42 healthy controls for two consecutive nights in the sleep laboratory. The DAT patients were in relatively early/mild stages of the disease, the severity of depression in the OAD group was moderate to severe. Depressed patients showed characteristic 'depression-like' EEG sleep alterations, i.e. a lower sleep efficiency, a higher amount of nocturnal awakenings and decreased sleep stage 2. Sleep continuity and architecture in DAT was less disturbed. Nearly all REM sleep measures differentiated significantly between the diagnostic groups. OAD patients showed a shortened REM latency, increased REM density and a high rate of Sleep Onset REM periods (SOREM), whereas in DAT REM density was decreased in comparison to control subjects. REM latency in DAT was not prolonged as expected. To assess the discriminative power of REM sleep variables a series of discriminant analyses were conducted. Overall, 86% of patients were correctly classified, using REM density and REM latency measures. Our findings suggest that REM density as an indicator of phasic activity appears to be more sensitive as a biological marker for the differential diagnosis of OAD and DAT than REM latency. The results support the role of central cholinergic neurotransmission in REM sleep regulation and the pathogenesis of DAT and OAD.
Disturbances of sleep are typical for most depressed patients and belong to the core symptoms of the disorder. Polysomnographic sleep research has demonstrated that besides disturbances of sleep continuity, in depression sleep is characterized by a reduction of slow wave sleep and a disinhibition of REM sleep, with a shortening of REM latency, a prolongation of the first REM period and increased REM density. These findings have stimulated many sleep studies in depressive patients and patients with other psychiatric disorders. In the meantime, several theoretical models, originating from basic research, have been developed to explain sleep abnormalities of depression, like the two-process-model of sleep and sleep regulation, the GRF/CRF imbalance model and the reciprocal interaction model of non-REM and REM sleep regulation. Interestingly, most of the effective antidepressant agents suppress REM sleep. Furthermore, manipulations of the sleep-wake cycle, like sleep deprivation or a phase advance of the sleep period, alleviate depressive symptoms. These data indicate a strong bi-directional relationship between sleep, sleep alterations and depression.
In rheumatic joints, high concentrations of interleukin-8 (IL-8) have been measured in synovial fluid and in pannus tissue. In both locations aminopeptidase N (APN)/CD13, an exopeptidase with reported activity towards IL-8 is also present. The surprising stability of IL-8 in the presence of an alleged IL-8-degrading peptidase prompted us to undertake the present study. Cocultivation of fibroblast-like synoviocytes (SFC) with T cells or with T lymphocytic cell membranes, or of T cells with SFC cell membranes, all resulted in increased IL-8 mRNA expression and IL-8 secretion into the medium, and an increase of APN expression on lymphocytes. IL-8 degradation was monitored by Western blots and HPLC. IL-8(72), as a partially processed form, was used throughout this study since it is abundant in tissues and has increased biological activity in comparison to IL-8(77). Thus its degradation/inactivation is considered of high biological significance. Whereas trypsin as a positive control rapidly degraded IL-8, we did not see any IL-8 degradation, either by a variety of soluble APNs, by leucine aminopeptidase or by APN expressed on the surface of SFC, or on ECV304 cells transfected with an APN expression vector. The much more sensitive HPLC technique resulted in negative results as well.
The reciprocal interaction model of NonREM- and REM sleep regulation suggests that the cycling alternating pattern of Non-REM- and REM sleep is under the control of noradrenergic/serotonergic and cholinergic neuronal networks. This model was tested in healthy humans by administration of cholinergic agonists/antagonists and noradrenergic antagonists prior to or during sleep. Cholinomimetics like physostigmine, RS 86 and galanthamine provoked an earlier onset of REM sleep, whereas subchronic treatment with scopolamine, a cholinergic antagonist, only led to a heightening of REM density. Simultaneous administration of noradrenergic antagonists with a cholinergic agonist did not provoke a more pronounced REM sleep advance. Comparative studies with the cholinergic agonist RS 86 in depressed patients, schizophrenic patients and patients with other psychiatric disorders revealed the most pronounced REM sleep response in the depressed group. The REM sleep response to cholinergic stimulation in depression did however not predict the treatment response to a differential-therapeutic strategy.