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Biomedical subjects

J Staedt

Publications and source records attributed to J Staedt.

At least 37 records · Page 2Linked to original sources
PubMed1996

Nocturnal melatonin secretion and sleep after doxepin administration in chronic primary insomnia.

Nocturnal melatonin secretion and polysomnographic sleep patterns were investigated in ten patients with chronic primary insomnia (age 41.3 +/- 9.5 years) and in five healthy subject, (age 27.2 +/- 0.7 years) after either a single intravenous administration of 25 mg doxepin or placebo in a randomized, double blind, and cross-over setting. In the patient group a third session was performed after a three-week open oral treatment with 25 mg doxepin daily. The single-dose administration of doxepin did not affect plasma melatonin concentrations in either the patients on the healthy subjects. After three weeks of oral doxepin intake by the patients, the area under the curve of total nocturnal plasma melatonin concentration was significantly increased by 26% and the peak values were increased by 30%. Both after the single i.v. treatment as well as after long-term oral administration, doxepin also significantly improved sleep latency, total sleep time, and sleep efficiency in the insomniacs as well as the healthy subjects, whereas the nocturnal wake time was decreased. These findings indicate that this tricyclic antidepressant not only improves sleep and but also preserves the secretion of a hormone which is believed to play a special role in the circadian sleep-wake rhythm. Long-term doxepin treatment of chronic insomniac patients not only improves sleep but also restores nocturnal melatonin secretion in these patients.

Adult↗
PubMed1996

[Cerebral cognitive deficits in the aged. Diagnostic and therapeutic standards: organization of strategies for problem detection and solution].

This paper reports the results of a representative survey which was performed in cooperation with 145 family physicians and 14 primary care neuropsychiatrists (response rate 83.2%) in the area of Göttingen, Germany. With the use of a standardised interview referring to written sample case histories, we investigated the diagnostic and therapeutic management of memory disturbances in old age. The results showed, that dementia and depression are underdiagnosed in primary care, and that memory disturbances are mainly regarded as consequences of disturbed cerebrovascular perfusion. About 70% of all physicians would prescribe a cognition enhancer, however about a third of them would do it in spite of major doubts about their efficacy. The results underline the necessity of continuing education especially with regard to early diagnosis of dementive and affective disorders in later life. The development of therapeutic standards in this area should take "irrational" motives into account. Appropriate exemplary case histories seem to be a potentially useful tool for the measurement of physicians' competence and its changes.

Aged↗
PubMed1995

[Factors influencing the prescribing of nootropic drugs. Results of a representative inquiry in Lower Saxony].

AIM OF INVESTIGATION: To discover (1) to what extent patients' wishes and the extent of any abnormality of brain performance influence the frequency with which "nootropic" drugs (those thought to affect brain activity, e.g. piracetam, pyritinol, or improve cerebral circulation, e.g. xanthine derivatives, Ginkgo biloba, secale alkaloids, calcium antagonists) are prescribed; (2) the medical practitioner's expectations of the effectiveness of such medications. METHOD: In a personal interview, 145 family doctors and 14 neurologists in private practice in the Göttingen area of Germany (participation rate: 83.2% of those asked to participate) were questioned about fictitious cases (case 1: mild memory problem with or without expressed wish for medication; case 2: moderate dementia, of Alzheimer or multi-infarct type). The previously arranged interviews, which took place in the doctors' practice rooms, consisted of standardized open questions to the written case reports. RESULTS: Regardless of the wish of the patient and the extent and type of the abnormal brain function about 70% of all participating doctors would prescribe those drugs, even though about 56% had doubts about their effectiveness. About 28% expected a positive effect on brain performance. A nearly equal proportion of doctors would continue an existing drug regimen as would prescribe one. CONCLUSION: The prescription of the named group of drugs is influenced less by medical criteria than by factors which concern doctor-patient relationship.

Adult↗
PubMed1995

Single photon emission tomography (SPET) imaging of dopamine D2 receptors in the course of dopamine replacement therapy in patients with nocturnal myoclonus syndrome (NMS).

Single photon emission tomography (SPET) permits the in vivo measurements of regional cerebral radioactivity in the human brain following the administration of compounds labeled with photon-emitting isotopes. According to our SPET findings of a reduced binding of [123I]labeled (S)-2-hydroxy-3-iodo-6-methoxy-([1-ethyl-2-pyrrolidinyl]methyl) benzamide (IBZM) (a highly selective CNS D2 dopamine receptor ligand) to D2 dopamine receptors in striatal structures in untreated patients with nocturnal myoclonus syndrome (NMS) it seemed to be of interest to investigate whether there are changes in D2 receptor binding under dopamine replacement therapy or not. We studied the uptake and distribution of [123I]IBZM before and in the course of dopamine replacement therapy in four patients with severe insomnia caused by a nocturnal myoclonus syndrome (NMS). We found an increase of the IBZM binding to D2 receptors in the course of treatment, which was associated with an improvement of sleep quality. Reasons for this are discussed. The [123I]IBZM SPET technique in conclusion offers an intersting tool for in vivo investigations of functional changes in the dopaminergic neurotransmitter system in longitudinal studies.

Aged↗
PubMed1995

99mTc-HMPAO-SPECT in the diagnosis of senile dementia of Alzheimer's type--a study under clinical routine conditions.

This study was designed to evaluate, whether investigations of cerebral blood flow can be a helpful diagnostic tool in the differential diagnosis between (senile) dementia of Alzheimer's type [(S)DAT] and geriatric depression with cognitive impairment. Under clinical routine conditions we performed Single Photon Emission Computed Tomography (SPECT) using 99mTc-Hexamethylpropyleneamine Oxime (HMPAO) in 23 patients with (S)DAT (14f, 9m; mean age 68.9 y), 17 patients with geriatric depression (9 f, 8 m; mean age 66.4 y) and 12 age-matched controls (9 f, 3 m; mean age 69.2 y). Semiquantitative analysis (corticocerebellar ratios) of eight different regions of interest (ROI) revealed a significantly (p < 0.05) reduced perfusion in the (S)DAT patients compared to the control group. The depression group exhibited perfusion values between the (S)DAT and control group. The difference between the depression and (S)DAT group was most prominent in the left parieto-occipital ROI (p = 0.008). We discuss the data with extensive regard to the literature and conclude that 99mTc-HMPAO SPECT is a valuable additional tool in the differential diagnosis of depression and dementia in the elderly.

Aged↗
PubMed1995

Nocturnal myoclonus syndrome (periodic movements in sleep) related to central dopamine D2-receptor alteration.

The nocturnal myoclonus syndrome (NMS) consists of stereotyped, repetitive jerks of the lower limbs that occur during sleep or wakefulness. NMS is often related with restless-legs syndrome (RLS) and can cause severe sleep disturbances and daytime sleepiness. The efficacy of dopamine agonists in the treatment points to a dopaminergic dysfunction in NMS. We investigated the central dopamine D2-receptor occupancy with [123I] labeled (S)-2-hydroxy-3-iodo-6-methoxy-([1-ethyl-2-pyrrolidinyl]methyl) benzamide (IBZM) (a highly selective CNS D2 dopamine receptor ligand) ([123I]IBZM) and single photon emission tomography (SPET) in 20 patients with NMS and in 10 healthy controls. In most of the patients with NMS there was a lower [123I]IBZM binding in the striatal structures compared to controls. The results indicate that NMS is related to a decrease of central D2-receptor occupancy.

Adult↗
PubMed1995

Changes of central benzodiazepine receptor density in the course of anticonvulsant treatment in temporal lobe epilepsy.

The first investigation of the central-type benzodiazepine (BZ) receptor density before and following 2 months successful treatment with carbamazepine (CBZ) in a patient with temporal lobe epilepsy (TLE) using 123I-labelled Iomazenil (a specific lipophile central BZ receptor compound) and single photon emission tomography (SPET) is reported. First, a focal slowing of the EEG in the left temporal area was noted and a corresponding reduction of the central BZ density of the left temporal lobe was found. After 2 months of treatment the patient was symptom-free, and a normal BZ receptor density and no pathological EEG signs were found. The increase in central BZ receptor binding sites might be related to the anticonvulsant effects of CBZ mediated by the so-called peripheral BZ receptor sites.

Adult↗
PubMed1995

[Sleep disorders--what can be done when hypnotics no longer help? Overview and case report].

We report on the case of a 45-year old female with chronic insomnia and refractory to hypnotics, who also has a - polygraphically documented - tolerance to the imidazopyridine "zolpidem". We discuss the main differential diagnosis and demonstrate a therapeutic regimen which allows a step-by-step replacement of hypnotics by sedative antidepressants. This interval replacement treatment reduces on the one hand the risk of developing a severe withdrawal syndrome. On the other hand the replacement by sedative antidepressants improves insomnia and insomnia-associated depressive symptoms. Finally, the clinical implications and rationale of a therapeutic approach with sedative antidepressants in chronic insomnia are discussed.

Antidepressive Agents↗
PubMed1995

[Patchy changes in white matter in cranial computerized and magnetic resonance tomography--significance for (differential) diagnosis of dementia of the Alzheimer type and vascular dementia].

With the advancement of technical progress, especially with respect to magnetic resonance imaging, patchy cerebral white matter lesions (WML) are being found with increasing frequency. The (differential) diagnosis between the two main dementias of old age, (senile) dementia of the Alzheimer type ([S]DAT) and vascular dementia (VD) is made more frequently in favour of the latter, since the detection of WML leads to support a vascular origin for dementia. The present article reviews the literature concerning X-ray computed tomography (CT) and magnetic resonance imaging (MRI) in these disorders. For comparison purposes some methodological problems must be taken into account including different scoring systems for WML severity, differences in imaging techniques and in the criteria for the selection of patients and controls. A great number of studies demonstrates a strong association of frequency and severity of WML with increasing age and presence of cerebrovascular risk factors such arterial hypertension. Some studies revealed an association with neuropsychiatric deficits including gait disorders, urinary incontinence, affective lability and reduced attention and information processing speed. In CT studies, about 30% of patients with (S)DAT had WML but 36-88% in MR studies. However, only few studies controlled for the presence of cerebrovascular risk factors. More recent studies - with improved techniques - revealed a higher frequency of (slight or moderate) WML in the (S)DAT group compared to controls. The prevalence of WML in VD patients was 75-97% in CT studies and about 100% in MR studies. Therefore, without the presence of WML, the diagnosis of VD is currently in doubt. A number of in vivo investigations proved consistently - and with different methods - that cerebral blood flow was reduced in WML regions. As shown in some studies the neuropathologic correlates of WML have in common that the relative tissue water content is increased: This includes inflammation, gliosis, complete and incomplete infarctions, dilation of the perivascular (Virchow-Robin) spaces with myelin atrophy. Thus the finding of WML in watershed areas can be understood. Three case reports serve to illustrate the problems pointed out. In conclusion, the occurrence of WML is an unspecific finding which is observed in up to 50% of the elderly. Diagnostic classification as "vascular lesions" or signs of "vascular encephalopathy" or VD based on CT or MRI alone, should not be made.

Aged↗
PubMed1995

Sleep disturbances in the demented elderly: treatment in ambulatory care.

We report the results of a representative survey in Lower Saxony, Germany, that focused on the treatment of sleep disturbances in the moderately demented elderly. Two written sample case histories (vignettes) described either a vascular demented patient suffering from nocturnal wandering or an Alzheimer's-type demented patient without apparent psychotic or behavioral (sleep) disorder. These were randomly assigned and presented to 145 family physicians and 14 neuropsychiatrists working in private practice by a trained investigator, who then conducted a standardized interview with the physicians. The study was representative of physicians (response rate: 83.2%). In response to the question concerning how they would treat the patient's sleep disturbances, about 20% of the physicians (with respect to both versions) answered that they would not choose drugs. More than 40% considered neuroleptics to be the drugs of choice. Benzodiazepines, antidepressants and other substances were seldom considered. No significant difference was noted in the response to the two different case histories. The results allow for the conclusion that non-drug treatments, which (at least initially) should be the treatment of choice, are mainly disregarded by the majority of the ambulatory care physicians. The reason for this seems to be a lack of education in sleep medicine and also in geriatric medicine.

Aged↗
PubMed1995

Cerebral perfusion during sleep-disordered breathing.

Snoring, a leading symptom of the sleep apnoea syndrome (SAS), has been reported to be one of the risk factors for sleep-related cerebral strokes. Episodes of apnoea are accompanied by hypoxaemia as well as hypercapnia. As CO2 constitute a major regulatory factor controlling cerebral blood flow, it is likely that changes in cerebral perfusion are to be found in patients with SAS, which may be related to nocturnal stroke. A computer-assisted pulsed (2 mHz) Doppler ultrasonography system has been modified for continuous long-term and on-line recording of cerebral haemodynamics together with simultaneous polysomnography, continuous blood pressure recordings, and measurement of the end-expiratory CO2. The dynamics of cerebral blood flow velocity (CBFV) during sleep were measured in the right middle cerebral artery in 10 SAS patients. CBFV showed a characteristic nocturnal pattern with decreases during non-rapid eye movement (NREM) sleep and increases during REM sleep. Changes in sleep stage patterns as well as awakenings from NREM sleep were not regularly accompanied by corresponding changes in CBFV. Dramatic increases in CBFV could be observed during apnoeic episodes, with maximum increases during REM sleep. CO2 reactivity and changes in CBFV related to apnoea duration were markedly increased during sleep compared with the waking state in SAS patients. The dynamic feature of CBFV in relation to sleep patterns reflects quantitative uncoupling between cerebral electrical activity and cerebral perfusion during sleep in SAS patients as has been previously reported for normal subjects (Hajak et al. 1994). It supports a dissociation in the activity of central regulatory mechanisms during human sleep which might cause abnormal cerebral perfusion under certain circumstances. The increased CO2 reactivity during sleep in SAS suggests a 'hypersensitivity' of intracranial vasoactive receptors and/or disturbances in the central autonomic control of cerebrovascular functions. It may be concluded that, under certain conditions, the interaction of decreased cerebral perfusion in SAS patients with sleep-related cerebral perfusion patterns and haemodynamic changes during apnoeic episodes might lead to a critical reduction in cerebral perfusion.

Journal Article↗
PubMed1995

Nocturnal plasma melatonin levels in patients suffering from chronic primary insomnia.

Polysomnographic sleep patterns and melatonin secretion were investigated in 10 patients (age: 41.3 +/- 9.5 years) who suffered from chronic primary insomnia and complained predominantly about difficulties in maintaining sleep and in five healthy controls (age 27.2 +/- 0.7 years). Nocturnal plasma melatonin concentrations were obtained hourly, measured by direct radioimmunoassay and statistically compared between insomniacs and controls with age as a covariate. Plasma melatonin levels in the patient group tended to begin increasing earlier in the evening and were significantly (P < or = 0.01) lower during the middle of the night (peak value 82.5 +/- 26.5 pg/ml) than in the healthy controls (peak value 116.8 +/- 13.5 pg/ml). Among the patients, the most severely reduced nocturnal plasma melatonin levels were found in those patients with a history of sleep disturbance lasting for longer than five years (N = 6; age 41.8 +/- 11.7 years; duration 15.3 +/- 5.9 years; peak value 72.1 +/- 25.0 pg/ml); whereas those chronic insomniacs affected for fewer than five years had relatively higher nocturnal levels (N = 4; age 40.6 +/- 6.5 years; duration 3.8 +/- 1.5 years; peak value 98.2 +/- 23.9 pg/ml). These results show that the circadian rhythm of melatonin secretion is disturbed in patients with chronic primary insomnia, and that the nocturnal plasma melatonin secretion is increasingly more affected the longer the patients are unable to maintain a regular sleep pattern.

Adult↗
PubMed1995

Reasons for prescribing cognition enhancers in primary care. Results of a representative survey in Lower Saxony, Germany.

With regard either to the controversial debate about the efficacy of cognition enhancers (CEs) or to the high costs which the frequent prescription of these drugs causes the German health system's economy, we wanted to know what physicians expect from a therapy with these drugs. We performed a representative survey (response rate 83.2%) in Lower Saxony, Germany from February to July 1993. We designed two written case vignettes which described either a patient with slight memory problems or a moderately demented patient who also suffers from common systemic disorders. In a face-to-face interview 145 general practitioners and primary care internists (family physicians) and 14 community neuropsychiatrists answered the question, whether they would prescribe CEs to each of the patients described and what they would expect from this therapy. 70.4% of all physicians would prescribe a cognition enhancer to the slightly impaired patient and 63.5% to the multimorbid moderately demented patient, respectively. More than 50% of the family physicians would not expect any positive therapeutic effect in both patients, while the neuropsychiatrists did so in 57.1% in the patient with slight memory disturbances and in 35.7% in the moderately demented patient. A positive effect on cognition was expected by 28.2% of all physicians in the slight and by 18.3% in the moderately impaired patient, respectively. Other reasons mentioned were amelioration of cerebral perfusion and drive, as well as effects on disease progression. In conclusion, the results of this study clearly demonstrate that cognition enhancers are prescribed in spite of major doubts in their efficacy.

Aged↗
PubMed1994

[Ambulatory treatment of sleep disorders in the aged].

An enquiry into the handling by medical practitioners of sleeping problems among elderly patients was conducted in southern Lower Saxony by personal interview, combined with a standard questionnaire. A typical case report had been drafted concerning a 70-year-old, previously healthy widow: her complaints were "nonspecific" and could be classified as an example of either depression, of the onset of senile dementia or as within normal limits for age. This case report was presented by two interviewers to 145 general practitioners (GPs) and 14 neurologists in private practice (response rate of 83.2%) who were asked how they would have treated the patient's sleeping disorder. 30.3% of the GPs and 14.3% of the neurologists would initially not have prescribed medication. Only GPs (19.5%) mentioned possible herbal medication. Sedative neuroleptics were preferred by 57.1% of neurologists and 26.2% of GPs, while benzodiazepines would have been given by 14% of both groups. Antidepressive drugs and chloral hydrate were chosen less often (5.7% and 2.5%, respectively). These data support the finding of a high frequency of neuroleptic prescriptions given to the elderly. They also make clear that the possibility of treatment without drugs is usually not sufficiently explored.

Aged↗
PubMed1994

Diagnosis of dementia in primary care: results of a representative survey in lower Saxony, Germany.

To investigate whether an early diagnosis of dementia is established, whether a differentiation is made between vascular and primary degenerative etiology, and whether treatable causes of dementia are considered in primary care, we performed a survey using three written sample case histories describing slight memory impairment (case 1) or moderate dementia (case 2a: vascular dementia; case 2: degenerative dementia of Alzheimer type). The combinations 1 and 2a or 1 and 2b were randomly assigned and presented to ambulatory-care physicians (145 general practitioners and primary care internists and 14 neuropsychiatrists in private practice) in Göttingen and rural surroundings by a trained investigator who then performed a standardized interview. The study was representative (response rate 83.2%). For the sample case with slight memory complaints 13.8% of all physicians arrived at a primary diagnosis of depression and 44.0% considered depression for differential diagnosis. Senile dementia of Alzheimer type was considered less often. In the sample cases with moderate dementia according to established scientific criteria, there was a striking under-diagnosis of dementia, and in both cases an over-diagnosis of underlying vascular etiology. Treatable causes of dementia, such as possible drug interactions and substance abuse, were considered only by a minority of physicians. In conclusion, memory deficits seem to be regarded mainly as consequences of disturbed cerebral perfusion, and dementia as well as depression and drug adverse effects seem to be under-diagnosed in primary care.

Aged↗
PubMed1994

[Nightly myoclonus syndrome (NMS) and restless legs syndrome (RLS)--review and case report].

The paper gives a brief review of the existing literature concerning the nocturnal myoclonus syndrome (NMS). The clinical symptomatology, criteria for differential diagnosis and the relation to the restless legs syndrome (RLS) are discussed. Recently we investigated central dopamine receptor density with 123I-labeled 3'-iodo-6-methoxybenzamide (IBZM) (a highly selective CNS D2 dopamine receptor ligand) and single photon emission tomography (SPECT) in patients with NMS and found a reduced density of dopamine D2-receptors in the striatal structures, indicating a dopaminergic dysfunction in NMS and RLS. We present a report concerning a 58-year old female with NMS-associated insomnia and present IBZM SPECTs and hypnograms before and after a 3-month treatment with L-dopa and discuss the results with regard to pathophysiological theories.

Epilepsies, Myoclonic↗
PubMed1993

[Early diagnostic differentiation of primary dementia from primary depressive syndromes in the aged--a contribution to the discussion of pseudodementia].

The syndromes associated with dementia and depression in old age show a considerable overlap and even coincidence, not only for statistical reasons. Starting with a critical evaluation of the term "pseudodementia", possibilities for a differentiation of both types of syndromes by characteristics of clinical features and history and by additional investigations are shown. A critical review of the literature with focus on the differentiating properties of the following methods is given: neuropsychology and rating scales (e.g., "cortical" mediated versus motivational changes), neurophysiology (electroencephalography, EEG; evoked potentials, EP; event-related potentials, ERP), sleep physiology (REM-sleep changes; sleep deprivation results), neuroendocrinology (dexamethasone suppression test), neuroradiology (cranial computed tomography, CCT; magnetic resonance imaging, MRI) and especially the dynamic imaging methods of nuclear medicine (cerebral glucose metabolism with fluorodeoxyglucose and positron emission tomography, FDG-PET; cerebral blood flow (CBF) measurements with PET and single photon emission tomography, SPET). Developments during recent years concerning better imaging of early hippocampal lesions (MRI) or analysis of CBF--changes induced by activation methods may be very helpful. In conclusion, one can say that the diagnosis of dementia and depression remains primarily a clinical one that can be ascertained by means of valuable diagnostic tools.

Aged↗