Your search for: 'author:("Riepe, Matthias W.")' has returned 6 results. (0.012s) Save search

Authors: Neumeister, Katharina L. | Riepe, Matthias W.

Article Type: Research Article

Abstract: Current treatment of Alzheimer's disease rests on cholinergic and anti-glutamatergic substances. It has been suggested that acetylcholine is required for memory acquisition but is less important for memory retrieval. It was our goal to investigate the effects of treatment with donepezil, memantine, and a combination thereof on spatial memory. We assessed spatial memory of male wild type and B6C3-Tg(APPswe,PSEN1dE9)85Dbo (APP23) transgenic animals in a complex dry-land maze. Animals were treated with donepezil (1 mg/kg) and memantine (10 mg/kg). Total time to escape from the maze decreased in 4.5 month old sham-treated wild-type animals and, to a lesser extent, in APP23 …animals. Analysis of time spent moving and resting revealed that the treatment effect is conferred by a reduction of the moving time for donepezil and a reduction of the resting time for memantine. Combination treatment with donepezil and memantine fostered a greater improvement than treatment with either substance alone. We conclude that enhancement of spatial learning in a dry-land maze on cholinergic or anti-glutamatergic treatment is differentially conferred during moving of the animals, possibly reflecting acquisition of spatial information, and resting of the animals, possibly reflecting retrieval of spatial information. Combination treatment with donepezil and memantine exerts a synergistic effect improving both moving time and resting time and thus possibly both spatial learning and retrieval. Show more

Keywords: Alzheimer's disease, awake immobility, donepezil, maze, memantine, spatial learning, transgenic animal model

DOI: 10.3233/JAD-2012-111643

Citation: Journal of Alzheimer's Disease, vol. 30, no. 2, pp. 245-251, 2012

Authors: Sejunaite, Karolina | Lanza, Claudia | Riepe, Matthias W.

Article Type: Research Article

Abstract: Background: Errors of omission are an established hallmark of memory impairment in Alzheimer’s disease (AD). Much less is known about other memory errors in AD such as false memories. Objective: We investigated false memories in healthy elderly controls (HC; n  = 23) and patients with AD (n  = 20) using real-life tasks of watching news and commercials. Methods: Participants received a comprehensive neuropsychological assessment and were shown original news and commercials with a subsequent recognition task to assess veridical and false memories. Results: Subjective estimate of the number of errors were alike in HC and patients with AD. However, memory performance in …both the news and the commercials task was significantly worse in patients with AD. Trail-Making Test and Symbol-Span Test were significant predictors of false memories on viewing news and commercials. In patients with AD, levels of Aβ1 - 42 , but not levels of tau-protein were correlated with false memories in both tasks. Conclusions: Everyday life in patients with AD is impeded not due to the incompleteness of memory but also due to its distortions. Furthermore, it is hindered by the lack of awareness towards these deficits. False memory content in patients with AD is associated with Aβ42 levels in the CSF as a surrogate of the overall extent to which the brain has been affected by AD pathology. Future studies will need to address the impact of this duality of memory failure on everyday life of patients with AD and their proxies in greater detail. Show more

Keywords: Alzheimer’s disease, cerebrospinal fluid markers, episodic memory, everyday life, false memories, memory disorders, neuropsychology

DOI: 10.3233/JAD-170493

Citation: Journal of Alzheimer's Disease, vol. 60, no. 4, pp. 1489-1498, 2017

Authors: Lanza, Claudia | Knörzer, Oliver | Weber, Michael | Riepe, Matthias W.

Article Type: Research Article

Abstract: Background/Objective: Spatial orientation declines early in patients with Alzheimer’s disease (AD) and is a major cause for institutionalization of patients. Methods: Use of either an aerial map or an assistive device to get from start to goal zone, both located on the campus of the hospital (distance between start and goal zone 300 m to 500 m). Use of the assistive device was trained for 15 minutes prior to the task. Results: We assessed 14 patients with mild to moderate AD (DSM-IV and NINCDS-ADRDA criteria; 9 female patients, 5 male patients; age 71.9 ± 7.4 years; MMSE 21.7 ± 2.9 …(mean ± SD), range 16–26). Each patient had to find the way for three different routes with different start and goal zones. None of the patients found their way to the goal zone for any of the routes when using an aerial map in which the way was highlighted. With use of the assistive device, patients found their way from start to goal zones autonomously for 20 of 42 routes (3 routes each for 14 patients). For 22 of 42 routes intermediate re-assurance was necessary, but herewith routes were completed. Conclusion: This study lays ground for the use of mobile technical devices in patients with mild to moderate AD. Mobile assistive devices may enable patients with mild to moderate AD to maintain autonomous spatial orientation in unfamiliar environments. Improvement of the familiarization of patients with the device and further sophistication of assistive cues is likely to further improve autonomous use of navigational devices in patients with mild to moderate AD. Show more

Keywords: Alzheimer's disease, assistive devices, spatial orientation

DOI: 10.3233/JAD-140063

Citation: Journal of Alzheimer's Disease, vol. 42, no. 3, pp. 879-884, 2014

Authors: Ludolph, Albert C. | Meyer, Thomas | Riepe, Matthias W. | Volkel, Helge

Article Type: Research Article

Abstract: Amyotrophic lateral sclerosis is a progressive fatal disorder devastating the spinal cord and brain in humans. Excitotoxicity has been suggested to be involved in the pathogenesis of amyotrophic lateral sclerosis. This hypothesis has driven a wealth of basic research and stimulated development of neuroprotective therapies for chronic neurodegenerative disorders. As a result of these efforts, riluzole, an antiglutamatergic drug, has been established in the therapy of amyotrophic lateral sclerosis. A transgenic mouse showing features of amyotrophic lateral sclerosis has been subsequently engineered enabling studies of the disease in vivo. However, despite considerable progress, the etiology of amyotrophic lateral sclerosis remains …obscure and the disturbances in excitatory neurotransmission should by no means be regarded as exclusive to the pathogenesis of the disease. Show more

Keywords: amyotrophic lateral sclerosis, Cu/Zn SOD, EAAT2, excitotoxicity, neurolathyrism, riluzole

Citation: Restorative Neurology and Neuroscience, vol. 13, no. 1-2, pp. 59-67, 1998

Authors: Sejunaite, Karolina | Gaucher, Frederic | Lanza, Claudia | Riepe, Matthias W.

Article Type: Research Article

Abstract: Background: Clock Drawing Test (CDT) is a commonly used screening tool for cognitive disorders, known for its ease of administration and scoring. Despite frequent use by clinicians, CDT is criticized for its poor predictive value in mild cases of impairment. Objective: To evaluate CDT as a screening tool for early stage of cognitive impairment in biomarker-verified Alzheimer’s disease (AD) and depressive disorder (DD). Methods: We analyzed CDT of 172 patients with verified AD, 70 patients with DD, in whom neurodegenerative disorder was excluded using cerebrospinal fluid biomarkers, and 58 healthy older adults. CDT was scored using the semi-quantitative (Shulman) and …itemized criteria (adapted from Mendez). Results: Logistic regression showed that for both DD and AD patients with high Mini-Mental State Examination (MMSE) scores (27 and above) the significant predicting variable is uneven number spacing. As MMSE deteriorates (24-26 points), an additional error of setting clock hands is predictive of the disease. In the low MMSE condition, CDT showed an acceptable discrimination for AD (AUC itemized 0.740, Shulman 0.741) and DD (AUC itemized 0.827, Shulman 0.739) using both scoring methods. In the high MMSE condition, discrimination rates were acceptable using itemized scoring but poor using Shulman scoring for both AD (AUC itemized 0.707, Shulman 0.677) and DD (AUC itemized 0.755, Shulman 0.667) groups. Conclusion: Ideally, modern diagnostic process should take place before the cognitive performance drops beneath the healthy range. This makes CDT of little use when screening patients with very mild cognitive deficits. Show more

Keywords: Alzheimer’s disease, dementia, depressive disorder, mental status and dementia tests, screening

DOI: 10.3233/JAD-230110

Citation: Journal of Alzheimer's Disease, vol. 95, no. 4, pp. 1597-1608, 2023

Authors: Bittner, Daniel M. | Wieseler, Isabel | Wilhelm, Helmut | Riepe, Matthias W. | Müller, Notger G.

Article Type: Research Article

Abstract: It was investigated whether alterations of the pupil's light reflex might reflect Alzheimer's disease (AD) pathology. Changes in the pupil's system might be expected due to AD pathology present in the oculomotor system of the Edinger-Westphal nucleus, and a cholinergic deficit caused by degeneration of the nucleus basalis Meynert. A rather new method of repetitive light stimulation was applied assessing variations in pupil size, latency, and amplitude over time. We analyzed 44 healthy controls, 42 subjects with mild cognitive impairment (MCI), and 66 AD patients. AD and MCI showed a less pronounced pupil size decrease and amplitude increase over time …than controls. A higher MMSE was associated with a higher increase of relative amplitude and greater decrease of latency in AD and MCI, and absolute amplitude increase in AD alone. Pupil size increase correlated with cerebrospinal fluid markers in AD. Summarized pupil light reflex is not stable under repetitive stimulation, but changes systematically and less pronounced in AD and MCI. Thus repetitive stimulation of the pupil's response potentially indicates AD pathology. Show more

Keywords: Alzheimer's disease, amyloid-β 1-42, cerebrospinal fluid, mild cognitive impairment, parasympathetic system, pupil light reflex, repetitive stimulation, sympathetic inhibition, tau

DOI: 10.3233/JAD-140969

Citation: Journal of Alzheimer's Disease, vol. 42, no. 4, pp. 1469-1477, 2014