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ABSTRACT: Cognitive screening methods are useful, although non-exclusive instruments in dementia diagnosis. One such screening is the DemTect-A, which was introduced in Germany in 2000 and has since found widespread use. In the form of the DemTect-B an equivalent test for the DemTect-A is presented. Due to its identical level of difficulty, the DemTect-B is also suitable for follow-up investigations. No other screening test in German-speaking countries has a parallel version.
80 control subjects with a mean age of 65 years (SD = 0.83, 46 women, 34 men) participated in the investigation. To test for equivalence, Dem-Tect-A and DemTect-B were offered in randomised order. With all the control subjects, the CDR (Clinical Dementia Rating Scale) has been carried out to exclude cognitive impairment. The structure of the DemTect-B is nearly identical to that of the DemTect, only the semantic fluency task "supermarket" has been replaced with an animal naming task in the B version. For this task, a separate conversion had to be calculated. Upon completion of this transformation, the total test values did not differ on a statistically significant level.
The DemTect-B is a replication of the DemTect-A and both can be mutually interchanged. It is applied especially in the course of examinations and is a useful tool to identify even patients with mild dementia and mild cognitive impairment.
Fortschritte der Neurologie · Psychiatrie 09/2010; 78(9):532-5. · 0.74 Impact Factor
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ABSTRACT: The aging of the population leads to increasing incidence rates of dementia. Besides pharmacotherapy, non-pharmacological interventions are becoming more and more recognised. Although the data can be regarded as insufficient, many studies indicate that neuropsychological therapy can lead to an improvement of cognitive and non-cognitive symptoms in patients with dementia and mild cognitive impairment, or even decelerate the course of decline. Regulating guidelines of the local health insurance companies do not yet include this type of intervention. However, they are recommended in the recently published German guidelines for the diagnosis and treatment of dementia. Scientific efforts for the evaluation of specific training programmes can be expected; implementation of the results into clinical practice is desirable.
Fortschritte der Neurologie · Psychiatrie 09/2010; 78(9):519-31. · 0.74 Impact Factor
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M. Bar,
N. Barreau,
F. Couzinie-Devy,
S. Pookpanratana,
J. Klaer,
M. Blum,
Y. Zhang,
W. Yang,
J. D. Denlinger,
H.-W. Schock,
L. Weinhardt, J. Kessler,
C. Heske
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ABSTRACT: The chemical structure of the interface between a nominal In <sub>2</sub> S <sub>3</sub> buffer and a Cu ( In , Ga ) Se <sub>2</sub> (CIGSe) thin-film solar cell absorber was investigated by soft x-ray photoelectron and emission spectroscopy. We find a heavily intermixed, complex interface structure, in which Cu diffuses into (and Na through) the buffer layer, while the CIGSe absorber surface/interface region is partially sulfurized. Based on our spectroscopic analysis, a comprehensive picture of the chemical interface structure is proposed.
Applied Physics Letters 06/2010; · 3.84 Impact Factor
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ABSTRACT: Inconsistent changes of cognitive functioning have been reported in patients with Parkinson disease (PD) with deep brain stimulation (DBS) of the subthalamic nucleus (STN). To investigate the underlying pathomechanisms, we correlated alterations of cognitive test performance and changes of neuronal energy metabolism in frontal basal ganglia projection areas under bilateral STN stimulation.
We conducted verbal fluency, learning, and memory tests and 18-fluorodeoxyglucose (FDG) PET in nine patients with PD with STN-DBS before and 6 months after surgery. Using coregistered MRI, postoperative changes of the normalized cerebral metabolic rates of glucose (nCMRGlc) in the dorsolateral prefrontal cortex (DLPFC), lateral orbitofrontal cortex (LOFC), ventral and dorsal cingulum (v/dACC), and in Broca area were determined and correlated with alterations of neuropsychological test results.
After surgery, highly variable changes of both cognitive test performance and frontal nCMRGlc values were found with significant correlations between verbal fluency and FDG uptake in the left DLPFC (Brodmann area [BA] 9, 46), left Broca area (BA 44/45), and the right dACC (BA 32). A decrease of nCMRGlc in the left OFC (BA 11/47) and dACC (BA 32) correlated with a decline of verbal learning. All patients showed reduced metabolic activity in the right anterior cingulate cortex after DBS. Baseline cognitive abilities did not predict verbal learning or fluency changes after surgery.
These data show a significant linear relationship between changes in frontal 18-fluorodeoxyglucose PET activity and changes in cognitive outcome after deep brain stimulation of the subthalamic nucleus (STN) in advanced Parkinson disease. The best correlations were found in the left frontal lobe (dorsolateral prefrontal cortex and Broca area). Baseline performance on cognitive tests did not predict cognitive or metabolic changes after STN electrode implantation.
Neurology 02/2009; 72(1):42-9. · 8.31 Impact Factor
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ABSTRACT: This paper discusses development of a 6-24 GHz mixer in a novel chip scale package. The mixer and package was fabricated together using Avago's enhancement mode (E-mode) PHEMT technology. This chip scale package is high performance, low cost and it totally eliminates all the assembly steps (such as die attach, bond wire etc) required to package a singulated die in a package. The mixer has been tested at two different stages of fabrication, first Un-Capped (like without top-lid in case of conventional package) and after final GaAs-Capped (with top-lid on). The measured conversion loss of un-capped mixer is ~9 dB upto 22 GHz @LO=+16 dBm. Conversion loss of capped wafer is marginally lower than uncapped mixer upto 22 GHz. The IIP3 of uncapped mixer mixer is about +19 dBm and capped mixer IIP3 is about 1-2 dB lower than Capped mixer in most of the band. Rest of the performances of (Capped and Un-capped) mixers are very similar. L-R Isolation ~35 dB, L-I Isolation ~40 dB. IF test frequency is 2 GHz. To the best of author's knowledge this is the first reported chip scale packaged Mixer.
Microwave Integrated Circuit Conference, 2008. EuMIC 2008. European; 11/2008
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ABSTRACT: This paper presents a 1 mm times 0.5 mm times 0.25 mm miniaturized package fabricated using internal E-PHEMT 6" wafers and industry-first Wafer-Scale Packaging technology. To demonstrate this technology, a set of three distinct amplifiers were developed. The 1-12 GHz 50-Ohm gain block operates with a 5 V, 55 mA supply and achieves 14 dB gain, 3.7 dB NF, 28 dBm OIP3 and 17 dBm OP1dB. The 0.5-6 GHz Bypass LNA requires a 5 V, 24 mA supply and has 14.5 dB gain, 2 dB NF in the gain state. The low-voltage LNA operates with a 1.8 V, 20 mA and produces 14.3 dB gain, 2.2 dB NF and -3 dBm IP-1 dB. These three SMT compatible products are unique and industry-leading in all aspects of performance, packaging and cost.
Microwave Integrated Circuit Conference, 2008. EuMIC 2008. European; 11/2008
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ABSTRACT: In continuation of our previous work on visual, appearance-based localization in manually built maps in this paper we present a novel appearance-based, visual SLAM approach. The essential contribution of this work is, an adaptive sensor model which is estimated online and a graph matching scheme to evaluate the likelihood of a given topological map. Both methods enable the combination of an appearance-based, visual localization concept with a Rao-Blackwellized Particle Filter (RBPF) as state estimator to a real-world suitable, online SLAM approach. In our system, each RBPF particle incrementally constructs its own graph-based environment model which is labeled with visual appearance features (extracted from panoramic 360deg snapshots of the environment) and the estimated poses of the places where the snapshots were captured. The essential advantages of this appearance-based SLAM approach are its low memory and computing-time requirements. Therefore, the algorithm is able to perform in real-time. Finally, we present the results of SLAM experiments in two challenging environments that investigate the stability and localization accuracy of this SLAM technique.
Intelligent Robots and Systems, 2008. IROS 2008. IEEE/RSJ International Conference on; 10/2008
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ABSTRACT: The crystal structure of high Ga-content Cu In <sub>1-x</sub> Ga <sub>x</sub> Se <sub>2</sub> (CIGSe) compounds has been further investigated with the help of single crystal x-ray diffraction technique. It is known that CIGSe compounds adopt the chalcopyrite crystal structure. In the case of Cu-poor, Ga-rich CIGSe, the present study shows that an alternative structure should be considered. This structure is derived from that of stannite in which there is a Ga / In segregation on two different atomic planes. The diffuse reflectance measurements of the Cu-poor compound reveal a slightly different band gap and a smoother transition compared with those of the stoichiometric compound.
Applied Physics Letters 07/2008; · 3.84 Impact Factor
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ABSTRACT: We report a case of a delusional patient who had killed two of her children in an attempted 'extended suicide'. She was convinced of a genetic defect that caused autobiographical memory and emotional deficits and made life 'senseless'. Neuropsychological tests revealed dysfunctions in remembering emotional details of personal episodes and theory of mind. Water positron emission tomography (15O) with a paradigm used in a former study by Fink et al. (1996) with healthy controls elicited abnormal activations during autobiographical memory retrieval characterised by a lack of prefrontal and limbic activity. We conclude that these imaging findings reflect neural correlates of the self-reported and objectified autobiographical dysfunctions. Furthermore, they indicate that beliefs or prejudices may have a major impact on the brain's processing of the personal past.
Neurocase 02/2008; 14(1):15-28. · 1.11 Impact Factor
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ABSTRACT: Recent research proposes that theory of mind (ToM), that is the ability to infer other people's mental state, is a multidimensional construct and that a distinction may be made between affective and cognitive ToM. We examined whether these two subcomponents of ToM correspond to different levels in skin conductance responses (SCRs). Seventeen healthy adults listened to ten affective (faux pas) ToM stories, ten cognitive ToM stories and ten non-ToM stories. Results demonstrated significantly elevated SCR for affective ToM as compared with cognitive ToM and control stories, with no differences in SCR levels in the latter two story types. We discuss the possible underlying mechanisms for these differential psychophysiological correlates of affective and cognitive ToM processing, and suggest further investigations especially in clinical populations.
Journal of Neuropsychology 04/2007; 1(Pt 1):27-38. · 1.74 Impact Factor
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E Kalbe,
E Salmon,
D Perani,
V Holthoff,
S Sorbi,
A Elsner,
S Weisenbach,
M Brand,
O Lenz, J Kessler,
S Luedecke,
P Ortelli,
K Herholz
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ABSTRACT: To study awareness of cognitive dysfunction in patients with very mild Alzheimer's disease (AD) and subjects with mild cognitive impairment (MCI).
A complaint interview covering 13 cognitive domains was administered to 82 AD and 79 MCI patients and their caregivers. The patient groups were comparable according to age and education, and Mini Mental State Examination (MMSE) scores were > or =24 in all cases. The discrepancy between the patients' and caregivers' estimations of impairments was taken as a measure of anosognosia.
Self-reports of cognitive difficulties were comparable for AD and MCI patients. However, while in comparison to caregivers MCI patients reported significantly more cognitive impairment (p < 0.05), AD patients complained significantly less cognitive dysfunctions (p < 0.001).
While most MCI patients tend to overestimate cognitive deficits when compared to their caregiver's assessment, AD patients in early stages of disease underestimate cognitive dysfunctions. Anosognosia can thus be regarded as a characteristic symptom at a stage of very mild AD (MMSE > or =24) but not MCI. Accordingly, medical history even in mildly affected patients should always include information from both patient and caregiver.
Dementia and Geriatric Cognitive Disorders 01/2005; 19(5-6):349-56. · 2.14 Impact Factor
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Brain and Cognition 04/2004; 54(2):135-6. · 3.17 Impact Factor
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ABSTRACT: To design a new, highly sensitive psychometric screening to identify patients with mild cognitive impairment (MCI) and patients with dementia in the early stages of the disease.
Five tasks were included in the DemTect: a word list, a number transcoding task, a word fluency task, digit span reverse, and delayed recall of the word list. The normation was performed with 145 healthy control subjects (CG). Furthermore, 97 MCI patients and 121 patients with possible Alzheimer's disease (AD) were tested with the DemTect and the MMSE. Classification rates for both tests were analysed.
On the basis of the CG data, age-dependant transformation algorithms for the DemTect subtests were defined, and an education correction was provided for the total transformed score. The patient groups scored significantly below the CG in both the DemTect and the MMSE. Compared to the MMSE, classification rates of the DemTect were superior for both the MCI and the AD group, with high sensitivities of 80% and 100%, respectively.
The DemTect is short (8-10 minutes), easy to administer, and its transformed total score (maximum 18) is independent of age and education. The DemTect helps in deciding whether cognitive performance is adequate for age (13-18 points), or whether MCI (9-12 points) or dementia (8 points or below) should be suspected.
International Journal of Geriatric Psychiatry 03/2004; 19(2):136-43. · 2.42 Impact Factor
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ABSTRACT: Patients with idiopathic Parkinson's syndrome (IPS) show dysexecutive deficits which are not related to dementia. We investigated whether these deficits may be caused by a disturbed interaction of prefrontal cortex and selective basal ganglia loops. 5 healthy right-handed volunteers and 5 non demented IPS patients were studied with FDG PET while performing a gambling task paradigm. Control subjects and patients showed consistent bilateral activation of the dorsolateral prefrontal cortex (DLPFC) and the left caudate. Only controls activated the right cingulate, mesial prefrontal and frontoorbital cortex. Patients significantly deactivated the right thalamus. Thus missing frontoorbital and frontomesial activity may indicate an impairment of the basal ganglia loop in IPS, connecting those regions to the thalamus via the ventral striate. The connections between DLPFC and Thalamus via the left caudate remained intact. This impairment may be the neuroanatomical correlate for dysexecutive syndromes in IPS more related to misjudgement than cognitive impairment.
Acta Neurovegetativa 12/2003; 110(11):1289-301. · 2.73 Impact Factor
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ABSTRACT: Disturbance of neurologic function in disorders of the central nervous system is expressed as an altered activation pattern in functional networks employed by specific tasks and can be studied by functional imaging modalities, e.g., positron emission tomography. Language, a complex brain function, is based on the interplay of a distributed network in which partial functions are executed in various centers, the primary language areas. These areas are hierarchically organized and activated according to the complexity of the specific language task. The specialization of different centers and the lateralization of integrative functions into the dominant (usually left) hemisphere are achieved by collateral and transcallosal inhibition of secondary language areas which normally are not employed for performance of a specific language task.
NeuroImage 12/2003; 20 Suppl 1:S42-9. · 5.89 Impact Factor
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ABSTRACT: Patients with idiopathic Parkinsons syndrome (IPS) show dysexecutive deficits which are not related to dementia. We investigated whether these deficits may be caused by a disturbed interaction of prefrontal cortex and selective basal ganglia loops. 5 healthy right-handed volunteers and 5 non demented IPS patients were studied with FDG PET while performing a gambling task paradigm. Control subjects and patients showed consistent bilateral activation of the dorsolateral prefrontal cortex (DLPFC) and the left caudate. Only controls activated the right cingulate, mesial prefrontal and frontoorbital cortex. Patients significantly deactivated the right thalamus. Thus missing frontoorbital and frontomesial activity may indicate an impairment of the basal ganglia loop in IPS, connecting those regions to the thalamus via the ventral striate. The connections between DLPFC and Thalamus via the left caudate remained intact. This impairment may be the neuroanatomical correlate for dysexecutive syndromes in IPS more related to misjudgement than cognitive impairment.
Acta Neurovegetativa 01/2003; 110(11):1289-1301. · 2.73 Impact Factor
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ABSTRACT: In this prospective study we analyzed the prognostic value of topographical quantitative EEG (qEEG) in poststroke aphasia. Twenty-three right-handed patients (ages 56 +/- 12 years) with different types of aphasia were studied. Quantitative EEG under resting conditions and an aphasia test battery were applied twice, 2 and 8 weeks after a stroke. EEG power fast Fourier transform was performed for delta (2-3.5 Hz), theta (4-7.5 Hz), alpha (8-13 Hz), and beta (13.5-20 Hz) frequency bands. EEG abnormalities within and outside speech relevant areas are related to restitution of poststroke aphasia. In the ischemic regions they indicate local disturbances; outside they reflect failures in neuronal networks involved in the generation and propagation of the alpha rhythm.
Brain and Language 08/2002; 82(1):87-94. · 3.12 Impact Factor
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ABSTRACT: In this review, studies on number processing and calculation in demented patients are summarized. Single cases, group studies and our own examinations all show that acalculia is a frequent symptom of dementia and correlates with severity of dementia. While calculation and numeral transcoding deficits are often prominent in early courses of the disease, deficits in semantic processing and basic number processing are less severe. Still, single cases demonstrate that very specific dysfunctions in number processing and calculation can occur in dementia. In number transcoding, a characteristic error type occurs in demented patients that has not (or rarely) been described in other brain damaged people so far. In these "shift errors" or "intrusion errors" the wrong number code is used or the number codes are mixed (e.g. patients write "2hindert11" instead of zweihundertelf (two hundred eleven)). Due to the frequent occurence of acalculia in dementia and its specific features, it is suggested that acalculia should be integrated into the criteria for dementia and that number processing and calculation tests are used in the diagnosis of dementia.
Zeitschrift für Gerontologie + Geriatrie 05/2002; 35(2):88-101. · 0.61 Impact Factor
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ABSTRACT: In dieser Arbeit werden Befunde zu Zahlenverarbeitungs- und Rechenstörungen bei Demenzpatienten referiert. Die dargestellten In dieser Arbeit werden Befunde zu Zahlenverarbeitungs- und Rechenstörungen bei Demenzpatienten referiert. Die dargestellten
Einzelergebnisse, Gruppenstudien und eigene Studien deuten insgesamt darauf hin, dass Akalkulien zum Erscheinungsbild der Einzelergebnisse, Gruppenstudien und eigene Studien deuten insgesamt darauf hin, dass Akalkulien zum Erscheinungsbild der
Demenzen dazugehören und mit zunehmender Krankheitsausprägung ansteigen. Wenngleich in Einzelfällen sehr spezifische Defizite Demenzen dazugehören und mit zunehmender Krankheitsausprägung ansteigen. Wenngleich in Einzelfällen sehr spezifische Defizite
der Zahlenverarbeitung oder des Rechnens auftreten können, sind in der Regel das Rechnen und das Zahlentranskodieren besonders der Zahlenverarbeitung oder des Rechnens auftreten können, sind in der Regel das Rechnen und das Zahlentranskodieren besonders
früh und deutlich vom kognitiven Abbau betroffen, während die semantische Zahlenverarbeitung und basale Zahlenverarbeitungsleistungen früh und deutlich vom kognitiven Abbau betroffen, während die semantische Zahlenverarbeitung und basale Zahlenverarbeitungsleistungen
länger erhalten bleiben. Beim Zahlentranskodieren tritt neben anderen Beeinträchtigungen ein Fehlertyp auf, der bislang nicht länger erhalten bleiben. Beim Zahlentranskodieren tritt neben anderen Beeinträchtigungen ein Fehlertyp auf, der bislang nicht
bei anderen hirngeschädigten Patienten beobachtet werden konnte und somit demenzspezifisch sein könnte – der sog. „Shiftfehler” bei anderen hirngeschädigten Patienten beobachtet werden konnte und somit demenzspezifisch sein könnte – der sog. „Shiftfehler”
oder „Intrusionsfehler”, bei dem ein falscher Zahlencode verwendet wird oder eine Vermischung der Zahlencodes auftritt (z.B. oder „Intrusionsfehler”, bei dem ein falscher Zahlencode verwendet wird oder eine Vermischung der Zahlencodes auftritt (z.B.
wird aus zweihundertelf „2hindert11”). Das häufige Auftreten von Akalkulien bei Demenzen und ihre spezifischen qualitativen wird aus zweihundertelf „2hindert11”). Das häufige Auftreten von Akalkulien bei Demenzen und ihre spezifischen qualitativen
Merkmale lassen eine Aufnahme von Akakulien in die Demenzkriterien und eine Berücksichtigung von Zahlenverarbeitungs- und Merkmale lassen eine Aufnahme von Akakulien in die Demenzkriterien und eine Berücksichtigung von Zahlenverarbeitungs- und
Rechentests in der Demenzdiagnostik sinnvoll erscheinen. Rechentests in der Demenzdiagnostik sinnvoll erscheinen.
In this review, studies on number processing and calculation in demented patients are summarized. Single cases, group studies In this review, studies on number processing and calculation in demented patients are summarized. Single cases, group studies
and our own examinations all show that acalculia is a frequent symptom of dementia and correlates with severity of dementia. and our own examinations all show that acalculia is a frequent symptom of dementia and correlates with severity of dementia.
While calculation and numeral transcoding deficits are often prominent in early courses of the disease, deficits in semantic While calculation and numeral transcoding deficits are often prominent in early courses of the disease, deficits in semantic
processing and basic number processing are less severe. Still, single cases demonstrate that very specific dysfunctions in processing and basic number processing are less severe. Still, single cases demonstrate that very specific dysfunctions in
number processing and calculation can occur in dementia. In number transcoding, a characteristic error type occurs in demented number processing and calculation can occur in dementia. In number transcoding, a characteristic error type occurs in demented
patients that has not (or rarely) been described in other brain damaged people so far. In these „shift errors” or „intrusion patients that has not (or rarely) been described in other brain damaged people so far. In these „shift errors” or „intrusion
errors” the wrong number code is used or the number codes are mixed (e.g. patients write „2hindert11” instead of zweihundertelf (two hundred eleven)). Due to the frequent occurance of acalculia in dementia and its specific features, it is suggested errors” the wrong number code is used or the number codes are mixed (e.g. patients write „2hindert11” instead of zweihundertelf (two hundred eleven)). Due to the frequent occurance of acalculia in dementia and its specific features, it is suggested
that acalculia should be integrated into the criteria for dementia and that number processing and calculation tests are used that acalculia should be integrated into the criteria for dementia and that number processing and calculation tests are used
in the diagnosis of dementia. in the diagnosis of dementia.
Zeitschrift für Gerontologie + Geriatrie 03/2002; 35(2):88-101. · 0.61 Impact Factor
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ABSTRACT: Disturbance of neurologic function in disorders of the central nervous system is expressed as altered activation pattern in functional networks after specific tasks, and can be studied by functional imaging modalities, e.g. positron emission tomography (PET). Language, a complex brain function is based on the interplay of a distributed network in which partial functions are executed in various centers and tasks are hierarchically organized according to their complexity. The specialization of different centers and the lateralization of integrative functions into the dominant (usually left) hemisphere is achieved by collateral and transcallosal inhibition of structures of lower order in the network. Patients with ischemic stroke often suffer from aphasia; the features and the prognosis of this disturbance is determined by the localization and the extent of the infarct in the dominant hemisphere. The preservation of the left superior temporal gyrus or its functional reintegration, respectively, is of utmost importance for the recovery of the deficits and for a satisfactory outcome. Reactivation of this region in repeated PET-activation studies were related to a favorable outcome, activation of other eloquent regions or of contralateral areas were accompanied by some improvements, but never indicated recovery of sufficient speech production. Symptoms develop slowly in patients with tumors in the left hemisphere, and the functional network can adapt to the lesion. In these patients a dislocation of areas activated during language tasks was observed, either to ipsilateral regions usually not involved or to contralateral homotopic areas. Aphasia was frequent in cases with activation shift to the subdominant hemisphere, and the right over left asymmetry in activation of the cerebellum was correlated to the severity of language impairment. The shift of dominance in activation could be reversed after surgical resection of the tumor leading to improved speech performance. The patterns of intrahemispheric as well as interhemispheric compensation may be explained by reduction of collateral inhibition of specific centers on other structures within the network (disinhibition): circumscript and/or slowly developing lesions disinhibit surrounding areas leading to increases and to displacements of activated centers; large morphological defects reduce the transcallosal inhibition leading to the activation of contralateral regions.
Zentralblatt für Neurochirurgie 02/2002; 63(4):133-40. · 0.63 Impact Factor
