PubMed Health⌕ Search

Biomedical subjects

E Donnemiller

Publications and source records attributed to E Donnemiller.

At least 19 recordsLinked to original sources
PubMed2006

Knowing 7 x 8, but not the meaning of 'elephant': evidence for the dissociation between numerical and non-numerical semantic knowledge.

Patients affected by semantic dementia (SD) and other severe cognitive deficits may show preserved numerical skills, including the retrieval of multiplication facts from long-term memory. No studies so far specifically investigated the network of arithmetic facts in semantic dementia. Thus, it is unknown whether preserved multiplication in SD truly reflects intact semantic knowledge or preserved retrieval of verbal sequences (just as the recitation of rhymes or poems). In the present study a patient (SG) with SD underwent an extensive assessment of number processing and calculation abilities. In particular, multiplication knowledge was investigated through a series of computerised tasks (production task, multiple-choice task, number bisection task with multiplicative triplets, number-matching task). SG demonstrated excellent performance in all number processing and calculation tasks. In computerised tasks tapping multiplication fact knowledge, SG was as accurate and fast as healthy controls. Analyses on individual regression slopes indicated that SG's reaction time effects (problem-size effect, problem-difficulty effect, interference effects, and facilitation effect) were comparable to those found in controls in each task. These results add new evidence to the independence of numerical knowledge from other semantic information and provide further insight into the organisation of stored arithmetic knowledge.

Dementia↗
PubMed2006

[The clinical syndrome of posterior cortical atrophy].

Posterior cortical atrophy (PCA) is a syndrome that involves distinct neuropsychological deficits. This paper presents the clinical and neuropsychological findings recorded in four patients with PCA and reviews the characteristics of the syndrome and other conditions that need to be considered in the differential diagnosis. The cardinal symptoms of PCA are deficits of higher visual and spatial functions (mostly taking the form of Balint's syndrome), variably associated with disorders of visual perception, topographical disorientation, visual object agnosia and prosopagnosia, and deficits affecting reading, copying, drawing, and calculation. PCA is mostly associated with histopathological changes similar to those found in dementia of Alzheimer type (DAT), which are located predominantly in posterior brain regions. Memory and language functions tend to be preserved better and for a longer time in PCA than in the normal variant of DAT. SPECT and PET show deficits of perfusion and metabolism in both parietal and occipital lobes. The diagnosis of PCA is based on neuropsychological and imaging findings.

Cerebral Cortex↗
PubMed2005

Number processing in posterior cortical atrophy--a neuropsycholgical case study.

Posterior cortical atrophy (PCA) is an uncommon syndrome of dementia with early onset, characterised by disorders of higher visual function, variable symptoms of Balint's syndrome, visual agnosia, alexia, agraphia, finger agnosia, right-left disorientation and dyscalculia [Benson D. F., Davis R. J., & Snyder B. D. (1988). Posterior cortical atrophy. Archives of Neurology, 45, 789-793]. In a single case study specific numerical deficits were observed which may be predicted by parietal neurodegeneration (more pronounced on the right side; verified by SPECT). Besides impairments in all tasks involving visuo-spatial abilities (e.g., dot counting, analog number scale task), deficits appeared in tasks requiring access to an internal representation of numbers such as mental number bisection, approximation, estimation and semantic facts. In number comparison an increased distance effect was found. In simple arithmetic, a striking dissociation between operations was found-multiplication and addition facts being preserved at a superficial level, subtraction and division being severely impaired. The study confirms the close relation between spatial and numerical processing and highlights the modular organisation of the semantic system (number semantics impaired). Moreover, the study adds evidence about the clinical manifestation of the particular degenerative syndrome.

Atrophy↗
PubMed2004

Subacute dementia and imaging correlates in a case of Fahr's disease.

We report a case of idiopathic bilateral basal ganglia calcinosis, or Fahr's disease (FD) in a 50 year old patient who developed rapidly progressive behavioural abnormalities and severe neuropsychological impairments, but no movement disorder. Neuropsychological deficits included a severe dysexecutive syndrome, anterograde amnesia, and attentional impairment. Neuropsychiatric features comprised apathy with intermittent disinhibition, anxiety, irritability, frequent mood changes, ritualistic and antisocial behaviour, and psychosis. Fluorodeoxyglucose positron emission tomography showed a massive reduction of glucose metabolism in the basal ganglia and the frontal brain. The observed abnormalities possibly result from a disruption of frontostriatal circuits, presumably at the basal ganglia level. This case indicates that FD may cause exclusively behavioural alterations and that the associated hypometabolism in certain frontal areas is closely related to the clinical picture.

Aggression↗
PubMed2003

Fluoxetine in Alzheimer's disease with severe obsessive compulsive symptoms and a low density of serotonin transporter sites.

The treatment of behavioral disturbances is particularly challenging in patients suffering from dementia. In an 80-year-old female patient with probable AD and severe obsessive and compulsive symptoms, we demonstrated a significant reduction in the density of serotonin transporter sites using 1231-beta-CIT SPECT. Treatment with fluoxetine for 6 months resulted in significant symptom relief and an increasing density of serotonin transporter sites when compared to the beginning of treatment. Therefore, this report provides evidence that fluoxetine is a treatment option for patients with AD and severe obsessive-compulsive symptoms and highlights the importance of the serotoninergic system.

Aged↗
PubMed2002

Mania caused by a diencephalic lesion.

We describe the case of a young male patient, SN, who suffered a MR-documented ischaemic lesion of both dorsomedial thalami and presented with a transient maniform syndrome. SN's neuropsychological, structural and functional imaging findings are compared with similar reported cases and are discussed in the framework of fronto-subcortical circuits and their proposed behavioural disorders. SN's mania was characterized by restlessness, mood elevation, a tendency for pleasurable activities, inflated self-esteem and loss of disease awareness. Other symptoms were sexual disinhibition, tactlessness, abnormal discourse, and reduced need for food and sleep. His neuropsychological assessment revealed an anterograde amnesia, and an impairment of frontal-executive functions. A SPECT-study showed diaschisis-related areas of hypoperfusion in both prefrontal regions which were interpreted as equivalents of SN's frontal-dysexecutive syndrome. In addition, there was a perfusion deficit in the right orbitofrontal cortex, which was taken as the imaging correlate of SN's secondary mania and personality disorder. These findings suggest that SN's mania and his other symptoms result from the twofold disruption of fronto-subcortical connections, namely of the right orbitofrontal loop which is concerned with mood regulation and socially appropriate behaviour, and of the dorsolateral prefrontal loop which mediates executive cognitive functions.

Adult↗
PubMed2002

[The diagnosis of frontotemporal dementia].

Frontotemporal Lobar Degeneration (FTDL) is a neurodegenerative disorder which is predominantly characterized by changes in behaviour and loss of cognitive abilities. Three major clinical syndromes have been identified, Frontotemporal dementia (FTD), in which changes in social behaviour predominate, Semantic Dementia (SD) which is characterized by a loss of semantic knowledge, and Primary Progressive Aphasia (PPA), a disorder of phonological and syntactic aspects of language. All subtypes of FTLD have insiduous onset and stepwise progression. The present review lists the clinical symptoms and main findings of the three FTLD-subtypes, and discusses the difficulties of their diagnosis and differential diagnosis. The diagnosis of FTLD is based on the clinical consensus criteria of the Lund and Manchester groups, neuroradiological and neuropsychological investigations.

Dementia↗
PubMed2001

Striatal dopamine transporter function in dementia with Lewy bodies and Parkinson's disease.

The aim of this study was to compare parkinsonian features and loss of striatal dopamine transporter (DAT) function in patients with dementia with Lewy bodies (DLB) and Parkinson's disease (PD), matched for age and disease duration. Twenty patients with DLB. 24 PD patients and 10 matched controls were examined with SPET using a dual-head camera and the dopamine-transporter ligand 123I-beta-CIT (148 MBq). Moreover, in a subgroup of patients (16 DLB and 20 PD patients), subscores of the Unified Parkinson's Disease Rating Scale (UPDRS)-motor examination (ME) subscale were obtained during "practical off", i.e. 12 h following withdrawal of antiparkinsonian therapy. Compared with controls, striatal/cerebellar (S/C) ratios of DAT binding were significantly reduced in both DLB and PD, deficits being more marked in DLB patients (controls 7.2 +/- 1.2, DLB 3.3 +/- 1, PD 4.2 +/- 1.4; means +/- SD). The side-to-side differences in the S/C ratios were lower in the DLB group and the controls than in PD patients (0.4 +/- 0.4. 0.2 +/- 0.2 and 0.6 +/- 0.3, respectively, P<0.05). The total UPDRS-ME scores during practical-off were significantly higher in the DLB than in the PD group (41.2 +/- 12.7 vs 26.6 +/- 15.3, P<0.01). The side-to-side differences of the summed UPDRS extremity subscores were smaller in the DLB than in the PD group (2.2 +/- 2.3 vs 7.4 +/- 3.9, P<0.0001). Our findings suggest that parkinsonism evolves largely symmetrically and progresses more rapidly with more severe loss of striatal dopamine transporter function in DLB compared to PD. Whether these findings are helpful in the differential diagnosis of DLB and PD needs to be examined in further studies.

Aged↗
PubMed2001

Improved scintigraphic assessment of occult leakages in adjustable gastric bands using 99mTc-labelled human albumin colloid.

BACKGROUND: Adjustable gastric banding has become the preferred procedure in Europe for the treatment of morbid obesity. A complication of this treatment is the presence of leakage in the system. The knowledge of the localization of the leak is essential for planning the reoperation procedure. PATIENTS AND METHODS: In a series of 325 adjustable gastric bandings, we observed 10 band leakages. In 3 cases, fluoroscopy failed to detect fluid extravasation. We present a sensitive and simple scintigraphic method for the detection of gastric band leakage in these patients using 37 MBq of a 99mTc-human albumin colloid suspension. Imaging was started immediately after the dose application. During the first minute, images were acquired dynamically with 1 frame every 2 seconds. Afterwards, a static image was obtained every 10 minutes, up to 60 minutes post-injection. Then the system was emptied completely to detect tracer extravasation and consecutive reabsorption during 60 minutes. The study was analyzed by using the regions of interest (ROI) technique drawn on the following points: injection reservoir, tube, anterior band, posterior band, and an adjacent region which was taken as background. RESULTS: During the first hour, ROI analysis showed a clear diminution in the number of counts contained in the defect parts of the band, whereas it remained constant in the other locations. After system emptying, detection of tracer extravasation further strengthened the diagnosis of band leakage in all patients. CONCLUSION: This new approach using the 99mTc-human albumin colloid suspension with ROI analysis is an effective and simple method to detect occult leakages in adjustable gastric bands which escaped detection by fluoroscopy. In contrast to previously described scintigraphic methods, this investigation is able to demonstrate the exact site of leakage.

Adult↗
PubMed2000

99mTc-EDDA/HYNIC-TOC: a new 99mTc-labelled radiopharmaceutical for imaging somatostatin receptor-positive tumours; first clinical results and intra-patient comparison with 111In-labelled octreotide derivatives.

[111In-diethylene triamine penta-acetic acid-D-Phe1]-octreotide (DTPA-octreotide) scintigraphy has gained widespread acceptance as a diagnostic clinical procedure in oncology for imaging somatostatin receptor-positive tumours. However, indium-111 as a radiolabel has several drawbacks, including limited availability, suboptimal gamma energy and high radiation burden to the patient. We have recently reported on the preclinical development of 99mTc-EDDA/HYNIC-TOC, a new octreotide derivative which showed promising results both in vitro and in vivo. We now report our initial clinical experiences with this new radiopharmaceutical in ten oncological patients. The clinical diagnoses were: carcinoid syndrome (n=5), thyroid cancer (n=3), pancreatic cancer (n=1) and pituitary tumour (n=1). The biodistribution and kinetics of 99mTc-EDDA/HYNIC-TOC were compared with those of 111In-DTPA-octreotide in six cases, and with those of 111In-DOTA-TOC in five cases. With the new tracer tumours were imaged within 15 min after injection and showed the highest target/non-target ratios 4 h after injection. Tumour uptake persisted up to 20 h p.i. The rate of blood clearance was similar to that of 111In-DTPA-octreotide but faster than that of 111In-DOTA-TOC, while urinary excretion was lower compared with the 111In derivatives. Semi-quantitative region of interest analysis showed that 99mTc-EDDA/HYNIC-TOC produced higher tumour/organ (target/non-target) ratios than the 111In derivatives, especially in relation to heart and muscle. Significantly more lesions could be detected in 99mTc images. We conclude that 99mTcEDDA/HYNIC-TOC shows better imaging properties for the identification of somatostatin receptor-positive tumour sites than currently available 111In-labelled octreotide derivatives.

Adult↗
PubMed2000

Impaired dopaminergic neurotransmission in patients with traumatic brain injury: a SPECT study using 123I-beta-CIT and 123I-IBZM.

Structural imaging suggests that traumatic brain injury (TBI) may be associated with disruption of neuronal networks, including the nigrostriatal dopaminergic pathway. However, to date deficits in pre- and/or postsynaptic dopaminergic neurotransmission have not been demonstrated in TBI using functional imaging. We therefore assessed dopaminergic function in ten TBI patients using [123I]2-beta-carbomethoxy-3-beta-(4-iodophenyl)tropane (beta-CIT) and [123I]iodobenzamide (IBZM) single-photon emission tomography (SPET). Average Glasgow Coma Scale score (+/-SD) at the time of head trauma was 5.8+/-4.2. SPET was performed on average 141 days (SD +/-92) after TBI. The SPET images were compared with structural images using cranial computerised tomography (CCT) and magnetic resonance imaging (MRI). SPET was performed with an ADAC Vertex dual-head camera. The activity ratios of striatal to cerebellar uptake were used as a semiquantitative parameter of striatal dopamine transporter (DAT) and D2 receptor (D2R) binding. Compared with age-matched controls, patients with TBI had significantly lower striatal/cerebellar beta-CIT and IBZM binding ratios (P< or =0.01). Overall, the DAT deficit was more marked than the D2R loss. CCT and MRI studies revealed varying cortical and subcortical lesions, with the frontal lobe being most frequently affected whereas the striatum appeared structurally normal in all but one patient. Our findings suggest that nigrostriatal dysfunction may be detected using SPET following TBI despite relative structural preservation of the striatum. Further investigations of possible clinical correlates and efficacy of dopaminergic therapy in patients with TBI seem justified.

Adolescent↗
PubMed1999

Thallium-201 gated single-photon emission tomography for the assessment of left ventricular ejection fraction and regional wall motion abnormalities in comparison with two-dimensional echocardiography.

Simultaneous assessment of myocardial perfusion and function by gated single-photon emission tomography (GS) after a single tracer injection provides incremental information and is feasible with technetium-99m sestamibi. The present study validated the use of GS with thallium-201 for the assessment of left ventricular ejection fraction (LVEF) and regional wall motion by comparison with two-dimensional (2D) echocardiography (echo), which has not been done before. After injection of 111 MBq 201Tl at peak bicycle exercise (n = 55) or pharmacological stress (n = 17), GS was acquired 15 (post stress) and 120 min post injection (rest) on a double-head camera. An automatic algorithm (QGS) was used for processing. Echo (Acuson Sequoia C256) was performed immediately after rest GS. LVEFs assessed by GS and echo were correlated. The overall and segmental sensitivity and specificity of GS for the detection of regional wall motion abnormalities (WMAs) were calculated, echo serving as the gold standard. Perfusion abnormalities were scored. The success rate of the automatic algorithm was 100%, and visually assessed image quality was good to excellent in 88% of cases. Post-stress and rest LVEF as assessed by GS were highly correlated (r = 0.91). Good correlations were obtained between post-stress LVEF (GS) and rest LVEF (echo) and between rest LVEF (GS) and rest LVEF (echo) (r = 0.76 and 0.86 respectively). In patients with a reduced LVEF of less than 50% (n = 23), these correlations were even better (r = 0.84 and 0.89 respectively). Regional wall motion abnormalities (WMAs) were identified by GS with high sensitivity and specificity (88%-100% and 82%-98% respectively) and were directly related to the extent and severity of stress as well as of resting perfusion defects. It is concluded that GS with 201Tl is a feasible and reliable tool for the evaluation of patients with compromised left ventricular function in the context of coronary artery disease, and thus improves diagnosis and prognostic stratification. Regional WMAs were identified with high diagnostic accuracy and the method may prove helpful for the detection of myocardial viability.

Female↗