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Biomedical subjects

F van Harskamp

Publications and source records attributed to F van Harskamp.

At least 37 records · Page 2Linked to original sources
PubMed1994

Assessment of cerebral perfusion with single-photon emission tomography in normal subjects and in patients with Alzheimer's disease: effects of region of interest selection.

The shape, size and location of regions of interest (ROIs) show considerable variability between single-photon emission tomography (SPET) studies in aging and Alzheimer's disease, but the possible influence on study results remains unknown. We compared three different ROIs in a SPET study with 60 controls and in 48 patients with probable Alzheimer's disease diagnosed according to the NINCDS-ADRDA criteria. Regional cerebral blood flow (rCBF) was assessed with SPET using technetium-99m d,l-hexamethylpropylene amine oxime (99mTc-HMPAO), normalized to the mean activity in a cerebellar reference slice. The three different ROIs were: a multi-slice and a single-slice ROI with reference to the normal brain anatomy (using an anatomical atlas), and a rectangular (2 x 4 pixels) ROI in the frontal, temporal, temporoparietal and occipital cortices. No differences were observed for the means of rCBF values between the single-slice and multi-slice ROI's with reference to the normal anatomy, but some variability was present for individual comparisons. In contrast, significantly higher mean rCBF values were obtained with the single-slice rectangular ROIs in all four regions for both patients and controls and considerable variability was shown for individual subjects. After analysis with multivariate logistic regression and receiver operator characteristic curves, the ability of SPET to discriminate between controls and Alzheimer patients was similar in the three methods for mild and moderate Alzheimer patients (Global Deterioration Scale = GDS of 3 and 4). However, with increasing dementia severity (GDS > 4) the rectangular ROIs showed lower ability to discriminate between groups compared to the single-slice and multi-slice anatomically defined ROIs.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1994

Cognitive correlates of ventricular enlargement and cerebral white matter lesions on magnetic resonance imaging. The Rotterdam Study.

BACKGROUND AND PURPOSE: Ventricular enlargement and white matter lesions are frequent findings on cerebral magnetic resonance imaging scans of elderly subjects. In demented subjects they seem related to the severity of the dementia, but in nondemented subjects their clinical significance is less clear. We investigated the relation of size of the lateral ventricles and white matter lesions with cognitive function in a population-based random sample of nondemented elderly persons. METHODS: The study population consisted of 90 subjects, aged 65 to 84 years, who were randomly selected from the cohort of the Rotterdam Study, and who were not demented. The presence of white matter lesions and the ventricle-to-brain ratio were assessed on magnetic resonance scans. Participants were tested with a neuropsychological battery that covered a broad range of cognitive functions. RESULTS: Ventricular enlargement and white matter lesions were both and independently associated with poorer performance on all tests. After adjustment for age and sex, ventricular enlargement was significantly associated with worse scores on tests assessing global cognitive function (Mini-Mental State Examination, P = .02; Groninger Intelligence Test, P = .01), memory (Word List Learning delayed recall, P = .03), and executive control functions (Stroop part II, P = .02; Trial Making Test B, P < .01); for white matter lesions the differences were significant for tests measuring executive control functions and mental speed (Trail Making Test A and B, P = .01 and P < .01, respectively; verbal fluency, P = .01), and memory (Word List Learning delayed recall, P = .04). CONCLUSIONS: This study suggests that white matter lesions are primarily related to impairment of subcorticofrontal functions, whereas enlargement of the lateral ventricles is associated with disturbances of cortical functions as well.

Age Factors↗
PubMed1994

The diagnostic value of SPECT with Tc 99m HMPAO in Alzheimer's disease: a population-based study.

We studied the diagnostic accuracy of single-photon emission computed tomography (SPECT) with technetium 99m-labeled hexamethylpropylene amine oxime (Tc 99m HMPAO) in 48 patients with probable Alzheimer's disease (AD) according to NINCDS-ADRDA criteria and in 60 controls recruited from a population-based study. With logistic regression, we identified decreased temporal regional cerebral blood flow as the best discriminating variable between patients and controls. Receiver-operator characteristic curves showed that the discriminative ability of SPECT improved with increasing dementia severity. With specificity set at 90%, sensitivity figures were 42% in mild, 56% in moderate, and 79% in severe AD. The diagnostic gain as a function of the prior probability of the disease being present was computed for those with mild AD. When the prior probability varied at around 50%, the diagnostic gain for mild AD patients was substantial (a maximum of 34%) for a positive test result but poor for a negative test result. The results suggest that the practical usefulness of SPECT as a diagnostic adjunct in patients suspected of having mild AD is confined to situations in which, on clinical grounds, there is considerable diagnostic doubt.

Aged↗
PubMed1994

Cerebral white matter lesions, vascular risk factors, and cognitive function in a population-based study: the Rotterdam Study.

Cerebral white matter lesions are a common finding on MRI in elderly persons. We studied the prevalence of white matter lesions and their relation with classic cardiovascular risk factors, thrombogenic factors, and cognitive function in an age- and gender-stratified random sample from the general population that consisted of 111 subjects 65 to 84 years of age. Overall, 27% of subjects had white matter lesions. The prevalence and severity of lesions increased with age. A history of stroke or myocardial infarction, factor VIIc activity, and fibrinogen level were each significantly and independently associated with the presence of white matter lesions. Significant relations with blood pressure level, hypertension, and plasma cholesterol were present only for subjects aged 65 to 74 years. White matter lesions tended to be associated with lower scores on tests of cognitive function and were significantly associated with subjective mental decline. This study suggests that classic cardiovascular risk factors, as well as thrombogenic factors, are associated with white matter lesions in subjects over 65 years of age in the general population, and that these lesions may be related to cognitive function.

Aged↗
PubMed1993

Trait-anxiety and achievement motivation are positively correlated with memory performance in patients who visit a geriatric outpatient clinic with amnestic symptoms.

Memory performance was studied in relation to anxiety and achievement motivation in a sample of 35 patients who were referred to a geriatric outpatient clinic for their complaints of memory dysfunction. State-anxiety appeared not to be associated with memory performance or the severity of dementia. Trait-anxiety and achievement motivation were associated positively with memory performance and negatively with the severity of dementia. The evaluation of anxiety symptoms in the assessment of dementia is recommended.

Achievement↗
PubMed1992

Presenile dementia and cerebral haemorrhage linked to a mutation at codon 692 of the beta-amyloid precursor protein gene.

Several families with an early-onset form of familial Alzheimer's disease have been found to harbour mutations at a specific codon (717) of the gene for the beta-amyloid precursor protein (APP) on chromosome 21. We now report, a novel base mutation in the same exon of the APP gene which co-segregates in one family with presenile dementia and cerebral haemorrhage due to cerebral amyloid angiopathy. The mutation results in the substitution of alanine into glycine at codon 692. These results suggest that the clinically distinct entities, presenile dementia and cerebral amyloid angiopathy, can be caused by the same mutation in the APP gene.

Adult↗
PubMed1992

Value of the Mini-Mental State Examination and informants' data for the detection of dementia in geriatric outpatients.

The Dutch version of the Mini-Mental State Examination was administered to 138 elderly patients who were referred to a geriatric outpatient clinic for a variety of reasons. An optimal cut-off point of 24/25 was found for the detection of dementia. At this cut-off point, the Mini-Mental State Examination was 87.6% sensitive and 81.6% specific in detecting dementia. The discriminative validity was influenced by education and by the presence of psychiatric disorders other than dementia. Informants' data showed better sensitivity and specificity than the Mini-Mental State Examination for the detection of dementia. The findings suggest that informants' data are a primary source of information for the detection of dementia in geriatric outpatients.

Aged↗
PubMed1989

Landau-Kleffner syndrome: a case study with a fourteen-year follow-up.

In a 14-year follow-up the improvement of language functions and the decrease of EEG abnormalities are described in a girl with the Landau-Kleffner syndrome. In this case, the results of subsequent EEG recordings do not permit conclusions about the course of the aphasia. Disappearance of focal spike and waves, bilateral paroxysms and slow background activity lack synchronicity with improvement of language. Finally, subtle language deficits were still present 14 years after the onset of the aphasia; the lastly recorded EEG showed mild abnormalities.

Aphasia↗
PubMed1984

Problems in measuring cognitive recovery after acute brain injury.

The measurement of cognitive recovery after traumatic brain damage raises a number of methodological and practical problems. The precise schedule of testing, the specification of functions to be measured, the separation of practice from recovery, and the specification of appropriate control or comparison groups must all be considered by the researcher. In addition, strenuous efforts must be made to achieve as high a follow-up rate as possible.

Brain Injuries↗
PubMed1982

Spatial disorientation in right-hemisphere infarction.

Spatial orientation was tested with the rod orientation test. The subjects were 40 normal controls and 68 brain-damaged patients with cerebral infarcts. Patients in whom the lesion included the post-rolandic region of the right hemisphere performed worse than controls or patients with lesions at other sites. Patients with an exclusively postrolandic (usually occipital) lesion showed higher error rates than patients with a combined prerolandic and postrolandic lesion, but only for the visual part of the test. These patients were re-examined one year after the stroke. Most of them showed an incomplete recovery of spatial function.

Adult↗