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Biomedical subjects

O Almkvist

Publications and source records attributed to O Almkvist.

At least 55 records · Page 3Linked to original sources
PubMed1996

Neuropsychological assessment of dementia: state of the art.

A comprehensive neuropsychological examination includes an assessment of both cognitive functions and personality characteristics. In order to evaluate dementia, the patient's present as well as the premorbid functioning has to be assessed, which is performed by means of tests, behavioral observations, rating scales, and inquiries. These methods are used for diagnostic purposes, for differential diagnostics, follow-up studies, and for evaluation of treatment effects. Recent research has shown that neuropsychological methods have a high sensitivity and specificity in detection of dementia, utilizing measures of episodic memory. For staging of dementia, episodic memory as well as other cognitive functions are necessary. The effectiveness of dementia differentiation by means of neuropsychological methods varies from quite good regarding frontal lobe degeneration to less good regarding cerebrovascular dementias, probably due to the variation in site, extent, number, and temporal characteristics of the lesion. Future development is required regarding methods for evaluation of premorbid functioning, instruments for assessment of executive functions, and personality characteristics in dementia. Furthermore, brain-behavior studies are needed to learn more about the relation between neuropsychological measures vs neuropathology, neurochemistry, and neuroimaging.

Aged↗
PubMed1996

Neuropsychological features of early Alzheimer's disease: preclinical and clinical stages.

In the preclinical stage of Alzheimer's disease (AD), studies of asymptomatic mutation carriers have identified impairments in episodic memory. Other cognitive functions show no or slight impairment suggesting that preclinical AD is a unifunctional cognitive syndrome; the brain is affected selectively and predominantly in the medial temporal structures. In the early clinical stage, deficits occur in episodic memory, verbal abilities, visuospatial functions, attention, and executive functions. AD becomes a multifunctional cognitive syndrome and the brain's association cortices are affected. Nevertheless, sensory-motor performance and procedural memory seem to be intact and only slight impairment may be seen in primary memory. In advanced AD, cognitive dysfunction including deficits is global in primary memory, although sensory-motor performance may be well preserved. The brain's association cortices are severely affected. The sequence of cognitive decline; from unifunctional to global deficits, conforms to the three-stage development of neurofibrillary tangles described by Braak and Braak.

Alzheimer Disease↗
PubMed1995

EEG in successful aging; a 5 year follow-up study from the eighth to ninth decade of life.

Fifteen out of 25 successfully aged individuals completed a 5 year EEG follow-up study from the eighth to ninth decade of life with comprehensive neuropsychological investigation. One subject suffered from stroke and one developed symptoms of dementia during the follow-up. Of 13 subjects who completed the follow-up as being healthy, MRI showed subtle enlargement of ventricles or subarachnoid spaces and mild signal hyperintensities in a few regions in 2 subjects. General cognitive decline was not observed (WAIS-R IQ: 113.4 at entry, 114.3 five years later). There were no EEG dominant frequencies below 8 c-sec and no more background slowing than a few theta waves per 10 sec, either at entry or 5 years later. Intermittent slowing was observed in 9 subjects at entry and in 8 subjects 5 years later. The prevalence of intermittent slowing was suggested to increase with advancing age when compared to previous studies with younger elderly. However, intermittent slowing occurred only a few times in an EEG test and lasted for less than 2 sec. Moreover, the presence of intermittent slowing did not correlate with any neuropsychological decline or any MRI change. This type of intermittent slowing was regarded as non-specific and clinically silent.

Aged↗
PubMed1995

Neuropsychiatric function of housepainters with previous long-term heavy exposure to organic solvents.

Neuropsychiatric effects were examined among 206 men, of whom 135 had been house painters and 71 had been house carpenters, affiliated with their respective trade unions for at least 10 years before 1970. Their lifetime organic solvent exposure was evaluated through the aid of an interview. Relevant potential confounding factors were accounted for in the statistical analysis. Neuropsychiatric symptoms compatible with chronic toxic encephalopathy were more common among the painters than among the carpenters, and these symptoms became increasingly prevalent with increasing cumulative solvent exposure. On only one of 12 psychometric tests, block design, did the painters perform worse than the carpenters, and in this test the painters' performance deteriorated with increasing cumulative exposure. For the majority of the psychometric tests, and for the coordination tests, there were no differences between the painters and carpenters, but the painters with "low" exposure tended to show better, and "heavily" exposed painters worse, results than the carpenters. The 52 painters with the heaviest cumulative exposures and 45 carpenters were examined for psychiatric diagnosis according to DSM-III, with electroencephalography and auditory evoked potential, P-300. Three painters and two carpenters had diagnoses compatible with an organic mental disorder. There were no overall differences between the painters and carpenters, either for the visually examined electroencephalograms or the P-300 latencies. The excess of neuropsychiatric symptoms among the painters was probably causally linked to solvent exposure. However, these symptoms seemed only rarely, if ever, serious enough to entail a psychiatric diagnosis. Concerning other outcomes, the investigation may not lead to a determination of whether the exposure-response relationship among the painters, with no difference between the entire group of painters and carpenters, is caused by solvent exposure or by selection factors within the group of painters.

Adult↗
PubMed1994

White matter hyperintensities in dementia: does it matter?

The aim of the study was to investigate whether the regional distribution of white matter hyperintensities (WMH) observed by magnetic resonance imaging differed between vascular dementia and patients with late onset Alzheimer's disease. Another aim was to investigate the relations between the occurrence and degree of WMH and clinical and laboratory data as well as measures of cognitive decline. White matter hyperintensities were assessed with a low field magnetic resonance imager on 23 subjects with probable Alzheimer's disease, 25 with possible Alzheimer's disease and 31 subjects with vascular dementia. The degree and regional distribution of the WMH (expressed as relative volumes) were calculated and compared in the three groups. The relation between cognitive impairment and the degree of the WMH was also studied. The regional distribution of the WMH differed between the groups with significantly more changes in the posterior part of the brain (p < .0001) as well as in the right hemisphere (p < .0005) in the vascular demented as compared to the patients with Alzheimer's disease. No significant correlations between cognitive impairment and the degree of the WMH were found in any of the groups. The total volume of the WMH as well as the regional distribution of these changes differed significantly between vascular dementia and Alzheimer's disease. White matter hyperintensities seem not to be related to the degree of global cognitive decline in dementia and whether it plays a causative role in the development of dementia symptoms needs to be more thoroughly investigated.

Aged↗
PubMed1993

Cognitive functions and brain structures: a quantitative study of CSF volumes on Alzheimer patients and healthy control subjects.

In the present study we have investigated the connection between cerebrospinal fluid spaces and cognitive function in patients with senile dementia of Alzheimer type (SDAT) and in successfully aged control subjects. The cerebrospinal fluid (CSF) volumes were measured using a low field MRI technique, and the cognitive functions were assessed with a number of psychometric tests. We found that the SDAT patients showed significantly larger relative volumes in all examined CSF spaces. The largest differences between the groups were found in the volumes of the temporal horns. We also found a significant correlation between the relative CSF volumes in the basal parts of the brain, and episodic memory tests. Significant correlations were also detected between the relative volumes of the lateral ventricles, and degree of dementia as well as between the relative volumes of the lateral ventricles and episodic memory tests.

Aged↗
PubMed1993

Patterns of neuropsychological performance in Alzheimer's disease and vascular dementia.

The hypothesis that Alzheimer's disease (AD) and vascular dementia (VD) may be associated with specific patterns of neuropsychological dysfunction was tested by assessing sensory-motor performance, attention, memory, visuospatial functions, verbal ability, and intelligence in AD (N = 83) and VD (N = 42) patients stratified into four levels of severity based on the Mini-Mental State Examination. Results showed a progressive deterioration due to severity of dementia in both AD and VD patients in all cognitive tasks, but not in the sensory-motor tasks, and no significant interaction between type and severity of dementia in any measure, indicating a similar pattern and course of neuropsychological deterioration in AD and VD. Yet it was possible to differentiate the two groups with moderate success using tests drawing predominantly on motor speed and, to a lesser extent, on cognitive speed. In all these speeded tests, the AD patients outperformed the VD patients.

Aged↗
PubMed1993

Detection and staging of early clinical dementia.

In order to find neuropsychological indicators for detection and staging of dementia, groups of very mild, mild, and moderate dementia were compared to healthy aged individuals in neuropsychological tests tapping various cognitive and finger-motor functions. Results showed that the groups differed significantly in all cognitive tests, but not in the finger-motor tests. A stepwise discriminant analysis indicated that detection of very mild dementia was best accomplished by three tests assessing episodic memory, semantic memory, and visuospatial functioning. Staging of dementia was best accomplished by means of only one canonical function based on tests tapping episodic memory, semantic memory, visuospatial functions, and psychomotor speed. These results indicate that the pattern of dysfunction is similar for different levels of dementia, suggesting that similar cognitive functions may be involved in detection and staging of dementia.

Aged↗
PubMed1992

White-matter hyperintensity and neuropsychological functions in dementia and healthy aging.

The relationship between quantitative measurements of brain white-matter hyperintensity (WMH), assessed by magnetic resonance imaging and neuropsychological functions, was explored in demented patients and healthy aged individuals with and without WMH in 12 brain regions. The prevalence of WMH was significantly higher in vascular dementia compared with Alzheimer's disease, especially in posterior periventricular regions. Results showed no difference in any neuropsychological measurement between healthy aged adults with and without WMH. The demented patients with WMH were more impaired in tests of visuoconstruction, attention, finger-motor speed, and latency of tactile identification of objects compared with patients without WMH. These impairments were related mainly to posterior periventricular WMH. There was no relationship between WMH and global cognitive functioning in the demented patients. The degree of WMH was related to age and blood pressure. The data suggest that specific regional WMH may result in specific neuropsychological impairments.

Aged↗
PubMed1992

Effects of occupational exposure to mercury vapour on the central nervous system.

Possible effects of mercury on the central nervous system (CNS) were examined in a group of chloralkali workers exposed to mercury (n = 89) and compared with a control group (n = 75), by registration of subjective symptoms, personality changes, forearm tremor, and performance on six computerised psychometric tests in the two groups. The groups were similar in age, education, verbal comprehension, and work tasks. In the chloralkali group, median blood mercury concentration (B-Hg) was 55 nmol/l, serum mercury concentration (S-Hg) 45 nmol/l, and urine mercury concentration (U-Hg) 14.3 nmol/mmol creatinine (25.4 micrograms/g creatinine). Corresponding concentrations in the control group were 15 nmol/l, 4 nmol/l, and 1.1 nmol/mmol creatinine (1.9 micrograms/g creatinine) respectively. The number of self reported symptoms, the scores for tiredness and confusion in the profile of mood states (POMS), and the degree of neuroticism in the Eysenck personality inventory (EPI), were significantly higher in the mercury exposed group compared with the controls. Performance on the psychometric tests and tremor frequency spectra did not differ significantly between the two groups. Dose-response calculations showed weak but statistically significant relations between symptom prevalence and current mercury concentrations in both blood and urine. The performance on three of the psychometric tests was negatively correlated with earlier peak exposures. The findings indicate a slight mercury induced effect on the CNS among the chloralkali workers.

Adult↗
PubMed1990

Carbamazepine-10,11-epoxide in epilepsy. A pilot study.

The effects of carbamazepine-10,11-epoxide, an active metabolite of carbamazepine, were evaluated in seven outpatients with frequent epileptic seizures. The study included an initial 4-week period with the carbamazepine dose optimized for each patient. Patients were then crossed over, dose by dose, to carbamazepine-10,11-epoxide and followed up for another 4 weeks. Dosing was single blind. The evaluation of the anticonvulsant effect was hampered by marked fluctuations in plasma levels during treatment with carbamazepine-10,11-epoxide. There was, however, no significant change in seizure control. During epoxide treatment, no subjective side effects were reported despite epoxide plasma concentrations up to 57 mumol/L. Neuropsychological assessment revealed a significant improvement in finger motor speed and logical reasoning during the carbamazepine-10,11-epoxide period. Subnormal serum sodium levels in two patients were normalized after switching from carbamazepine to the epoxide. Continued investigations with this active metabolite of carbamazepine in epilepsy are therefore justified.

Adult↗
PubMed1990

Amino acid concentrations in cerebrospinal fluid and plasma in Alzheimer's disease and healthy control subjects.

Cerebrospinal fluid (CSF) and plasma levels of 18 amino acids were studied in 22 subjects with dementia of the Alzheimer type (DAT) and in 11 healthy volunteers with no clinical or family history of dementia. Significant decreases of plasma taurine and glutamate were seen in the DAT cases compared with the controls. The CSF concentrations of glycine, leucine and valine were also significantly reduced in the DAT cases. Furthermore, in the DAT cases significant decreases were observed in the ratio between CSF and plasma (CSF/P) levels for alanine, glutamine, glycine, phenylalanine and valine, when compared with controls. In the DAT group there were significant correlations between behaviour and CSF glutamine; memory and cognitive functions and CSF valine; copying ability and CSF glutamate. CSF/P ratios of glutamine and glutamate correlated with behaviour and copying performances, respectively. The results of this study provide further evidence for a disruption of amino acid metabolism in DAT.

Aged↗
PubMed1990

Temporary peripartal impairment in memory and attention and its possible relation to oxytocin concentration.

The aim of the present study was to investigate peripartal performance on cognitive tests and its possible relationship with plasma oxytocin concentrations. Twenty women (cases) were tested on five experimental occasions, the first toward the end of pregnancy and the last 12 months postpartum. On each experimental occasion performance on cognitive tests of memory and attention was recorded and oxytocin concentrations were simultaneously assayed in plasma-samples. Twenty non-pregnant women (controls) were investigated at similar intervals. Cases were found to have improved their performance on some cognitive tests significantly more than controls when results at 6 and 12 months after delivery were compared with those from the end of pregnancy and up to three months after partus. This observation strongly suggests impairment in cognitive performance during the peripartal period. Cases had significantly higher oxytocin concentrations than controls in plasma samples up to three months post partum. No correlation was, however, found between cognitive test results and levels of oxytocin concentration.

Adult↗
PubMed1990

Physical and psychological capabilities during substitution therapy with recombinant growth hormone in adults with growth hormone deficiency.

In a double-blind cross-over study with recombinant methionyl growth hormone (GH) and placebo during 12 weeks, the effect of GH substitution therapy (0.5-06 IU.kg-1.week-1) on physical performance, muscle strength, bone mineral density, and mood and cognitive functions was investigated in 6 GH-deficient adults. During GH substitution serum concentrations of insulin-like growth factor-I and procollagen-III peptide increased in all 6 patients, whereas concentrations of serum urea decreased. Five of the patients identified the GH period and reported improved well-being with increased mental alertness and vitality and improved physical capacity and muscle strength. There was, however, no change of the isokinetic muscle strength during GH substitution therapy, and the working capacity on the bicycle ergometer was just slightly improved in some patients. The bone mineral density was low and unchanged in all patients. Mood and cognitive functions did not change during GH therapy. A reversible fluid retention was observed in one patient during the GH period. In conclusion, short-term GH substitution therapy to GH-deficient adults induced a subjective improvement of general well-being. Longer treatment periods will be necessary to establish the effect on physical capacity, muscle strength, bone mineral density, and mood and cognitive functions.

Adult↗
PubMed1987

The effect of oral contraceptive pills on levels of oxytocin in plasma and on cognitive functions.

Millions of healthy women use combined oral contraceptives (o.c.) for decades. In spite of that, little is known about their possible effects on cognitive functions. In this open cross-over study, 20 women were examined twice at four-week intervals at a fixed period of the menstrual cycle when they were and when they were not taking o.c. They were examined with a test-battery to assess cognitive functions. Blood samples were taken before and after breakfast to assess levels of oxytocin and prolactin. A significant increase in levels of oxytocin was registered when the women were on o.c. There was no significant difference in performance on the psychometric tests when the participants were on o.c. compared to when they were without o.c.

Adult↗
PubMedDate not supplied

The short human figure drawing scale for evaluation of suspect cognitive dysfunction in old age.

Human figure drawings have been widely used to assess cognitive development in children. In the present study, free-hand human figure drawings were examined for 62 demented patients, and 60 normal elderly subjects. The drawings were scored for 53 body details using a method derived from work with children. A short scale of 15 details was developed by selecting body details with high item-total correlations which are simple to score even for untrained staff. This short scale had excellent interscorer and test-retest reliability and excellent concurrent validity as well. It correlated highly with the Mini-Mental State Examination, a commonly used screening test for dementia. The short scale discriminated demented and non-demented subjects and different levels of dementia severity as graded by the Clinical Dementia Rating Scale. However, no differences were observed between Alzheimer patients and patients with vascular dementia concerning presence of details in human figure drawings.

Journal Article↗
PubMedDate not supplied

Apolipoprotein E epsilon4 allele, skin vessel reactivity and vascular risk factors in Alzheimer's disease.

The apolipoprotein E (ApoE) epsilon4 allele is strongly associated with Alzheimer's disease (AD), and is, at the same time, a risk factor for cardiovascular disease. Recently, it has also been suggested that skin vessel reactivity is impaired in AD. The aim of this study was to assess the impact of the ApoE epsilon4 allele on the results of skin vessel reactivity tests and vascular risk factors such as cholesterol and blood pressure in AD. Fourteen non-smoking patients, who were in good general health and took no medicines, were tested. Three vasodilating substances with different modes of action, acetylcholine (ACh), isoprenaline and nitroprusside, were iontophoresed into the skin and the resultant vasodilation of the skin vessels was evaluated with the aid of a newly developed laser Doppler perfusion imager. The results of the tests did not differ significantly between the patient group with (n=10) and without (n=4) the ApoE epsilon4 allele, perhaps due to the small number of patients. The results of the skin vessel reactivity tests of the patient subgroups were also compared to those of healthy, non-smoking, non-medicating, age-matched controls. The findings of that comparison suggest, that the presence of the epsilon4 allele in AD might have an impact on skin vessel reactivity to the cholinergic agonist ACh.

Journal Article↗