Biomedical subjects

E L Helkala

Publications and source records attributed to E L Helkala.

66 records · Page 4Linked to original sources

PubMed1987

Dementia without cholinergic deficit.

We examined the role of cholinergic system in multi-infarct dementia (MID) by measuring acetylcholinesterase (AChE) activities in cerebrospinal fluid (CSF) of clinically diagnosed MID patients, Alzheimer's disease (AD) patients and controls. In spite of the similar clinical severity of dementia, MID patients had unaltered AChE levels, whereas AD patients had significantly reduced AChE levels in CSF when compared to controls. In the autopsy study we analyzed choline acetyltransferase (ChAT) levels in four cortical brain areas from clinically and neuropathologically studied AD patients, demented non-AD patients and controls. ChAT activities in the cerebral cortex in non-AD patients were on the same level as in controls, but AD patients had a marked loss of ChAT activity in all four cortical brain areas studied. Although cholinergic deficit is a usual phenomenon associated with cognitive failure, severe dementia can exist without cholinergic dysfunction.

Acetylcholinesterase↗

PubMed1987

Recent progress in the research of Alzheimer's disease.

The purpose of this review is to survey some of the recent advances made in the understanding of the basic mechanisms underlying cognitive functions and dysfunctions in Alzheimer's disease (AD). Cholinergic projections from the nucleus basalis of Meynert (nbM), which are involved in AD, have been related to certain memory functions. Information processing, attention or arousal may, however, be influenced by nbM neurons more than primary memory mechanisms. Perforant pathway and subiculum projections, which presumably use glutamate as a neurotransmitter, are involved in AD leading to the disconnection of the hippocampus from the neocortical areas. The hippocampus and entorhinal cortex seem to play an important role in learning and memory. The hippocampus can be regarded as a relay station for the processing of recent episodic memory, but information is bound to memory storage in the cortical association areas. An important finding has been the plasticity changes in the hippocampus seen after the destruction of entorhinal cortex. Antemortem markers of AD have been under extensive study. Alz-50 antigen may be one of the most promising findings in this area, but no definite biological marker of AD currently exists. A medication for treatment of AD is also under development.

Acetylcholine↗

PubMed1985

Treatment of Alzheimer's disease with a synthetic ACTH 4-9 analog.

The synthetic ACTH 4-9 analog, Org 2766, was administered to 77 Alzheimer's patients for 6 months in a double-blind, placebo-controlled study. Although Org 2766 was tolerated well, no significant effect of Org 2766 could be demonstrated in terms of rating scales or cognitive functions.

Adrenocorticotropic Hormone↗

PubMed1982

Clinical stages of progressive myoclonus epilepsy in adult patients.

Nineteen hospitalized adult patients with progressive myoclonus epilepsy were studied. According to their clinical status they were divided into three groups of severity. The ages and duration of the disease did not differ significantly between the groups. The groups showed significant differences in ability of daily living, amount of spontaneous myoclonus, IQ and psychomotor reaction time. In EEG the groups differed in respect to the dominant occipital rhythm and amount of myoclonic spikes but not in respect to universal paroxysms. Myoclonic spikes and paroxysms in EEG were only loosely related. The results yield a conclusion that the deterioration caused by the disease is individual and the progression may even cease. In this respect progressive myoclonus epilepsy differs clearly from many hereditary neurometabolic and storage diseases.

Activities of Daily Living↗

PubMed1982

EEG findings in senile dementia and normal aging.

EEG findings in 62 patients with senile dementia of alzheimer type (SDA), 22 patients with multi-infarct dementia (MID) and 90 controls of same age and sex were studied. The SDA patients differed significantly from the controls in EEG normality, over-all disturbance, dominant occipital, rhythm, accentuation of theta and delta, fluctuations in alertness, paroxysmal activity and H-reaction. Even the least severely affected SDA patients differed significantly from the controls in all EEG variables except paroxysmal activity. With increasing degree intellectual impairment in the SDA group the dominant occipital rhythm became slower. The MID group differed from the controls in all EEG parameters including asymmetric findings. The EEG findings of the SDA patients differed significantly from those of the MID patients only in asymmetric findings which were more common in the MID patients. 29% of the normal elderly people had EEG alterations, Abnormalities were mild. Asymmetric findings, mainly theta activity in left temporal region were common. H-reaction (occipital driving response greater than or equal to 18 c/s) was well preserved in the controls. EEG is valuable in differentiation of dementia patients from normal elderly people, but differentiation between MID and SDA is not reliable by using EEG, only.

Aged↗

PubMed1978

Effects of anaesthesia on the psychological function of patients.

The psychological effects of halothane, methoxyflurane, combined analgesic-relaxant anaesthesia, and epidural anaesthesia were assessed before one, and seven days after anaesthesia in 72 patients having operations for varicose veins. Subjective anxiety evaluation (Hamilton Anxiety Rating Scale) and personality tests of self-appraisal (Minnesota Multiphasic Personality Inventory) as well as of superficial (Wartegg's test) and profound (Rorschach's test) projection showed no significant differences among these methods of anaesthesia. Performance tests measuring memory for designs (modified Graham-Kendall memory for designs), short-term memory (digit span of Wechsler Adult Intelligence Scale), learning (nonsense word series), perception (symmetry-drawing), speed of observation (Bourdon-Wiersma) and visualization also revealed no significant psychological changes compared to the control (epidural anaesthesia) group. The methods of anaesthesia used therefore showed no harmful psychological effects and are in this respect safe in clinical use.

Anesthesia, Epidural↗

PubMedDate not supplied

Diabetes mellitus and brain atrophy: a computed tomography study in an elderly population.

Previous studies have suggested that noninsulin dependent diabetes mellitus (NIDDM) could lead to learning and memory deficits. We studied cognitive performance and computed tomography (CT) findings of the brain in elderly subjects with drug treated NIDDM (n = 12), with diet treated NIDDM (n = 13), and in nondiabetic individuals (ND, n = 59). The cognitive performance (orientation and up-to-date knowledge, praxic functions, understanding of speech, expressive speech, memory, general reasoning) did not differ between the groups. The drug treated diabetics had more pronounced central temporal atrophy compared to that in the ND subjects as evidenced by wider right temporal horn (ANCOVA adjusted for age, p = 0.011). The drug treated diabetics (all women) also had wider frontal horns than did the ND women. The CT measures of diet treated diabetics were comparable with those of the ND group. The fasting glucose level was positively correlated with the width of the right temporal horn but not with other CT measures in diabetic subjects. The results suggest that NIDDM and poor glucose control may carry a risk for accelerated brain atrophy in the elderly.

Aged↗

PubMedDate not supplied

MR T2 relaxometry in Alzheimer's disease and age-associated memory impairment.

A prolonged MR T2 relaxation time was proposed to mark the presence and severity of Alzheimer's disease (AD). We studied the value of T2 relaxometry in diagnosing early AD. T2 was measured from 54 patients with AD, 25 subjects with age-associated memory impairment (AAMI), 18 elderly and 16 young controls. The AD patients had longer T2 in the right hippocampal head (104 +/- 11 ms) and tail (98 +/- 10 ms) than age-matched controls (95 +/- 5 and 92 +/- 9 ms, respectively). This prolongation was not related to age. In the AD group, the T2 of the left hippocampal head also correlated with the clinical severity. The T2 of the amygdala did not differ across the groups. Increased T2 in the temporal and parietal white matter and the thalamus related to increasing age rather than to the diagnostic category. The AAMI subjects had T2 comparable with those of age-matched controls. Despite the prolongation of T2 in the AD group the possible diagnostic value was compromized by a substantial overlap between the study groups. We, thus, conclude that the T2 relaxometry is not a reliable method for diagnosing early AD.

Adult↗

PubMedDate not supplied

MRI of the hippocampus in Alzheimer's disease: sensitivity, specificity, and analysis of the incorrectly classified subjects.

In this study, magnetic resonance imaging (MRI) of the hippocampus for the diagnosis of early Alzheimer's disease (AD) is evaluated. We measured hippocampal volumes and the area of the medial hippocampus with a 1.5 T MR imager in 160 subjects: 55 patients with probable AD according to the NINCDS-ADRDA criteria, 43 subjects fulfilling the NIMH criteria of age-associated memory impairment (AAMI), 42 cognitively normal elderly controls, and 20 controls younger than 50 years. Three methods for normalization were compared. The hippocampi were atrophied in the AD patients, but not in the AAMI subjects or the elderly controls. There was no significant correlation between hippocampal volumes and age in the nondemented subjects. The discrimination based on volumetry resulted in an overall correct classification of 92% of AD patients vs. nondemented elderly subjects, whereas discrimination based on hippocampal area was less accurate, producing a correct classification in 80% of the subjects. We conclude that the hippocampus as assessed by MRI volumetry is atrophied early in AD, and spared by aging or AAMI. A brief critical review of previous studies is in concordance with the presented data: all the previous studies that have used volumetry, have similarly ended up with a good classification, whereas simpler or subjective measurements, subject to various sources of bias, have produced most variable results.

Aged↗

PubMedDate not supplied

Apolipoprotein E phenotype alone does not influence survival in Alzheimer's disease: a population-based longitudinal study.

Apolipoprotein E4 (ApoE4) phenotype is a known risk factor for development of Alzheimer's disease (AD). Contradictory results exist concerning the role of ApoE4 in the rate of decline and mortality in AD. Conflicting findings have also been reported about ApoE and gender interactions with respect to survival. We examined the survival of subjects with AD and non-AD controls with respect to ApoE phenotype and gender in a population-based longitudinal study. Cognitive evaluation was performed for a total of 980 subjects (then aged 69-78 years), and 48 cases with AD were identified. ApoE4 phenotype was more frequently present among subjects with AD. In the whole study population, survival was not related to the presence of AD or ApoE4 phenotype. Risk of death was increased for men compared to women, independently of the ApoE4 phenotype (HR 0.5, 95% confidence interval 0.44-0.69). In subjects with AD, the presence of ApoE4 alone did not influence survival. However, in the AD group, ApoE4-negative men had significantly increased risk of mortality compared to the risk in ApoE4-negative women (p < 0.01). We conclude that the presence of ApoE4 phenotype or AD did not influence mortality in the aged population. Once AD had become manifest, ApoE4 alone did not relate to survival. However, in subjects with AD not carrying ApoE4, men had reduced survival compared to women.

Aged↗

PubMedDate not supplied

Psychometric discrimination of tetrahydroaminoacridine responders in Alzheimer patients.

Fourteen patients with probable Alzheimer's disease (AD) participated in an open tetrahydroaminoacridine (THA) treatment trial. Before initiation of THA treatment, a brief battery of neuropsychological tests was performed by an experienced neuropsychologist. The tests were repeated 120 min after a single dose of 50 mg THA had been administered perorally. Thereafter, the patients had a 4-week active treatment with THA 100 mg/day. After the treatment period, eight patients were defined as responders (increase of Mini-Mental State Examination score > or = 3) and six patients as nonresponders to the treatment. The responders showed significant improvement on Digit Span, Trail Making B, and on both Clock Setting and Clock Recognition tests after 50 mg of THA. The results suggest that in this subgroup of AD patients augmentation of the brain cholinergic systems mainly led to improvement of attentional and frontal-lobe rather than mnemonic functions.

Aged↗

PubMedDate not supplied

Population-based dementia screening program in Kuopio: the effect of education, age, and sex on brief neuropsychological tests.

A neuropsychological screening battery including the Mini-Mental State Examination and four other brief cognitive tests (Russell's Adaptation of the Visual Reproduction Test, Trail Making Test, Verbal Fluency Tests on letters and category, and the Buschke Selective Reminding Test) was administered to a randomly selected population sample of 403 subjects aged 68 to 77 years to evaluate the effect of education, age, and sex on test scores. The difference in neuropsychological screening tests between various education groups (3 years or less, 4 to 6 years, 7 years or more) was statistically highly significant, even after the adjustment for the effect of age. The subscores and total scores were lowest in the minimal education group on every neuropsychological test. Education correlated more strongly than age with all neuropsychological test scores and subscores. The effect of sex on test results was seen only in some subscores of brief neuropsychological tests but not in a single item of the Mini-Mental State Examination. On the basis of our results, the effects of education, age, and sex have to be evaluated before using brief neuropsychological tests in population-based dementia screening.

Age Factors↗