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Biomedical subjects

A Gade

Publications and source records attributed to A Gade.

34 records · Page 2Linked to original sources
PubMed1991

[HIV infection and the development of dementia].

Progressive dementia has been described in AIDS patients as the most significant neurologic complication, related to HIV-1 infection directly rather than to opportunistic infections. As the virus seems to enter brain early in the course of infection, incipient dementia or subclinical cognitive impairment have been assumed to occur in otherwise asymptomatic HIV-1 seropositive individuals. A review of relevant neuropsychological studies indicates that this suspicion receives no support in large well-controlled studies. The natural history of AIDS dementia is still not clearly delineated, but encephalopathy seems to develop only with or after systemic immunosuppression.

AIDS Dementia Complex↗
PubMed1991

A critical note on Lezak's 'best performance method' in clinical neuropsychology.

A fundamental problem in clinical neuropsychology is the estimation of premorbid levels of cognitive functioning. Lezak (1983) described the so-called 'best performance method' of estimating premorbid abilities. Essentially, this method consists in using the highest test scores or the best performance in everyday tasks as the best estimate of premorbid ability. This paper describes three studies of the empirical consequences of using the 'best performance method': The first study demonstrates that application of this method on WAIS subtests leads to a gross overestimation of intelligence as measured by the IQ. The second study corroborates this finding and also shows that overestimation of intelligence leads to systematic errors in the expected performance in neuropsychological tests in normal subjects. Finally, the third study shows that this is also the case in patients with diffuse cerebral atrophy.

Adult↗
PubMed1990

Temporal gradient in the remote memory impairment of amnesic patients with lesions in the basal forebrain.

Recall and recognition of premorbid public events were studied in four groups of subjects. Dementia patients showed equal losses from all time periods compared to normal controls. In contrast, two groups of amnesic patients showed extensive remote memory losses, which were most marked for the last few years prior to onset. The difference between recall and recognition was similar in the groups. The results indicate that the retrograde amnesia associated with aneurysms of the anterior communicating artery cannot be distinguished from that of amnesia with other etiologies. Implications of the finding of a temporal gradient in the retrograde amnesia of non-alcoholic amnesics are discussed.

Adult↗
PubMed1988

"Chronic painter's syndrome". A reanalysis of psychological test data in a group of diagnosed cases, based on comparisons with matched controls.

Twenty solvent-exposed workers, most of them painters, had been diagnosed as cases of toxic encephalopathy in 1978/79. Two years later they were re-examined with an extensive battery of neuropsychological tests. Their performance was unchanged on retesting. We have now compared their test results with those of non-exposed control subjects. Previous impressions of significant intellectual impairment in the solvent-exposed patients could not be confirmed when the influence of age, education, and intelligence was taken into consideration. The present group with presumed toxic encephalopathy is assumed to be representative of other patients who were similarly diagnosed in our department. The presently reanalyzed cases had been diagnosed as brain damaged and reported as such in the literature. Thus, they may have contributed to the formation of the concept of the "chronic painters' syndrome" with dementia.

Adult↗
PubMed1987

High-resolution nuclear magnetic resonance imaging and single photon emission computerized tomography--cerebral blood flow in a case of pure sensory stroke and mild dementia owing to subcortical arteriosclerotic encephalopathy (Binswanger's disease).

Pure sensory stroke (PSS) is typically caused by a lacunar infarct located in the ventral-posterior (VP) thalamic nucleus contralateral to the paresthetic symptoms. The lesion is usually so small that it cannot be seen on computerized tomography (CT), as illustrated by our case. In our moderately hypertensive, 72-year-old patient with PSS, CT scanning and conventional nuclear magnetic resonance imaging (NMRI) scanning using a 7-mm-thick slice on a 1.5 Tesla instrument all failed to visualize the thalamic infarct. Using the high-resolution mode with 2-mm slice thickness it was, however, clearly seen. In addition, NMRI unexpectedly showed diffuse periventricular demyelinization as well as three other lacunar infarcts, i.e., findings characteristic of subcortical arteriosclerotic encephalopathy (SAE). This prompted psychometric testing, which revealed signs of mild (subclinical) dementia, in particular involving visiospatial apraxia; this pointed to decreased function of the right parietal cortex, which was structurally intact on CT and NMRI. Single photon emission computerized tomography by Xenon-133 injection and by hexamethyl-propyleneamine-oxim labeled with Technetium-99m showed asymmetric distribution of cerebral blood flow (CBF), with an 18% lower value in the right parietal cortex compared to the left side; this indicated asymmetric disconnection of the cortex by the SAE. Thus, the tomograms of the functional parameter, CBF, correlated better with the deficits revealed by neuropsychological testing than by CT or NMRI.

Aged↗
PubMed1985

Pneumococcal meningitis: an evaluation of prognostic factors in 164 cases based on mortality and on a study of lasting sequelae.

During the period 1966-76, 164 patients with pneumococcal meningitis were admitted to the University Hospital, Copenhagen. Of 111 survivors 94 underwent a series of clinical examinations. The findings in each patient were assessed for their aetiological relationship to meningitis. Of these patients 54% had neurological sequelae, 42% had neuropsychological sequelae, 25% had otological sequelae and 16% had sequelae as judged by computer-assisted tomography of the brain. On the basis of the general clinical condition, each patient was evaluated for the presence of sequelae of meningitis by means of a rating of nil, mild, moderate or severe. These ratings and mortality rates were used to evaluate the prognostic significance of various features present during the acute illness. A fatal outcome was significantly associated with increasing age, concomitant pneumonia, altered consciousness on admission, transfer from another hospital and development of complications while in hospital. There was a statistically significant association between lasting sequelae and the female sex, the age group of 16-50 years, patients who had not received any pre-admission antibiotic therapy and those with positive bacterial cultures of specimens from sites other than blood or cerebrospinal fluid.

Adolescent↗
PubMed1984

Catecholamine microfluorometry of nigral perikarya and tyrosine hydroxylase assay in some telencephalic structures of rats exposed to different behavioral situations.

In an earlier attempt to detect biochemical changes in the prefrontal system of rats performing a task sensitive to prefrontal damage, significant changes in amount of synaptic proteins were found only in the prefrontal cortex and only in the yoked control group. In a similar experimental paradigm, we measured presently activity of tyrosine hydroxylase in several telencephalic formations and intensity of dopamine fluorescence in neurons of the substantia nigra. The neurons in the medial and anterior portion of the substantia nigra of all experimental groups fluoresced significantly stronger than those in the lateral and posterior portions. The activity of tyrosine hydroxylase was 3-4 times higher in the medial prefrontal area than in the occipital cortex. No significant behavior-induced changes were detected in either of these variables. These results-in turn (1) demonstrate an unexpectedly strong dopamine concentration in the nigral neurons which innervate the prefrontal target of the neostriatum; (2) support the evidence of a strong dopaminergic innervation of the prefrontal cortex; and (3) indicate that the dopaminergic transmission in the prefrontal system was not affected by presumed activation of the system to a degree detectable by the presently used methods.

Animals↗
PubMed1982

Amnesia after operations on aneurysms of the anterior communicating artery.

All patients with ruptured aneurysms admitted to neurosurgical departments in Denmark after April, 1978, are the subjects in the prospective study that includes neuropsychological examinations. Data from 48 patients with aneurysms of the anterior communicating artery have been analyzed. Trapping of the aneurysm was done in 11 patients and resulted in an amnesic syndrome in 9. Thirty-seven patients were operated upon by ligation of the neck of the aneurysm or similar procedures, resulting in 6 cases of amnesia. Trapping invariably disrupts blood supply through newly described dorsal perforating branches from the anterior communicating artery. These perforating branches may supply areas of vital importance to memory function.

Amnesia↗
PubMed1982

Cerebral blood flow in chronic toxic encephalopathy in house painters exposed to organic solvents.

Cerebral blood flow (CBF) was studied in 11 controls and 9 house painters occupationally exposed to organic solvents for a mean of 22 years. They had mild to moderate intellectual impairment, and no or only minor cerebral atrophy was seen in a CT-scan of the brain. The 133Xe inhalation technique was used and the flow was calculated from the initial slope of the 133Xe wash out curve (ISI). ISI averaged 36.8 ml/100 g/min in the painters and 45.4 ml/100 g/min in the controls, representing a significant difference (P less than 0.05). The reduced CBF in these painters with slight to moderate intellectual impairment might be due to limited neuronal loss or to permanently decreased metabolism of the neurones.

Adult↗
PubMed1979

Effects of dimepramine fumarate on physiological and cognitive behaviors of Parkinson patients.

Nine patients 55 to 74 years old with Parkinson's disease were tested before and after treatment with 50 to 225 mg dimepramine fumarate (CIBA G-31406) for about three weeks daily in order to determine the drug's effects on electrodermal responsiveness to a series of unpredictably occurring loud sounds. Twelve control subjects were tested and retested with the same procedure. In addition, the Parkinson patients received a number of cognitive tests before and after drug treatment. Results indicated that the drug tends to decrease autonomic arousal responses as measured by resting conductance levels, number of fluctuations in skin conduction per minute, orienting response, and habituation rate. These decreases in measures of arousal generally were accompanied by lowered performance scores on several tests of memory and temporal discrimination ability.

Aged↗
PubMedDate not supplied

Evidence for diabetic encephalopathy.

Auditory brain stem responses were recorded in 20 normoacoustic long-duration Type 1 diabetic patients (duration of diabetes 26 (range 13-46) years, age 44 (25-66) years) with peripheral neuropathy and retinopathy and in 19 sex-matched normoacoustic short-duration Type 1 diabetic patients (duration of diabetes 2 (0-6) years, age 23 (18-50) years) without clinical signs of neuropathy or microangiopathy. Abnormal brain stem auditory evoked responses were demonstrated in 40% of the long-duration and in 5.3% of the short-duration diabetic patients (p less than 0.01). Interpeak latencies Jv-JI and JIII-JI were significantly prolonged in both patient groups compared with the non-diabetic control group (p less than 0.01). Magnetic resonance imaging was performed in 16 of the long-duration patients and in 40 age-matched healthy volunteers on a whole body MR-scanner. Subcortical and/or brain stem lesions with abnormally high signals were seen in 69% of the long-duration Type 1 patients and in 12% of the healthy volunteers (p less than 0.02). Neuropsychological examination including 17 tests for intelligence and cognition were performed in the 20 long-duration Type 1 diabetic patients. The results indicated a performance close to that seen in a control group of healthy age-matched control subjects. Our study demonstrates that a considerable proportion of long-duration Type 1 diabetic patients suffering from retinopathy and peripheral neuropathy additionally have signs but no symptoms of central nervous system affection, diabetic encephalopathy.

Adult↗