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Biomedical subjects

T Benke

Publications and source records attributed to T Benke.

52 records · Page 3Linked to original sources
PubMed1993

Two forms of apraxia in Alzheimer's disease.

Apraxia was tested in 12 DAT patients with mild to moderate dementia using two assessment procedures: conceptual tasks requiring object use and pantomime knowledge, and tasks based on the imitation of meaningless oral and hand movements. Both object use and pantomime performance were markedly impaired in the DAT group; imitation of hand postures, hand movements and multiple oral movements was also defective while single oral movements could be well imitated. Error analysis revealed several underlying deficits: on conceptual tasks, deficits in object and action knowledge and poor action planning were frequent, whereas impaired recall and coordination of spatial and temporal movement features were found on imitation tasks. A correlation analysis between both types of apraxia showed low and nonsignificant results. These and previous observations suggest that motor control is organized by two functionally separate systems: a conceptual system for purposeful and symbolic motor acts, and a system controlling sensorimotor and spatiotemporal movement features. Both systems may be subject to early damage in Alzheimer's disease.

Aged↗
PubMed1993

[Clinical and experimental use of Cogimir].

This paper introduces 3 applications of a computer-based methodology for the assessment of cognitive abilities which has been developed during the Cogimir space project: an experimental study comparing gender-related lexical decision abilities, an investigation of hemisphere-specific reading in a subject with a partial split-brain syndrome, and a follow-up study measuring the effect of rehabilitation in a patient with frontal brain damage. Computerized tasks have several advantages over conventional neurobehavioral measurement procedures, among them exact stimulus and response control, the ability to generate numerous alternate forms, and the capability of a subject and level-oriented approach. In addition to their broad experimental application they can easily be adapted for the diagnosis and treatment of patients suffering from cognitive deficits.

Adult↗
PubMed1993

Space and cognition: the measurement of behavioral functions during a 6-day space mission.

We measured nonspecific (attention, mental flexibility, psychomotor speed) and visuospatial cognitive processing in a single case study during a 6-d visit on the Russian orbital complex MIR, using computer-based psychometric tasks. Reaction times and accuracy scores showed only minor, nonsignificant changes between preflight, flight, and postflight assessments. These results suggest that several behavioral functions, among them complex visuospatial processing skills, remain essentially intact on short space visits, provided that the performing subject experiences no symptoms of space motion sickness or other physical impairments. Computerized psychometric tasks are a sensitive and flexible tool to measure behavioral functions in space life sciences.

Cognition↗
PubMed1991

High-speed memory scanning in Parkinson's disease: adverse effects of levodopa.

High-speed memory scanning as assessed by the Sternberg paradigm was studied in 12 nondemented patients with fluctuating Parkinson's disease and 13 age-matched healthy controls. Patients were first assessed before taking their morning dose of levodopa ("off") and again after that dose had produced full clinical effect ("on") after that dose had produced full clinical effect ("on"). Although motor components of the measured choice reaction time were slower in patients when off than in control subjects, memory scanning speed was not different. After levodopa (on), patients' motor time normalized, but cognitive processing speed became significantly slower when compared with previous performance in the off condition and with controls. Contrary to previous concepts of bradyphrenia in patients with Parkinson's disease, these results indicate that dopaminergic stimulation can reduce cognitive processing speed.

Frontal Lobe↗
PubMed1991

Effects of treatment with trihexyphenidyl on cognitive function in early Parkinson's disease.

13 patients with PD of recent onset underwent a series of neuropsychological tests for frontal lobe associated functions (Sternberg paradigm, WCST, CVLT) before and during treatment with Artane. Test results at baseline were not significantly different from those of an age-matched control group (n = 13). Retesting after a mean of 2 weeks' treatment with trihexyphenidyl revealed only slight impairment in CVLT while performance on the other tests remained unchanged.

Adult↗
PubMed1991

Neuropsychological deficits in asymptomatic carotid artery stenosis.

A total of 20 subjects with asymptomatic carotid artery stenosis (ACAS) and a group of healthy controls were compared as to their cognitive performance. Subjects with ACAS showed substantial deficits on tasks of mental speed, learning, visuospatial abilities, verbal processing and deductive reasoning. The cognitive profile of ACAS--subjects indicated non-specific impairment, possibly related to widespread cerebral vascular disease, of which the presence of ACAS may be one indicator.

Brain Ischemia↗
PubMed1990

[Speech changes in dementia].

This review analyzes the spectrum of language deficits commonly encountered in dementia. A specific communication profile is found in dementia of the "cortical" type, such as Alzheimer's disease. With advancing disease lexical, comprehension and pragmatic functions deteriorate, whereas syntax and phonology tend to be preserved. This pattern bears some resemblance to aphasia types like transcortical and Wernicke's aphasia, however, a much broader range of communicative functions is impaired in Alzheimer's disease than in aphasia. Differentiation of dementia and aphasia, especially in elderly patients requires careful neuropsychological assessment of language, memory and other psychological functions. "Subcortical" dementia commonly presents with dysarthria as the leading symptom and linguistic impairment is rarely of crucial importance until late stages. Thus, the interetiologic dissociation of language and speech impairment can be used for dementia differentiation. Aphasia batteries are not sufficient to comprehend the range of language deficits in demented patients. Testing the communication impairment in dementia requires specific tasks for spontaneous speech, naming, comprehension, reading, writing, repetition and motor speech functions. Tasks for verbal learning and metalinguistic abilities should also be performed. Language deficits are frequent initial symptoms of dementia, thus language assessment may be of diagnostic relevance. Many data support the concept that the communication deficit in dementia results from a particular impairment of semantic memory.

Aged↗
PubMed1989

Sex equality in intrahemispheric language organization.

Sex differences in inter- and intrahemispheric cerebral organization, found in previous studies, have been used to explain sex differences in cognitive abilities. This study highlights data to contradict such widely held beliefs. Intrahemispheric language organization was examined by determining the location of lesions causing aphasia by computed tomography. No sex differences in the incidence of anterior, posterior, or central lesions was found. The distribution of left-hemisphere lesions in stroke patients, with or without aphasia, was also equal among the sexes. This study does not support the postulated gender difference in intrahemispheric cerebral organization.

Anomia↗
PubMed1988

Periventricular and subcortical hyperintensities on magnetic resonance imaging. 'Rims, caps, and unidentified bright objects'.

Magnetic resonance imaging hyper-intensities were classified as periventricular rim, caps, and unidentified bright objects (UBOs). These were quantitated in 100 acute stroke and 23 hemorrhage patients and 59 control subjects selected from 590 consecutive scans. The rims, caps, and ventricular size were rated on a scale from 0 to 3 for severity, and the UBOs were counted. The results indicated that the rim is also frequent in control subjects and increases with age. Unidentified bright objects, caps, and severe rims usually signify pathology, occurring much more frequently in patients with strokes and hemorrhages than in control subjects. Hypertension is a significant risk factor in UBOs and caps, but in rims, the incidence of diabetes is higher. The clinical and pathologic significance of these hyperintensities and their relationship to Binswanger's disease, lacunar state, and "état criblé" is discussed.

Acute Disease↗
PubMed1988

Visual agnosia and amnesia from a left unilateral lesion.

This case report describes the behavior of a patient with a visual agnosia of the associative type, developing to optic agnosia at a later stage. Language, general intelligence and right hemisphere functions were well preserved, but recognition of visually presented objects, colors, faces, words, and complex stimuli was impaired. Agnosia was accompanied by a multimodal amnestic syndrome. CT displayed a focal left hemisphere lesion. The observed pathomorphology is not consistent with a bilateral visuolimbic disconnection syndrome, as suggested from previous case studies. Significant components of visual semantic processing may be executed by the left hemisphere.

Adult↗
PubMed1984

[The epileptic mother and her child].

This study is a review of the literature on the influence of epilepsy and antiepileptic medication on the course of pregnancy and the foetus, as well as of the effect of pregnancy on the disease. Antiepileptic treatment is supposedly responsible for the increased rate of abnormal bleeding after delivery. Data on the perinatal mortality of epileptics are conflicting. The offspring of epileptic women are often smaller than normal neonates, indicating retarded growth, and the incidence of malformations is 1.25 times higher. Until now there has been no direct evidence of a teratogenic effect of the commonly used antiepileptic drugs, and the risk of malformations may possibly be correlated with the severity of the epilepsy. The effect of pregnancy on seizure frequency seems to be quite variable. Higher seizure frequency is seen during pregnancy, but this is not a universal phenomenon. The incidence of seizures in gestational epilepsy has no predictive value with respect to the course of later pregnancy. A positive correlation seems to exist between the development of eclampsia and later epilepsy, a family history of epilepsy and cerebral dysrhythmias. Status epilepticus is uncommon in pregnancy. The requirement of several antiepileptic drugs is increased during pregnancy. The metabolism of carbamazepine, primidone, and clorazepate is probably accelerated in the gestational period, but data on other antiepileptic drugs are inconclusive or lacking. The intestinal absorption of antiepileptic drugs may be impaired during pregnancy.(ABSTRACT TRUNCATED AT 250 WORDS)

Anticonvulsants↗
PubMed1980

The effects of adenosine-5'-ethylcarboxamide on liver blood flow and hepatic glucose, lactate and pyruvate balances in dogs.

The actions of adenosine-5'-ethylcarboxamide (744-96), a long-acting adenosine analogue, on liver, portal and intestinal balances of glucose, lactate and pyruvate and on hepatic and portal blood flow were investigated in 6 chloralose-anaesthetized mongrel dogs. 744-96 led to an increase in portal and hepatic blood flow. Glucose release by the liver and glucose uptake by the non-hepatic splanchnic area (portal balance) were markedly increased by 744-96. Hepatic lactate and pyruvate balances were reversed from uptake to release by the adenosine analogue. The changes in glucose balances compare closely to the actions of glucagon, which is known to be released by 744-96. Apart from these possible glucagon-mediated actions, a direct action of the adenosine analogue must be assume from the changes in lactate metabolism. The results of this study are indicative of a substrate-mobilising action of adenosine in addition to its well-known vasodilatory action.

Adenosine↗
PubMedDate not supplied

Coronary reactive hyperaemia and coronary dilator action of adenosine during intracoronary infusion of angiotensin II.

Investigations were carried out in chloralose-anesthetized, thoracotomized dogs. The effects of an intracoronary infusion of angiotensin II (3 ng/ml coronary blood) on reactive hyperaemic blood flow and adenosine-induced coronary vasodilation were established. Coronary artery occlusions were performed over periods of 5, 10 and 25 heart beats and adenosine was injected intracoronarily at dosages of 2, 4, and 8 microgram/kg body weight. The vasodilator effect of adenosine and reactive hyperaemia after 10 and 25 heart beats were both significantly diminished by angiotensin II. By contrast, reactive hyperaemia after coronary artery occlusion lasting 5 heart beats remained unchanged. The present results obtained with angiotensin II further confirm that adenosine is only partially involved in mediating reactive hyperaemia and that this involvement takes place only after sufficiently long periods of coronary artery occlusion.

Adenosine↗