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Biomedical subjects

L Deecke

Publications and source records attributed to L Deecke.

At least 181 records · Page 10Linked to original sources
PubMed1989

[Prognostic factors for long-term mortality and risk of stroke in patients with transient ischemic attacks].

The aim of the present study was to evaluate the natural course of patients with transient ischaemic attacks and to determine prognostic factors concerning long-term mortality and the incidence of stroke. 159 patients, who were hospitalized after transient ischaemic attacks at the Neurological University Department Vienna during the years 1976 to 1985, were asked about the further course of their illness using questionnaires. 22 patients had moved to unknown addresses and the return rate of the remaining questionnaires was 73.0%. Thus, the results of 100 patients were included in the present study. The follow-up period was 71 +/- 32 months (x +/- s; range: 19-135 months). During the follow-up period, 11 patients had died and 25 had eventually incurred full-blown cerebral infarction. The following variables were analyzed for their prognostic relevance with respect to long-term mortality and stroke occurrence: sex, age, vessel territority involved clinically, number of vessel territories involved clinically, number of strokes, and severity of clinical symptoms. The clinical symptoms (motor deficits, sensory deficits, speech disorders, visual field defects and organic mental syndrome) were graded semiquantitatively and added up to a "total score". Age had a significant influence on survival, but not on stroke occurrence. All other variables had no significant impact on long-term mortality and stroke occurrence. It is concluded that transient ischaemic attacks are warning symptoms of an impending stroke. However, prognostic assumptions cannot be made of the basis of clinical features in this subacute stage. Thus, all patients suffering from transient ischaemic attacks should have a comprehensive and thorough vascular investigation as soon as possible.

Adolescent↗
PubMed1989

Negative cortical DC shifts preceding and accompanying simple and complex sequential movements.

Negative cortical DC shifts preceding and accompanying the execution of four different motor tasks were analysed in 18 subjects (Ss): Repetitive flexions and extensions of the forefinger had to be performed either by the right (1) or the left (2) hand. This simple motor task was compared to a complex one in which flexions and extensions of forefinger and hand had to be alternated in a fixed sequence. The complex task had either to be performed by the right (3) or the left (4) hand. Thus, the four conditions differed in the side of the performing hand (right/left) and in task-complexity (simple/complex). After its voluntary initiation, each task had to be performed for at least a period of six seconds. A Bereitschaftspotential (BP) preceded the voluntary initiation of the movement. Task-performance was accompanied by a negative DC shift called a performance-related negativity (N-P). Amplitudes of BP and N-P were compared by analysis of variance (ANOVA) using the factors "performing hand" (right/left) and "task-complexity" (simple/complex). "Performing hand" had significant effects on N-BP and N-P in C3* and C4* (positioned over the primary motor cortex) but did not influence mid-central (Cz*), frontal (F3, Fz, and F4) or parietal (P3, Pz, P4) recordings. "Task-complexity" had significant effects on N-P in mid-central (Cz*, C1*, C2*) and parietal (P3, Pz) recordings with higher negativity for complex movements. Recordings in C3* and C4* did not vary with "task complexity".(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

The cerebral localization of neuropsychological impairment in Alzheimer's disease: a SPECT study.

Twenty-three patients with a clinical diagnosis of Alzheimer's disease were examined with a set of neuropsychological tests and with 99mTc-hexamethyl-propyleneamineoxime (HMPAO) single photon emission computed tomography (SPECT). Correlations between test results and indices of regional HMPAO distribution were analysed by multidimensional scaling (MDS). Test results covaried positively with relative HMPAO uptake of frontal, inferior parietal and superior temporal regions but not, or in a negative way, with the remainder of the regions. When only positive correlations were analysed, MDS suggested two dimensions of organization: one was related to a dichotomy between frontal and temporo-parietal regions. The relationship of test results to this dimension was largely consistent with common neuropsychological knowledge. A second, less stringent dimension of organization opposed right and left hemisphere regions. The ordering of test results with respect to this dimension was only partly consistent with what is known about the lateralization of neuropsychological deficits from the study of localized brain lesions. The possibility is considered that these inconsistencies may reflect the effect of disproportionally severe involvement of extended cortical systems which modulates the sequels of localized brain damage.

Aged↗
PubMed1989

Regional cerebral blood flow patterns in visual imagery.

Regional cerebral blood flow patterns were investigated by means of single photon emission computerized tomography in subjects who solved cognitive tasks which either did or did not require the use of visual imagery. In a first experiment judging the correctness of visual imagery sentences like "a grapefruit is bigger than an orange" led to increases of regional activity in inferior temporal and in the left inferior-occipital region when compared to blood flow patterns elicited by judgements about low imagery sentences or by responding differentially to "yes" and "no". Motor imagery sentences did not cause such an increase. In a second experiment a condition in which visual images were used for counting the corners of letters was compared to a condition in which subjects internally rehearsed the alphabet. The only difference concerned the inferior frontal regions which showed higher activity in rehearsing the alphabet. However, activity in inferior temporal and inferior occipital regions showed a positive correlation to the self-rated vividness of the visual images in the corner counting condition. The results of both experiments yield converging evidence that visual imagery is selectively related to activity of inferior-temporal and occipital regions. They thus support the hypothesis that the cerebral correlate of visual imagery is different from that of non-imaginal thinking.

Adult↗
PubMed1989

Cerebral correlates of imagining colours, faces and a map--I. SPECT of regional cerebral blood flow.

The distribution of regional cerebral blood flow (rCBF) was assessed by single photon emission computerized tomography (SPECT) in subjects during a resting state and during imagining either colours or faces or a route on a map. Twelve out of 30 subjects reported the spontaneous occurrence of mental visual images during the resting state. In these subjects flow in both orbitofrontal regions was higher than in those subjects who had not experienced spontaneous imagery. Voluntary imagery led to an increase of regional flow indices in basal temporal regions of both hemispheres and to a rightwards shift of global hemispheric asymmetry. The local changes were distinctly more marked with faces than with any of the other two stimuli. Imagining faces was also the only condition that led to an increase of activity in the left inferior occipital region which has been suggested by previous studies as being a crucial area for visual imagery. It is concluded that the observed differences of rCBF patterns between imagery conditions are related to the amount of information conveyed by the mental image. In contrast to the results of a companion study on DC-shifts accompanying imagery there was no effect of the visual versus spatial character of the images.

Adult↗
PubMed1989

Changes within the "normal" cerebral white matter of multiple sclerosis patients during acute attacks and during high-dose cortisone therapy assessed by means of quantitative MRI.

Changes in the apparently unaffected cerebral white matter of multiple sclerosis (MS) patients were studied during acute attacks as well as during high-dose prednisolone therapy. Serial MR scans of patients with a clinically definite diagnosis were performed on four defined occasions: before an episode, within three days after its onset, after 10 days of therapy as well as four weeks later. Thirteen patients agreed to cooperate in forming a MRI data base and to be rescanned immediately after the onset of an acute relapse. Within one year, six patients had such episodes, one of them had a second bout. Both T1 and T2 relaxation times within the apparently normal white matter were significantly prolonged in all cerebral lobes compared to a control group of healthy volunteers. During the acute attacks as well as during therapy the T1 values remained as before. The T2 values were elevated only in two out of six cases during the episode. After therapy a considerable clinical improvement was seen in all cases, but a significant T2 decrease as a possible effect of cortisone was noted in only one case. We conclude that the prolonged relaxation times T1 and T2 within the apparently normal cerebral white matter of MS patients are the result of a number of molecular events differing considerably among individual patients and that serial measurements of these relaxation times do not consistently change during an acute relapse and do not reflect clinical improvement after high dose prednisolone therapy.

Acute Disease↗
PubMed1989

Diffuse cerebrospinal gliomatosis presenting as motor neuron disease for two years.

A patient with symptoms and signs of motor neuron disease for 2 years finally developed sensory disturbances and increased intracranial pressure. MRI and CT showed enlargement of the right side of the cerebellum, the brainstem and parts of the cerebral hemisphere with focal hyperperfusion demonstrated by SPECT. Necropsy revealed a diffuse cerebrospinal gliomatosis with loss of spinal motor neurons in tumour infiltration of the anterior horns. This type of spinal cord involvement is considered responsible for the unusual clinical presentation of the neoplasm.

Adult↗
PubMed1989

Stabilizing and destabilizing effects of vision and foot position on body sway of healthy young subjects: a posturographic study.

A total of 800 posturographic measurements--each characterized by four values (sway path, sway area, anteroposterior sway and lateral sway)--was carried out for this study. Eight different conditions (interfoot distances of 0, 4, 10 and 20 cm, each with eyes open and eyes closed) were compared by statistical means. All sway values were diminished by vision in small interfoot distances. At large interfoot distances, however, the presence of visual control resulted in an increase of lateral sway. Comparing the different foot positions, an increase of anteroposterior sway and a decrease of all other components were found at large interfoot distances no matter whether the eyes were open or closed.

Adult↗
PubMed1989

Quantification of regional cerebral blood flow with IMP-SPECT. Reproducibility and clinical relevance of flow values.

Single-photon emission computed tomography with N-isopropyl[123I]-p-iodoamphetamine (IMP-SPECT) was performed in 14 normal volunteers (seven men and seven women aged 25.1 +/- 5.3 years) and 29 patients with cerebrovascular disease (18 men and 11 women aged 54.1 +/- 13.7 years). The fluid microsphere model was used to estimate cerebral blood flow (CBF). Normal subjects were scanned twice, 1 week apart, to determine the reproducibility of the CBF estimates. Hemispheric blood flow (hCBF) was calculated as the mean of regional cerebral blood flow (rCBF) values in 16 gray matter regions per hemisphere. In normal subjects mean hCBF was 68 ml/100 g/min. The highest rCBF was found in the occipital cortex, followed by the frontal, temporal, and parietal cortexes. CBF values were reproducible (p less than 0.001 except the right thalamic region, where p less than 0.01). Intraindividual variation ranged between 0.3% and 15%. Women exhibited significantly higher (16%, p less than 0.02) CBF than men. Patients were subdivided into groups with reversible (n = 19) and persistent (n = 10) symptoms. Significant hCBF differences between the affected and the contralateral hemispheres were recorded only in the group with reversible symptoms (p less than 0.005), whereas the group with persistent symptoms showed a significant bilateral decrease of hCBF compared with normal subjects and patients with reversible symptoms. Focal CBF was significantly lower in patients with completed stroke than in patients with transient symptoms (p less than 0.001). Our results indicate that IMP-SPECT can be used for the routine estimation of CBF in normal and pathologic states.

Aged↗
PubMed1989

[Considerations in hemodilution therapy of stroke].

Hemodilution therapy in patients with ischemic cerebrovascular disease has recently become increasingly controversial, since controlled prospective trials failed to prove unequivocal clinical effects. A general rejection of hemodilution, however, does not seem to be justified. Undoubtedly, there is a beneficial influence on some hemorheologically relevant parameters as well as on cerebral blood flow (CBF). In addition, there is no proof that subgroups of patients profiting from this kind of treatment do not exist. Hemodilution is not recommended for patients with cerebral hemorrhages or hemorrhagic infarctions. In cases with transient ischemic attacks or ischemic strokes, however, this treatment should be taken into consideration further on. The application of hemodilution therapy in patients with progressive strokes depends on clinical signs, the course, the CT scan result, and sonographical findings. Recently, hydroxyethyl-starch (HES) has increasingly been used as an hemodiluting agent. The application of Dextran 40 should be limited to young normotensive patients without cardiac or renal disease.

Cerebrovascular Disorders↗
PubMed1989

[The variability of the number and daily distribution of spike wave seizures in two 24-hour long-term EEG recordings made one shortly after the other].

30 patients suffering from primary generalized epileptic seizures were investigated twice in intervals of 1-7 days by means of mobile long-term-EEG monitoring. The total number of paroxysms showed a variability from 53% to 187%, the time of maximum paroxysmal activity varied in between 2.76 hours to 5.40 hours for the whole group; the results for adults, children and patients with/without antiepileptic medication did not differ much. Our findings suggest, that the results of one single 24 hours long-term-EEG investigation must be interpreted with great caution.

Adolescent↗
PubMed1989

[Clinical aspects of treatment and preventive treatment with thrombocyte aggregation inhibitors in cerebrovascular diseases].

Inhibitors of thrombocyte aggregation are generally accepted in the therapy and prophylaxis of ischemic cerebrovascular disease. The frequency of re-infarction, morbidity and mortality after TIA, PRIND and minor stroke is influenced favourably. There are controversial opinions, however, about the usefulness for patients suffering from completed strokes. In patients with progressive stroke, cerebral embolism of cardiac source, or non-infective thrombosis of sinuses or cerebral veins, inhibitors of thrombocyte aggregation are used if anticoagulation therapy is not possible. Additionally, they are applied in cases of infective thrombosis of sinuses or cerebral veins, after termination of anticoagulation therapy, after cardiac valve replacement, and after surgical reconstructions of craniocervical vessels. Acetylsalicylic acid is the clinically best examined substance; its effect--especially in males--was proven by numerous prospective trials. A combined treatment with dipyridamole, sulfinpyrazone or other drugs seems to be unnecessary. A daily dose of not more than 300 to 325 mg acetylsalicylic acid is recommended for prophylaxis after ischemic cerebral events; in connection with that dose severe gastrointestinal side effects are hardly to be expected. Whether even lower doses would yield the same prophylactic effects will have to be clarified by further studies.

Aspirin↗
PubMed1989

[Involvement of apparently normal white brain substance in the disease process of multiple sclerosis].

In a group of patients with a clinically definite diagnosis of multiple sclerosis (MS) the cerebral white matter was investigated by means of quantitative nuclear magnetic resonance imaging (MRI). Measurements were taken from plaque-free regions and compared to a control group of healthy volunteers. A significant prolongation of T1 and T2 values was seen for all regions investigated (frontobasal, temporal, temporoparietal, and upper parietal white matter). In a comparison of MS patients with a short duration of the disease (mean: 1.7 years) with MS patients with a long-standing course of the disease (mean: 15.2 years) a significant prolongation of T2 relaxation times was found in the upper frontal and upper parietal white matter only for the latter group. In keeping with neuropathological findings the noted prolongation of T2 values might most probably be due to an increase of extracellular water secondary to astroglial proliferation. The increase of relaxation times could either be due to degeneration of commissural fibers or be the result of an exhausted capacity for remyelination. Both events are known to occur predominantly in the later stage of the disease. It is concluded that MS represents a disease which is not restricted to limited areas of demyelination but rather involves the entire cerebral white matter. These findings imply possibilities for the assessment of disease progression as well as for therapy.

Adult↗
PubMed1989

[Evoked potentials in the follow-up and prognosis of patients with craniocerebral trauma].

The aims of this study were to find a reliable way of establishing the prognosis for the final outcome in the first week after head injury, to show the correlation between abnormalities in evoked potentials (EP) and clinical coma score, and finally, to document EP results in patients with the clinical diagnosis of brain death. We examined 46 patients, 23 in different states of coma and 23 with bulbar syndrome (complete absence of cortical and brain stem function). In the group of comatose patients brain stem auditory EP (BAEP) and somatosensory EP (SEP) were recorded in the first 48 h, 3-5 days, 1 week and 4 weeks after the head injury. The depth of coma was scaled with a scoring system devised by the authors and with the Innsbruck coma scale. Outcome was evaluated with the Glasgow outcome scale after 3, 6, and 9 months. BAEP were recorded bilaterally after stimulation with clicks; SEP were recorded from the neck (C2) and the contralateral cortex (C3', C4') after electrical stimulation of the median nerve. Evoked potentials were scored according to a four-point scale from grade 1 (normal) to grade 4 (only component I present in BAEP or absence of cortical responses on both sides in SEP). We found a significant correlation between the mean SEP score of the first week and the Glasgow outcome of the 3rd month, but no significant correlation between the BAEP score of the first week and the Glasgow outcome. There was a significant correlation between SEP (BAEP) scores and the corresponding clinical score.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

[Neuro-AIDS].

Various findings prove the neurotropism of the human immune deficiency virus (HIV). Besides an aseptic meningitis at the time of seroconversion and polyradiculoneuropathies clinical and neuropathological studies focus on subacute encephalitis leading to dementia and focal neurological complications. Therapeutic strategies, various considerations concerning the pathogenesis of other subacute, chronic and slow virus infections of the nervous system as well as prophylactic implications become more and more important.

Acquired Immunodeficiency Syndrome↗
PubMed1988

[Prognosis and documentation of the disease course in severe craniocerebral injuries].

35 survivors of severe head injury were consecutively admitted to the Neurological Department, University of Vienna for early rehabilitation. The outcome after a mean observation periods of 19 months was compared with clinical signs (best motor response, pupillary light reaction, pupil size) in the acute stage. The clinical signs were graded semiquantitatively. The outcome was assessed using the Glasgow Outcome Scale and compared with alternatives, the Karnofsky Performance Status and a self-designed neuropsychological rating scale. Both indexes appeared to possess certain advantages which included additional information and sensitivity to change. A significant correlation was established between the long-term outcome after severe head injury on the one hand and the "best motor response" and changes in pupillary light reaction in the acute stage on the other hand. However, the clinical parameter of pupil size in the acute stage does not provide a prognostic indicator of the disability status at the end of the observation period. There was good agreement between the outcome scores derived by means of the 3 rating scales. Solely with respect to the items "orientation and memory function" and "emotions" of the neuropsychological rating scale was no significant correlation obtained with the clinical sign "best motor response" in the acute stage. Our results indicate that it seems possible to assess the outcome after severe head injury not only be means of the widely-adopted Glasgow Outcome Scale, but also using the Karnofsky Performance Status and our neuropsychological rating scale without any marked loss of reliability. The clinical signs - "best motor response" and pupillary light reaction - are excellent prognostic indicators of the long-term outcome after severe head injury.

Adolescent↗
PubMed1988

[Does alcohol consumption promote the manifestation of strokes? Considerations on pathophysiology].

Arterial hypertension is the most important risk factor in all types of stroke. The significance of alcohol in the pathogenesis of stroke is less well defined. Chronic alcoholism leads to an elevation of blood pressure. Thus, the association between alcohol and stroke might be the blood pressure effect of alcohol. However, some studies have shown a significant influence of alcohol on the incidence of stroke--especially of intracerebral haemorrhage and subarachnoid haemorrhage--even after adjustment for blood pressure. Many possible pathomechanisms are discussed. Alcohol inhibits aggregation of thrombocytes, and chronic alcohol abuse may induce thrombocytopenia, which could lead to a haemorrhagic stroke. Alcohol withdrawal leads to rebound thrombocytosis. Acute alcohol ingestion induces a decrease in fibrinolytic activity and an increase in factor VIII activity, which enhances the thrombotic potential. Additionally, alcohol increases plasma osmolarity, erythrocyte aggregability, haematocrit and blood viscosity, and decreases deformability of erythrocytes. The effects of alcohol on cerebral blood flow are still under debate; there is a deterioration in autoregulation of cerebral blood flow anyway. In animal studies alcohol induced dose-dependent vasospasm of the cerebral blood vessels, which could be a possible pathomechanism in ischaemic, as well as in haemorrhagic stroke. Chronic alcoholism is the most common cause of secondary non-ischaemic cardiomyopathy, which can lead to cerebral embolism via rhythm disorders or intracardiac thrombus formation.(ABSTRACT TRUNCATED AT 250 WORDS)

Alcohol Drinking↗