Biomedical subjects

H Lechner

Publications and source records attributed to H Lechner.

At least 37 records · Page 2Linked to original sources

PubMed1994

Role of long-term EEG monitoring in diagnosis and treatment of epilepsy.

The value of long-term EEG recordings for diagnosis and differential diagnosis of epilepsy is described. It is emphasized that long-term EEF monitoring increases the scope of EEG techniques and improves the diagnostic value of standard EEG recordings providing up to 90% positive diagnostic information. In particular, the value of ambulatory cassette recording is stressed. Allowing quantification of epileptic activity recorded in real-life situation, useful information not available by means of standard EEG recordings can be obtained. Recording and scoring all-night sleep, it enables studying abnormalities of sleep patterns. In addition the value of long-term EEG recordings in therapy and control of epileptic patients is pointed out and discussed.

Ambulatory Care↗

PubMed1994

A new type of database of antiepileptic medication for everyday use.

AED InfoBase, a first concept for a personal computer based database with an adequate design for everyday use is presented. AED InfoBase operates under a hypertext control program. At present it provides information about pharmacodynamics, pharmacokinetics, side effects and availability of drugs on the market of first choice anticonvulsives. A certain accent is put on drug interactions and drug therapy in epileptics.

Adverse Drug Reaction Reporting Systems↗

PubMed1994

Long-term in vitro growth of human T cell clones: can postmitotic 'senescent' cell populations be defined?

The long-term in vitro growth characteristics of peripheral, nonspecifically expanded T cell clones from young (< 30 years old) and old (> 65 years old) Senieur-protocol compatible healthy blood donors were compared. Additionally, T cell clones derived from the sites of autoimmune events were studied. Until the 6th week in culture all clones showed a progressive increase in cell number. CD25 expression and proliferation in response to stimulation with recombinant IL-2 remained stable. Staining of DNA fragments with propidium iodide, however, revealed a small percentage of apoptotic cells. After 7-12 weeks in culture a rapid decrease in cell numbers accompanied by a striking increase in the number of apoptotic cells was noted in all peripheral clones. Although CD25 was still present on almost 100% of the cells, receptor density and proliferative response to IL-2 were greatly reduced. After a maximum of 14 weeks in culture, corresponding to 29 population doublings (PD), all peripheral T cell clones had died. No difference was noted between CD4 and CD8 T cell clones, but clones from old donors tended to have a shorter lifespan and a lower number of PD than clones from young persons (n.s.). Interestingly, T cells from autoimmune lesions had a longer lifespan and a higher number of PD than peripheral T cell clones (p < 0.01). In contrast to peripheral T cell clones, which died almost immediately after reaching the end of their proliferative capacity, a small but stable nondividing cell population could be distinguished in autoimmune clones.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1994

The Mattis Dementia Rating Scale: normative data from 1,001 healthy volunteers.

We administered the Mattis Dementia Rating Scale (MDRS) to 1,001 healthy volunteers, aged 50 to 80 years, randomly selected from our community. Multivariate regression analysis revealed educational level (p = 0.000004) and age (p = 0.00001), but no other sociodemographic or risk factors for stroke, to be significantly associated with the MDRS score. The age- and education-specific lowest quintile cutoff scores ranged from 140 in subjects aged 50 to 59 years with at least college experience to 130 in subjects aged 70 to 80 years with only 4 to 9 years of schooling. These percentile distributions obtained for decades of age and different levels of education should be useful reference values for clinicians and investigators when applying the MDRS to assess cognitive functioning.

Aged↗

PubMed1994

[Epidemiology of sleep disorders in Austria].

UNLABELLED: Epidemiologic data on sleep disturbances in Austria were collected for the first time in March/April 1993 in a representative inquiry ( SAMPLE: n = 1000, 471 males, 529 females). 26% of the subjects reported sleep disturbances which were mostly chronic (21% had suffered from sleep disturbance for more than one year). The incidence of sleep disturbances increased with age, namely 13% in 14-30 year-old subjects, 22% in 31-50 year-old ones and 41% in subjects over 50. 7% suffered from disturbances in sleep initiation, i.e., they had a sleep latency of over 30 minutes. 19% of them had difficulties in getting to sleep at least once a week. Disturbances in maintaining sleep were reported by 28% of subjects, 56% of them needing longer than one hour to get back to sleep. 30% suffered from daytime sleepiness, 43% of the subjects were impaired by their sleep disturbances in some way, but only 34% had consulted their doctor.

Adolescent↗

PubMed1993

[Hemorrheology and quality of life in fibrinogen- and lipid-lowering therapy].

Previous studies have demonstrated that heparin-induced extracorporeal LDL precipitation is able to reduce total cholesterol, LDL, triglycerides and plasma fibrinogen at the same time and thus improve the hemorheologic pattern. A combination of H.E.L.P. and bezafibrate, which also has a lipid- and fibrinogen-lowering potency, was applied in patients suffering from cerebral multi-infarct dementia and disturbances of the hemorheologic situation. In view of observations regarding improved quality of life after H.E.L.P., a prospective, randomized trial was conducted to determine possible interactions between improved hemorheology and better quality of life. To obtain a low baseline of laboratory parameters, all the patients underwent a single H.E.L.P. session and were then (double-blind) stratified into 2 groups: group 1 (16 males, 5 females, age 67.9 +/- 6.8 years) received sustained-release bezafibrate 400 mg (Bezalip) per day, while group 2 served as controls, and comprised 14 males and 5 females (age 69.2 +/- 6.8 years) who received placebo for a period of 56 days. After H.E.L.P. a statistically significant reduction of the following parameters relevant to hemorheology was obtained: fibrinogen (p < 0.0001), whole blood viscosity (low shear rate p < 0.007 and high shear rate p < 0.005), plasma viscosity (p < 0.002) and red cell transit time (p < 0.0001). Also, the metabolic parameters were influenced positively (p < 0.0001 for total cholesterol, LDL and triglycerides).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1993

EEG mapping in middle aged normal volunteers: the impact of cerebrovascular risk factors.

The impact of major risk factors for stroke on EEG mapping and routine EEG findings was evaluated in volunteers with no clinical signs of cerebrovascular or other neuropsychiatric disease. Focal changes were seen in 22 subjects (30%) by means of EEG mapping, but in only 12 cases (16%) when routine-EEG was used (p < .05). 4/35 (11%) volunteers without RF had focal changes while this was seen in 18/39 (46%) subjects in whom risk factors (RF) were found (p < .01). An association was seen between the presence of EEG foci and number of RF. 59% of subjects with 2 or 3 RF had focal abnormalities as opposed to 36% of those with 1 RF and 11% of RF free individuals (p < .05). The findings could be confirmed by averaging the EEG data according to the different number of RF revealing statistically significant differences between each of the 3 groups. Using routine EEG alone no significant correlation to the presence or number of RF was found. Our data demonstrate EEG abnormalities in a considerable portion of normal middle aged individuals which in part may be attributed to the presence of RF.

Aged↗

PubMed1993

First experience in application of heparin-induced extracorporeal LDL precipitation (H.E.L.P.) in acute thromboembolic stroke.

Heparin-induced Extracorporeal LDL < total cholesterol, triglycerides, fibrinogen > Precipitation (H.E.L.P.) was applied in cases of acute thromboembolic stroke within 48 to 96 hours after onset. 42 patients had been randomized for the trial. In Group A 12 patients underwent a single H.E.L.P. application, while remaining 10 patients formed a control group. In group B 10 patients had 10 H.E.L.P. applications, the other 10 patients firmed as controls. Results of group A: 4 days after H.E.L.P. an improvement in the Mathew Scale and in the Mini Mental State Examination could be obtained (p < 0.05 each). 10 days after H.E.L.P. all the tests showed significant changes (p < 0.05 in the Mathew Scale and in the Mini Mental State Examination and p < 0.01 in the Activities-of-Daily-Living Score). Relatet to the controls there appeared a statistically significant difference 4 days after H.E.L.P. in the Mini Mental State Examination and in the Activities-of-Daily-Living Score (p < 0.05 each). At day 10 all the tests showed a difference to the controls (p < 0.05 in the Mathew Scale and p < 0.01 in the other tests). Results of group B 10: One day after 1st H.E.L.P. a statistically significant difference could be observed in all the tests (p < 0.05 in the Mathew Scale and the Mini Mental State Examination and p < 0.01 in the Activities-of-Daily-Living Score). At that time even a difference to the controls became visible (p < 0.05 in the Mathew scale, p < 0.01 in the other tests).(ABSTRACT TRUNCATED AT 250 WORDS)

Activities of Daily Living↗

PubMed1993

Prevalence of antibodies to Borrelia burgdorferi flagellin in Styrian blood donors.

Lyme borreliosis and tick-borne encephalitis (TBE) are the most common diseases in Austria caused by tick bites. TBE endemic areas are well defined. It seemed to be of interest to compare prevalence data of antibodies against Borrelia burgdorferi (B.b.) to TBE endemic and non endemic areas. Blood samples (n = 1162) were obtained from healthy blood donors in combination with a standardized questionnaire during 21 excursions to 7 selected regions of Styria, Austria. Serum samples were screened for IgG antibodies against B.b. by a commercial flagellum ELISA. None of the tested persons showed symptoms of active Lyme borreliosis. A higher prevalence of antibodies against B.b. could be found in TBE endemic areas (7.7%) compared to TBE nonendemic areas (3.8%). There was a significant increase in positive antibodies against B.b. with age, exposure and number of tick bites remembered by test persons. The antibody prevalence to B.b. flagellin antigen is significantly higher in TBE endemic areas than in non-endemic comparative regions.

Adolescent↗

PubMed1993

Bilateral medial medullary infarction: magnetic resonance imaging and correlative histopathologic findings.

Bilateral medial medullary infarction is a rare event which clinically presents with flaccid tetraplegia sparing the face, bilateral disturbance of deep sensation, hypoglossal nerve palsy and respiratory failure. We here report a patient with such symptoms in whom magnetic resonance imaging enabled the detection of signal abnormalities in the lower brainstem as soon as 9 h after onset. Results of a control study 3 weeks later correlated well with the extent of infarction that was seen at autopsy. Early lesion detection in the lower medulla by magnetic resonance imaging and the unfavorable prognosis of patients with ischemic damage at that location may provide the rationale for aggressive therapeutic strategies in such a condition.

Cerebral Infarction↗

PubMed1993

Improved neurological recovery of cerebral infarctions after plasmapheretic reduction of lipids and fibrinogen.

BACKGROUND AND PURPOSE: High fibrinogen levels have been assessed in cerebrovascular disease with a direct relation to both plasma and whole-blood viscosity, as well as cerebral blood flow. Heparin-induced extracorporeal low density lipoprotein precipitation (HELP) is a new method that safely and effectively reduces fibrinogen and plasma lipoproteins and improves blood flow properties. METHODS: We studied 26 patients with acute embolic stroke and 22 with multi-infarct dementia. Each received two treatments with HELP within 8 days. Each patient had measurement of the important blood constituents and evaluation of changes in clinical signs and symptoms related to their cerebrovascular disease. RESULTS: Each HELP treatment safely produced an immediate and significant reduction in rheological measures, including fibrinogen (P < .001), whole-blood viscosity at high and low shear rates, plasma viscosity, and red cell transit time (P < .01 each). Total cholesterol, low density lipoprotein (P < .0001 each), lipoprotein(a) (P < .003), and triglycerides (P < .0001) were also reduced. The treated group in both the acute stroke group and the multi-infarct group showed improvement relative to the untreated control subjects in Mathew scale, Mini-Mental State Examination, and activities of daily living test scores. These uniform improvements persisted at least 3 days past the second HELP treatment. CONCLUSIONS: These results support the hypothesis that the improved hemorheologic property of blood is an important factor in clinical recovery as well as basic neurological function.

Activities of Daily Living↗

PubMed1993

Brain magnetic resonance imaging in coronary artery bypass grafts: a pre- and postoperative assessment.

We undertook a study to determine (1) the frequency and prognostic significance of preexisting MRI brain abnormalities in patients undergoing coronary artery bypass grafts (CABG) and (2) whether MRI can detect surgery-related brain damage in 31 neurologically asymptomatic CABG patients (mean age, 61.0 +/- 6.6 years). MRIs were performed within 7 days before and 8 to 17 days after surgery. When we compared the preoperative images with those of 31 age- and risk factor-matched neurologically asymptomatic controls free of cardiac disease (mean age, 60.3 +/- 6.1 years), higher rates of thromboembolic infarcts (16% versus 0%), lacunes (58.1% versus 32.3%), and brainstem lesions (22.6% versus 3.8%) were noted. Subjective rating demonstrated significantly larger ventricles in patients than in controls (p = 0.002). CABG candidates also had significantly increased ventricular-to-intracranial cavity ratios (VICR) as determined by semiquantitative volumetric measurements (6.9 +/- 2.5% versus 4.9 +/- 1.6%; p = 0.0004). Eleven patients had postsurgical complications, with eight having symptoms consistent with diffuse encephalopathy. The only MRI finding that separated encephalopathic from complication-free patients was ventricular size (VICR 9.0 +/- 2.5% versus 4.9 +/- 1.6%; p = 0.006). This difference remained statistically significant after adjustment for the effects of age (p = 0.04). Postoperative MRI consistently failed to demonstrate surgery-related brain damage responsible for the encephalopathy.

Aged↗

PubMed1993

Assessment of MRI criteria for a diagnosis of MS.

To test the reliability of four previously proposed MRI criteria for the diagnosis of MS, we reviewed 1,500 consecutive brain scans for the presence, number, size, and location of areas of increased signal (AIS) on proton-density and T2-weighted images, unaware of the patients' clinical presentations and ages. This series included 134 subjects with a clinical diagnosis of MS. Relying exclusively on the presence of at least three or four AIS for a positive diagnosis of MS resulted in high sensitivity (90% for three AIS and 87% for four) but inadequate specificity (71% for three AIS and 74% for four) and positive predictive value (23% for three AIS and 25% for four). If one of these lesions was required to border the lateral ventricles, specificity was 92% and positive predictive value was 50% at a sensitivity of 87%. Using the Fazekas criteria (at least three AIS and two of the following features: abutting body of lateral ventricles, infratentorial lesion location, and size > 5 mm) led to a further highly significant improvement of specificity (96%; p = 0.0000) and increase of the positive predictive value (65%) at the expense of a less significant decrease in sensitivity (81%; p < 0.01).

Adolescent↗

PubMed1993

Pathologic correlates of incidental MRI white matter signal hyperintensities.

We related the histopathologic changes associated with incidental white matter signal hyperintensities on MRIs from 11 elderly patients (age range, 52 to 82 years) to a descriptive classification for such abnormalities. Punctate, early confluent, and confluent white matter hyperintensities corresponded to increasing severity of ischemic tissue damage, ranging from mild perivascular alterations to large areas with variable loss of fibers, multiple small cavitations, and marked arteriolosclerosis. Microcystic infarcts and patchy rarefaction of myelin were also characteristic for irregular periventricular high signal intensity. Hyperintense periventricular caps and a smooth halo, however, were of nonischemic origin and constituted areas of demyelination associated with subependymal gliosis and discontinuity of the ependymal lining. Based on these findings, our classification appears to reflect both the different etiologies and severities of incidental MRI signal abnormalities, if it is modified to treat irregular periventricular and confluent deep white matter hyperintensities together.

Aged↗

PubMed1993

[Heparin-induced extracorporeal LDL precipitation (HELP): a new therapeutic intervention in cerebrovascular diseases and peripheral arterial occlusive disease].

Coronary heart disease, stroke and peripheral arterial disease are the major causes for death and disability in industrialized countries. These diseases have a common cause: Their development is based on atherosclerotic changes of blood vessels, induced by risk factors such as elevated values of lipoproteins and fibrinogen. There is no doubt that the risk factors mentioned above are even related to a dramatically deterioration of the hemorheologic pattern, thus reducing perfusion. Due to this massage there are attempts to treat ischemia via hemorheological intervention. Although a number of different methods is available--hemodilution, defibrinogenation or oral medication--it was not possible to improve the hemorheologic pattern fast, safe, and efficient to date. A new treatment modality, utilizing the heparin-induced extracorporeal LDL precipitation (HELP), now offers the possibility to obtain therapeutical success not only in cases of severe hypercholesterolemia but even in the field of hemorheology: Using HELP a safe and rapid reduction of lipid fractions and fibrinogen has become feasible, thus providing an acute improvement of red cell aggregation and filterability of blood cells, whole blood and plasma viscosity and thereby of microcirculation. As it is known that cerebrovascular diseases are related to disturbances of the hemorheological situation, the HELP system is used at the Department of Neurology, Karl-Franzens University of Graz, for the treatment of acute stroke, cerebral multi-infarct disease but even in cases of peripheral arterial disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1993

[Heparin-induced extracorporeal LDL precipitation (HELP). A new therapeutic possibility in cerebral multi-infarct dementia].

High fibrinogen levels have been assessed in cerebrovascular disease with a direct relationship to blood rheology. Heparin-induced extracorporeal LDL precipitation (HELP) is a method that effectively reduces fibrinogen and lipoproteins at the same time, thus improving the hemorheologic pattern. We studied 45 patients with cerebral multiinfarct dementia. After computer-randomization 30 patients received a HELP treatment, while the remaining 15 patients served as controls. HELP produced an immediate and statistically significant reduction on parameters relevant to hemorheology, such as fibrinogen (P < 0.001), total cholesterol, low-density lipoprotein, triglycerides (P < 0.0001 each) and whole blood viscosity (at high and low shear rate) as well as plasma viscosity and red cell transit time (P < 0.01 each). The treated group showed improvement after HELP (P < 0.05 for each test) on the Mathew Neurological Scale, Mini Mental State Examination and Activities-of-Daily-Living Test and also relative to the untreated controls (P < 0.05 each). These results may be regarded as a basis for some reflections about new hemorheological interventions in cases of cerebral multiinfarct dementia.

Activities of Daily Living↗

PubMed1993

Reopening of internal carotid artery occlusions during heparin-induced LDL precipitation (H.E.L.P.) associated with improved haemorheology: report of 2 cases.

As has already been reported, there is a direct relationship between the severity of cerebrovascular insufficiency and elevated plasma fibrinogen levels, as well as whole blood and plasma viscosity, Red Cell Transit Time (RCTT) and cerebral blood flow. By applying heparin-induced extracorporeal LDL < cholesterol, triglycerides, fibrinogen > precipitation (H.E.L.P.), a rapid reduction of fibrinogen has become possible which has proved to be very beneficial for the treatment of acute stroke and multi-infarct disease. The present report demonstrates the impact of H.E.L.P. in connection with Doppler and Duplex sonography: In one patient a complete occlusion at the origin of the right internal carotid artery was revealed by Doppler and Duplex sonography. In a second patient, a complete occlusion of the left internal carotid artery was verified. By applying H.E.L.P. once a week (seven times in patient #1, twelve times in patient #2), a consistent lowering of fibrinogen, whole blood and plasma viscosity, red cell transit time, total cholesterol, low density lipoprotein, lipoprotein (a) and triglycerides was achieved. After H.E.L.P. application, Doppler/Duplex sonography showed complete reopening of the previously occluded vessel in patient #1 and patency of the vessel of patient #2.

Brain Ischemia↗

PubMed1993

Cerebrovascular risk factors in an elderly Austrian population: first year results of the Austrian Stroke Prevention Study (ASPS).

During the first year the Austrian Stroke Prevention Study enrolled 599 volunteers without clinical signs or symptoms of cerebrovascular disease aged 50 to 70 years. Study participants were randomly selected from the official register of the city of Graz. The rate of positive response was 26.9 percent. All subjects underwent an extensive risk factor screening with Duplex scanning of the carotid arteries obtained from a subset of 176 individuals. The prevalence of well-documented cerebrovascular risk factors was 40.6% for arterial hypertension, 35.4% for cardiac disease, 8.5% for diabetes mellitus und 3% for elevated haematocrit. The less well-documented cerebrovascular risk factors dyslipidemia, overweight, physical inactivity, hyperfibrinogenemia and smoking were noted in 75%, 33.7%, 27.2%, 14.9% and 12.2% of subjects, respectively. Multiple well-documented risk factors were noted in 23.7% of the examined volunteers. Multiple linear regression analysis revealed body mass index (p < 0.0001) and age (p < 0.0001) as independent predictors of the frequency of well-documented risk factors observed in any individual. Atherosclerotic carotid disease occurred in 61.9% of study participants investigated by Doppler sonography and was significantly associated with age (p < 0.00001), life-time tobacco consumption (p < 0.0001) and the concentration of apolipoprotein B (p < 0.05). This study demonstrates high prevalence rates of vascular risk factors in an elderly Austrian community. Implications for stroke prevention result from the conjunction of overweight and frequency of risk factors noted in any study participant, as well as from the relationship of carotid atherosclerosis to smoking and dyslipidemia.

Aged↗