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H Lechner

Publications and source records attributed to H Lechner.

At least 55 records · Page 3Linked to original sources
PubMed1992

Magnetic resonance imaging signal hyperintensities in the deep and subcortical white matter. A comparative study between stroke patients and normal volunteers.

Mixed population studies suggest a relationship between deep and subcortical white matter hyperintensities on magnetic resonance imaging and cerebrovascular disease. To further clarify this issue we compared the prevalence and extent of such signal abnormalities between a group of 133 consecutive stroke patients (mean age, 54.7 +/- 16.7 years) and 101 normal volunteers (mean age, 54.7 +/- 13.1 years). Diabetes and cardiac disease were significantly more common in patients than in normal subjects. Prevalence rates of clinically silent lesions were 44% and 47.5%, respectively. Beginning confluent and confluent foci were seen in 19.5% of patients, but in only 7.5% of normal subjects. Significant univariate correlations were found for the presence and extent of lesions with age, diabetes, cardiac disease, severity of extracranial carotid arteriosclerosis, and arterial hypertension, but not with the diagnosis of stroke or the type of brain infarction. Multivariate regression analysis established age and diabetes mellitus as the only independent predictors of white matter damage. We conclude that more extensive white matter abnormalities in stroke patients stem from their higher rate of cerebrovascular risk factors but are unrelated to the occurrence of ischemic attacks per se.

Adolescent↗
PubMed1992

The prevalence of cerebral damage varies with migraine type: a MRI study.

Studies on the prevalence of MRI signal abnormalities in the brains of migraineurs have yielded controversial results. In order to provide further data on this issue we reviewed the MRI scans of 38 migraine patients without current neurologic symptoms (mean age 35.8 +/- 11.9 years). In addition, we compared the findings in those 24 migraineurs under 50 years without major cerebrovascular risk factors (mean age 30.1 +/- 9.0 years) to that in 14 headache and risk factor free volunteers (mean age 37.8 +/- 5.3 years). Overall, focal areas of hyperintense signal were seen in 15 (39%) patients. They were present on both proton density and T2-weighted spin-echo sequences. Lesion prevalence varied according to the type of headache (18% in migraine without aura, 53% in migraine with typical aura, 38% in basilar migraine). The subset of migraine patients under 50 years exhibited MRI signal abnormalities more than twice as often as controls (33% vs. 14%). Punctate white matter hyperintensities were the predominant finding and were seen in 10 of 15 individuals with MRI lesions. More striking signal abnormalities consisted of symmetrical areas of hyperintensity lateral to the posterior horns in two 24 year old patients and of extensive white matter damage with lacunar infarcts in a 59 year old woman. Our findings confirm a higher prevalence of MRI lesions in a mixed group of migraineurs than in headache free individuals. Signal abnormalities are most often non-specific, however their occurrence relates to the type of migraine.

Adolescent↗
PubMed1992

[A comparison of EEG mapping with and without visual artefact control in focal cerebral lesions].

In 163 patients with focal cerebral lesions, 43 of them with completed stroke, 43 patients with TIA, 33 patients with ICH and 29 patients with malignant and 15 patients with benign tumors EEG mapping and CT was performed. The results of EEG mapping obtained using automated artifact detection were compared to those achieved by means of visual control of raw EEG. Furthermore the impact of long (850 +/- 250s) or short (32s) analysis time was studied. Eliminating artifacts by means of visual control of raw EEG significantly more positive results were obtained than using automated artifact detection. That was found in patients with as well as in patients without lesions in CT. In relation to etiology a significant difference was found only in cerebrovascular diseases but not in the other patients-groups. Corresponding results were found in 75% of the patients. The visual control provided additional lateralization especially in patients with CS (37%) and TIA (26%). A longer duration of analysed EEG epochs did not increase the number of focal changes in EEG mapping.

Adult↗
PubMed1992

[The value of EEG mapping in intracerebral hematomas].

33 patients with intracerebral hemorrhage were studied and the findings of EEG mapping, routine EEG and CT were compared. It could be shown, that the EEG mapping revealed in 6 patients additional focal changes corresponding with the clinical signs compared to conventional EEG. Identical results of EEG mapping and CT were found in 27 patients. In 5 patients the focal changes were localised contralateral to the hyperdense lesion in CT, and in 1 patient the EEG mapping failed to show any lateralisation. A negative intercorrelation between the size of the hematoma and the frequency, which revealed the focal signs in EEG mapping, could be shown.

Adult↗
PubMed1992

[Hemorheology and H.E.L.P. in multi-infarct dementia].

Some papers report that the effect of heparin-mediated extracorporeal LDL less than cholesterol, LP(a), triglycerides, fibrinogen greater than precipitation (H.E.L.P.) in cardiovascular disease may results from an influence on the above-mentioned parameters. Hence, this method has been applied in multi-infarct dementia (MID), where fibrinogen, whole blood and plasma viscosity and red cell transit time (RCTT) are increased. The selection of patients was based on DMS-3, on NINCDS/ADRDA criteria and on the Hachinski Ischemic Stroke Scale. All the patients (n = 14) were examined magnet resonance imaging. Fibrinogen, cholesterol, LDL-cholesterol, HDL-cholesterol, LP(a), RCTT and plasma and whole blood viscosity were determined prior to, and after each two H.E.L.P. procedures. Fibrinogen was lowered (in a comparison of the data prior to the first and following the second plasmapheresis) from 526.4 +/- 114 to 314.1 +/- 80.1 mg/dl (p less than 0.01), cholesterol from 210.8 +/- 76.8 to 131.3 +/- 38.2 mg/dl (p less than 0.01), LDL from 125 +/- 53 mg/dl to 63.6 +/- 25.7 mg/dl (p less than 0.01), LP(a) from 26.2 +/- 13.2 to 12.0 +/- 9.5 mg/dl (p less than 0.01), HDL from 31.7 +/- 6.3 to 29.7 +/- 5.6 mg/dl (no significance), RCTT from 14.4 +/- 2.8 to 10.9 +/- 0.9 (p less than 0.01), whole blood viscosity (low shear rate) from 11.64 +/- 1.7 to 8.74 +/- 1.4 mPa/sec (p less than 0.01) and (high shear rate) from 5.38 +/- 0.58 to 4.28 +/- 0.83 mPa/sec (p less than 0.01). Plasma viscosity decreased from 1.51 +/- 0.12 mPa/sec to 1.25 +/- 0.1 mPa/sec (p less than 0.05). In cases of MID the implementation of H.E.L.P. therefore enabled an alteration of the hemorheological profile which has so far not been achieved by any hemorheologically active substance to a comparable degree and in comparable time.

Aged↗
PubMed1991

MRI in tuberculous meningoencephalitis: report of four cases and review of the neuroimaging literature.

The contribution of MRI is reported in four adult patients with tuberculous meningoencephalitis (TbM) and with autopsy correlation in one. Contrast-enhanced T1-weighted MRI revealed the characteristic basal meningeal inflammation of TbM and its focal spreading into adjacent brain. Mixed and T2-weighted pulse sequences delineated a plethora of parenchymal abnormalities. Their relation to TbM was established by a close matching of the patient's neurological findings, contrast enhancement or a change in lesion size. The latter accurately reflected the clinical course in all patients. It remained difficult, however, to distinguish between ischaemic and inflammatory changes, which in some locations were intermixed even histologically. From our experience and that of other groups, MRI provides more diagnostic information in TbM than CT. Moreover, MRI promises to be a useful tool for monitoring treatment response.

Adolescent↗
PubMed1991

Does cerebrovascular insufficiency contribute to Alzheimer's disease?

The differential diagnosis of vascular dementia (VD) and Alzheimer's disease (AD) based on clinical assessment and neuropsychologic testing is still associated with a relatively high degree of inaccuracy compared to neuropathology standards. This is especially true in the identification of mixed forms between AD and VD. The present study investigates the potential of neuroimaging methods in providing additional information in dealing with this problem. Magnetic resonance imaging (MRI) of the brain identified a relatively high percentage (39%) of patients with AD (with ischemia scores of 4 and less) with basal ganglia hyperintensities and also demonstrated basal ganglia lacunae and infarcts in some of these patients. These findings indicate that in these cases a vascular component, consistent with the mixed form of dementia, may contribute to the etiology of the disease. These findings also underscore the clinical usefulness of MRI in the further differentiation of the dementias.

Aged↗
PubMed1991

Brain magnetic resonance imaging and neuropsychologic evaluation of patients with idiopathic dilated cardiomyopathy.

We compared brain magnetic resonance imaging and neuropsychologic performance in 20 neurologically asymptomatic patients suffering from idiopathic dilated cardiomyopathy (mean age 41 [range 18-49] years) and 20 age-matched controls (mean age 38 [range 28-49] years). Patients exhibited a significantly higher rate of cerebral infarcts (20% versus 0%, p less than 0.05) and cortical (50% versus 5%, p less than 0.01) and ventricular (55% versus 15%, p less than 0.02) atrophy than controls. Accordingly, semiquantitative volumetric measurements yielded a significantly increased ventricular-to-intracranial cavity ratio in the patients (6.2 +/- 2.9% versus 4.1 +/- 1.3%, p less than 0.01). This ratio and the cortical atrophy ratings correlated positively with disease duration (r = 0.63 and 0.54, p less than 0.05). Cognitive test performance was significantly worse in patients than in controls and was most impaired in those patients with morphologic cerebral abnormalities.

Adult↗
PubMed1991

Multi-infarct dementia.

Clinicians have long recognized that dementia is a common symptom among the elderly. The diagnosis of dementia requires us to document the individual's current level of mental functioning and some higher level of intellectual function in the past. The recognition of early or mild cases is specially difficult. Out of epidemiological studies it has been shown that the incidence for multi-infarct dementia (MID) increases with age and is slightly higher among men.

Dementia, Multi-Infarct↗
PubMed1990

Long-term experience of a trial in multi-infarct dementia.

A report is given on the natural history of multi-infarct dementia (MID) in 94 patients over a period of 5 years and describes neuroimaging criteria that may be used in order to more reliably separate vascular (VD) from primary degenerative types of dementia (DTD). The annual mortality rate of MID patients was 13%. Age and nocturnal confusion were found to be the most efficient predictors for fatal prognosis. Psychosocial adjustment, in contrast, indicated better outcome. In respect to differential diagnosis MRI revealed infarcts, basal ganglia lacunes and confluent white matter lesions as the most effective discriminators between VD and DTD. The typical patchy pattern found in almost half of the patients with VD, and significant differences in 5-7 Hz range as shown by EEG mapping can also be used for increasing the accuracy of the clinical diagnosis.

Aging↗
PubMed1989

Topographic EEG brain mapping in cerebrovascular disease and dementia.

1. The results of brain mapping had been studied in 27 patients with different stages of ischemic stroke and in 20 patients with dementia, ten of SDAT and ten of vascular type. 2. It has been shown that in ischemic stroke the mapping correlates better with the severity of clinical symptoms than with anatomical and hemodynamic imaging methods. For the differentiation of SDAT and VD the mapping showed a clear cut possibility of differentiation.

Aged↗
PubMed1988

[EEG changes in early summer meningoencephalitis].

The nature and extent of EEG changes in 114 patients with tick-borne encephalitis were reported. The diagnosis was confirmed by the clinical picture, as well as the pathological increase in cells in the liquor and serologically by positive Ig-M titres. EEG findings were compared in patients with or without involvement of the brain. The EEG revealed pathological results in 76 patients, whereby the dominant pathological change was frequently occurring synchronous bursts of generalized slow bilateral waves. 12 patients with involvement of the brain all showed pathological EEG changes, a much higher rate than in the remaining patients and these findings were also more marked. However, 64 patients with clinical evidence of meningitic involvement showed pathological EEG changes, too.

Adolescent↗
PubMed1988

Penumbra around chronic cerebral infarction?

In a series of 13 patients with cerebrovascular occlusive disease regional cerebral blood flow (rCBF) measurements (two-dimensional intravenous 133Xe clearance method) and quantitative EEG analysis (sensorimotor rhythms) as well as electronic measurement of handforce were performed before and during intravenous infusion of 1 microgram kg/min of one of the lipophilic dihydropyridine calcium channel blocker nimodipine (Nimotop). The aim of the study was to test the hypothesis of the existence of hypoperfusion (ischaemic penumbra) in the surroundings of chronic cerebral infarcts. All 3 parameters improved in one patient. Sensorimotor rhythms increased in 5 patients, rCBF in 3. EEG and rCBF improved in 2 patients. In 3 instances, a redistribution of rCBF in favour of the peri-infarct zone was noted (significant increase of rCBF from 35 +/- 2 SEM to 53 +/- 4 ml/100 g/min (p less than 0.01), whereas rCBF fell from 61 +/- 5 to 46 +/- 2 ml/100 g/min on a collimator remote from the infarct but in the infarcted hemisphere. The parallel improvement of rCBF and EEG in brain regions surrounding chronic infarcts in 3 patients was interpreted as functional improvement as a consequence of nimodipine-induced normalization of peri-infarct hypoperfusion, i.e. reversal of flow-dependent neuronal silence and/or dysfunction.

Adult↗
PubMed1988

White matter signal abnormalities in normal individuals: correlation with carotid ultrasonography, cerebral blood flow measurements, and cerebrovascular risk factors.

We studied 52 asymptomatic subjects using magnetic resonance imaging, and we compared age-matched groups (51-70 years old) with and without white matter lesions with respect to carotid ultrasonography, cerebral blood flow (xenon-133 injection), and cerebrovascular risk factors. In the group with white matter signal abnormalities, we noted a higher frequency of extracranial carotid artery disease, a lower mean gray matter blood flow (F1), and a significant reduction (p less than 0.05) in blood flow of the slow-flowing (F2) compartment. Hypertension, diabetes mellitus, and cardiac diseases (p less than 0.002) were found more often in this group. Our results indicate that a higher incidence of changes known to be associated with an increased risk for stroke exists in the presence of white matter lesions in normal elderly individuals.

Adult↗
PubMed1988

Nuclear magnetic resonance image white matter lesions and risk factors for stroke in normal individuals.

The incidence, average number, and localization of lesions of the white matter detected by the T2-weighted nuclear magnetic resonance images among volunteers without cerebrovascular symptoms have been correlated with the number of risk factors for stroke. Accepted risk factors were arterial hypertension, diabetes mellitus, smoking, hypercholesterolemia, and cardiac disease. The 42 subjects examined were divided into Group A (0-1 risk factor, mean age 59.36 +/- 5.73 years), Group B (2 risk factors, mean age 61.54 +/- 8.33 years), and Group C (greater than or equal to 3 risk factors, mean age 62.57 +/- 9.83 years). Multiple risk factors among the age-matched groups was accompanied by a highly significant increase (p less than 0.001, Group A versus Group B; p less than 0.01, Group A versus Group C) of the incidence of white matter lesions. The average number of white matter lesions was increased (p less than 0.001) when Group A was compared with Groups B and C. Ninety-two percent of the white matter lesions were localized in watershed zones. Only 11 of the 155 abnormalities of the white matter detected by nuclear magnetic resonance imaging could be detected by computed tomography. White matter lesions in T2-weighted images appear to be an early stage of cerebrovascular disease.

Brain↗