Helmut Lechner

The Mattis Dementia Rating Scale Normative data from 1,001 healthy volunteers

Article abstract 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.

Magnetic Resonance Imaging and Spectroscopy Findings After Focal Status Epilepticus

Summary: The etiology of cerebral abnormalities after focal status epilepticus (SE) is unknown. Possible causes include hypoxia and the excessive release of excitatory amino acids. Magnetic resonance imaging (MRI) of a 21–year‐old patient with “cryptogenic” continuous motor seizures showed swelling and signal hyperintensity of the contralateral panetotemporal cortex, the thalamus, and the ipsilateral cerebellum on T2‐weighted images. These regions are connected by glutamatergic pathways. Proton magnetic resonance spectroscopy (MRS) of the cortical lesion yielded a signal peak at the resonance frequency of 2.29 ppm, suggesting a focal increase of glutamate or its degradation product glutamine. At 3–month follow‐up, structural alterations had disappeared, but the N‐acetylaspartatelcholine ratio was still reduced in the previously abnormal area. These findings are the first to demonstrate the contribution of MRS to pathophysiologic studies of focal SE in humans and, in combination with the pattern of imaging abnormalities, support a major role of glutamate for seizure‐related brain damage.

Assessment of Cerebrovascular Risk Profiles in Healthy Persons: Definition of Research Goals and the Austrian Stroke Prevention Study (ASPS)

The advent of new laboratory methods and noninvasive imaging modalities has extended the diagnostic possibilities in normal individuals. This article elaborates the new options for the assessment of stroke risk offered by these techniques. In this context we present the Austrian Stroke Prevention Study, which is the first prospective long-term investigation of normals that includes Doppler sonography, magnetic resonance imaging and single photon emission computed tomography. The design, utility and limitations of this study are discussed.

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

SummaryThe 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 patients 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.

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.

EEG, CT and neurosonographic findings in patients with postischemic seizures

Seventy-two patients with postischemic seizures were evaluated with electroencephalography (EEG), computerized tomography (CT) and neurosonography. There were 24% early-onset and 76% late-onset initial seizures. Early-onset seizure was more likely to be simple partial (53%), whereas late-onset seizure was more likely to be primarily generalized (56%). 76% early-onset and 80% late-onset seizures were single. Status epilepticus was more frequent in early-onset that late-onset seizures (p = 0.023). The possibility of recurrence was greater in late-onset than early-onset seizures (p < 0.001). 88% patients had EEG abnormalities, and the most common finding was focal slowing. 75% patients had cerebral infarctions on CT scan, and the majority of them involved cortex. 89% postischemic seizures had carotid lesions which mostly were carotid plaques < 50%. We failed to find these data to be useful in predicting the time of onset of initial seizures after acute ischemic stroke and recurrence.

Prevalence of White Matter and Periventricular Magnetic Resonance Hyperintensities in Asymptomatic Volunteers

Magnetic resonance imaging (MRI) of 101 asymptomatic volunteers ranging in age from 31 to 84 years (mean, 55 yr) was performed to determine the prevalence and extent of unexpected white matter (WMH) and periventricular hyperintensities (PVH) in the “normal” population. Twenty‐nine had followup studies after 11 to 28 months (mean, 15 mo). Predominantly punctate WMHs were present in 48%. Increasing prevalence was associated with aging and was significantly higher in individuals with major cerebrovascular risk factors (P < 0.05). PVH was noted in 45% and consisted mainly of caps and lines. Volunteers with more extensive WMHs (6%) or PVH (4%) had risk factors or were above 60 years of age. The repeat scans exhibited no significant changes.

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.

Increased Cerebral Perfusion following Reduction of Fibrinogen and Lipid Fractions

High levels of plasma fibrinogen in cerebrovascular disease cause deterioration in the hemorheologic pattern, microcirculation and cerebral perfusion. We compared the value of heparin-induced extracorporeal LDL precipitation (HELP) which is a method that safely and effectively reduces plasma fibrinogen and lipoproteins and so improves the hemorheologic pattern and blood flow properties. Regional cerebral blood flow (rCBF) was measured by the 133Xe SPECT clearance method. After first measuring rCBF, 15 patients suffering from cerebral multi-infarct disease underwent a single HELP application. One hour later a second measurement of rCBF was performed. Fifteen other patients with similar clinical symptoms and findings on CAT scans who were not subjected to HELP served as controls. The HELP treatment produced an immediate and statistically significant reduction of all parameters relevant to hemorheology, such as plasma fibrinogen, whole blood viscosity at both high and low shear rate, plasma viscosity, and red cell transit time. Total cholesterol, low density lipoprotein, and triglycerides were also reduced. The treated group showed 9.7-19.9% increased rCBF in different vascular regions examined relative to the untreated controls. The results obtained indicate that HELP has a potent effect in a situation demanding rapid and significant improvement of the blood flow.

Does cerebrovascular insufficiency contribute to Alzheimer's disease?

The differential diagnosis of vascular dementia (VD) and Alzheimers 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.