PubMed Health⌕ Search

Biomedical subjects

M Kaps

Publications and source records attributed to M Kaps.

At least 19 recordsLinked to original sources
PubMed1999

Sonographic monitoring of midline shift in hemispheric infarctions.

BACKGROUND AND OBJECTIVE: Transcranial color-coded sonography (TS) allows a noninvasive, accurate evaluation of lateral displacement of the third ventricle. The authors studied the prognostic value of TS monitoring of the midline shift (MLS) in acute hemispheric stroke. METHOD: Sixteen patients with acute middle cerebral artery (MCA) occlusion were investigated. On admission, the median modified Scandinavian Stroke Scale (mSSS) score was 6.0 (range, 5 to 8). Five patients died from cerebral herniation (group 1), 10 survived (group 2), and 1 patient (Patient 16) survived after decompressive surgery. TS was performed on days 1 to 4 (10 +/- 3, 32 +/- 4, 57 +/- 5, and 82 +/- 5 hours after onset of symptoms). Distance from the TS probe to the center of the third ventricle was measured both from the symptomatic (A) and asymptomatic (B) sides. MLS was calculated using the formula MLS = (A - B)/2. RESULTS: Ten hours after stroke onset, MLS and mSSS scores were not significantly different between the two groups. At 32, 57, and 82 hours, MLS was higher in group 1 (32 hours, p = 0.001; 57 hours, p = 0.003; 82 hours, p = 0.023) whereas there was no difference in mSSS score after 32 hours. All patients with an MLS < 4 mm at 32 hours survived, whereas patients with an MLS > 4 mm died as a result of cerebral herniation, with the exception of the one patient who underwent decompressive hemicraniectomy. CONCLUSIONS: The study of MLS at 32 hours after stroke onset in patients with severe MCA infarctions may identify patients who are unlikely to survive. The value of MLS in determining the indication of decompressive craniectomy merits further study.

Adult↗
PubMed1999

Assessment of intracranial venous hemodynamics in normal individuals and patients with cerebral venous thrombosis.

BACKGROUND AND PURPOSE: Despite ongoing improvements in noninvasive imaging techniques, transcranial color-coded duplex sonography (TCCS) has so far been used only on a limited basis in patients with cerebral venous thrombosis. We evaluated the diagnostic value of both noncontrast and contrast-enhanced TCCS by comparing normal volunteers and patients with acute cerebral venous thrombosis. METHODS: In 75 healthy volunteers (aged 45.8+/-17.4 years), normal values for the deep cerebral veins (DCVs) and the posterior fossa sinuses were established by transtemporal insonation. Eight patients with cerebral venous thrombosis were assessed by TCCS, through which the hemodynamics of the DCVs were measured, and the patients were followed-up over a period of between 33 and 387 days after examination. MR angiography served as the "gold standard" technique for confirming the venous status in all 8 patients. RESULTS: No side differences in flow velocities were detected in the paired venous structures in normal volunteers. As indirect signs of (and diagnostic criteria for) cerebral venous thrombosis, pathologically increased flow velocities or significant side differences in the DCVs were registered in 5 of the 8 patients; the other patients showed nonsignificant increases in flow velocity which decreased over time. During follow-up, the status of the posterior fossa sinuses could be diagnosed correctly in seven patients after contrast enhancement when these results were compared with those of venous MR angiography. In 1 patient, a partial recanalization was mistakenly diagnosed as an occlusion. CONCLUSIONS: TCCS allows a reliable evaluation of the major DCVs and posterior fossa sinuses. The anterior and mid portions of the superior sagittal sinus and cortical veins cannot be assessed. Increased venous blood flow velocity can be used as an indirect criterion for indicating a cerebral venous thrombosis. Clinical recovery coincided with decreases in blood flow velocity in the series of patients investigated in this study.

Adult↗
PubMed1998

[Apoptosis and ischemic infarct].

Apoptosis and programmed cell death have attracted major scientific interest during the last few years. Apoptosis can be differentiated from necrosis by means of morphological, biochemical, molecular and pharmacological parameters. Several molecular pathways leading to apoptosis have been elucidated over the last few years. Apoptosis is not only important for physiological cell turnover, but also plays a role in many pathological processes. Recently, a number of laboratories have found evidence of apoptotic cell death in cerebral ischemia in animal models. Quantitatively, apoptosis seems to be important in the border zone of the infarction, the so-called penumbra. Since parts of the apoptotic cascade can be inhibited, pharmacological treatment seems feasible. The so-called caspase inhibitors are promising therapeutic agents for the treatment of acute stroke and may be administered with other neuroprotective medications in humans in the near future.

Animals↗
PubMed1998

Low frequency of clinically silent circulating emboli in patients with mitral valve prolapse or patent foramen ovale detected by bigated transcranial Doppler ultrasound.

Patent foramen ovale (PFO), but not uncomplicated mitral valve prolapse (MVP), is a possible source of cardiac embolism to the brain. There are only a few reports on the frequency of clinically silent circulating microemboli in these two conditions. We performed 1-hour recordings of one middle cerebral artery in 4 patients with MVP and 14 patients with PFO to detect circulating microemboli. For the identification of microembolic signals we used blinded off-line evaluation and bigated transcranial Doppler sonography (sampling from two different depths in the vessel). Microembolic signals were detected conventionally in 3 out of 14 patients with PFO (3, 8, and 14 microemboli/h), and in none out of the 4 patients with MVP. The absence of microembolic signals in patients with MVP and the low frequency of microemboli in patients with PFO reflect the different embolic potential of these two cardiac abnormalities.

Adult↗
PubMed1998

The influence of different gases on acoustic properties of a spherosome-based ultrasound contrast agent (BY963). A transcranial Dopplersonography study.

Ultrasound contrast agents improve the signal-to-noise ratio of reflected ultrasound, enhancing the diagnostic value of transcranial Doppler (TCD). In dog studies, we investigated the time course of TCD signal amplitude after application of a phospholipid-containing ultrasound contrast agent (BY963) filled with different gases. The median time of Doppler amplitude enhancement exceeding 5 dB was determined using isoflurane-, isopentane-, trichlortrifluoroethane-, air-, argon-, and perfluoropentane-filled BY963 (69, 72, 75, 78, 88, and 245 seconds respectively). The decrease of time-intensity curve and the duration of signal enhancement showed significant differences comparing the different gases (p = 0.04 and 0.03, respectively). The time course of in vitro stability of BY963 agitated with the different gases measured by absorbance of light (500 nm) showed a retarded decay for perfluoropentane, a rapid decrease for air, isopentane, trichlortrifluoroethane, and argon, and a very rapid decrease using isoflurane. The time course of the different gases depended on the physiochemical properties (lipophilicity and the solubility in water) of the gas encoated in the phospholipid shell. Perfluoropentane-filled BY963 showed the highest in vitro stability and the longest duration of TCD enhancement compared with the other gases used.

Acoustics↗
PubMed1998

Administration of modified spherosome suspension (BY963) leads to an increase of acoustic impedance in dog brain tissue.

Ultrasound contrast agents change the acoustic properties of brain tissue. This can be quantified with acoustic densitometry. In a dog model, the authors examined changes in acoustic impedance in the thalamic and parietal white-matter regions of the brain after intravenous injection of the spherosome containing an ultrasound contrast agent (BY963) filled with perfluoropentane gas. The authors examined six sedated mongrel dogs with a Hewlett-Packard Sonos 1500 device. BY963 filled with perfluoropentane (0.2 ml/kg body weight) was injected three times with a time interval between injections of 5 minutes. Time-dependent changes in mean acoustic impedance were calculated. The authors found a significant increase in peak acoustic impedance after fractional injection of 0.6 ml/kg body weight (3 x 0.2 ml/kg body weight) in the thalamus region up to 7.0 IU (p = 0.006). In the parietal white matter the increase in peak acoustic impedance was not significant (p = 0.06). Statistical comparison of the increase in peak acoustic impedance between placebo and BY963 injection in the thalamus region showed a significant difference after the first injection (p = 0.01) but showed no significance after the second and third injections. The authors concluded that thalamus and parietal white matter of the brain showed different accumulations of BY963.

Animals↗
PubMed1998

Consensus on microembolus detection by TCD. International Consensus Group on Microembolus Detection.

Transcranial Doppler ultrasound is capable of detecting microembolic material, both gaseous and solid, within the intracranial cerebral arteries. To avoid discrediting this promising and exciting new technique, experts in this field met in January 1997 in Frankfurt, Germany, to discuss the limitations and problems of embolus detection and to determine guidelines for its proper use in clinical practice, as well as in scientific investigations. In particular, the authors suggest that studies report the following parameters: (1) ultrasound device, (2) transducer type and size, (3) insonated artery, (4) insonation depth, (5) algorithms for signal intensity measurement, (6) scale settings, (7) detection threshold, (8) axial extension of sample volume, (9) fast Fourier transform (FFT) size (number of points used), (10) FFT length (time), (11) FFT overlap, (12) transmitted ultrasound frequency, (13) high-pass filter settings, and (14) recording time. There was agreement that no current system of automatic embolus detection has the required sensitivity and specificity for clinical use.

Humans↗
PubMed1998

Transcranial sonographic monitoring during thrombolytic therapy.

Two patients with acute occlusion of the middle cerebral artery (MCA) were treated with intravenous alteplase. Neurovascular monitoring, which was performed simultaneously via transcranial sonography, enabled precise documentation of MCA recanalization. This information was used to tailor the dosage and duration of alteplase treatment. Sonographic information concerning the arterial segments involved in the occlusive process, the actual hemodynamic status, and the collateral blood supply may help to identify those patients most likely to benefit from thrombolysis.

Arterial Occlusive Diseases↗
PubMed1997

Circulating microemboli in patients after aortic valve replacement with pulmonary autografts and mechanical valve prostheses.

BACKGROUND: The pulmonary autograft procedure (Ross) is now considered the gold standard for aortic valve replacement. One of its advantages is the freedom from macroemboli without anticoagulation. Whether this holds true for circulating microemboli, detectable as high-intensity transient Doppler signals (HITS), has not yet been verified. METHODS AND RESULTS: We investigated 8 patients (2 women, 6 men; mean age, 50.6+/-17.9 years) after the Ross procedure, 9 patients (3 women, 6 men; mean age, 67.2+/-9.46 years) after aortic valve replacement with a mechanical valve prosthesis, and 12 young healthy volunteers by unilateral 1-hour recording of the middle cerebral artery on digital audio tape. Patients with extracranial carotid artery disease were excluded by color duplex sonography. During the off-line evaluation, the investigator was not aware of any patient details. No HITS were detected in healthy volunteers (95% confidence interval [CI], 0% to 26.46%). After the Ross procedure, 1 patient had 11 and 1 patient had 1 HITS (95% CI, 3.19% to 65.09%). All recipients of mechanical valves had HITS, ranging from 2 to 84 per hour (95% CI, 66.7% to 100%). Significantly more recipients of mechanical valves exhibited HITS than recipients of pulmonary autografts (P<.05) or control subjects (P<.05). CONCLUSIONS: In contrast to mechanical valves, pulmonary autografts are seldom the source of microemboli, confirming the pulmonary autograft as the superior substitute for aortic valve replacement.

Adult↗
PubMed1997

[Microembolizatoins during heart surgery under extracorporeal circulation].

OBJECTIVE: By means of transcranial Doppler sonography (TCD), microembolic signals (MES) representing embolic events can be registered during cardiac surgery and extracorporeal circulation in a considerable number of patients. We conducted the present study to determine the neuro-psychiatric consequences of MES. METHODS: 25 patients scheduled for elective aorto-coronary bypass grafting (ACBG; n = 10) or aortic valve replacement (AVR; n = 15) were studied pre- and postoperatively with neuropsychiatric testing. Results were related to the number of MES noted intraoperatively. In addition, we registered the intraoperative changes of middle cerebral artery blood flow velocity, mean arterial pressure, arterial blood gases, haemoglobin and haematocrit. Statistics included t-test, two-way analysis of variance, Mann-Whitney-U-test and Spearman correlation with p < 0.05 considered significant. RESULTS: Regarding demographic data and intraoperative parameters, both study groups (ACBG vs. AVR) were comparable except for age. AVR patients showed significantly more MES than those undergoing ACBG (p < 0.012) which was most pronounced in the late state of surgery (aortic clamp off; p < 0.0003). However, MES counts did not correlate with neuropsychiatric test results. CONCLUSIONS: In contrast to recent reports, we were unable to show a deterioration of postoperative neuropsychiatric state related to high intraoperative MES count in our patients. Future TCD studies should focus on the differentiation between gaseous emboli and particles even in the clinical setting, as the latter may well play a major role for the development of cerebral dysfunction following cardiac surgery and extracorporeal circulation.

Analysis of Variance↗
PubMed1997

[CADASIL: 2 case reports of hereditary multi-infarct dementia].

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a hereditary stroke disease linked to chromosome 19 q 12. We report on two families affected by this disease, which is characterised by recurrent subcortical ischaemic strokes, progressive pseudobulbar palsy, and presenile dementia. Neuroimaging revealed multiple deep infarcts and diffuse leukoencephalopathy. Diagnosis of CADASIL based on the typical clinical feature without vascular risk factors, the neuroradiological signs of extensive leukoencephalopathy, and the autosomal dominant pattern of inheritance. CADASIL might be an underestimated cause of familial stroke and should be considered in the differential diagnosis of hereditary stroke.

Brain↗
PubMed1997

Comparison of ultrasonic and histopathological features of carotid artery stenosis.

Besides the degree of carotid artery stenosis, the composition of the plaque may help to predict the thromboembolic risk. Low echogenicity on ultrasound and hemorrhage into the atheroma demonstrated histopathologically have been shown to be associated with a higher risk of embolism. Twenty-nine consecutive patients with carotid artery stenosis and scheduled for carotid endarterectomy were investigated preoperatively by B-mode ultrasound. Post-operatively the endarterectomy specimens were examined histopathologically. Neither atheroma with hemorrhage nor atheroma without hemorrhage were significantly associated with echolucent ultrasound presentation. Out of the 10 lesions echolucent and homogeneous on ultrasound, six corresponded to atheroma with hemorrhage, two corresponded to atheroma with hemorrhage plus thrombus, two corresponded to fibrous plaque plus thrombus, and one corresponded to pure thrombus. Out of the 4 lesions heterogeneous and predominantly echolucent, one corresponded to atheroma without hemorrhage plus thrombus, one corresponded to atheroma with hemorrhage, one corresponded to atheroma with hemorrhage plus thrombus, one corresponded to atheroma with hemorrhage plus fibrous plaque. Seven out of the 18 atheromas with hemorrhage did not present as purely or predominantly echolucent lesions, six of them were even homogeneously echogenic. Plaque surface could not reliably be predicted by ultrasound. In our study, there was no significant correlation between ultrasound and histology of the lesion.

Aged↗
PubMed1997

Transcranial Doppler echo contrast studies using different colour processing modes.

OBJECTIVES: To study the effects of different colour imaging modes on the contrast-medium-enhanced image of the intracranial cerebral arteries. METHODS: Twelve healthy volunteers were studied transcranially after administration of 10 ml BY963 successively with Power Doppler (p-TCCS) and with colour Doppler frequency imaging mode (f-TCCS) in a randomized order. RESULTS: The latency time (mean+/-SD) from the injection until the signal enhancement in the middle cerebral artery was 17.1+/-5.8 s for p-TCCS and 17.8+/-4 s for f-TCCS, and the duration of the optimal diagnostically useful signal enhancement was 44.2+/-8.2 s and 40.2+/-12.6 s respectively. CONCLUSIONS: Based on the measured parameters, both imaging modes were of equal value. Theoretical differences in sensitivity of the two methods play no particular role facing the immense signal enhancement after echo contrast application.

Adult↗
PubMed1997

Acute exacerbation of multiple sclerosis increases plasma levels of S-100 protein.

OBJECTIVES: To determine whether an increase in plasma concentration of S-100 protein can serve as a marker for acute exacerbation of multiple sclerosis. MATERIAL AND METHODS: The plasma level of S-100 protein was investigated in 28 patients suffering from multiple sclerosis. Of these, 17 patients were admitted for acute exacerbation and 11 patients had a stable disease with no clinical signs for acute exacerbation. S-100 protein concentrations in plasma were determined with an immunofluorometric sandwich assay. RESULTS: Plasma concentrations were significantly elevated in patients who were examined within 7 days after the onset of acute exacerbation (n = 6). S-100 levels of patients 8 to 28 days after the onset of acute exacerbation (n = 11) did not differ from healthy controls (n = 120). Eleven patients with multiple sclerosis without acute exacerbation had moderately elevated plasma levels. CONCLUSION: The plasma concentration of S-100 protein is a sensitive although unspecific indicator of neuronal damage and may be of use as a marker of disease activity in multiple sclerosis.

Acute Disease↗
PubMed1997

Basilar branch disease presenting with progressive pure motor stroke.

OBJECTIVES: Isolated infarcts of the pons cause well definable neurological syndromes with distinct pathomechanism, clinical course and prognosis. PATIENTS AND RESULTS: We report 8 cases suffering from a pure motor hemiparesis that was severely progressive within the 1st 3 days and unresponsive to aspirin. A relatively good recovery was observed in all patients, however, stroke recurrence occurred in 2 cases within 3 months and resulted in pseudobulbar paralysis and tetraparesis. MRI displayed unilateral (n=6) and bilateral (n=2) ventromedial pontine infarctions (VPI). Angiographic evaluation (n=4) or color Duplex examination (n=4) revealed atherosclerotic lesions but no basilar artery occlusion. CONCLUSION: Although VPI due to basilar branch disease may clinically mimic a classical lacunar syndrome, it is related to a particular pathogenetic mechanism different from microangiopathy or embolism. In contrast to the MRI feature of lacunes, VPI typically extend to the basal surface of the pons. The progressive pattern, ending up in a relative uniform clinical picture, is probably caused by propagating thrombosis.

Aged↗
PubMed1997

Focal expression of intercellular adhesion molecule-1 in the human carotid bifurcation.

BACKGROUND AND PURPOSE: In the carotid bifurcation, atherosclerotic plaques usually develop in the outer wall of the internal carotid artery. The aim of this study was to analyze the expression of the cell adhesion molecules intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin in the carotid bifurcation. These molecules play a role in inflammatory cell recruitment and atherosclerosis. METHODS: We examined the expression of ICAM-1, VCAM-1, and E-selectin in 22 human carotid bifurcation specimens by means of immunohistochemistry. Double immunostaining was performed with antibodies against CD-3, CD-31, CD-68, and alpha-smooth muscle actin combined with each of the cell adhesion molecule antibodies. In situ hybridization for ICAM-1 was performed in selected specimens. RESULTS: A profound focal expression of ICAM-1 in the outer wall of the internal carotid artery could be demonstrated (86% of all specimens). This focal expression could be shown in histologically normal appearing bifurcations of young adults. ICAM-1 was expressed by subsets of macrophages and smooth muscle cells and by endothelial cells. VCAM-1 and E-selectin showed no focal expression and were not found in normal carotids. In advanced plaques all three adhesion molecules-ICAM-1, VCAM-1, and E-selectin-were expressed. CONCLUSIONS: We were able to demonstrate a focal expression of ICAM-1 in the outer lateral wall of the internal carotid artery, which is a high-risk region for the development of atherosclerotic lesions.

Adult↗
PubMed1997

S-100 protein and neuron-specific enolase concentrations in blood as indicators of infarction volume and prognosis in acute ischemic stroke.

BACKGROUND AND PURPOSE: Better techniques are needed to monitor infarction volume and predict neurological outcome after ischemic brain infarction. We evaluated the usefulness of serial measurements of S-100 protein versus neuron-specific enolase (NSE) in blood samples from patients with acute stroke. METHODS: Using nonisotopic sandwich immunoassays, we measured plasma concentrations of S-100 protein and NSE on admission and on days 3, 4, 7, and 14 after infarction in 44 patients (age range, 22 to 86 years; mean age, 65.1 years; 12 female, 32 male). Infarct volume was measured by volumetric CT on day 4 after ictus, and clinical outcome was assessed at discharge from hospital with the Activities of Daily Living Scale and 6 months after infarction with the Glasgow Outcome Scale. RESULTS: Peak blood levels of S-100 protein were found on day 2.5 +/- 1.3, and peak levels of NSE were found on day 1.9 +/- 0.8 after infarction. Peak plasma levels of S-100 protein correlated well with infarct volume (r = .75, P < .001) and with clinical outcome assessed with the Glasgow Outcome Scale (r = .51, P < .001). Serum levels of NSE correlated with infarct volume (r = .37, P < .05) but not with clinical outcome (r = .18, P > .05). CONCLUSIONS: The results of our study indicate that measuring blood concentrations of S-100 protein periodically in the first 10 days after cerebral infarction helps to predict infarct volume and the long-term neurological outcome more accurately than periodic measurements of blood concentrations of NSE.

Activities of Daily Living↗