Ralph Winter

Role of CT Angiography in Patient Selection for Thrombolytic Therapy in Acute Hemispheric Stroke

BACKGROUND AND PURPOSE It has been shown that thrombolytic therapy can improve clinical outcome in a subgroup of patients with acute cerebral ischemia. This subgroup was characterized by certain clinical and imaging findings (eg, moderate to severe neurological deficit for less than 3 to 6 hours, occlusion of the middle cerebral artery, lack of extended infarct signs on CT, and efficient leptomeningeal collaterals). Although not part of published prospective randomized rtPA trials, information about the status of the brain vessels would be helpful in the selection of patients who may benefit the most. Our purpose was to determine the feasibility of CT angiography (CTA) in patients with acute hemispheric ischemia and to evaluate its relevance for thrombolytic therapy. METHODS CTA was performed in 40 consecutive patients (11 women and 29 men; age range, 19 to 80 years) with moderate or severe symptoms (National Institutes of Health Stroke Scale score of > or =8) of acute hemispheric ischemia. CTA findings were compared with Doppler ultrasonography (US; n=22) and intra-arterial digital subtraction angiography (DSA; n=7). Twenty patients received thrombolytic therapy, the remaining patients received intravenous heparin. RESULTS Images and 3-dimensional reconstructions of diagnostic quality could be obtained in all patients. Thirty-four patients had a vessel occlusion. The extent of leptomeningeal collaterals correlated significantly with the outcome after thrombolytic therapy (rs=0.46, P<0.05). The evaluation of diagnostic accuracy showed a high agreement with US (22 of 22) and DSA (6 of 7). CONCLUSIONS CTA can provide important information for the initiation of therapy in patients with acute hemispheric ischemia. Identification of patients with autolyzed thrombi, occlusion of the internal carotid artery bifurcation, and poor leptomeningeal collaterals is feasible with the use of CTA. These patients may have little potential for benefit from thrombolytic therapy.

Elevated plasma concentrations of homocysteine in antiepileptic drug treatment.

Summary: Purpose: Homocysteine is an experimental convulsant and an established risk factor in atherosclerosis. A nuritional deficiency of vitamin B6, vitamin B12, or folate leads to increased homocysteine plasma concentrations. During treatment with carbamazepine (CBZ), phenytoin, or phenobarbital, a deficiency in these vitamins is common. The objective of the study was to test the hypothesis that antiepileptic drug (AED) treatment is associated with increased homocysteine plasma concentrations.

Course of Platelet Activation Markers After Ischemic Stroke

Background and Purpose— The aim of this study was to evaluate the time course of platelet activation after ischemic stroke and to investigate whether platelet activation and inflammation are correlated with each other. Methods— We serially determined expression of p-selectin (CD62p) and lysosome-associated membrane protein (CD63) by platelets using flow cytometry at 10 time points between days 1 and 90 in patients after ischemic stroke (n=50), in healthy subjects (n=30), and in risk factor control subjects (n=20). Furthermore, we correlated leukocyte count, C-reactive protein, and fibrinogen levels with platelet activation markers. Results— CD62p and CD63 expression was higher on day 1 after stroke than in both control groups (P <0.005 for both). CD62p expression rapidly declined, whereas CD63 expression remained significantly elevated until day 90. Stroke severity and different medication for secondary stroke prevention did not influence CD62p or CD63 expression. Platelet activation markers and inflammatory parameters were not correlated with each other at any time point after stroke. Conclusions— The initial increase in both CD62p and CD63 expression by platelets is followed by a differential regulation of both parameters after stroke. The rapid decrease in CD62p expression may be caused by shedding from the cell surface. Its persistent elevation makes CD63 a good candidate for studies on predictors for stroke recurrence. Our findings suggest that the expression of CD62p and CD63 by platelets is regulated independently from inflammatory indexes.

Clinical and Biochemical Analysis in Infection-Associated Stroke

BACKGROUND AND PURPOSE Currently, recent infection (primarily bacterial infection) is discussed as a risk factor for cerebrovascular ischemia. The aim of this study was to investigate whether the association of ischemic stroke with recent infection is restricted to stroke subtypes and whether recent infection influences the severity of the postischemic deficit; we also aimed to define biochemical pathways linking infection and ischemic stroke. METHODS Analyzing the data of a prospective case-control study, we classified the etiology of cerebrovascular ischemia on the basis of clinical, neuroradiological, sonographical, cardiological, and biochemical data in 159 patients without and in 38 patients with infection within 1 week before ischemia. We assessed the severity of neurological deficits using the Scandinavian Stroke Scale. RESULTS In patients with recent infection compared with patients without infection, the neurological deficit on admission was more severe (median of scores, 41 versus 30.5; P < .005), cortical infarcts in the middle cerebral artery territory were more frequent (60% versus 26%; P < .001), the prevalence of extracranial artery stenoses was lower (9% versus 26%; P < .05), and definite or presumed cardioembolic stroke was more frequent (34% versus 19%; P < .05), as was stroke from cervical artery dissection (8% versus 1.3%; P = .05). Serum levels of C-reactive protein were higher in patients with (20.7 +/- 26.8 mg/L) than in those without infection (9.2 +/- 23.7 mg/L; P < .01). CONCLUSIONS Recent infection may be associated with a more severe postischemic deficit and with an increased risk of stroke from cardioembolic origin and from cervical arterial dissection.

Infection-Associated Cervical Artery Dissection Three Cases

BACKGROUND The pathogenesis of cervical artery dissection remains unknown. Infection-mediated damage of the arterial wall may be one contributing mechanism. We present three male patients with respiratory infection prior to cervical artery dissection. CASE DESCRIPTIONS Case 1: During an upper respiratory tract infection, a 49-year-old patient developed bilateral carotid and vertebral artery dissection with complete vessel restitution. Case 2: Within 3 years, a 40-year-old patient experienced two episodes of bilateral internal carotid artery dissection, both preceded by febrile upper respiratory tract infection. Case 3: A 52-year-old patient developed right-sided and, 2 years later, left-sided internal carotid artery dissection, each following upper respiratory tract infection. CONCLUSIONS Infection may be a trigger factor in the pathogenesis of cervical artery dissection.

Elevated plasma concentrations of lipoprotein(a) in medicated epileptic patients

Abstract Lipoprotein(a) [Lp(a)] has been identified as an independent risk factor for vascular diseases. There are no data on Lp(a) levels in patients on long-term medication with carbamazepine, phenytoin, phenobarbital, or valproate. To investigate the effects of such treatment on Lp(a) levels and common carotid artery intima media thickness we studied 51 epileptic outpatients on long-term antiepileptic medication and 51 age- and sex-matched controls. Lp(a) levels above 45 mg/dl were found in 11 of 50 patients, but in only 4 of 51 controls (P<0.05). The mean serum concentration of Lp(a) was 33.0±7.0 mg/dl in patients and 16.9±2.7 mg/dl in controls (P<0.05). Epileptic patients also had a thicker intima media of the common carotid artery (0.79±0.04 mm) than controls (0.69±0.02 mm, P<0.05) as measured by B-mode ultrasonography. Our results suggest an untoward effect of long-term antiepileptic medication on Lp(a) serum concentrations. Elevated Lp(a) levels might be a risk factor for arteriosclerosis in epileptic patients.

Inflammatory response after acute ischemic stroke

BACKGROUND AND PURPOSE This study aimed to characterize the time course of inflammatory parameters after acute ischemic stroke. METHODS We serially determined high sensitivity C-reactive protein (CRP), fibrinogen, and leukocyte counts at 10 time points between days 1 and 90 after ischemic stroke and in control subjects. RESULTS CRP did not significantly change, whereas fibrinogen increased after stroke. At all time points, CRP and fibrinogen were higher than in healthy control subjects, but not risk factor control subjects. The leukocyte count declined after stroke and was significantly elevated as compared to both control groups only on day 1 but not later. NIHSS levels were positively correlated with CRP and fibrinogen at all time points. Larger infarcts were associated with a higher CRP and leukocyte counts on day 90. Treatment with aspirin was associated with lower values for all three inflammatory parameters in the subacute phase after ischemia. CONCLUSIONS The course after stroke was different between the parameters of inflammation. Only the leukocytes followed the paradigm of an acute phase response.

CT-Angiographie bei Dissektionen der A. carotis internaWertigkeit einer neuen Untersuchungstechnik im Vergleich zur DSA und Dopplersonographie

ZusammenfassungZiel der vorliegenden Studie war es, den Stellenwert der CT-Angiographie (CTA) bei der Diagnose von Dissektionen der A. carotis interna (ACI) zu ermitteln. Die Befunde der CTA wurden mit Ergebnissen der digitalen Subtraktionsangiographie (DSA) und der cw-Dopplersonographie (cw-DS) verglichen. Wir untersuchten 21 Patienten mit klinischem oder dopplersonographischem Verdacht auf eine ACI-Dissektion. Bei akuter extrakranieller ACI-Dissektion war die Sensitivität der CTA 100 % (14/14). Eine intrakranielle ACI-Dissektion wurde durch die CTA nicht erfaßt, da sie außerhalb des Scanbereichs lag. Die in der cw-DS unspezifischen pathologischen Befunde konnten mit der CTA geklärt werden. Häufigster Befund in der CTA war eine exzentrische Lumeneinengung und Wandverdickung sowie eine spitzauslaufende Verschmächtigung (sog. tapering) in der dreidimensionalen (3D-) Rekonstruktion. Die CTA ist bei akuter extrakranieller Karotisdissektion eine verläßliche und wenig invasive Untersuchungsmethode. Vergleichende Studien mit CTA, Duplexsonographie und Magnetresonanztomographie (MRT) sollten noch durchgeführt werden.SummaryPurpose: To evaluate the role of CT angiography (CTA) in the diagnosis of dissection of the internal carotid artery (ICA). Methods: In 21 patients who were clinically or sonographically suspected of having a dissection of the ICA, we performed CTA covering the extracranial course of the ICA. Our technique included spiral scanning (Picker PQ 2000), slice thickness 3 mm, index 1.5 mm, pitch factor 1.25, tube voltage 130 kV, amperage 125 mA, i. v. bolus injection of 100 ml nonionic contrast medium, injection rate 4 ml/s and scan delay 15 s. Spiral data were processed using a workstation (Picker Voxel Q) to calculate 3D “angiographic” reconstructions, maximal intensity projections and multiplanar reconstructions. In 20 of the 21 patients transfemoral angiography was performed, and in all patients cw-Doppler ultrasonography of the carotid arteries was performed. Results: Sensitivity of CTA in acute extracranial dissection of the ICA was 100 % (14/14). One patient had a pseudoaneurysm of the ICA, two patients had excessive kinking and one patient showed an atheromatous carotid ulcer. DSA could confirm this in all cases. One intracranial ICA dissection, not covered by the scan field, was missed by CTA. CTA source images demonstrated mural thickening and eccentric luminal narrowing in cases of dissection. 3D reconstructions showed tapering of the ICA. Conclusion: CTA is a reliable tool in the diagnosis of ICA dissection. Further studies comparing CTA, MRI and duplex ultrasound are necessary.

Farbkodierte duplex-sonographische Darstellung einer intimalen fibromuskulären Dysplasie der A. carotis

ZusammenfassungDie intra vitam Diagnose der fibromuskulären Dysplasie (FMD) hirnversorgender Arterien gilt als eine Domänie der selektiven Katheterangiographie. Bislang liegen nur zwei Mitteilungen über die Diagnose der FMD durch B-Bild- beziehungsweise Duplex-Sonographie der A. carotis vor, eine davon mit Darstellung eines membranösen intimalen Subtyps der FMD. Wir konnten bei einem Patienten die spezifischen Kriterien einer septalen intimalen FMD des Bulbus caroticus Duplex-sonographisch dokumentieren.SummaryTraditionally, intra-vitam diagnosis of fibromuscular dysplasia (FMD) of brain supplying arteries is a domain of conventional selective angiography. We are aware of only two publications reporting of ultrasound displayed intimal and medial variants of carotid artery FMD, in one case each. We present a patient in whom color-coded duplex-sonography revealed a web-like carotid artery bulb stenosis meeting the specific criteria of a subtype of intimal FMD.