Lp(a) lipoprotein and plasminogen activity in patients with different etiology of ischemic stroke.

BACKGROUND AND PURPOSE: Lp(a) lipoprotein plays an important part in atherothrombogenesis and is considered an independent risk factor for coronary heart disease. However, its role in cerebrovascular disease remains unclear, in particular because of the heterogeneous nature of strokes. We investigated whether elevated Lp(a) is more frequent in ischemic stroke related to atherothrombosis than in other etiologies of stroke. Because of the close structural homology between Lp(a) and plasminogen, we also studied the role of plasminogen in different stroke subtypes and whether there is a dependency on Lp(a) plasma levels. METHODS: Lp(a) levels and plasminogen activity were measured in 253 consecutive patients with acute ischemic stroke and in 63 controls (CS). Subtypes of stroke were established according to the TOAST criteria. RESULTS: Median Lp(a) levels were found to be higher in the total cerebral infarction group and in patients with large artery atherosclerosis (LAA) when compared with CS (20.9 and 22.0 mg/dl, respectively, vs. 16.0 mg/dl; p < 0.05). In addition, elevated Lp(a) levels >30 mg/dl were more frequent among the LAA subgroup than among CS (39.4 vs. 11.1%; p < 0.001). Mean plasminogen activity was lower in the total cerebral infarction group (110.8 vs. 120.3%; p < 0.001) and in patients with cardioembolic stroke (109.8 vs. 120.3%; p < 0.05) when compared with CS. There was no correlation between Lp(a) levels and plasminogen activity. CONCLUSIONS: Our results support the hypothesis that elevated Lp(a) is a risk factor for ischemic stroke and especially for strokes caused by LAA. Low plasminogen activity may play a role in the pathogenesis of cerebrovascular disease, especially for the development of cardioembolic stroke.

Impaired cerebral glucose metabolism in eclampsia: a new finding in two cases.

The pathophysiology of the reversible neurological manifestation in eclamptic women remains unclear. We report on 2 women with eclampsia who were repetitively examined by (1) transcranial Doppler (TCD), (2) magnetic resonance imaging (MRI) including T1- and T2-weighted images, fluid attenuated inversion recovery sequence, dynamic susceptibility-weighted perfusion imaging and magnetic resonance angiography (MRA), and (3) (18)fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET). In both cases repetitive TCD revealed no signs of vasospasm; the same was true for MRA. MRI perfusion imaging showed completely homogenous cerebral blood flow in both cases. In the initial phase T2-weighted images revealed hyperintensities in both patients (predominantly bilateral frontal and parietal in 1 and in the temporo-occipital subcortex and the basal ganglia in the other). FDG-PET showed inhomogeneous glucose metabolism (GM) in both patients. Primary increased glucose utilization in the hyperintense T2-weighted areas as well as an attenuated GM parieto-occipital were observed in the 1st case; a high GM was found bilaterally in the basal ganglia and an attenuated one in the occipital cortex in the 2nd. In both cases MRI, and FDG-PET normalized within 3 weeks. These case reports document an altered cerebral GM in the presence of homogenous perfusion in eclamptic women. The high GM may be explained by a decoupling of cerebral perfusion and GM, possibly indicating an increased neuronal activity. The attenuation of the GM is most probably due to a deafferentation of cortical neurons.

Echo contrast-enhanced transcranial ultrasound: frequency of use, diagnostic benefit, and validity of results compared with MRA.

BACKGROUND AND PURPOSE: The present study was undertaken to determine the frequency of use of the ultrasound contrast agent (UCA) Levovist in routine transcranial ultrasound (TU). Additionally, we evaluated the diagnostic validity of contrast-enhanced TU using 3-dimensional time of flight MR angiography. METHODS: Indication for the UCA was an insufficient evaluation of the intracranial arteries after a combined approach with transcranial color-coded Duplex and transcranial Doppler examination. We prospectively analyzed every patient referred for TU over 6 months. Additionally, over a 3-month period, TU results were compared with 3-dimensional time-of-flight MR angiography. RESULTS: Indication for use of UCA was met in 61 of 687 patients (8.8%). After UCA application, a diagnostic result was achieved in 75% of cases during transtemporal and in 81% during transforaminal insonation. The sensitivity and specificity of TU in the diagnosis of intracranial stenosis were 83% and 82%, respectively. CONCLUSIONS: Use of UCA was necessary in 8.8% of the patients. A diagnostic benefit was achieved in 75% to 80% of cases. Contrast-enhanced TU demonstrated a high sensitivity and specificity in the diagnosis of intracranial stenosis.

Unusual presentation of carcinomatous meningitis: case report and review of typical CSF findings.

This paper describes a previously unreported clinical onset of carcinomatous meningitis with bilateral deafness. Typical changes in the cerebrospinal fluid aside from positive cytology findings are reviewed. In cases of suspected carcinomatous meningitis the clustering of increased CSF protein, lactate, decreased glucose, and a high opening pressure is suggestive of the diagnosis.

Post-partum cerebral angiopathy: repetitive TCD, MRI, MRA, and EEG examinations.

We report of a woman with post-partum cerebral angiopathy (PCA), in whom we repetitively performed transcranial Doppler sonography (TCD), MR imaging (MRI), and MR angiography (MRA) to evaluate the underlying pathophysiology. A 31-year-old woman, Gemini pregnant, complained of severe throbbing frontal headache four days after an uneventful delivery by Cesarean section. Blurred vision occurred eight days after delivery, followed by three generalized tonic-clonic seizures. Neurological examination revealed a somnolent woman without focal neurological deficits. At the day of the seizures increased flow velocities and disturbed flow were observed in the right posterior and anterior cerebral artery on transcranial Doppler (TCD). MRI showed infra- and supratentorial patchy hyperintensities in T2-weighted images and in the FLAIR sequence. Diffusion-weighted imaging revealed corresponding multi-focal hyperintense areas indicating increased diffusion and MRA showed a diffuse multisegmental narrowing of all pial arteries. MRI at day 10 was completely normal, but MRA still revealed vascular narrowing in the right posterior cerebral artery. General slight flow accelerations in all basal arteries occurred after 10 days and lasted for three weeks. PCA is apparently associated with a vascular narrowing causing cerebral ischemia with increased diffusion. Later reactive cerebral hyperperfusion is observed. Vascular narrowing and cerebral hyperperfusion still persist after MRI has normalized.