Circulating endothelial cells and stroke: influence of stroke subtypes and changes during the course of disease.

Background: Circulating endothelial cells (CECs) are a novel and valuable marker of endothelial damage in a variety of vascular disorders. There is limited information as to CEC counts and the time course of CECs in subtypes of stroke.

Methods: We studied 49 patients with stroke (18 with atherothrombotic infarction in the territory of the middle cerebral artery, 16 with cardioembolic stroke, and 15 with lacunar stroke).

Blood-brain barrier permeability for ammonia in patients with different grades of liver fibrosis is not different from healthy controls.

Increased blood-brain barrier (BBB) permeability for ammonia is considered to be an integral part of the pathophysiology of hepatic encephalopathy (HE) in patients with liver cirrhosis. Increased glutamate-/glutamine-signal intensity in magnetic resonance spectroscopic studies of the brain in cirrhotic patients was explained as a consequence of increased cerebral ammonia uptake. As similar spectroscopic alterations are present in patients with liver fibrosis, we hypothesized that BBB permeability for ammonia is already increased in liver fibrosis, and thereby contributing to the development of HE.

Intra-arterial thrombolysis using rt-PA in patients with acute stroke due to vessel occlusion of anterior and/or posterior cerebral circulation.

Introduction: The aim of our study was to evaluate the safety and efficacy of intra-arterial (IA) thrombolysis using recombinant tissue plasminogen activator (rt-PA) in patients with acute stroke due to occlusion in the anterior or posterior circulation.

Methods: We retrospectively analyzed the clinical and radiological data of 88 consecutive patients with acute ischemic stroke who underwent emergency cerebral angiography for the purpose of subsequent IA thrombolysis. The neurological deficit on admission and discharge was graded using the National Institutes of Health Stroke Scale (NIHSS) score.

Correlations between magnetic resonance spectroscopy alterations and cerebral ammonia and glucose metabolism in cirrhotic patients with and without hepatic encephalopathy.

Background: Hepatic encephalopathy is considered to be mainly caused by increased ammonia metabolism of the brain. If this hypothesis is true, cerebral glucose utilisation, which is considered to represent brain function, should be closely related to cerebral ammonia metabolism. The aim of the present study was to analyse whether cerebral ammonia and glucose metabolism in cirrhotic patients with early grades of hepatic encephalopathy are as closely related as could be expected from current hypotheses on hepatic encephalopathy.

Bradykinesia in cirrhotic patients with early hepatic encephalopathy is related to a decreased glucose uptake of frontomesial cortical areas relevant for movement initiation.

Background/aims: Bradykinesia is one of the first symptoms of hepatic encephalopathy (HE). Recently it has been suggested that bradykinesia in HE is due to disturbances in movement initiation. Areas involved in self-initiated movement are the motor- and premotor cortex, the supplementary motor cortex, the motor areas of the cingulate gyrus, and part of the frontomesial- and parietal cortex.

Monoaminergic neurotransmission is altered in hepatitis C virus infected patients with chronic fatigue and cognitive impairment.

Background: The majority of patients with hepatitis C virus (HCV) infection suffer from disabling fatigue, cognitive dysfunction, and quality of life reduction. Meanwhile, there is increasing evidence that HCV infection can affect brain function. Recent studies have shown that fatigue and psychomotor slowing may resolve in patients with hepatitis C after treatment with ondansetron.

Correlative assessment of cerebral blood flow obtained with perfusion CT and positron emission tomography in symptomatic stenotic carotid disease.

Twelve patients with ICA stenosis underwent dynamic perfusion computed tomography (CT) and positron emission tomography (PET) studies at rest and after acetazolamide challenge. Cerebral blood flow (CBF) maps on perfusion CT resulted from a deconvolution of parenchymal time-concentration curves by an arterial input function (AIF) in the anterior cerebral artery as well as in both anterior choroidal arteries. CBF was measured by [(15)O]H(2)O PET using multilinear least-squares minimization procedure based on the one-compartment model.

Attention, memory, and cognitive function in hepatic encephalopathy.

Deficits in attention and arousal play a major role in the clinical presentation of hepatic encephalopathy. Attention deficits are also the main components of minimal hepatic encephalopathy. The present paper summarizes some findings about attentional and memory dysfunction in hepatic encephalopathy, with reference to basic knowledge about normal attention and memory function and their cerebral representation.

Neurological and neuropsychiatric syndromes associated with liver disease.

The clinical presentation of acute liver failure and hepatic encephalopathy (HE) in patients with cirrhosis differs significantly. The most serious neurological complication of acute liver failure is the development of devastating brain oedema. Therefore, intracranial pressure monitoring is urgently needed in these patients.

Functional imaging of the brain in patients with liver cirrhosis.

Brain imaging techniques have provided substantial insight into the pathophysiology of hepatic encephalopathy (HE). Magnetic resonance imaging gave hint to the fact that there is an increased deposition of manganese especially in the basal ganglia. Single photon emission computed tomography (SPECT) and positron emission tomography (PET) showed that the preference of the basal ganglia might be due to differences in regional cerebral blood flow and an additional redistribution of blood flow from the cortex to subcortical regions in cirrhotics.

Comparison of perfusion computed tomography with diffusion-weighted magnetic resonance imaging in hyperacute ischemic stroke.

Objective: In this study, perfusion CT and diffusion-weighted magnetic resonance imaging (DWI) were compared as means of assessing the ischemic brain in hyperacute stroke.

Methods: Twenty patients with ischemic stroke underwent perfusion computed tomography (CT) and magnetic resonance imaging (MRI) studies <3 hours after stroke onset. Cerebral blood flow thresholds were used to delineate the ischemic lesion, penumbra, and infarct.

Hepatitis C virus infection affects the brain-evidence from psychometric studies and magnetic resonance spectroscopy.

Background/aims: Up to 50% of patients infected with the hepatitis C virus (HCV) complain of chronic fatigue and difficulties in concentration and memory. The aim of the present study was to seek evidence for the presence of central nervous system involvement in HCV infected patients with only mild liver disease.

Methods: Thirty HCV infected patients with normal liver function, 15 of whom were identified as having mild and 15 moderate to severe fatigue using the fatigue impact scale, underwent neurological and neuropsychological examination, electroencephalography (EEG) and cerebral proton magnetic resonance imaging (MRI) and spectroscopy (MRS).

Regional differences in cerebral blood flow and cerebral ammonia metabolism in patients with cirrhosis.

Clinical and histopathological findings hint at regional differences in the brain's sensitivity to metabolic changes in cirrhosis. The aim of the present study was to examine regional differences in cerebral ammonia metabolism in patients with cirrhosis and grade 0-to-I hepatic encephalopathy (HE). (13)N-ammonia, (15)O-water positron emission tomography (PET) and magnetic resonance imaging (MRI) were performed.