Progressive multifocal cerebral infarction in a young kidney transplant recipient due to thrombotic microangiopathy.

BACKGROUND: Renal transplant recipients frequently experience neurological complications. Whereas ischemic stroke, cerebral haemorrhage or hypertensive encephalopathy often result from vascular alterations prior to transplantation, other cerebral diseases like CNS infections, primary brain tumors and drug induced neurotoxicity may develop as consequences of the required post-transplant immunosuppressive treatment. CASE PRESENTATION: Here we report on an unusual clinical course of a young kidney transplant recipient with a cluster of fulminant necrotic brain lesions within a period of two months due to thrombotic microangiopathy. CONCLUSION: Cerebral ischemia in organ transplant recipients should prompt one to consider thrombotic microangiopathy.

Active at night, sleepy all day--sleep disturbances in patients with hepatitis C virus infection.

BACKGROUND & AIMS: More than 50% of patients with chronic hepatitis C with only mild liver disease complain about chronic fatigue, daytime sleepiness and poor sleep quality. The aim of the present study was to characterize and objectify the sleep disturbances in hepatitis C virus-infected patients. METHODS: Twenty-five women who had been infected with hepatitis C virus contaminated anti-D immunoglobulin in 1978/79 and 22 age-matched female healthy controls underwent actigraphy over a period of 5 days to measure motor activity and thereby sleep-wake-rhythm and in addition completed questionnaires for depression, health-related quality of life, fatigue and sleep, and a sleep diary. Liver cirrhosis, a history of neurological or psychiatric disease, history of intravenous drug abuse, shift work, or current medication with effect upon the central nervous system were exclusion criteria. RESULTS: The patients achieved higher scores for depression, fatigue and sleep disturbances and lower quality of life scores than the healthy controls. Actigraphy showed higher nocturnal activity and worse sleep efficiency in the patients, while the 24-h activity level did not differ between groups. Fatigue and quality of life scores correlated with bad sleep quality and daytime sleepiness. CONCLUSIONS: Our data indicate that chronic fatigue is associated with bad sleep quality and increased nocturnal activity in HCV-infected patients suggesting an alteration of sleep architecture behind fatigue in HCV-associated encephalopathy.

Quantitative MRI shows cerebral microstructural damage in hemolytic-uremic syndrome patients with severe neurological symptoms but no changes in conventional MRI.

INTRODUCTION: Severe neurological symptoms in Shiga toxin-producing Escherichia coli infection associated hemolytic-uremic syndrome (STEC-HUS) are often accompanied by none or only mild alterations of cerebral magnetic resonance imaging (MRI). This study aims to analyze if quantitative MRI is able to reveal cerebral pathological alterations invisible for conventional MRI. METHODS: In nine patients with STEC-HUS associated severe neurological symptoms but inconspicuous cerebral MRI findings maps of the parameters T2 relaxation time, relative proton density (PD), apparent diffusion coefficient (ADC), and fractional anisotropy (FA) were generated. Quantitative values of these parameters were measured at the basal ganglia, thalamus, and white matter of the frontal and parietal lobe and compared to those of nine age- and sex-matched controls. RESULTS: Significant T2 prolongation (p < 0.01) was found in the basal ganglia of all patients compared to controls. PD and ADC were not significantly altered. A significant reduction of FA in patients was seen at caput nuclei caudati (p < 0.01). CONCLUSION: Prolonged T2 relaxation time indicates cerebral microstructural damages in these patients despite their inconspicuous MRI findings. T2 relaxometry could be used as a complementary tool for the assessment of metabolic-toxic brain syndromes.

Temporal pattern of cytotoxic edema in the perihematomal region after intracerebral hemorrhage: a serial magnetic resonance imaging study.

BACKGROUND AND PURPOSE: Knowledge about cytotoxic edema (CE) in intracerebral hemorrhage is still limited. We aimed to analyze its presence, temporal pattern, and prognostic meaning. METHODS: Twenty-one patients with primary intracerebral hemorrhage underwent magnetic resonance imaging at days 1, 3, and 7 after symptom onset. CE was identified using diffusion-weighted imaging. Hematoma and perihematomal edema volumes were measured on fluid-attenuated inversion recovery images. National Institutes of Health Stroke Scale score was assessed at admission and with each magnetic resonance imaging. Clinical outcome was assessed by modified Rankin scale at 90 days. RESULTS: CE appeared in half of the patients within the first 24 hours. The apparent diffusion coefficient values decreased until day 3 and were significantly reversed from days 3 through 7 (P<0.01). Patients with CE showed significantly faster perihematomal edema growth from day 0 to 1 (P=0.036) than those without. Larger 3-day perihematomal edema volume (P=0.02) and presence of CE on day 3 (P=0.07) were associated with poor clinical outcome. CONCLUSIONS: CE is associated with stroke severity, perihematomal edema volume, and poor outcome. It is considered to indicate ongoing neuronal injury and, thus, might emerge as new treatment target.

Circulating endothelial cells as potential diagnostic biomarkers in primary central nervous system vasculitis.

OBJECTIVE: Histological evidence is considered the only proof of primary central nervous system vasculitis (PCNSV). However, brain biopsy is often omitted or delayed because of the invasiveness and possible complications of the procedure. Circulating endothelial cells (CEC) were shown to be elevated in patients with active antineutrophil cytoplasmic antibody-associated vasculitis. We hypothesise that CEC are also elevated in patients with active PCNSV and may contribute to the diagnosis. METHODS: CEC were assessed in 18 patients, 3 of whom had biopsy-proven PCNSV and 15 clinical, cerebrospinal fluid and imaging data, highly suggestive of PCNSV. In 3 of these 15 patients CEC assessment was performed after initiation of successful immunosuppressive therapy. CEC numbers of all patients were compared to those of 16 healthy volunteers and 123 subjects with cerebrovascular risk factors and/or ischaemic stroke, who had been studied in our group before. CEC were assessed by immunomagnetic isolation from peripheral blood. RESULTS: In patients with proven and suspected active PCNSV, CEC were extremely elevated (>400 cells/ml in most of the patients) and significantly higher than in healthy and disease controls (p≤0.01 for each group). CEC significantly decreased with immunosuppressive treatment. CONCLUSIONS: For the first time it is shown that CEC are significantly elevated in patients with active PCNSV in contrast to other pathologies associated with brain infarction and correlate with disease activity. Sensitivity and specificity of the method for diagnosing PCNSV and the use of the method for treatment monitoring should be addressed in future prospective studies with a larger patient group.

Circulating microRNAs in patients with Shiga-Toxin-producing E. coli O104:H4 induced hemolytic uremic syndrome.

BACKGROUND: In early May 2011, an outbreak of hemorrhagic colitis associated with hemolytic-uremic syndrome (HUS) first developed in Northern Germany and spread to 15 other countries in Europe. The outbreak-strain O104:H4, which combined virulence factors of typical enteroaggregative and Shiga-Toxin-producing E. coli was associated with an unusual high rate of hemolytic uremic syndrome. Also an unexpected high rate of coma and seizures leading to mechanical ventilation and ICU treatment was observed. MicroRNAs are small ribonucleotides orchestrating gene expression. We tested whether circulating microRNAs in serum of HUS patients during the 2011 epidemics are altered in this patient cohort and related to clinical manifestations. METHODOLOGY/PRINCIPAL FINDINGS: We profiled microRNAs using RNA isolated from serum of patients and healthy age-matched controls. The results were validated in 38 patients at baseline, 29 patients during follow-up and 21 age-matched healthy controls by miRNA-specific quantitative RT-PCR. Circulating levels of miR-24, miR-126 were increased in HUS patients versus controls. There was no association between these microRNAs and renal function or the need for renal replacement therapy. In contrast, levels of miR-126 were associated with neurological symptoms at baseline and during follow-up. In addition, miR-126 (on admission) and miR-24 (on admission and during follow-up) were associated with platelet count. CONCLUSIONS/SIGNIFICANCE: Circulating microRNAs are strongly altered in this patient cohort and associated with neurological symptoms as well as platelet count.

Neurologic manifestations of E coli infection-induced hemolytic-uremic syndrome in adults.

OBJECTIVE: To describe the neurologic and neuroradiologic complications of Shiga toxin producing Escherichia coli infection (STEC)-associated hemolytic-uremic syndrome (HUS) in adults. METHODS: All 52 adult patients with STEC O104:H4 infection cared for at Hannover Medical School during the outbreak in Germany through May-July 2011 are considered in this observational study. Forty-three of the 52 patients underwent a standard neurologic diagnostic procedure including clinical examination, Mini-Mental State Examination, and Glasgow Coma Scale Score. Thirty-six patients underwent EEG, and 26 had cerebral MRI, 9 of them repeatedly. Case records of 9 patients who had not been seen by a neurologist were analyzed retrospectively. RESULTS: Forty-eight of the 52 patients had HUS. All but 1 of these showed neurologic symptoms. Focal neurologic signs like double vision, difficulties in finding words, or hyperreflexia were present in 23, additional deficits in orientation, attention, memory, or constructive abilities in 9, and marked impairment of consciousness in 15. MRI showed brainstem, midbrain, thalamus, corpus callosum, and white matter lesions in half of the patients, predominantly in diffusion-weighted images. The extent of MRI lesions did not correlate with clinical symptoms. General slowing but no focal alteration was found in half of the patients examined by EEG. CONCLUSION: Our findings suggest a toxic-metabolic pathology behind the neurologic impairment instead of multiple infarction due to microthrombosis. Future studies should aim to clarify if early antibiotic therapy or bowel cleansing might help to decrease the rate of neurologic complications in STEC-HUS.

Anticoagulants affect matrix metalloproteinase 9 levels in blood samples of stroke patients and healthy controls.

OBJECTIVES: Matrix metalloproteinase-9 (MMP-9) represents a promising marker for acute stroke management. In clinical studies MMP-9 has been quantified by ELISA using differing protocols. We aimed to establish a valid protocol by evaluation of preanalytics. DESIGN AND METHODS: Blood from stroke patients (n=28) and healthy controls (n=28) was drawn into tubes containing different anticoagulants (EDTA, citrate, lithium-heparin (heparin) and heparin with proteinase inhibitors) and processed after 0, 60 and 240 min. MMP-9 plasma protein and mRNA from mononuclear leukocytes were determined. RESULTS: In regard to anticoagulants used, samples showed different MMP-9 protein baseline values and kinetics. Stable MMP-9 protein concentrations were only measured from EDTA samples. Particularly in samples with proteinase inhibitors protein and mRNA concentrations increased over time. Kinetics did not differ between patients and controls. CONCLUSIONS: Preanalytics plays a key role for determination of MMP-9. EDTA seems to be a valid anticoagulant for MMP-9 protein measurement.

Cerebral glucose utilisation in hepatitis C virus infection-associated encephalopathy.

Patients with hepatitis C virus (HCV) infection frequently show neuropsychiatric symptoms. This study aims to help clarify the neurochemical mechanisms behind these symptoms and to add further proof to the hypothesis that HCV may affect brain function. Therefore, 15 patients who reported increasing chronic fatigue, mood alterations, and/or cognitive decline since their HCV infection underwent neurologic and neuropsychological examination, magnetic resonance imaging, (18)F-fluoro-deoxy-glucose positron emission tomography of the brain, and single photon emission tomography of striatal dopamine and midbrain serotonin transporter (SERT) availability. None of the patients had liver cirrhosis. Patients' data were compared with data of age-matched controls. In addition, regression analysis was performed between cognitive deficits, and mood and fatigue scores as dependent variables, and cerebral glucose metabolism, dopamine, or SERT availability as predictors. Patients showed significant cognitive deficits, significantly decreased striatal dopamine and midbrain SERT availability, and significantly reduced glucose metabolism in the limbic association cortex, and in the frontal, parietal, and superior temporal cortices, all of which correlated with dopamine transporter availability and psychometric results. Thus, the study provides further evidence of central nervous system affection in HCV-afflicted patients with neuropsychiatric symptoms. Data indicate alteration of dopaminergic neurotransmission as a possible mechanism of cognitive decline.

Growth differentiation factor 15 plasma levels and outcome after ischemic stroke.

BACKGROUND: Growth differentiation factor 15 (GDF-15) is a stress-responsive cytokine that is induced after experimental brain injury. We hypothesized that the circulating levels of GDF-15 are increased and associated with neurological outcome in patients with ischemic stroke. METHODS: Serial blood samples were obtained between 6 h and 7 days after symptom onset in 57 consecutive patients with acute ischemic stroke (n = 51) or transient ischemic attack (n = 6). GDF-15 was measured by immunoradiometric assay. Neurological outcome using the modified Rankin Scale (mRS) at 7 and 90 days was classified as favorable (mRS 0 or 1) or unfavorable (mRS >1). RESULTS: Six hours after symptom onset, GDF-15 levels were abnormally high (>1,200 ng/l) in 68% of the patients. They declined by 8% over the course of 7 days (p < 0.001). GDF-15 levels were correlated with the circulating levels of the inflammatory marker interleukin-6 and the glial protein S100 calcium binding protein B, and with carotid intima-media thickness. Ischemic stroke patients with an mRS score >1 at 7 or 90 days had higher circulating levels of GDF-15 at all preceding sampling time points compared to patients with an mRS score of 0 or 1 (p ≤ 0.002). Similarly, in a logistic regression analysis, GDF-15 levels measured between 6 h and 7 days after symptom onset were associated with mRS at 7 and 90 days. CONCLUSIONS: These data show for the first time that the circulating levels of GDF-15 are elevated and associated with neurological outcome in patients with ischemic stroke.

Hepatitis C virus infection and the brain.

There is growing evidence that hepatitis C virus (HCV)-infection may affect the brain. About half of the HCV-infected patients complain of chronic fatigue irrespective of their stage of liver disease or virus replication rate. Even after successful antiviral therapy fatigue persists in about one third of the patients. Many patients, in addition, report of deficits in attention, concentration and memory, some also of depression. Psychometric testing revealed deficits in attention and verbal learning ability as characteristic for HCV-afflicted patients with normal liver function. Magnetic resonance spectroscopic studies showed alterations of the cerebral choline, N-acetyl-aspartate, and creatine content in the basal ganglia, white matter and frontal cortex, respectively. Recently, pathologic cerebral serotonin and dopamine transporter binding and regional alterations of the cerebral glucose utilisation compatible with alterations of the dopaminergic attentional system were observed. Several studies detected HCV in brain samples or cerebro-spinal fluid. Interestingly, viral sequences in the brain often differed from those in the liver, but were closely related to those found in lymphoid tissue. Therefore, the Trojan horse hypothesis emerged: HCV-infected mononuclear blood cells enter the brain, enabling the virus to reside within the brain (probably in microglia) and to infect brain cells, especially astrocytes.