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ABSTRACT: It has previously been reported that serum levels of vascular endothelial growth factor are raised after acute ischemic stroke compared to healthy controls. The aim of this prospective study was to ascertain whether serum vascular endothelial growth factor measurements could be used to distinguish between acute ischemic stroke and common stroke mimics in the emergency room.
Blood samples were taken on arrival to hospital and daily for six-days, in 44 patients with suspected ischemic stroke (29 acute infarcts and 15 stroke mimics), arriving within 24 h of symptom onset. Vascular endothelial growth factor levels were measured by enzyme-linked immunoassay. The neurological deficit was recorded daily using the National Institute of Health Stroke Scale. Evaluation of infarct volumes was based on diffusion-weighted magnetic resonance imaging.
Serum vascular endothelial growth factor levels were significantly raised in acute ischemic stroke patients on the day of symptom onset and at all other time points, compared to healthy controls (P < 0·01). The sensitivity and specificity of vascular endothelial growth factor for diagnosing acute ischemic stroke on admission to hospital were only 69% and 73%, respectively. Vascular endothelial growth factor levels were also elevated in four out of 15 stroke mimics, including three patients presenting with postictal paresis.
Vascular endothelial growth factor has limited clinical utility in the diagnosis of acute ischemic stroke in the emergency room because levels are also raised in common stroke mimics. Further studies are required to establish the mechanism of vascular endothelial growth factor elevation in postictal paresis.
International Journal of Stroke 11/2011; 7(6):454-9. · 2.38 Impact Factor
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ABSTRACT: To prospectively compare tumor volume, relative cerebral blood volume (rCBV), and apparent diffusion coefficient (ADC) and short-term changes of these parameters as predictors of time to malignant transformation and time to death in patients with low-grade gliomas (LGGs).
Patients gave written informed consent for this institutional ethics committee-approved study. Patients with histologically proved LGGs underwent conventional, perfusion-weighted, and diffusion-weighted magnetic resonance (MR) imaging at study entry and at 6 months. At both time points, tumor volume, maximum rCBV, and ADC histogram measures were calculated. Patient follow-up consisted of MR imaging every 6 months and clinical examinations. To investigate the association between MR imaging variables and time to progression and time to death, a Cox regression curve was applied at study entry and at 6 months. The models were corrected for age, sex, and histologic findings.
Thirty-four patients (22 men, 12 women; mean age, 42 years) with histologically proved LGGs (eight oligodendrogliomas, 20 astrocytomas, and six oligoastrocytomas) were followed up clinically and radiologically for a median of 2.6 years (range, 0.4-5.5 years). Tumor growth over the course of 6 months was the best predictor of time to transformation, independent of rCBV, diffusion histogram parameters, age, sex, and histologic findings. When only single-time-point measurements were compared, tumor volume helped predict outcome best and was the only independent predictor of time to death (P < .02).
Six-month tumor growth helps predict outcome in patients with LGG better than parameters derived from perfusion- or diffusion-weighed MR imaging. Tumor growth can readily be calculated from volume measurements on images acquired with standard MR imaging protocols and may well prove most useful among various MR imaging findings in clinical practice.
Radiology 09/2009; 253(2):505-12. · 5.73 Impact Factor
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ABSTRACT: This article focuses on pathologic processes affecting the optic nerve, optic nerve/sheath complex, and chiasm. Pathology of the visual pathways posterior to the chiasm is beyond the scope of this article and is discussed only briefly.
Neuroimaging Clinics of North America 06/2008; 18(2):243-59, preceding x. · 1.51 Impact Factor
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ABSTRACT: We report the case of malignant oligodendroglioma in a 36-year-old man who underwent diffusion-weighted, perfusion-weighted, and volumetric MR imaging before and after PCV (procarbazine, CCNU, vincristine) chemotherapy. The tumor regions exhibiting a low apparent diffusion coefficient and increased relative cerebral blood volume showed a marked response to chemotherapy and dramatic decrease in volume, whereas the remaining tumor regions showed little change. Diffusion-weighted and perfusion-weighted MR imaging may be helpful in predicting chemosensitivity of glial tumors.
American Journal of Neuroradiology 03/2005; 26(2):274-8. · 2.93 Impact Factor
