Journal of neuroimaging : official journal of the American Society of Neuroimaging
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Over the course of treatment for Parkinson's disease (PD), the clinical effects of dopaminergic medication diminish and side effects emerge. Therefore, searching for new therapeutic alternatives or complementary treatments is required. Transcranial direct current stimulation (tDCS) could potentially complement the current therapeutic armamentarium, but only a few studies have investigated the therapeutic effects of tDCS in PD. The present pilot study aimed to investigate the effects of repeated tDCS treatment on motor symptoms and regional cerebral blood flow (rCBF) in patients with PD using single photon emission computed tomography (SPECT). ⋯ This study shows that tDCS application may improve rCBF in the frontal and parietal lobes in patients with PD, suggesting beneficial effects of tDCS on brain function. Our results are preliminary and further large-scale studies are needed to confirm our findings.
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Brain MRI-derived lesions and atrophy are related to multiple sclerosis (MS) disability. In the Serially Unified Multicenter MS Investigation (SUMMIT), from Brigham and Women's Hospital (BWH) and University of California, San Francisco (UCSF), we assessed whether MRI methodologic heterogeneity may limit the ability to pool multisite data sets to assess 5-year clinical-MRI associations. ⋯ MRI acquisition and processing differences may result in some degree of heterogeneity in assessing brain lesion and atrophy measures in patients with MS. Pooling of data across sites is beneficial to correct for potential biases in individual data sets.
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Pulsatility index (PI) in the middle cerebral artery (MCA) is considered a measure of peripheral vascular resistance. Several established cardiovascular risk factors are common for both MCA PI and carotid atherosclerosis. Accordingly, in the present study we hypothesized an association between ultrasound-derived indices of carotid atherosclerosis and MCA PI. ⋯ In a population-based sample of middle-aged adults, ultrasound-derived indices of carotid atherosclerosis were independently associated with MCA PI. However, the overall explained variance of MCA PI was low, suggesting other factors than atherosclerosis and cardiovascular risk factors to play an important role for MCA PI.
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Microembolic signals (MES) are detectable by transcranial Doppler monitoring and associated with increased risk of first or recurrent ischemic stroke. MES detection can also illuminate stroke etiology and the effect of prophylactic treatment. MES detection cannot accurately distinguish between stroke-related microemboli and ultrasound contrast agents. These agents contain microbubbles and are frequently used in neuro- and cardiovascular diagnostics. We aimed to assess how long after contrast infusion microbubbles are detectable by transcranial Doppler monitoring. ⋯ None of the subjects had detectable MES for more than 77 minutes after ultrasound contrast infusion. MES detection with the intent to detect stroke-related microemboli should wait for at least this long after completed infusion.
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In the setting of an extended time window for endovascular treatment (EVT) for acute stroke patients, computed tomography perfusion (CTP) has become a major tool in patient selection. However, there are some data suggesting that the initial ischemic core may be overestimated by CTP depending on stroke onset time. This study aims to evaluate possible predictors of overestimation of infarct core by CTP. ⋯ Over estimation of the infarct core by CTP in patients undergoing EVT is time dependent and so CTP results among early arrivers should be interpreted cautiously.