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Background Postoperative intracranial hypotension-associated venous congestion (PIHV) is a rare event. The authors report the case of a patient presenting with PIHV after spinal surgery following the sudden loss of cerebrospinal fluid (CSF) induced by suction drainage. Methods A 69-year-old patient underwent uneventful revision surgery for wound dehiscence after lumbar surgery with placement of a subfascial suction drain. Results Postoperatively, the patient presented with fluctuating consciousness and a generalized tonic–clonic seizure. Computed tomography (CT) and serial magnetic resonance imaging (MRI) were performed showing convexity subarachnoid hemorrhages (SAHs), diffuse swelling of the brain and thalami and striatum bilaterally without diffusion restriction, and signs of intracranial hypertension resulting in pseudohypoxic brain swelling in PIHV. A dural leak at L3–L4 was treated with several CT-guided patches combining autologous blood and fibrin glue injections. The patient recovered without neurologic deficit and follow-up MRI revealed progressive complete reversal of brain swelling, and re-expansion of CSF spaces. Conclusion PIHV is a rare but potentially fatal entity. Awareness of PIHV after cranial or spinal surgery leads to early treatment of CSF hypovolemia and possibly better clinical outcome. Following acute CSF volume loss, an acute elevation of cerebral blood volume overcoming autoregulatory mechanisms seems a likely explanation for diffuse cerebral vasogenic edema and SAH in PIHV.

Background Graph theory (GT) is a mathematical field that analyses complex networks that can be applied to neuroimaging to quantify brain's functional systems in Parkinson's disease (PD) and essential tremor (ET). Objectives To evaluate the functional connectivity (FC) measured by the global efficiency (GE) of the motor network in PD and compare it to ET and healthy controls (HC), and correlate it to clinical parameters. Methods 103 subjects (54PD, 18ET, 31HC) were submitted to structural and functional MRI. A network was designed with regions of interest (ROIs) involved in motor function, and GT was applied to determine its GE. Clinical parameters were analyzed as covariates to estimate the impact of disease severity and medication on GE. Results GE of the motor circuit was reduced in PD in comparison with HC (p .042). Areas that most contributed to it were left supplementary motor area (SMA) and bilateral postcentral gyrus. Tremor scores correlated positively with GE of the motor network in PD subgroups. For ET, there was an increase in the connectivity of the anterior cerebellar network to the other ROIs of the motor circuit in comparison with PD. Conclusions FC measured by the GE of the motor network is diminished in PD in comparison with HC, especially due to decreased connectivity of left SMA and bilateral postcentral gyrus. This finding supports the theory that there is a global impairment of the motor network in PD, and it does not affect just the basal ganglia, but also areas associated with movement modulation. The ET group presented an increased connectivity of the anterior cerebellar network to the other ROIs of the motor circuit when compared to PD, which reinforces what it is known about its role in this pathology., This study is a graph theory evaluation of the functional connectivity measured by the global efficiency of the motor network in Parkinson's disease (PD) in comparison with essential tremor (ET) and healthy controls (HC). We have found that global efficiency is decreased in PD when compared to ET and HC. Areas that contributed to it were the left SMA and bilateral postcentral gyrus.

Our goal was to estimate the diagnostic accuracy of substantia nigra fractional anisotropy (SN-FA) for Parkinson’s disease (PD) diagnosis in a sample similar to the clinical setting, including patients with essential tremor (ET) and healthy controls (HC). We also performed a systematic review and meta-analysis to estimate mean change in SN-FA induced by PD and its diagnostic accuracy. Our sample consisted of 135 subjects: 72 PD, 21 ET and 42 HC. To address inter-scanner variability, two 3.0-T MRI scans were performed. MRI results of this sample were pooled into a meta-analysis that included 1,432 subjects (806 PD and 626 HC). A bivariate model was used to evaluate diagnostic accuracy measures. In our sample, we did not observe a significant effect of disease on SN-FA and it was uninformative for diagnosis. The results of the meta-analysis estimated a 0.03 decrease in mean SN-FA in PD relative to HC (CI: 0.01–0.05). However, the discriminatory capability of SN-FA to diagnose PD was low: pooled sensitivity and specificity were 72 % (CI: 68–75) and 63 % (CI: 58–70), respectively. There was high heterogeneity between studies (I2 = 91.9 %). SN-FA cannot be used as an isolated measure to diagnose PD. • SN-FA appears insufficiently sensitive and specific to diagnose PD. • Radiologists must be careful when translating mean group results to clinical practice. • Imaging protocol and analysis standardization is necessary for developing reproducible quantitative biomarkers.

Parkinson's disease (PD) is a neurodegenerative disorder that affects motor skills and cognition. As brain structure and function are compromised, functional magnetic resonance imaging (fMRI) can be a helpful tool to further investigate how intrinsic connectivity is impaired on the disease. The precuneus and medial prefrontal cortex (mPFC) are hub regions involved on the default mode network (DMN), a system that is active during rest and related to cognitive processes. We hypothesized that PD patients would present a decrease in functional connectivity among these two regions and the rest of the brain. Our goal was to identify regions in which functional connectivity to precuneus and mPFC was altered in PD. This study was based on resting-state fMRI data from 37 healthy subjects and 55 PD patients. Precuneus and mPFC were selected as seed regions in a whole brain functional connectivity mapping. As expected, we found abnormal connectivity from precuneus to motor system regions in PD patients, pointing toward a decreased connectivity in the disease. No significant group effects were found for the mPFC. Our findings suggest that internetwork connectivity from DMN to motor system is impaired in PD.

Summary Background The intrapleural instillation of a sclerosing agent produces an inflammatory process frequently followed by pain. The treatment can include the use of analgesics or anti-inflammatory drugs. Previously, it was demonstrated (experimental studies) that corticoids and nonsteroidal anti-inflammatory drugs (diclofenac) reduce the inflammation and fibrosis produced by talc but not by transforming growth factor-β or silver nitrate. The objective of this study was to determine whether parecoxib (COX-2 inhibitor) affects pleurodesis induced by talc or silver nitrate. Methods 140 rabbits received intrapleural injection (2mL) of 400mg/kg of talc or 0.5% silver nitrate. A subgroup of 70 animals received additional daily intramuscular parecoxib (1mg/kg). They were sacrificed at 4, 24, 48, 72h or 7, 14, or 28 days after the procedure. The pleural fluid was quantified; biochemical examinations (glucose, lactic dehydrogenase, and proteins) and immunologic dosages (interleukin-8, vascular endothelial growth factor, and transforming growth factor-β 1 ) were analyzed in pleural fluid and blood. Finally, macro- and microscopic pleura and lung studies were performed. Results Evaluation after 28 days demonstrated that parecoxib reduced pleural and pulmonary inflammation but not pleural adhesions. The changes were observed precociously ( ≅ 72 h ) and were more evident after silver nitrate injection. Conclusion Systemic parecoxib injection does not interfere with talc or silver nitrate pleurodesis. These results suggest that use of COX-2 inhibitors can be considered and depending of the results of other studies, recommended in human pleurodesis.