Browsing by Author "Canto-Moreira, N"
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- Comparison of Cerebral Perfusion in Perimesencephalic Subarachnoid Hemorrhage and Aneurysmal Subarachnoid HemorrhagePublication . Fragata, I; Canto-Moreira, N; Canhão, PPurpose: Perimesencephalic hemorrhage (PMH) is a benign subtype of nonaneurysmal subarachnoid hemorrhage (SAH). We aimed to investigate if cerebral perfusion in PMH is less affected than in aneurysmal SAH (aSAH). Methods: From a prospective cohort of 80 patients with spontaneous SAH, we included PMH patients (n = 15) and selected aSAH patients (n = 39) with similar clinical grade at admission (World Federation of Neurosurgeons Scale-WFNS I/II). Computed tomography (CT) perfusion was performed at < 72 h and/or at 8-10 days. Cerebral perfusion parameter values were compared between groups with nonparametric tests. Subgroup analyses compared PMH and aSAH patients stratified according to aneurysmal location (anterior or posterior circulation) and blood burden (Fisher grade). Results: At < 72 h, no significant differences in perfusion parameters were found between PMH and aSAH patients. At 8-10 days, PMH patients had lower MTT than aSAH patients, and a trend for higher CBF. PMH patients had higher CBF and CBV at < 72 h when compared to posterior circulation aSAH patients. When compared to aSAH patients with similar blood burden, PMH patients had higher CBF and lower MTT at < 72 h, and lower MTT at 8-10 days. Conclusion: PMH patients had better cerebral perfusion compared to patients with aSAH, particularly during the vasospasm time window. After stratifying for the amount of blood, PMH patients also had better cerebral perfusion in the first 72 h after SAH. These results are in line with the better clinical presentation and prognosis of PMH, and possibly with a different etiology.
- Evolution of Diffusion Tensor Imaging Parameters after Acute Subarachnoid Haemorrhage: a Prospective Cohort StudyPublication . Fragata, I; Canhão, P; Alves, M; Papoila, AL; Canto-Moreira, NINTRODUCTION: Few studies assessed diffusion tensor imaging (DTI) changes in the acute phase of subarachnoid haemorrhage (SAH). We prospectively evaluated DTI parameters in the acute phase of SAH and 8-10 days after and analysed whether changes could be related to SAH severity or to the development of delayed cerebral ischemia (DCI). METHODS: Apparent diffusion coefficient (ADC) and fractional anisotropy (FA) changes over time were assessed in a prospective cohort of patients with acute SAH. Two MRI studies were performed at <72 h (MRI-1) and 8-10 days (MRI-2). DTI parameters were recorded in 15 ROIs. Linear mixed regression models were used. RESULTS: Forty-two patients were included. Subtle changes in DTI parameters were found between MRI-1 and MRI-2. At the posterior limb of internal capsule (PLIC), a weak evidence of a 0.02 mean increase in FA (p = 0.064) and a 17.55 × 10-6 mm2/s decrease in ADC (p = 0.052) were found in MRI-2. Both FA and ADC changed over time at the cerebellum (increase of 0.03; p = 0.017; decrease of 34.73 × 10-6 mm2/s; p = 0.002, respectively). Patients with DCI had lower FA values on MRI-1 and lower ADC on MRI-2, although not reaching statistical significance, compared to non-DCI patients. DTI parameters on MRI-1 were not correlated to clinical admission scales. CONCLUSION: ADC and FA values show subtle changes over time in acute SAH at the PLIC and cerebellum although not statistically associated with the severity of SAH or the occurrence of DCI. However, DTI changes occurred mainly in DCI patients, suggesting a possible role of DTI as a marker of DCI.