BOLD CVR corresponded well to CBF perfusion reserve measurements obtained with (O-)HO-PET, especially for detecting hemodynamic failure in the affected hemisphere and middle cerebral artery territory and for identifying hemodynamic failure stage II. BOLD CVR may, therefore, be considered for prospective studies assessing stroke risk in patients with chronic cerebrovascular steno-occlusive disease, in particular because it can potentially be implemented in routine clinical imaging.
ObjectiveTo improve quantitative cerebrovascular reactivity (CVR) measurements and CO
2 arrival times, we present an iterative analysis capable of decomposing different temporal components of the dynamic carbon dioxide‐ Blood Oxygen‐Level Dependent (CO
2‐BOLD) relationship.Experimental DesignDecomposition of the dynamic parameters included a redefinition of the voxel‐wise CO
2 arrival time, and a separation from the vascular response to a stepwise increase in CO
2 (Delay to signal Plateau – DTP) and a decrease in CO
2 (Delay to signal Baseline –DTB). Twenty‐five (normal) datasets, obtained from BOLD MRI combined with a standardized pseudo‐square wave CO
2 change, were co‐registered to generate reference atlases for the aforementioned dynamic processes to score the voxel‐by‐voxel deviation probability from normal range. This analysis is further illustrated in two subjects with unilateral carotid artery occlusion using these reference atlases.Principal ObservationsWe have found that our redefined CO
2 arrival time resulted in the best data fit. Additionally, excluding both dynamic BOLD phases (DTP and DTB) resulted in a static CVR, that is maximal response, defined as CVR calculated only over a normocapnic and hypercapnic calibrated plateau.ConclusionDecomposition and novel iterative modeling of different temporal components of the dynamic CO
2‐BOLD relationship improves quantitative CVR measurements.
The authors present a microsurgical technique for the resection of a heterogeneous group of pineal-region tumors and discuss the key points for successfully performing this surgery. Twenty-six consecutive patients with pineal-region tumors were resected by the senior author (H.B.) and analyzed retrospectively. For all 26 patients, the operation was conducted using the infratentorial supracerebellar (ITSC) approach in the sitting (23 patients) or Concorde (three patients) positions. Twenty-five patients had symptomatic obstructive hydrocephalus and were treated with ventricular drainage, a previously inserted ventriculoperitoneal shunt, or an endoscopic third ventriculostomy before undergoing resection of the pineal-region tumor. The gross total removal of the tumor was achieved in 23 patients and subtotal removal was achieved in three patients. The tumors were pathologically diagnosed mainly as pineocytomas (10), pilocytic astrocytomas (6), or pineal cysts (4). Twenty-five of the patients clinically improved after surgery, and there was no mortality. Two patients experienced transient postoperative neurological deterioration: one patient developed Parinaud syndrome, and one patient developed intermittent diplopia. Successful surgery and patient outcome when treating tumors of the pineal region using the ITSC approach requires: (i) preservation of the venous flow of the Galenic draining system; (ii) preservation of the thick bridging veins of the tentorial surface of the cerebellum, especially the hemispheric bridging veins; and (iii) minimizing retraction of the cerebellum during surgery to avoid adverse effects caused by both direct cerebellar compression and disturbance of the venous circulation.
BackgroundThe aesthetic outcome after burr hole trepanation for the evacuation of chronic subdural hematomas (cSDH) is often unsatisfactory, as the bony skull defects may cause visible skin depressions. The purpose of this study was to evaluate the efficacy of burr hole cover placement to improve the aesthetic outcome.MethodsWe reviewed consecutive patients treated by burr hole trepanation for cSDH with or without placement of burr hole covers by a single surgeon between October 2016 and May 2018. The clinical data, including complications, were derived from the institution’s prospective patient registry. The primary endpoint was the aesthetic outcome, as perceived by patients on the aesthetic numeric analog (ANA) scale, assessed by means of a standardized telephone interview. Secondary endpoints were skin depression rates and wound pain, as well as complications.ResultsFrom n = 33, outcome evaluation was possible in n = 28 patients (n = 24 male; mean age of 70.4 ± 16.1 years) with uni- (n = 20) or bilateral cSDH (n = 8). A total of 14 burr hole covers were placed in 11 patients and compared to 50 burr holes that were not covered. Patient satisfaction with the aesthetic outcome was significantly better for covered burr holes (mean ANA 9.3 ± 0.74 vs. 7.9 ± 1.0; p < 0.001). Skin depressions occurred over 7% (n = 1/14) of covered and over 92% (n = 46/50) of uncovered burr holes (p < 0.001). There was no difference in wound pain (p = 0.903) between covered and uncovered sites. No surgical site infection, cSDH recurrence, or material failure was encountered in patients who had received a burr hole plate.ConclusionsIn this retrospective series, placement of burr hole covers was associated with improved aesthetic outcome, likely due to reduction of skin depressions. A randomized controlled trial is developed to investigate whether adding burr hole covers results in superior aesthetic outcomes, without increasing the risk for complications.
The results of this large series support the notion that microsurgical removal of a brainstem cavernoma represents an effective therapy in experienced hands and is generally associated with good clinical outcome, both neurologically and in terms of QoL.
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