Daniel Pinggera

Preoperative prediction of language function by diffusion tensor imaging

For surgery of eloquent tumors in language areas, the accepted gold standard is functional mapping through direct cortical stimulation (DCS) in awake patients. Ever since, neuroscientists are searching for reliable noninvasive detection of function in the human brain, with variable success. The potential of diffusion tensor imaging (DTI) in combination with computational cortical parcellation to predict functional areas in language eloquent tumors has not been assessed so far. We present a proof-of-concept report involving awake surgery for a temporodorsal tumor. Postoperatively, the imaging was extensively studied and a predictive value of multimodal MR imaging for the possible extent of resection was analyzed. After resection using DCS, the extent of resection and functional outcome were correlated with the processed imaging. Preoperative imaging of our patient was taken to compute the lesion volume as a seed for tractography (DTI) and combined with a tractography of the entire hemisphere. For better spatial resolution, an elastic image fusion was performed to correct the distortion of DTI data. After subtotal resection and imaging analysis, the status of the superior part of the lesion could be identified and predicted as functional cortex. There was a strong correlation between the tumor remnant during surgery and the imaging parameters of DTI connectivity of the eloquent tissue. A combination of complex DTI processing may be able to predict function in a patient suffering eloquent brain tumors and thus allow estimation of extent of resection.

Disseminated Intravascular Coagulation in Secondary Glioblastoma due to Excessive Intraoperative Bleeding: Case Report and Review of the Literature.

BACKGROUND Disseminated intravascular coagulation (DIC) describes a pathologic activation of coagulation mechanisms, leading to thrombi in various organs with contribution to multiple organ failure. In clinical practice, diagnosis of DIC can often be made by laboratory values, including prolonged coagulation times, thrombocytopenia, or high levels of fibrin degradation products. DIC is frequently observed after neurotrauma, but rarely occurs in patients with primary brain tumors. There are only few case reports of DIC in patients with primary brain tumors, all sharing the highly elevated mortality. We report the case of a young patient presenting with secondary glioblastoma, who developed multiorgan failure induced by DIC after extensive intraoperative bleeding. CASE DESCRIPTION A 30-year-old patient was admitted in poor general condition with insomnia, severe headache, and vomiting. She had undergone surgery for secondary glioblastoma twice. Magnetic resonance imaging revealed a left temporoparietal mass lesion with indication for resection. Surgery then was complicated by diffuse intraoperative bleeding due to a high content of microvascular proliferation as shown in the histopathologic workup. Subsequently, an uncontrollable multiorgan failure developed, causing the patients death 4 days after surgery. CONCLUSIONS Although a rare complication, excessive intraoperative bleeding, especially in surgery for brain tumors located next to the ventricular system, DIC should be kept in mind as a possible diagnosis.

Adjustable and Rigid Fixation of Brain Tissue Oxygenation Probe (Licox) in Neurosurgery: From Bench to Bedside

Multimodal neuromonitoring has become a fundamental part of management for many neurosurgical disorders such as subarachnoid hemorrhage and severe traumatic brain injury. Brain tissue oxygen tension monitoring requires insertion of a probe into the brain parenchyma through a single multiple lumen bolt, or in a subcutaneously tunneled fashion. As those patients often require early magnetic resonance imaging, typically using bolts is disadvantageous due to massive metal artifact. Similarly, subcutaneous tunneling is often problematic as suture fixation can loosen over time. We hereby report a new method of fixation of the Licox brain tissue oxygenation probe with 1 or 2 3-way taps that are attached to a standard plastic cannula, resulting in a stable connection with no need for further direct sutures around the probe and above all with no metal artifacts, which negates magnetic resonance imaging. The extended fixation system was first tested with cardiopulmonary resuscitation in a brain injured porcine model. It was thereafter adopted in our daily clinical practice.

Accuracy Validation of Neuronavigation Comparing Headholder-Based System with Head-Mounted Array—A Cadaveric Study

BACKGROUND Neuronavigation is widely used for intracranial neurosurgical procedures and is commonly based on the standard reference array being fixed to the headholder. Some cases require the reference array to be attached directly to the head. The aim of this cadaveric study was to compare operational accuracy of a head-mounted reference array with the standard headholder-based system. METHODS Navigation accuracy was evaluated with 10 cadaveric specimens. Each specimen was prepared with 8 titanium microscrews that served as reference points on the external skull, and computed tomography was performed. Registration of all specimens was done using surface matching with infrared laser on three-dimensional reconstructed high-resolution computed tomography. In all 10 specimens, the head-mounted reference array and headholder-based system were compared by 10 repetitive measurements. The deviation was evaluated for each screw and compared using nonparametric Mann-Whitney U test between groups and screws. A Bland-Altman plot was generated for comparison. RESULTS A total of 1600 measurements were conducted. Mean deviation was 1.97 mm (95% confidence interval, 1.90-2.03 mm) with the head-mounted reference array and 2.10 mm (95% confidence interval, 2.04-2.18 mm) with the headholder based system. There was no significant difference between methods in 9 of 10 specimens. In 1 specimen, the head-mounted array was superior. The deviation in either method showed a significant correlation, indicating high pertinence for registration (P < 0.001). CONCLUSIONS Navigation with the head-mounted reference array demonstrated comparable accuracy to the headholder-based system and can be used without reduced accuracy. Careful registration is mandatory.

The Volume of the Third Ventricle as a Prognostic Marker for Shunt Dependency After Aneurysmal Subarachnoid Hemorrhage

BACKGROUND Hydrocephalus is a common sequelae of aneurysmal subarachnoid hemorrhage (aSAH). However, in daily routine it is difficult to predict a patients need for ventricular shunt placement in the course of the disease. OBJECTIVE The purpose of this study was to identify radiologic predictors for development of a shunt-dependent hydrocephalus after aSAH. METHODS A cohort of 217 patients with aSAH with adequate pretreatment computed tomography (CT) imaging was retrospectively reviewed. All variables, including demographic data, treatment, and initial CT imaging were gathered and grading was performed using Hunt and Hess, Graeb, LeRoux, and modified Fisher scores. Analysis of the radiographic parameters consisted of straight measurement and three-dimensional volumetry using manual segmentation. Univariate and multivariate statistical analyses were performed to identify predictive parameters. RESULTS Of 217 patients, 36 (17.5%) required a ventricular shunt (VS). A receiver operating characteristic analysis between the volume of the third ventricle and shunt-dependent hydrocephalus showed a significant cutoff at a volume of 2.3 cm3 with a 4.3-fold higher risk for shunt dependency (P < 0.001). However, the treatment modality and classification according to the mentioned scores were not associated with the need for VS after aSAH. In univariate and multivariate analysis, the volume of the third ventricle on admission remained a significant prognostic marker for the need of a VS. CONCLUSIONS Our data suggest that the volume of the third ventricle in the initial CT is a strong predictor for shunt dependency after aSAH.