Minimally invasive cerebral cavernoma surgery using keyhole approaches - solutions for technique-related limitations.

Cavernomas are often small in size and located in difficultly accessible regions. Preoperative identification of the ideal surgical approach as well as the precise intraoperative implementation of the surgical plan are of critical importance for successful surgery. While aiming for minimally invasive surgical techniques and maximally effective cavernoma resection, we envisaged that employing a combination of precise and technically sophisticated virtual reality surgery planning, modern navigation systems with augmented reality features and endoscope-assisted surgical techniques should contribute to achieve this goal. Between December 2002 and November 2005, 66 patients were operated on for …

<title>Follow-up in patients with subdural haematomas using near-infrared spectroscopy (NIRS)</title>

Secondary haemorrhage is an important cause of brain injury following initial therapy of subdural haematoma (SDH). Early identification and treatment of secondary haemorrhage improves neurologic outcome. Near infrared light at a wavelength of 760 nm shows a high absorption for haemoglobin. The difference in absorbance of light ((Delta) OD) at the wavelength of 760 nm between both hemispheres is measured to detect SDH. We have prospectively studied 20 patients with the CT diagnosis of SDH using near infrared spectroscopy (NIRS). Unilateral subdural haematomas were detected by NIRS in 15 out of 16 patients. Bilateral SDH were detected in 2 out of 3 patients. The median of (Delta) OD was reduc…

Effect of intraarterial papaverine or nimodipine on vessel diameter in patients with cerebral vasospasm after subarachnoid hemorrhage.

Papaverine (P) and nimodipine (N) are the most widely used vasodilators when angiographic and symptomatic vasospasm is present after subarachnoid aneurysmatic hemorrhage (SAH). Their effect is only short-lived and no direct comparisons have been undertaken to evaluate the action of both substances directly. We retrospectively assessed the effect of either P or N on angiographic diameter reduction and capillary blood flow.Fifteen SAH patients with secured aneurysms and cerebral vasospasm received intraarterial P, fifteen similar patients received N. As the primary endpoint, pre- and post-infusion arterial diameters and capillary blood flow were rated retrospectively on angiographies and comp…

Virtual endoscopy of the inner ear and the auditory canal.

To assess the role of virtual endoscopy (VE) in the examination of intracisternal structures and of the inner ear, we studied the anatomy of the labyrinth and internal auditory canal using the original CT slices and VE on the unaffected side in three female and three male patients, age range 3–46 years, with contralateral retrocochlear hearing loss. We also examined seven patients with different pathological findings. VE was performed using an advanced postprocessing program with high- resolution 3D data sets of CT (1–1.5 mm thickness, pitch 1.25) and MRI-CISS-3D (constructive interference in steady state) images of the basal cisterns (1.5 T, slice thickness 0.7–1 mm). VE provides an endosc…

Fehlerquellen der Navigation in der lateralen Sch�delbasischirurgie

Die Identifikation moglicher Storfaktoren navigationsunterstutzter Eingriffe an der lateralen Schadelbasis ermoglichen dem Anwender die Vermeidung und Behebung dieser Fehler. Anhand unserer Erfahrungen von 85 navigationsunterstutzten Eingriffen im Bereich der lateralen Schadelbasis werden Fehler der Hard- und Software, der Bildgebung und des -transfers, der Patientenregistrierung, durch den Anwender und solche strategischer Art analysiert. Bei optischen CAS-Systemen fuhrt eine Blockade des Sichtfelds der Kameras zu Funktionsbeschrankungen, wahrend elektromagnetische Systeme durch ferromagnetisch aktive Materialien beeinflusst werden konnen. Die bisherigen Verfahren der Patientenregistrierun…

Combined spike-related functional MRI and multiple source analysis in the non-invasive spike localization of benign rolandic epilepsy.

Abstract Objective To localize the irritative zone in children by combined spike-related fMRI and EEG multiple source analysis (MSA) in children with benign rolandic epilepsy. Methods Interictal spikes were averaged and localized using MSA, and source locations were displayed in the anatomical 3D-MRI in 11 patients (5–12 yrs, median 10). Interictal spikes were additionally recorded during the fMRI acquisition (EEG-fMRI), and the fMRI sequences were correlated off-line with the EEG spikes. Results MSA revealed an initial central dipole in all patients, including the face or hand area. A second dipolar source was mostly consistent with propagated activity. BOLD activations from EEG-fMRI, cons…

<title>Noninvasive detection of intracerebral hemorrhage using near-infrared spectroscopy (NIRS)</title>

Intracerebral Hemorrhage (IH) is an important cause of secondary brain injury in neurosurgical patients. Early identification and treatment improve neurologic outcome. We have tested Near Infrared Spectroscopy (NIRS) as an alternative noninvasive diagnostic tool compared to CT-Scans to detect IH. We prospectively studied 212 patients with neurologic symptoms associated with intracranial pathology before performing a CT-scan. NIRS signals indicated pathologies in 181 cases (sensitivity 0.96; specificity 0.29). In a subgroup of subdural hematomas NIRS detected 45 of 46 hematomas (sensitivity 0.96; specificity 0.79). Identification of intracerebral hemorrhage using NIRS has the potential to al…

CT Angiography as a Confirmatory Test in Brain Death

Objective: From recent studies, it remains unclear whether CT angiography could be an alternative to other established ancillary tests for the diagnosis of brain death. We examined intracranial contrast enhancement in CT angiography after clinically established brain death and compared the results with EEG and TCD findings.

Virtual reality system for planning minimally invasive neurosurgery

Object The authors report on their experience with a 3D virtual reality system for planning minimally invasive neurosurgical procedures. Methods Between October 2002 and April 2006, the authors used the Dextroscope (Volume Interactions, Ltd.) to plan neurosurgical procedures in 106 patients, including 100 with intracranial and 6 with spinal lesions. The planning was performed 1 to 3 days preoperatively, and in 12 cases, 3D prints of the planning procedure were taken into the operating room. A questionnaire was completed by the neurosurgeon after the planning procedure. Results After a short period of acclimatization, the system proved easy to operate and is currently used routinely for pre…

Endovascular therapy for vasospasm after aneurysmatic subarachnoid hemorrhage

Balloon angioplasty and/or selective intra-arterial vasodilator therapies are treatment options in patients with vasospasm after subarachnoid hemorrhage (SAH). We analyzed the effect of balloon angioplasty and/or selective intra-arterial vasodilator therapy in our patients.Twenty-six patients (vasodilation group, VDT) were treated with intra-arterial nimodipine. The balloon angioplasty with nimodiopine-group (BAP-N group) comprised 21 patients. The primary endpoint of this study was successful angiographic vessel dilation in vasospastic vessels after balloon angioplasty, together with nimodipine (BAP-N group), compared to intra-arterial vasodilator therapy (VDT group) with nimodipine alone.…

Evaluation of robot-guided minimally invasive implantation of 2067 pedicle screws

ObjectiveRecent studies have investigated the role of spinal image guidance for pedicle screw placement. Many authors have observed an elevated placement accuracy and overall improvement of outcome measures. This study assessed a bi-institutional experience following introduction of the Renaissance miniature robot for spinal image guidance in Europe.MethodsThe medical records and radiographs of all patients who underwent robot-guided implantation of spinal instrumentation using the novel system (between October 2011 and March 2015 in Mainz and February 2014 and February 2016 in Regensburg) were reviewed to determine the efficacy and safety of the newly introduced robotic system. Screw posit…

Detection of intracranial circulatory arrest in brain death using cranial CT-angiography.

Background and purpose Computed tomographic-angiography (CT-A) is becoming more accepted in detecting intracranial circulatory arrest in brain death (BD). An international consensus about the use and the parameters of this technique is currently not established. We examined intracranial contrast enhancement in CT-A after clinically confirmed BD, compared the results with electroencephalography (EEG) and Transcranial Doppler Ultrasonography (TCD) findings and developed a commonly applicable CT-A protocol. Methods Prospective, monocentric study between April 2008 and October 2011. EEG, TCD and CT-A were performed in 63 patients aged between 18 and 88 years (mean, 55 years) who fulfilled clini…

Minimally invasive superficial temporal artery to middle cerebral artery bypass through a minicraniotomy: benefit of three-dimensional virtual reality planning using magnetic resonance angiography

Object The aim of the authors in this study was to introduce a minimally invasive superficial temporal artery to middle cerebral artery (STA-MCA) bypass surgery by the preselection of appropriate donor and recipient branches in a 3D virtual reality setting based on 3-T MR angiography data. Methods An STA-MCA anastomosis was performed in each of 5 patients. Before surgery, 3-T MR imaging was performed with 3D magnetization-prepared rapid acquisition gradient echo sequences, and a high-resolution CT 3D dataset was obtained. Image fusion and the construction of a 3D virtual reality model of each patient were completed. Results In the 3D virtual reality setting, the skin surface, skull surface…

Safety of endovascular treatment in acute stroke patients taking oral anticoagulants

International journal of stroke 12(4), 412-415 (2017). doi:10.1177/1747493016677986

Intraoperative Navigation in der Chirurgie der Nasennebenhöhlen und der vorderen Schädelbasis

Hintergrund und Fragestellung. Beim Einsatz der computerassistierten Chirurgie im Bereich der Nasennebenhohlen und vorderen Schadelbasis sind einige Fehlerquellen zu beachten, die durch physikalische Gesetze, den technischen Entwicklungs- und individuellen Kenntnisstand des Anwenders bedingt sind. Patienten/Methodik. Anhand unserer Erfahrungen von 436 navigationsunterstutzten Eingriffen werden Hard- und Softwarefehler, Fehler der Bildgebung und des -transfers, Fehler der Patientenregistrierung, Anwenderfehler und strategische Fehler analysiert. Ergebnisse. Bei optischen CAS-Systemen fuhrt die Blockade des Sichtfeldes der Kamera zu Funktionseinschrankungen, wahrend elektromagnetische Systeme…

EP46* First pass effect and associated clot characteristics in the EXCELLENT registry – Interim analysis

Introduction EXCELLENT (NCT03685578) is a prospective, single-arm, multicenter, real-world international registry of mechanical thrombectomy (MT) for stroke with the EmboTrap device as first line treatment. The study entails thrombus analysis of specimens collected with each MT pass. Aim of the Study To compare rates of mRS 0–2 at 90 days and clot characteristics in subjects with and without first pass effect (FPE). Methods FPE was defined as mTICI 2c/3 after one pass and non-FPE as mTICI 2c/3 after >1 pass as adjudicated by an independent core lab. Clot analysis was performed by independent central labs blinded to clinical data. mRS at 90 days was scored by investigators blinded to procedu…

Brainstem Anatomy of White Matter Tracts Using Diffusion Weighted Imaging

EEG-related Functional MRI in Benign Childhood Epilepsy with Centrotemporal Spikes

The localization of epileptic foci is an important issue in children with extratemporal epilepsies. However, the value of noninvasive methods such as the EEG-assisted functional magnetic resonance imaging (fMRI) has not been sufficiently investigated in children. As a model of extratemporal epilepsies, we studied 7 patients aged 5 to 12 (median 10) years with benign childhood epilepsy and centrotemporal (rolandic) spikes. Interictal spikes were recorded during the fMRI acquisition on a MR-compatible battery-powered digital EEG system with 16 channels. The fMRI sequences were correlated off-line with the EEG spikes and analyzed with the software Statistical Parametrical Mapping SPM99. The fM…

Blindness, tetraspasticity, and other signs of irreversible brain damage in hereditary angioedema

Asymmetrie des Planum temporale bei Zwillingen und Schizophrenen

Anhand eines Zwillingskollektivs und einer Gruppe ersterkrankter Schizophrener (zehn eineiige und zehn zweieiige Zwillingspaare, 38 ersterkrankte Schizophrene, 15 Kontrollen) wird ein moglicher genetischer Einflus auf Grose und Windungsmuster des Planum temporale untersucht. MRT: FLASH-3D-T1-gewichtete Datensatze aus koronaren 3-mm-Schichten; 3D-Rekonstruktion mit ISG-Workstation Allegro. Gemessen wurden Lange und Flache des Planum temporale und Lange des Heschlschen Gyrus. Der Windungsverlauf wurde nach qualitativen Kriterien beurteilt. Schizophrene zeigen im Gegensatz zu gesunden Kontrollen, eineiigen und zweieiigen Zwillingen vor allem bei der Lanlge und weniger bei der Flache des Planum…