Spinal intramedullary schwannomas-report of a case and extensive review of the literature.

Intramedullary schwannomas (IMS) represent exceptional rare pathologies. They commonly present as solitary lesions; only five cases of multiple IMS have been described so far. Here, we report the sixth case of a woman with multiple IMS. Additionally, we performed the first complete systematic review of the literature for all cases reporting IMS. We performed a systematic review of the literature in PubMed, EMBASE and Cochrane Central Register of Controlled (CENTRAL) to retrieve all relevant studies and case reports on IMS. In a second step, we analysed all reported studies with respect to additional cases, which were not identified through the database search. Studies published in other languages than English were included. One hundred nineteen studies including 165 reported cases were included. In only five cases, the patients harboured more than one IMS. Gender ratio showed a ratio of nearly 3:2 (male:female); mean age of disease presentation was 40.2 years; 11 patients suffered from neurofibromatosis (NF) type 1 or 2 (6.6%). IMS are rare. Our first systematic review on this pathology revealed 166 cases, including the here reported case of multiple IMS. Our review offers a basis for further investigation on this disease.

Suitability of intravascular imaging for assessment of cerebrovascular diseases.

PURPOSE: Arteriosclerosis of the vascular system is associated with many accompanying diseases. Especially cerebral arteriosclerosis is a main risk factor for ischemic strokes. We want to verify the practicability of intravascular imaging like intravascular ultrasound and optical coherence tomography for the assessment of cerebral vessel walls and plaques. METHODS: We examined 18 Circuli arteriosi willisii postmortem. The data contained 48 plaques from 48 different vessel parts. The samples underwent intravascular and histological imaging to conduct a quantitative assessment of vessel wall parameters (healthy vessel wall, thinnest vessel wall, plaque thickness and vessel diameter) as well as to qualitatively evaluate the healthy vessel wall, fibrotic plaques, calcifications and cholesterol deposits in diseased vessels. RESULTS: The comparison showed statistically significant smaller measurements for thinnest vessel walls, normal vessel walls and vessel diameters in histology than in imaging. No statistically significant difference was reached for plaque diameters. Fibrotic plaques were characterized as hyper-intense with dorsal attenuation and calcifications as hypo-intense with dorsal attenuation in optical coherence tomography. In intravascular ultrasound, fibrotic plaques showed a homogeneous echogenicity without distal attenuation and calcifications were depicted as hyperechoic with dorsal sound shadows. Cholesterol deposits were hyper-intense in optical coherence tomography with strongly attenuated signals and in intravascular ultrasound; the deposits were hyper-intense with almost no attenuation. CONCLUSION: Both intravascular methods allow for plaque characterization and quantification of plaque diameter in cerebral vessel walls. When compared with histology, a statistically significant bias was obtained for the ex vivo measurements of the normal vessel wall diameters.

A gesture-controlled projection display for CT-guided interventions.

PURPOSE: The interaction with interventional imaging systems within a sterile environment is a challenging task for physicians. Direct physician-machine interaction during an intervention is rather limited because of sterility and workspace restrictions. METHODS: We present a gesture-controlled projection display that enables a direct and natural physician-machine interaction during computed tomography (CT)-based interventions. Therefore, a graphical user interface is projected on a radiation shield located in front of the physician. Hand gestures in front of this display are captured and classified using a leap motion controller. We propose a gesture set to control basic functions of intervention software such as gestures for 2D image exploration, 3D object manipulation and selection. Our methods were evaluated in a clinically oriented user study with 12 participants. RESULTS: The results of the performed user study confirm that the display and the underlying interaction concept are accepted by clinical users. The recognition of the gestures is robust, although there is potential for improvements. The gesture training times are less than 10 min, but vary heavily between the participants of the study. The developed gestures are connected logically to the intervention software and intuitive to use. CONCLUSIONS: The proposed gesture-controlled projection display counters current thinking, namely it gives the radiologist complete control of the intervention software. It opens new possibilities for direct physician-machine interaction during CT-based interventions and is well suited to become an integral part of future interventional suites.

Surpass flow diverter in the treatment of intracranial aneurysms: a prospective multicenter study.

BACKGROUND AND PURPOSE: Incomplete occlusion and recanalization of large and wide-neck brain aneurysms treated by endovascular therapy remains a challenge. We present preliminary clinical and angiographic results of an experimentally optimized Surpass flow diverter for treatment of intracranial aneurysms in a prospective, multicenter, nonrandomized, single-arm study. MATERIALS AND METHODS: At 24 centers, 165 patients with 190 intracranial aneurysms of the anterior and posterior circulations were enrolled. The primary efficacy end point was the percentage of intracranial aneurysms with 100% occlusion on 6-month DSA. The primary safety end point was neurologic death and any stroke through a minimum follow-up of 6 months. RESULTS: Successful flow-diverter delivery was achieved in 161 patients with 186 aneurysms (98%); the mean number of devices used per aneurysm was 1.05. Clinical follow-up (median, 6 months) of 150 patients (93.2%), showed that the primary safety end point occurred in 18 subjects. Permanent neurologic morbidity and mortality were 6% and 2.7%, respectively. Morbidity occurred in 4% and 7.4% of patients treated for aneurysms of the anterior and posterior circulation, respectively. Neurologic death during follow-up was observed in 1.6% and 7.4% of patients with treated intracranial aneurysms of the anterior and posterior circulation, respectively. Ischemic stroke at ≤30 days, SAH at ≤7 days, and intraparenchymal hemorrhage at ≤7 days were encountered in 3.7%, 2.5%, and 2.5% of subjects, respectively. No disabling ischemic strokes at >30 days or SAH at >7 days occurred. New or worsening cranial nerve deficit was observed in 2.7%. Follow-up angiography available in 158 (86.8%) intracranial aneurysms showed 100% occlusion in 75%. CONCLUSIONS: Clinical outcomes of the Surpass flow diverter in the treatment of intracranial aneurysms show a safety profile that is comparable with that of stent-assisted coil embolization. Angiographic results showed a high rate of intracranial aneurysm occlusion.

Decerebrate posturing following traumatic brain injury: MRI findings and their diagnostic value.

AIM: To determine the pathomorphological and clinical background to decerebrate posturing in humans following serious traumatic brain injury. MATERIALS AND METHODS: One hundred and twenty patients who had been unconscious for more than 24 h underwent diagnostic MRI within 8 days after trauma. The presence of decerebrate rigidity as the clinical parameter was correlated to MRI findings, such as traumatic lesions in defined brain areas. Significance was presumed as p < 0.05. RESULTS: On the day of MRI 43 (36%) patients exhibited decerebrate posturing: 19 (23%) cases were unilateral and 24 (77%) bilateral. There was a significant correlation between midbrain lesions and the presence of rigidity. If a midbrain lesion was found in the absence of pontine lesions, decerebrate rigidity could be concluded (p < 0.05). There was no significant correlation to the rigidity in the case of midbrain lesions accompanied by pontine lesions, and no correlation to the rigidity could be detected for other regions of the brain. Both the occurrence of decerebrate posturing and the detection of brainstem lesions at MRI correlated with the Glasgow Outcome Scale. The combination of both parameters improved the probability of predicting the outcome. CONCLUSION: The rate of decerebrate posturing increases significantly in the presence of midbrain lesions. The presence of pontine lesions appears to be of secondary importance. The chances of predicting the Glasgow Outcome Scale are improved by the combination of clinical information (decerebrate posturing) and radiological parameters (type of brainstem lesion).

A novel technique for the measurement of CBF and CBV with robot-arm-mounted flat panel CT in a large-animal model.

BACKGROUND AND PURPOSE: Endovascular therapy is an emerging treatment option in patients with acute ischemic stroke and especially in cases presenting late after symptom onset. Information about remaining viable tissue as measured with perfusion imaging is crucial for proper patient selection. The aim of this study was to investigate whether perfusion imaging with C-arm CT in the angiography suite is feasible and provides measurements comparable with ones made by CTP. MATERIALS AND METHODS: The MCA was occluded surgically in 6 sheep. Perfusion studies were performed before surgery, immediately after, and at 3 hours after MCA occlusion by using a robotic flat panel detector C-arm angiographic system. For comparison, conventional CTP was performed at the same time points. Two different protocols with the C-arm CT were tested. Images were analyzed by 2 readers with regard to the presence and size of perfusion abnormalities. RESULTS: With C-arm CT, perfusion abnormalities were detected with a high sensitivity and specificity when vessel occlusion was confirmed by criterion standard DSA. No difference was found between lesions sizes measured with the 2 C-arm CT protocols and CTP. Growth of the CBV lesions with time was captured with C-arm CT and CTP. CONCLUSIONS: In this small study, it was feasible to qualitatively measure CBV and CBF by using a flat panel detector angiographic system.

Gadolinium-enhanced magnetic resonance angiography in brain death.

Confirmatory tests for the diagnosis of brain death in addition to clinical findings may shorten observation time required in some countries and may add certainty to the diagnosis under specific circumstances. The practicability of Gadolinium-enhanced magnetic resonance angiography to confirm cerebral circulatory arrest was assessed after the diagnosis of brain death in 15 patients using a 1.5 Tesla MRI scanner. In all 15 patients extracranial blood flow distal to the external carotid arteries was undisturbed. In 14 patients no contrast medium was noted within intracerebral vessels above the proximal level of the intracerebral arteries. In one patient more distal segments of the anterior and middle cerebral arteries (A3 and M3) were filled with contrast medium. Gadolinium-enhanced MRA may be considered conclusive evidence of cerebral circulatory arrest, when major intracranial vessels fail to fill with contrast medium while extracranial vessels show normal blood flow.

[Injuries to the upper cervical medulla in severe brain injuries]. / Verletzungen des oberen zervikalen Myelons beim schweren Schädel-Hirn-Trauma.

BACKGROUND: Cranial magnetic resonance imaging (MRI) was performed in 250 patients who had been unconscious post-trauma for at least 24 hours. The frequency and the characteristics of injuries to the upper cervical myelon were determined. PATIENTS AND METHODS: Between 1996 and 2009, MRI was carried out within 8 days of trauma. RESULTS: No lesions of the upper cervical medulla were found without accompanying damage to the medulla oblongata. Two groups were found to have a lesion in the upper cervical myelon. (i) In 3.2 % of the patients in a state of deep coma MRI revealed lesions in the entire brain stem. These died without waking from coma. (ii) 2 % of the patients were found to have additional damage to the distal medulla oblongata. These victims of high-speed traumas awoke from coma after 2-3 days. They revealed frontal contusions of the brain and traumatic subarachnoidal hemorrhages. Injuries to the bony upper cervical spine and/or the skull base were frequent. Four of them died, one patient survived with severe disabilities. CONCLUSION: Two types of lesions involving the upper cervical myelon could be differentiated, both of which occur only in association with lesions in the medulla oblongata.

Detecting artery occlusion and critical flow diminution in the case of an acute ischemic stroke--methodological pitfalls of common vascular diagnostic methods.

PURPOSE: None of the vascular emergency diagnostic methods commonly used in the case of acute ischemic stroke, i. e. CTA, color-coded duplex sonography (CCDS), MRA, and DSA, is free of restrictions due to physical and physiological characteristics. As a result, misleading results initiating an inappropriate acute therapeutic intervention or hampering a promising one cannot be excluded. We aimed to assess the type and frequency of methodological pitfalls occurring in this situation. MATERIALS AND METHODS: We retrospectively analyzed data of 269 consecutive patients admitted to our stroke unit with a clinical syndrome of an acute stroke. All patients underwent one or more vascular emergency diagnostic methods on a routine basis. RESULTS: 37 patients were excluded because of a final diagnosis other than ischemic stroke. 76 of 232 ischemic stroke patients underwent emergency diagnostic methods with two or more vascular examination techniques. Controversial results occurred in 20 patients and related to the detection and localization of large artery occlusion and its differentiation from a low/slow flow situation and the identification of critical cerebral flow diminution distal to large artery occlusion/severe stenosis. Methodological pitfalls were able to be most reliably resolved by CCDS. Within the whole cohort of ischemic stroke patients, vascular constellations susceptible to misinterpretation were diagnosed in 40 (17.2 %) patients. CONCLUSION: We recommend providing several techniques including CCDS in an emergency stroke setting and applying techniques with respect to diagnostic findings.

[Predictive quality of the injury severity score in the systematic use of cranial MRI]. / Prädiktorqualität des Injury Severity Score bei systematischem Einsatz der kraniellen Kernspintomografie.

AIM: The ABBREVIATED INJURY SCORE (AIS) for the head is mostly coded on the basis of cranial computed tomography (CT). It defines, to a large extent, the predictive potency of the INJURY SEVERITY SCORE (ISS). The present study investigates whether the predictive capacity of the ISS can be improved by the systematic use of data from cranial MRI. METHOD: 167 patients, who had been in a coma for at least 24 hours following trauma, underwent an MRI examination within 8 days. All had been found to have an intracranial injury on initial CT. 49 % had also suffered extracranial injuries. The GLASGOW OUTCOME SCALE (GOS) was determined 6 months post trauma. AIS, ISS and GOS values were rated as ordinal measurements. A contingency table was used as the statistical method of analysis, with a significance assumed as p < 0.05 (Chi (2) test). RESULTS: The median ISS based on CT was 16 and did not correlate with the GOS. 63 % of the patients revealed brain stem lesions on MRI. If these were coded with an AIS of 5, the median ISS increased significantly to 29. Thus, the correlation to the GOS was now significant. At ISS scores of 5-9, 18 % of the patients died; at scores of 50-54 the rate of favourable treatment outcomes still amounted to 50 %. Since it is now known that brain stem lesions can also have a favourable prognosis, the AIS coding was modified and adapted to the mortality of the singular types of lesion. Hence the median ISS again decreased to 16. The correlation to the GOS was significant, and the predictive potency of the ISS further improved. The prognostic potency of the REVISED INJURY SEVERITY CLASSIFICATION (RISC) score was improved by use of adapted MRI data. CONCLUSION: If visible brain stem lesions on MRI were coded according to the AIS guidelines, there was a significant increase in the ISS which correlated significantly to the GOS. If the AIS coding was adjusted to the prognostic significance of individual brain stem lesions, there was a further improvement in the prognostic potency of the ISS. The study encourages the inclusion of data obtained from MRI diagnostics in the ISS calculation. There are alternative ways.

[Cranial magnetic resonance imaging and serum marker S-100 for expert opinions in severe brain injuries]. / Kranielle Kernspintomographie und S-100 Serumdiagnostik in der Begut- achtung schwerer Schädelhirntraumen.

Detailed imaging of the brain is necessary to come to an expert opinion on the consequences of severe brain injuries (BI). As lesions are not visualised on computerised tomography, magnetic resonance imaging (MRI) data and serum marker S-100 are currently favoured. Our study analyses the predictive qualities of MRI and S-100 for the outcome in severe BI in 100 patients. The location of brain stem lesions identified with the aid of MRI significantly correlated with the outcome. Special types of brain stem lesions could be distinguished. S-100 was a rough measure for the amount of destruction of CNS tissue, but the exact location of the destroyed tissue appeared to be more significantly related with the outcome than its volume. For an expert opinion on severe BI, follow up MRI after brain injury can definitely not exclude relevant lesions. Early MRI is recommended.

The predictive value of ICP as compared to magnetic resonance imaging in comatose patients after head injury.

INTRODUCTION: While highly increased intracranial pressure (ICP) is of high predictive value indicating a fatal outcome, the predictive value of moderately increased ICP early after head injury remains uncertain. We compared the predictive value of ICP to the predictive value of magnetic resonance imaging (MRI) early after head injury. METHODS: 55 patients with a Glasgow Coma Scale (GCS) of less than 8, for more than 24 hours after head injury were investigated. Outcome was classified according to the Glasgow Outcome Scale (GOS). All patients received registration of ICP upon arrival at the hospital and an initial cranial computerized tomography scan. An MRI study was subsequently performed within 10 days of admission. The highest mean ICP registered within one hour in the first day of admission and the location of lesions as identified by MRI were related with outcome. RESULTS: ICP was neither related with mortality nor with GOS of survivors. The location of lesions as depicted by MRI proved to be statistically significantly related with the GOS (p < 0.001). Age proved to be clearly and significantly related with outcome (p = 0.019). CONCLUSIONS: Our current MRI findings suggest that the location of the initial brain injury lesion correlates with outcome at 6 months. No such correlation could be identified for intracranial pressure on the first day after head injury (p = 0.766).

Anatomy of the cerebral ventricular system for endoscopic neurosurgery: a magnetic resonance study.

BACKGROUND: Endoscopy has developed into an integral part of minimally invasive neurosurgery. For further technological innovations, detailed knowledge about the pathological anatomy is essential. The gross anatomy of the cerebral ventricular system has been meticulously investigated with ventriculography and casts. Extensive volumetric measurements based on neuroradiological images have been performed, but only little is known about the surgically relevant linear distances in patients with hydrocephalus. METHOD: Thirty healthy volunteers and thirty patients suffering from hydrocephalus were scanned with high-resolution 3-D magnetic resonance imaging sequences. The image volumes were sliced identically with the help of Siemens Prominence software. Individual anatomical measurements of the ventricular system were carried out, mean values and standard deviations were calculated, and different endoscopic approaches were investigated. FINDINGS: In healthy volunteers the measurements confirmed the results obtained from ventriculography and anatomic casts. In hydrocephalic patients the ventricular system was found to be enlarged asymmetrically. The optimal neuroendoscopic approach showed considerable, interindividual variation. INTERPRETATION: This 3-D magnetic resonance imaging study revealed surgically and clinically relevant aspects of the pathologic anatomy of hydrocephalic patients, in comparison to healthy volunteers. Individualized planning of the endoscopic approach appears to be warranted. Finally, the data provided a sound basis for the further development of neuroendoscopes.

[Interdisciplinary concept for classification and treatment of vascular anomalies in the head and neck]. / Interdisziplinäres Konzept zur Dignostik und Therapie gefässreicher Febhlbildungen im Gesichts- und Halsbereich.

PURPOSE: In patients with extended vascular anomalies in the head and neck, therapeutic decisions may pose a challenge to maxillofacial surgeons, dermatologists, and interventional radiologists. We analyzed the value of an interdisciplinary classification and treatment concept. PATIENTS AND METHODS: The classification distinguishes hemangiomas and vascular malformations. Whereas hemangiomas are endothelial proliferations, vascular malformations are considered to be developmental anomalies, which are further classified into high-flow or low-flow lesions and according to the vascular channels into capillary, venous, or lymphatic malformations. Since 2000 we have provided interdisciplinary consultation for patients with vascular anomalies. In patients with hemangiomas and venous malformations, the clinical diagnosis is confirmed by color-coded duplex sonography and magnetic resonance imaging; angiography is performed as part of the treatment planning for patients with arteriovenous malformations. Patients with hemangiomas are treated surgically by cryosurgery or laser surgery or conservatively according to lesion size and behavior. In patients with venous malformations, percutaneous sclerotherapy is combined with surgical reduction; patients with arteriovenous malformations undergo transarterial embolization prior to surgical excision of the nidus. RESULTS: A total of 73 patients attended the interdisciplinary consultation. This group included 53 patients with facial hemangiomas, 7 with venous malformations, 2 with capillary malformations, 5 with lymphatic malformations, and 6 with high-flow arteriovenous malformations. CONCLUSIONS: The interdisciplinary protocol increases diagnostic accuracy and helps to establish individual treatment plans for patients with extended vascular anomalies.

Primary cerebral non-Langerhans cell histiocytosis: MRI and differential diagnosis.

We report a young woman with primary cerebral non-Langerhans cell histiocytosis of the juvenile xanthogranuloma family. The clinical course was complicated by extensive infiltration of cranial nerves and meninges and epi- and intramedullary spinal dissemination. Whereas the cutaneous form of juvenile xanthogranuloma is usually benign and self-limited, central nervous system involvement is associated with high morbidity and mortality and might therefore be considered a separate clinical entity.

New virtual system for planning of neuroendoscopic interventions.

OBJECTIVE: The demands on virtual planning systems are increasing, particularly for technically pretentious surgical interventions such as intracranial endoscopy. In this article, a new virtual system for neuroendoscopy (VIVENDI) is presented. The main purpose of this system is to provide support for planning and training in neuroendoscopic interventions. MATERIALS AND METHODS: The software is applied for virtual endoscopic visualization of three-dimensional magnetic resonance datasets, using a clinical magnetic resonance scanner. Rendering is performed on a Hewlett-Packard UNIX workstation. RESULTS: Virtual endoscopy provides a three-dimensional view of the cerebral ventricles, with good visualization of anatomic details. The rendering system used allows the generation of fly-through sequences for the entire ventricular system in real time. Navigation is controlled by mouse movements, and the visualization of the computer-generated intraventricular spaces is adapted to the characteristics of the optical endoscope. CONCLUSIONS: The presented virtual neuroendoscopy system is a promising tool for planning and training in neuroendoscopic procedures. It enables these procedures to be simulated prior to surgery based on the patient's individual anatomy.

Spontaneous occlusion of a cerebral arteriovenous malformation: angiography and MR imaging follow-up and review of the literature.

We present the angiographic and MR imaging course of a 62-year-old man with a right parietal high-flow arteriovenous malformation (AVM), which was diagnosed because of seizures. A spontaneous, complete, and asymptomatic occlusion of the AVM was confirmed by a second angiography 3 months later. The possible mechanisms leading to the occlusion are discussed, and a brief review of the literature is given.

Quality planning for minimally invasive procedures in neurosurgery.

Parallel to the introduction of a minimally invasive method in a department, a documentation system should be introduced for quality management. The first step of quality management of an innovation is quality planning. During the course of patients being treated neuroendoscopically, the pre- and postoperative imaging, the intraoperative video recording, the patient-relevant files and the data of the planning have to be documented. These amounts of data require a multimedial documentation concept. We found the CD-ROM as an optimal documentation media because the discs are both cheap and easily accessible and once stored extremely robust against external influences. Therefore, every neuroendoscopically treated patient is documented with all relevant pictures, files and video sequences on a single CD-ROM.