Olga I. Chrysou

Sudden death in a patient with a third ventricle colloid cyst.

Neurosurgical Department, Democritus University of Thrace Medical School, Alexandroupolis, Greece.Correspondence: Danilo Silva; Weill Cornell Medical College, New York NY, USA; Department of Neurological Surgery; Skull base fellow; 124 west 60th street Apt 37L; New York NY - USA; E-mail: daniloncr@gmail.comConflict of interest: There is no conflict of interest to declare.Received 21 October 2011; Received in final form 09 November 2011; Accepted 16 November 2011

Giuseppe Gradenigo: Much more than a syndrome! Historical vignette

Background: Giuseppe Gradenigo (1859–1926), a legendary figure of Otology, was born in Venice, Italy. He soon became a pupil to Adam Politzer and Samuel Leopold Schenk in Vienna, demonstrating genuine interest in the embryology, morphology, physiopathology, as well as the clinical manifestations of ear diseases. In this paper, the authors attempt to highlight the major landmarks during Gradenigos career and outline his contributions to neurosciences, which have been viewed as looking forward to the 20th century rather than awkward missteps at the end of the 19th. Methods: Several rare photographs along with many non-English, more than a century old articles have been meticulously selected to enrich this historical journey in time. Results: It was after Gradenigo that the well-known syndrome consisting of diplopia and facial pain due to a middle ear infection was named. However, Gradenigo was much more than a syndrome. Surprisingly, despite the fact that he is considered a pioneer of the Italian Otology of the late 19th and early 20th century, little is written of his life and his notable achievements in the English literature. Conclusions: Even though his name lives on nowadays only in the eponym “Gradenigos syndrome,” his accomplishments are much wider and cast him among the emblematic figures of science. His inherent tendency for discovering the underlying mechanisms of diseases and his vision of guaranteeing quality of services, professional proficiency, respect, and dedication toward the patients is in fact what constitutes his true legacy to the next generations.

An atypical meningioma demystified and advanced magnetic resonance imaging techniques

A 40-year-old male presented with visuospatial processing disturbances. Family history was free. Conventional and advanced magnetic resonance imaging (MRI) studies were performed. On T2 and fluid attenuation inversion recovery images, an increased signal intensity extra-axial lesion was demonstrated. Post-contrast scans depicted homogeneous intense contrast medium enhancement. T2* star sequence was negative for hemorrhagic or calcification foci. Diffusion-weighted imaging findings were indicative of malignant behavior and magnetic resonance venography confirmed superior sagittal sinus infiltration. Increased cerebral blood volume values were observed and peri-lesional oedema on perfusion-weighted imaging was also demonstrated. The signal intensity-time curve depicted the characteristic meningioma pattern. Spectroscopy showed increased choline and alanine levels, but decreased N-acetyl-aspartate levels. Conventional MRI is adequate for typical types of meningiomas. However, the more atypical ones, in which even the histopathologic specimen may demonstrate characteristics of typical meningioma, could be easier diagnosed with advanced MRI techniques.

Organizational issues in stroke treatment: The Swiss paradigm - Stroke units

Stroke represents the leading cause of acquired disability in adults and poses a tremendous socioeconomic burden both on patients and the society. In this sense, prompt diagnosis and urgent treatment are needed in order to radically reduce the devastating consequences of this disease. Herein the authors present the new guidelines recently adopted by the Swiss Stroke Society concerning the establishment of stroke units. Standardized treatment and allocation protocols along with an acute rehabilitation concept seem to be the core of the Swiss stroke management system. Coordinated multidisciplinary care provided by specialized medical, nursing and therapy staff is of utmost importance for achieving a significant dependency and death reduction. It is believed that the implementation of these guidelines in the stroke care system would be beneficial not only for the stroke patients, but also for the health system.

Metal external ventricular drainage catheters in the treatment of persistent ventriculitis - an old story made new: technical note and preliminary results.

AIM Conventional ventricular catheters have proven to be ineffective in the drainage of the cerebrospinal fluid in the long run in terms of infection rates. Consequently, the development and clinical evaluation of new catheters is urgently needed. MATERIAL AND METHODS We implanted a ventricular needle made of stainless steel in 3 neurosurgical patients in whom multiple conventional (silicon) ventricular catheters had been previously implanted. All of them developed persistent ventriculitis during the first 30 days post-admission. The infection did not respond to antibiotics neither intravenously nor intrathecally via conventional catheters. After the implantation of the needle, colistin mesilate sodium was administered (150,000 IU/day for 21 days) intrathecally, cerebrospinal fluid white blood cells were measured and cerebrospinal fluid cultures were obtained. RESULTS Within 15 days after the implantation of the metal catheter, a significant decrease of the cerebrospinal fluid white blood cell count was noted and all cultures were negative. No operation related complications were observed. CONCLUSION Our technique of a metal catheter implantation is safe and requires fewer reoperations. Moreover, it is cost-effective since metal catheters can be used for longer periods of time, can be reused in other patients, and are of low cost.

Robotics for spinal operations: reality or Alice in Wonderland?

Leonardo da Vinci (1452–1519)was the first to describe the precise curvatures and articulations of the spine (1). It was after him that a new category of minimally invasive alternative to traditional open surgery, the da Vinci W Surgical System (Intuitive Surgical, Inc, Sunnyvale, California, USA), was named (2,3). This endoscopic robotic platform has entered the surgical realm for more than a decade in urologic, gynaecologic, cardiothoracic, and general surgery procedures (2–6). However, as it is not image guided and without a haptic interface, its application in spinal operations has been limited (7). The da Vinci W system’s capabilities have been highlighted and its limitations have been clarified in several animal (5,8,9) and human studies (4,10–13). It has been implemented in the performance of anterior lumbar interbody fusion (ALIF) using the retroperitoneal approach in two porcine models in vivo (8,9). It was also tested on laminotomy, laminectomy, disc incision, and dural suturing procedures on the thoracolumbar spine of a porcine model in vivo (5). In humans, this platform was involved in robot-assisted transoral odontoidectomy for decompression of the craniocervical junction (4). Furthermore, it was applied in a retroperitoneal transdiaphragmatic robotic-assisted laparoscopic resection of a left thoracolumbar neurofibroma (11). Published articles suggest its utility in the thoracoscopical extirpation of paravertebral mediastinal neurogenic tumours (such as schwannomas) (12) and in the transperitoneal resection of paravertebral lumbosacral masses (13). A cadaveric study has also shown the technical feasibility of transoral robotic surgery for decompression of the craniocervical junction as well as resection of both intraand extradural tumours of this region (10). SpineAssist W (Mazor Surgical Technologies, Caesarea, Israel) is a bonemounted miniature robotic guidance system, tested for spinal surgery (2,3,14–16). With the aid of this system several cadaveric percutaneous placements of pedicle and translaminar facet screws have been performed (15,17). SpineAssist W was employed in spinal fusion procedures (open and percutaneous approaches) for transpedicular screw placement in 15 patients (14). Another study reported that 31 patients underwent posterior lumbar interbody fusion (PLIF) with percutaneous posterior pedicle screw insertion using the SpineAssist W technology (16). The advantages of robotic surgery include: ergonomics (4,12), significant dexterity enhancement that eliminates a neurosurgeon’s physiological tremor (5,9,11,12), reduction of radiation exposure (15,16), image-based semi-active guidance for inserting implants (14–16), excellent three-dimensional visualization (4,11), ability for repetitive motions and holding tools for long periods (2), quick adaptation to change in commands (2), and ability for accurate micromotions minimizing unintentional durotomies (2,4) and injuries to presacral sympathetic plexus (9). Various published articles propose the following features as additional advantages: small skin incision (13,15), minimal LETTER TO THE EDITOR

The Bigbrain Model: An Atlas, A Chimera Or A Glance Into The Future?

The past twenty years have witnessed a spectacular change of printed brain atlases into digital and multidimensional ones. This evolution has facilitated the meta-analysis of scientific information from all fields of neurosciences [1]. One further step in this dynamic process is considered to be the construction of the BigBrain model in the context of the European Human Brain Project [2] for which the European Commission awarded 500 million euros over 10 years this January (2013) [3]. The research was conducted by the Montreal Neurological Institute (Montreal, Canada) and the Research Centre Jülich (Jülich, Germany). The scientists used a microtome to cut a complete paraffin-embedded brain of a 65-year-old female coronally. Seven thousand four hundred sections of 20μm thickness were acquired and subsequently stained for cell bodies. Then the histological sections were digitized and reconstructed into a 3D digital brain, resulting in a total data volume of 1 Tbyte [2]. The BigBrain is actually a reference brain. It attempts to bring research to the microstructural level. Since now, structural imaging based on Magnetic Resonance Imaging (MRI) has achieved a spatial resolution of 1mm. This resolution may be good enough for accumulating information for brain gyri and sulci or even for subcortical nuclei, but by no means is it adequate for integrating information at the level of cortical layers or cells [2]. This gap could be bridged using a framework that builds on acquiring images with thickness of microns [3]. According to the researchers this highest resolution 3D digital brain model yet made could be of great value in the following cases [2]: ·Addressing stereotaxic positions in the brain at micrometer range. ·Localizing transmitter receptor distributions, fiber bundles, and genetic data. ·Generating realistic input parameters for modeling and simulation. The BigBrain data set is freely available on the web after a quick registration process [4]. This development in conjunction with the launch in USA (April 2013) of the Brain Research Through Advancing Innovative Neurotechnologies Initiative (a 100 million US dollars project) [3] signify a new era for brain research. The reconstruction of human brain at cellular resolution and thus redefining the traditional neuroanatomy maps, [2] seems now less than a Chimera.

Cerebral aspergillosis and acute myeloid leukemia.

A 32-year-old man with no previous medical history presented with weight-loss, frequent rhinorrhagia, gum swelling, cephalalgia, fatigue, fever, and somnolence. Neither motor nor sensory deficits were noted. The patient quickly became comatose and required mechanical ventilation. The complete blood count and the peripheral blood smear provided results compatible with leukemia (leukocytosis of 17,600/mm3, neutrophils 14,000/mm3, platelets 151,000/mm3, hemoglobin 13 g/dl, Auer rods). Consequently, bone marrow and CSF (cerebrospinal fluid) samples were collected and analyzed with the aid of cytochemistry and flow cytometry. The sandwich enzyme-linked immunosorbent assay (ELISA), “PlateliaAspergillus” (Bio-Rad Laboratories, Marnes La Coquette, France) detected galactomannan antigens both in CSF and serum. Brain magnetic resonance imaging [Figure ​[Figure1a1a-​-d]d] revealed a right frontal lesion with surrounding edema, which was ring enhancing after contrast administration. The DWI technique and the ADC values showed a limited diffusion [Figure ​[Figure2a2a and ​andb].b]. The diagnosis of cerebral aspergillosis was set. A stereotactic biopsy confirmed Aspergillus fumigatus as the cause of infection. Hyphae with branches of 45 degrees were seen (Grocott silver stain). The melanin-specific Masson-Fontana stain was used to exclude cerebral phaeohyphomycosis. Conidiophores of 8μm terminating in subclavate vesicles of 24 μm bearing uniseriate phialides were observed. The brain specimen was also inoculated on Sabouraud dextrose agar, and growth of white-dark grey colonies was observed. Amphotericin B (1 mg/Kg/day) was administered intravenously for a period of 6 weeks along with the liposomal formulation of daunorubicin (150 mg/m2) for 3 days. The new DWI images and the ADC map exhibited an increased diffusion [Figure ​[Figure2c2c and ​andd].d]. The primary focus of infection was not discovered. The patient failed to improve significantly, he did not regain consciousness and he eventually succumbed. An autopsy was not requested honoring the familys wishes. Figure 1 (a) T1: A hypo-intense lesion is depicted (right frontal lobe) (b) T2: A large area of edema is shown (c) FLAIR: The central portion exhibits a lower intensity signal as compared to the higher-signal perilesional area (angiogenic edema) (d) T1 postcontrast: ... Figure 2 (a) DWI (diffusion-weighted imaging) (b-value: 1,000): High signal of the lesion (diffusion is restricted) (b) ADC (apparent diffusion coefficient) values show a limited diffusion (values ranging between 0.45 and 0.65 mm2/s*10-3) (c) Same patient, 6 weeks ... This case represents one of a few reports depicting the presence of Aspergillus in the brain parenchyma in leukemia-harboring patients with the aid of modern magnetic resonance imaging techniques. Cerebral aspergillosis represents an opportunistic infection, which is commonly transmitted hematogenously.[1] It also manifests as a vascular insult or/and an abscess.[2] CT has always been the first line of evaluation but MRI still remains the method of choice due to its high sensitivity.[3,4] Additionally, diffusion techniques increase specificity,[1,2] and can evaluate the patients’ response to specific antifungal treatments. The three major neuroimaging findings in cerebral aspergillosis include infarction areas, ring lesions (post-infarct abscess formation), and dural/vascular infiltration.[5] Recognition of these patterns results in an effective treatment.[4,5] The authors’ scope was not only to draw the readerships attention to this rare fungal entity but also to raise awareness for the substantial help that new imaging modalities could provide in setting an accurate diagnosis for the benefit of the patient. Especially the absence or presence of restricted diffusion in the setting of brain fungal infections may be of great clinical utility.