Zafer Orkun Toktaş

Gamma knife stereotactic radiosurgery yields good long-term outcomes for low-volume uveal melanomas without intraocular complications.

We present the outcomes of 35 uveal melanoma patients treated with gamma knife stereotactic radiosurgery. All cases were previously untreated. During follow-up, regular MRI examinations were used to detect any changes in tumor size and estimate the local long-term tumor control rate. Treatment-related complications were also recorded. During follow-up, systemic dissemination was observed in two patients, one of whom died of metastases. The most frequent complication was retinal detachment (17.1%). Three patients required enucleation. Cumulative 1-year and 3-year local tumor growth control rates were 97% and 83%, respectively. The mean and median times to local tumor progression were 48.0 and 51.7 months, respectively. Gamma knife surgery may be a suitable alternative for the treatment of low-volume uveal tumors without intraocular complications, as the control rate and long-term outcomes compare favorably with those of surgical excision and brachytherapy.

Relationship of angiogenic potential with clinical features in cranial meningiomas: a corneal angiogenesis study.

BACKGROUND: Intracranial meningiomas constitute approximately one fourth of all primary intracranial tumors. The invention of cranial angiographic techniques has led to the recognition of the angiogenic potential of meningiomas, which has been the subject of extensive research. OBJECTIVE: To test the relationship between the angiogenetic potential of intracranial meningiomas and clinical/prognostic features such as World Health Organization (WHO) grade, peritumoral edema, tumor border shape, and recurrence using rat corneal angiogenesis assay. METHODS: Fifteen WHO grade I (typical), 10 WHO grade II (atypical), and 5 WHO grade III (malignant) meningioma samples were implanted in the micropockets formed on rat corneas, and the number of developed vessels were counted on days 5, 10, 15, and 20. Normal brain and glioblastoma multiforme tissues served as negative and positive controls, respectively. Patients were evaluated by magnetic resonance imaging preoperatively and every 6 months thereafter. RESULTS: The angiogenic potential of WHO grade II tumors was significantly lower than that of grade III tumors and higher than that of grade I tumors throughout the experiment. Tumors with a smooth border shape and nonrecurrent tumors exhibited significantly lower angiogenic activity compared with the tumors with irregular border shape and recurrent tumors, respectively. No association was found between angiogenic activity and peritumoral edema. However, multivariate analysis identified WHO grade, recurrence, and peritumoral edema as significant predictors of a high angiogenic potential. CONCLUSION: Our findings, based on a dynamic in vivo model to examine angiogenesis, demonstrate that the angiogenic potential of meningiomas is correlated with WHO grade, recurrence, and possibly with tumor border shape and peritumoral edema. Angiogenesis seems to be an important factor in the natural course of meningiomas, suggesting that inhibition of angiogenesis may be an option, particularly in the treatment of meningiomas with an aggressive course.

Magnetically Controlled Growing Rod in Early-Onset Scoliosis: A Minimum of 2-Year Follow-Up

Purpose: The magnetically controlled growing rod technique decreases complications, costs, and loss of functionality by avoiding successive surgical corrections every 6 months in patients with early-onset scoliosis. However, only a few studies have presented clinical experience with the magnetically controlled growing rod. In this study we aimed to present our single-center experience in patients with early-onset scoliosis who underwent the magnetically controlled growing rod technique and follow-up for at least 2 years. Materials and Methods: We made an observational study by evaluating patients with early-onset scoliosis who underwent the magnetically controlled growing rod technique between February 2012 and December 2013. Demographic and clinical data were obtained from the patients charts. We included patients who were followed up for at least 2 years. Radiological data were obtained from plain anterior-posterior and lateral scoliosis X-rays. Results: Eight patients with early-onset scoliosis who underwent surgery using the magnetic system were treated with dual rods. None of the spines were fused to the sacrum. We observed no intra- and/or postsurgical complications. The average number of external rod lengthenings was 7.6. The average amount of lengthening was 30.6 mm on the right side and 27.8 mm on the left side by the time of last clinical follow-up. The average coronal and sagittal Cobb values at the final clinical evaluation were 10.5° (thoracic coronal), 13.75° (lumbar coronal), 6.25° (lumbosacral coronal), 24.5° (thoracic sagittal), and 40° (lumbar sagittal), respectively. Conclusions: The magnetically controlled growing rod is beneficial in early-onset scoliosis, since it enables spinal growth and decreases additional surgeries, complications, and costs. Even though we had a small sample size, our follow-up period was enough to declare long-term outcomes of our patients. Multicenter and large sample-sized studies are needed to make more conclusive statements regarding this promising scoliosis treatment approach.

Temporal expression analysis of angiogenesis-related genes in brain development

BackgroundThe current knowledge on molecular pathogenesis of cerebral vascular malformations (CVM), which are believed to arise during development, is very limited. To unravel the molecular mechanisms involved in CVMs, a detailed understanding of the brain vascular development at molecular level is crucial. In this study, we aimed to explore the temporal and comparative expression profile of angiogenesis-related genes in the establishment of brain vasculature.MethodsExpression of a total of 113 angiogenesis-related genes during murine brain development has been analyzed using low-density array systems designed for angiogenesis-related genes. Bai1 (brain specific angiogenesis inhibitor-1), a recently identified novel anti-angiogenic gene, has been selected for further characterization.ResultsWe found that 62 out of 113 analyzed genes have expression in brain development at varying levels. Nineteen of these were differentially expressed between embryonic and postnatal stages (>1.5 fold). Bai1 is strongly expressed on growing blood vessels of cerebral cortex and hippocampus, partially expressed in the lateral regions of striatum, but mostly absent on the thalamus.ConclusionBy showing the comparative expression analysis of angiogenesis-related genes throughout brain development, the data presented here will be a crucial addition to further functional studies on cerebrovascular research.

Posterior epidural migration of lumbar disc fragment as an unusual ring-enhancing mass.

A 60-year-old man was admitted to the hospital because of 2-month history of low back pain and difficulty in walking. Bladder and bowel functions were normal. The clinical history was unremarkable. On physical examination, both lower limbs showed muscular weakness with increased muscle tone, especially on the right side. Sensation was intact in all dermatomes, and reflexes were normal. Laboratory tests revealed normal findings. Magnetic resonance imaging showed a wellcircumscribed smoothly marginated solid mass within the posterior epidural space at L2–L3, which compressed the dura. Signal intensity of the mass was similar to that of the intervertebral disc on all sequences (Fig. 1). The lesion revealed an intense rim enhancement on fat-saturated contrastenhanced magnetic resonance images (Fig. 1). There was no calcification in the epidural mass lesion on computed tomography scan (Fig. 2). Decompressive L2 laminectomy was

Diffusion tensor imaging of cervical spinal cord: A quantitative diagnostic tool in cervical spondylotic myelopathy.

Background: Diffusion tensor imaging (DTI) is a novel magnetic resonance imaging (MRI) technique potentially able to evaluate the microscopic structural organization of white matter fibers. Aim: This study aimed to compare fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values obtained by DTI in stenotic versus nonstenotic cervical spinal segments of patients with clinical and neurological evidence of cervical spondylotic myelopathy (CSM). Materials and Methods: This prospective study included 21 patients with CSM but without T2 changes on conventional MRI. Diffusion tensor (DT) images from the stenotic and nonstenotic segments of the subjects were obtained. FA and ADC values were estimated and compared with stenotic versus nonstenotic segments. Statistical Analysis: Paired t-test was used [Statistical Package for the Social Sciences (SPSS) 12.0]. Results: In the most stenotic segments, the mean FA value was significantly lower (0.4228 ± 0.1090 vs 0.6884 ± 0.0075, P < 0.001) and the mean ADC value was significantly higher (1.312 ± 0.2405 vs 0.9183 ± 0.1477, P < 0.001) when compared to nonstenotic segments. In addition, there was a negative correlation between FA and ADC values (r = 0.63, P = 0.002). Conclusions: DTI of the cervical spine seems to be a promising novel imaging modality in patients with CSM. Advances in Knowledge: DTI may offer increased diagnostic sensitivity as compared to standard MRI and enables earlier detection of the disease.

Rare and challenging extra-axial brain lesions: CT and MRI findings with clinico-radiological differential diagnosis and pathological correlation.

There are many kinds of extra-axial brain tumors and tumor-like lesions, and definitive diagnosis is complicated in some cases. In this pictorial essay, we present rare and challenging extra-axial brain lesions including neuroenteric cyst, primary leptomeningeal melanomatosis, isolated dural neurosarcoidosis, intradiploic epidermoid cyst, ruptured dermoid cyst, intraventricular cavernoma, and cavernous hemangioma of the skull with imaging findings and clinico-radiological differential diagnosis, including the pathologic correlation. Familiarity with these entities may improve diagnostic accuracy and patient management.

Multiple hemorrhages in brain after spine surgery supra- and infra-tentorial components together.

Remote cerebellar hemorrhage after cranial and spinal surgeries is a well-documented entity, so far concomitant supra- and infra-tentorial hemorrhage after spine surgery has rarely been reported in the literature. A 57-year-old woman presented with intractable low back pain and severely impaired mobility. One year ago, she underwent lumbar laminectomy and fusion with posterior spinal instrumentation between L2 and S1. She developed adjacent segment disease at the upper level of the instrumented vertebra. She had a revision surgery and underwent posterior laminectomy and fusion with bilateral transpedicular instrumentation between T10 and S1. She had severe headache, somnolence, and left hemiparesia 48 h after the surgery. Her emergent head computed tomography depicted intra-parenchymal hemorrhage in the right parietal lobe accompanying with subarachnoid hemorrhage, bilateral symmetrical cerebellar hemorrhages and pneumocephalus. She was treated nonsurgically and she got better despite some residual deficits. Symptoms including constant headache, nausea, vomiting, impaired consciousness, new onset seizure, and focal neurological deficit after spine surgeries should raise suspicion for intracranial intra-parenchymal hemorrhage.

Biological approaches to treating intervertebral disk degeneration: devising stem cell therapies.

Intervertebral disk (IVD) degeneration is a common, chronic, and complex degeneration process that frequently leads to back pain and disability, resulting in a major public health issue. In this review we describe biological therapies under preclinical or clinical development with an emphasis on stem cell-based multimodal approaches that target prevention and treatment of IVD degeneration. Systematical review of the basic science and clinical literature was performed to summarize the current status of devising biological approaches to treating IVD degeneration. Since the exact mechanisms underlying IVD degeneration have not yet been fully elucidated and conservative managements appear to be mostly ineffective, current surgical treatment focuses on removal of the pathological disk tissues combined with spinal fusion. The treatment options, however, often produce insufficient efficacy and even serious complications. Therefore, there have been growing demands and endeavors for developing novel regenerative biology-guided strategies for repairing the IVD via delivery of exogenous growth factors, introduction of therapeutic genes, and transplantation of stem cells, or combinatorial therapies. Overall, the data suggest that when applied under a recovery neurobiology principle, multimodal regimens comprising ex vivo engineered stem cell-based disks hold a high potential promise for efficacious clinical translations.

A Very Quickly Prepared, Colored Silicone Material for Injecting into Cerebral Vasculature for Anatomical Dissection: A Novel and Suitable Material for both Fresh and Non-Fresh Cadavers.

AIM Cadaveric studies have a great impact on neuroanatomy learning. Cadaver preparation may take a lot of effort, especially at the phase of intravascular color filling. The authors describe their silicone dye technique and a novel mixture which is self-curing, quick to prepare and easy to inject. MATERIAL AND METHODS The first one of these processes is undoubtedly embalming and decapitation of the cadaver. If possible, the most appropriate time that should be preferred is immediately after the donors death. Preparation for cadaveric dissection of the brain requires some fundamental steps that can be summarized into: a) Embalming and decapitation, b) Exposing, cannulization and irrigation of main vascular structures, c) Preparing colored silicone, d) Injection of colored silicone and staining the vascular tree, e) Sample maintenance RESULTS Our method of preparation of silicone dye and injection enables neurosurgeons and anatomists to fill cerebral and dural vascular structures, and even diploic veins nicely in both fresh and aged cadaveric heads. Moreover, the main vascular structures and their branches in the lateral and third ventricles are painted remarkably beautifully. CONCLUSION We tried to provide our experience about the preparation of head cadavers for anatomical dissection using a novel mixture of colored silicone that is very easy to prepare and inject with very satisfactory results.