Background: The prevailing view amongst neurosurgeons is that the larger the aneurysm, the higher the chance of rupture. This implies that very small aneurysms rarely rupture. To investigate this theory, we conducted a cross-sectional hospital-based study of aneurysmal subarachnoid hemorrhage, with an emphasis on aneurysm size at the time of rupture.Methods: We retrospectively reviewed hospital records and radiological tests of all patients admitted to Foothills Medical Center, Calgary, Alberta, with a ruptured saccular aneurysm from January 2008 to January 2012. The size of the dome and neck (in millimeters), the aspect ratio (aneurysm depth to aneurysm neck), and location of the aneurysms were determined using preoperative computed tomography angiography and digital subtraction angiography.Findings: One hundred and twenty-three patients with a ruptured saccular aneurysm were identified. The average size of the dome, neck, and the aspect ratio was 6.6±4.4 mm (range: 1.5-26 mm), 3.1 mm, and 2.6±0.9, respectively. Forty-six patients (37%) had a ruptured aneurysm with dome size < 5 mm (range: 1.5-4.9 mm). For these small aneurysms, the average size of the dome, neck, and the aspect ratio was 3.9+1.1 mm, 1.6 mm, and 2.1+0.6, respectively. The anterior communicating artery was the most common location regardless of size.Conclusion: Small aneurysms (< 5 mm) are a common cause of aneurysmal subarachnoid hemorrhage. When unruptured, looking for other risk factors for rupture is highly recommended before simply leaving them alone.

Aggrecan is the major component of intervertebral disk matrix proteoglycan with multiple functional domains. To understand the role of aggrecan polymorphism in a part of exon 12 encoding the CS1 domain in lumbar disk degeneration disease, we have analyzed genomic DNA from 71 patients with the disease and 108 healthy individuals in northern Iran. The AGC1 alleles were determined by PCR followed by gel electrophoresis. Twelve AGC1 alleles ranging from 18 to 29 repeats were detected in patients and controls. The most frequent AGC1 allele was 27, followed by 28 in patients and controls. The shorter AGC1 alleles (< or =24 repeats) were more frequent in patients than in controls (37 vs. 16%, P < 0.001). The odds ratio for lumbar disk degeneration was 3.28 (95% confidence interval 1.62-6.65) in carriers of the shorter AGC1 alleles. Our data suggest that carrying shorter AGC1 alleles with less than 24 repeats could predispose a subject to lumbar disk degeneration disease in northern Iran.

Background:Skull base tumors frequently encase or invade adjacent normal neurovascular structures. For this reason, optimal tumor resection with incomplete knowledge of patient anatomy remains a challenge.Methods:To determine the accuracy and utility of image-based preoperative segmentation in skull base tumor resections, we performed a prospective study. Ten patients with skull base tumors underwent preoperative 3T magnetic resonance imaging, which included thin section three-dimensional (3D) space T2, 3D time of flight, and magnetization-prepared rapid acquisition gradient echo sequences. Imaging sequences were loaded in the neuronavigation system for segmentation and preoperative planning. Five different neurovascular landmarks were identified in each case and measured for accuracy using the neuronavigation system. Each segmented neurovascular element was validated by manual placement of the navigation probe, and errors of localization were measured.Results:Strong correspondence between image-based segmentation and microscopic view was found at the surface of the tumor and tumor-normal brain interfaces in all cases. The accuracy of the measurements was 0.45 ± 0.21 mm (mean ± standard deviation). This information reassured the surgeon and prevented vascular injury intraoperatively. Preoperative segmentation of the related cranial nerves was possible in 80% of cases and helped the surgeon localize involved cranial nerves in all cases.Conclusion:Image-based preoperative vascular and neural element segmentation with 3D reconstruction is highly informative preoperatively and could increase the vigilance of neurosurgeons for preventing neurovascular injury during skull base surgeries. Additionally, the accuracy found in this study is superior to previously reported measurements. This novel preliminary study is encouraging for future validation with larger numbers of patients.

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