Sam Safavi-Abbasi

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OBJECT In this study the authors investigated the anatomical, clinical, and imaging features as well as incidence of congenital defects of the C-1 arch. METHODS The records of 1104 patients who presented with various medical problems during the time between January 2006 and December 2006 were reviewed retrospectively. The craniocervical computed(More)
OBJECT The authors measured relevant quantitative anatomical parameters to define safety zones for the placement of C-1 posterior screws. METHODS Nineteen linear, two angular, and four surface parameters of 20 dried atlantal specimens were evaluated. The Optotrak 3020 system was used to define the working area. Ideal angles for screw positioning were(More)
Astrocytes have the potential to acquire very different morphologies, depending on their regional location in the CNS and on their functional interactions with other cell types. Morphological changes between a flat or a fibroblast-like and a stellate or process-bearing appearance, and vice versa, can occur rapidly, but very little is known as to whether(More)
OBJECTIVE It is impossible to precisely anticipate the crooked course of the transverse and sigmoid sinuses and their individual relationship to superficial landmarks such as the asterion during retrosigmoid approaches. This study was designed to evaluate this anatomical relationship with the help of a surgical planning system and to analyze the impact of(More)
OBJECTIVE Image-guidance systems are widely available for surgical planning and intraoperative navigation. Recently, three-dimensional volumetric image rendering technology that increasingly applies in navigation systems to assist neurosurgical planning, e.g., for cranial base approaches. However, there is no systematic clinical study available that focuses(More)
OBJECT The authors evaluated the mechanisms and patterns of thoracic, lumbar, and sacral spinal injuries in a pediatric population as well as factors affecting the management and outcome of these injuries. METHODS The records of 89 patients (46 boys and 43 girls; mean age 13.2 years, range 3-16 years) with thoracic, lumbar, or sacral injuries were(More)
Cavernous malformations of the internal auditory canal are a rare clinical entity that, however, should be considered in the differential diagnosis of intracanalicular masses. Even though this type of malformation is usually associated with an evident gadolinium enhancement at MR examination, in some patients, like in this case, the signal characteristics(More)
OBJECT The authors quantitatively assessed the effects of balloon inflation as a model of tumor compression on the brainstem, cranial nerves, and clivus by measuring the working area, angle of attack, and brain shift associated with the retrosigmoid approach. METHODS Six silicone-injected cadaveric heads were dissected bilaterally via the retrosigmoid(More)
STUDY DESIGN In vitro human cadaveric study simultaneously quantifying sagittal plane flexibility and spinal canal stenosis. OBJECTIVE To compare biomechanical stability and the change in cross-sectional area during flexion and extension after laminectomy and open-door laminoplasty. SUMMARY OF BACKGROUND DATA Spinal canal stenosis has been quantified in(More)
OBJECTIVE Meningiomas involving the petrous apex regularly show a close relationship with the superior petrosal vein which is sometimes obliterated during surgery due to its proximity to the tumour. However, there is no study available so far focusing on the frequency of postoperative venous congestion related complications following petrosal vein(More)