World Neurosurg
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The most common cause of trigeminal neuralgia is neurovascular conflict, particularly arterial compression of the trigeminal nerve (ACTN). It is possible to show this condition preoperatively on fine-cut constructive interference in steady state magnetic resonance imaging (MRI), supplemented by time-of-flight magnetic resonance angiography. We have noticed significant variability in the interpretation of these studies between radiologists and the treating neurosurgeon. We have assessed the sensitivity and specificity of these 2 styles of interpretation compared with the intraoperative observations. ⋯ There was a strong tendency for radiologists to underreport ACTN on the preoperative MRI compared with the intraoperative findings. In this series, the neurosurgeon was able to accurately detect ACTN in 88% of patients preoperatively. However, the diagnosis of absent ACTN was still associated with a false-negative rate of 46.7% when the neurosurgeon performed the interpretation. At the current standard of fine-cut constructive interference in steady state MRI in Melbourne, underdetection of ACTN remains common. Clinicians using this test need to be acutely aware of its limitations in deciding whether to proceed to microvascular decompression.
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Surgical planning for treating brain arteriovenous malformations (bAVMs) is challenging because it entails visualizing 3-dimensional (3D) relationships between the nidus, its feeding and en passage arteries, and draining veins. Surgical experience in developing the capacity to mentally visualize pathological bAVM angioarchitecture could be complemented by this software, and thus potentially lower the steep learning curve for understanding complex bAVM angioarchitecture. We evaluated the clinical application of freely available online 3D reconstruction software in facilitating visualization of AVM angioarchitecture for presurgical planning. ⋯ Presurgical planning for resection of superficial bAVMs using Horos software allows for a comprehensive 3D analysis of the bAVM angioarchitecture. This technique is most useful for frontal and parietal lobe lesions, and aids the surgeon in formulating an optimal surgical strategy. The 3D reconstruction of the brain surface offers a surgical map not influenced by brain shift.
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Observational Study
Determination of availability of safety margin for placement of C3-C6 pedicle screw on CT angiography.
Cervical pedicle screws (CPS) in the subaxial cervical spine (C3-C6) are faced with high incidence of perforating the lateral pedicular cortex endangering the vertebral artery (VA). The present study analyzes the pedicle width (PW) from C3 to C6 and defines the relation of VA with regard to pedicle and transverse foramen (TF) to determine the safety margin in cases of lateral pedicular breach. ⋯ This study gives us an idea about the various parameters in placement of cervical pedicle screw in subaxial cervical spine and the probable reasons there are few vertebral artery injuries despite high incidence of cervical pedicle breach. LPVA, safety margin, and OR may explain why even very significant CPS misplacement does not lead to vascular injury or neurologic deficit.
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Hemangioendotheliomas are rare, intermediate-grade malignant tumors in the neuraxis, mainly involving the brain and meninges. Hemangioendotheliomas of the spine have been encountered more often in the vertebral body than the intradural space. Here, we present a rare case of a unique intradural hemangioendothelioma of the lumbar spine; only a few such cases exist in the literature.
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Cauda equina arteriovenous malformation (AVM) is extremely rare. To our knowledge, only 2 cases have been reported previously and are supplied by a unilateral lateral sacral artery (LSA). Here, we report a rare cauda equina AVM at the level of L5-S1, which is supplied by the bilateral LSAs. ⋯ The present case demonstrated the angioarchitecture of the bilateral arterial supplies and venous drainage of the cauda equina AVMs. Cauda equina AVM with bilateral arterial feeders is extremely rare. However, clinicians should be aware of the possibility of this condition and the importance of selective spinal angiography of bilateral LSAs.