World Neurosurg
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Comparative Study
Optic Canal Decompression: A Comparison Of Two Surgical Techniques.
The optic canal is a bony channel that connects the anterior cranial fossa and orbit and contains the optic nerve and ophthalmic artery. It can be affected by several pathologies, leading to compression of the nerve nearby or inside the canal, leading to visual impairment. The usual technique to decompress the canal is through a craniotomy, but recently endoscopic endonasal approaches (EEAs) have surfaced as an interesting alternative due to direct access to the canal without the need for manipulation of neurovascular structures. ⋯ The decision for an approach for optic canal decompression should be based on the site of the pathology and localization of canal involvement. Both techniques are equivalent in terms of proportion of nerve decompression.
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Case Reports
First report of coexistence of 2 ectopic pituitary tumors: Rathke cleft cyst and silent ACTH adenoma.
Rathke cleft cysts (RCCs) and pituitary adenomas (PAs) are thought to have a common embryonic ancestry; however, PAs with a concomitant RCC inside the sella turcica are rarely observed. Ectopic pituitary tumors are also rare. ⋯ To our knowledge, this is the first reported ectopic RCC located outside the sella turcica with a concomitant ACTH-staining PA. This also appears to be the first ACTH-staining adenoma concomitant with RCC reported in the literature, regardless of location, not presenting with Cushing disease. This case shows that we can now include pituitary adenoma with or without a concomitant RCC in the differential diagnosis of processes in the sphenoid sinus. As both PAs and RCCs are benign sellar lesions, surgical management of a concomitant occurrence of these tumors mainly depends on the size of the lesions and their clinical manifestations. For patients with PA and concomitant RCC, surgical resection should be considered, as there is an approximatrely 20% recurrence rate of the cyst after resection and the possibility of future clival erosion, if left untreated.
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Case Reports
Magnetic resonance spectroscopy findings in patients with dural arteriovenous fistulas: Three case reports.
Magnetic resonance spectroscopy (MRS) is a potentially useful modality for evaluating brain metabolites in patients with dural arteriovenous fistula (dAVF). Here we describe a different pattern of MRS-based cerebral metabolism findings in patients with dAVF. ⋯ Our results suggest that patients with dAVF can be classified based on a combination of metabolic and signal changes seen on T2-weighted MRI. MRS may allow significantly expanded evaluation of the metabolic changes associated with dAVF for appropriate classification and management.
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Clinically applicable hemodynamic risk factors to predict arteriovenous malformation (AVM) rupture are missing in the literature. The aim of this study was to use catheter angiography to identify hemodynamic parameters in ruptured and unruptured AVMs. ⋯ Ruptured AVMs have significantly prolonged venous drainage times compared with unruptured AVMs; this suggests restricted AVM drainage and increased blood pressure within the AVM nidus. Prospective studies are needed to determine the predictive power of these measurements.
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Several recent reports have implicated vascular ectasia and vessel contact in dysfunction of the visual apparatus. A subset of patients with prechiasmatic visual deterioration have an ectatic internal carotid artery (ICA) that displaces and flattens the optic nerve (ON) rostrally as the ON exits the skull base. We describe a proposed pathophysiologic mechanism and a straightforward surgical technique for dealing with this problem. ⋯ We propose that 3 mechanisms contribute to this caroticofalciform optic neuropathy: 1) mass effect from ICA ectasia, 2) ON irritation from vessel pulsatility, and 3) indirect compression by the falciform ligament from above. This disease process can be treated safely using standard microsurgical techniques with excellent outcomes.