Pneumosinus dilitans and meningioma: a case series and review of the literature.

Pneumosinus dilitans (PSD) is enlargement of the sinuses of the skull base and is frequently seen with meningiomas. Identifying PSD on imaging can assist with operative planning and preparation. Meningiomas associated with PSD are not more commonly high grade, and complete resection is frequently possible.

Spontaneous resolution of a Chiari malformation Type I and syrinx after supratentorial craniotomy for excision of a cavernous malformation.

The pathogenesis of Chiari malformation Type I (CM-I) and associated syringomyelia is incompletely understood. Patients often present in middle age with incidental or minimally symptomatic CM-I, whose management is controversial. One option is clinical and radiographic observation of asymptomatic and minimally symptomatic patients. The authors here present the case of a 36-year-old woman who had been monitored for 6 years for a minimally symptomatic CM-I and cervicothoracic syrinx. After 5 years of follow-up, she suffered spontaneous rupture of a cerebral cavernous malformation when she was 27 weeks pregnant. The ruptured cavernous malformation and hematoma were operatively managed via a right frontal craniotomy. Ten months after the craniotomy for resection of the ruptured cavernous malformation, follow-up MRI demonstrated resolution of the CM-I and syrinx. Few similar cases have been reported in adults. This case argues for the presence of dynamic factors in the development and maintenance of CM-I and supports the nonoperative treatment of asymptomatic and minimally symptomatic patients.

Primary holocord ganglioneuroblastoma: case report.

The authors present a case of extensive primary intramedullary spinal CNS ganglioneuroblastoma (GNB) in a 23-year-old man. Central nervous system GNB is a poorly differentiated neuroepithelial tumor composed of neuroblasts and differentiated ganglion cells, and these lesions are extremely uncommon. Most previously reported primary intraaxial neuroblastic tumors were described in the brain. There has been only one other report of primary spinal cord CNS GNB published to date; the clinical course and prognosis for primary spinal cord tumors of this type are unknown. Similar tumor types demonstrate poor prognoses. This 23-year-old man presented after 9 months of progressive myelopathy. Admission MR imaging showed an intraaxial enhancing mass extending from C-3 to the conus medullaris, with a holocord appearance in several areas. Due to the tumor size, operative intervention was initially limited to biopsy sampling. Chemotherapy resulted in histological maturation, but initial tumor regression was temporary. The patient suffered progressive quadriparesis, and neuroimaging demonstrated slow enlargement of the tumor and an associated syrinx. Nineteen months after diagnosis, the tumor was excised to gross-total resection in a 2-stage operation. One year following resection, the patient had no radiographic recurrence and was functional in a wheelchair with minimal paresis in the upper extremities. This case represents the most extensive example of primary spinal intramedullary CNS GNB reported to date. Holocord tumors present a significant challenge to the neurosurgeon, and resection bears substantial risk of morbidity. In spinal cord CNS GNB, chemotherapy followed by complete resection may be the most effective means of tumor control.

Crescent sign on magnetic resonance angiography revealing incomplete stent apposition: correlation with diffusion-weighted changes in stent-mediated coil embolization of aneurysms.

OBJECT: Few data are available on how closely stents appose the luminal vessel wall in stent-mediated coil embolization of intracranial aneurysms and on the effect of incomplete stent apposition on procedural thromboembolic complications. METHODS: Postprocedural 3-T MR diffusion-weighted imaging and time-of-flight angiography were obtained in 58 patients undergoing stent-mediated coil embolization of aneurysms using the Enterprise closed-cell and Neuroform open-cell self-expanding intracranial microstents. RESULTS: A distinctive semilunar signal pattern, identified using 3-T MR angiography, represented flow outside the confines of the stent struts in patients in whom Enterprise but not Neuroform devices were used. This pattern, designated as the crescent sign, was confirmed to correspond to incomplete stent apposition by use of high-resolution angiographic flat-panel CT scanning revealing flow ingress into and egress out of the isolated luminal wedge. The presence of the crescent sign was seen in 18 of 33 Enterprise-treated but in 0 of 25 Neuroform-treated cases, and was more likely in stents delivered in the tortuous internal carotid artery (p = 0.034). The crescent sign was strongly predictive of ipsilateral postprocedural lesions seen on diffusion-weighted imaging in the entire population (OR 18, 95% CI 4.33-74.8; p < 0.0001). In the Enterprise stent subset, ipsilateral lesions were detected on diffusion-weighted imaging in 15 (45%) of 33 cases; the crescent sign was seen in 12 (80%) of 15 patients with ipsilateral lesions on diffusion-weighted imaging, but in only 6 of 18 patients without lesions (OR 8, 95% CI 1.61-39.6; p = 0.006). CONCLUSIONS: Incomplete stent apposition is detectable on 3-T MR angiography as a crescent sign, and was found to be highly prevalent in Enterprise closed-cell design stents used to assist coil embolization of aneurysms. Incomplete stent apposition was also associated with periprocedural ipsilateral hyperintense lesions on diffusion-weighted imaging. These results identify an association between incomplete stent apposition and thromboembolic complications in stent-mediated coil embolization of intracranial aneurysms.