Faculty Bibliography

BACKGROUND:Sarcoidosis is a systemic disease with neurologic involvement in approximately 5% of cases. Ischemic events related to neurosarcoid vasculitis are rare. We report the successful treatment of symptomatic neurosarcoid vasculitis with angioplasty. CASE DESCRIPTION/METHODS:A 41-year-old African American with a diagnosis of neurosarcoid presented with aphasia and right-sided weakness. He was treated medically with antiplatelet agents, heparinization, and hypertensive therapy. Despite this treatment, he experienced clinical worsening and radiographic extension of his infarcts. He underwent successful angioplasty of a severe focal stenosis of the left middle cerebral artery. After the procedure, he experienced marked improvement in his symptoms and at follow-up continues to improve. CONCLUSIONS:We report the angiographic demonstration of neurosarcoidosis with large vessel changes and resultant strokes and its successful treatment with balloon angioplasty.

OBJECTIVE AND IMPORTANCE/OBJECTIVE:The ventriculus terminalis of the conus, or "fifth ventricle" refers to the ependymal-lined space in the middle of the conus that is present in childhood and whose persistence into adulthood is rare. A number of cases of cystic dilatation of the ventriculus terminalis have been described in adulthood. Patients tend to present with either pain alone or gradually progressive conus or cauda equina syndromes with varying degrees of recovery after cyst drainage. Presentation with an acute cauda equina syndrome and its successful surgical management has not been previously reported. CLINICAL PRESENTATION/METHODS:A 57-year-old woman experienced back pain and bilateral sciatica ascribed to diabetic neuropathy for 2 years. Over a 24-hour period she developed bilateral lower extremity weakness, saddle anesthesia, and bowel and bladder incontinence. Lumbosacral magnetic resonance imaging demonstrated a large cystic dilatation of the ventriculus terminalis. INTERVENTION/METHODS:She was taken for emergency surgical decompression and cyst drainage. Immediately after surgery, she experienced significant increase in lower extremity strength and has since regained continence. CONCLUSION/CONCLUSIONS:Cystic dilation of the ventriculus terminalis should be part of the differential diagnosis for a cauda equina syndrome; surgical decompression with simple cyst drainage can result in excellent clinical results.

SUMMARY/CONCLUSIONS:To characterize the clinical presentation, imaging features and endovascular treatment of paraspinal non-vertebral arteriovenous fistulas along the segmental nerve. Retrospective review was performed on the five patients identified in our database covering 1985 to 2003. All patients presented with an incidentally found continuous murmur over the upper paraspinal or parasternal regions before three years old. In four patients, the AV fistula was in the mid-thoracic level and at L3 in one. All AV fistulas were a high-flow single-hole fistula at the neural foramen with venous drainage into paraspinal and epidural veins without intradural reflux. All fistulas were endovascularly occluded in the same session as the diagnostic angiography. The fistula was occluded with detachable coils in one case and with N-butylcyanoacrylate (NBCA) with flow control in four cases. Complete occlusion of the fistula was obtained in all cases and all patients remained neurologically intact at the last follow up (average six years). Non-vertebral paraspinal arteriovenous fistula along the segmental nerve is a specific disease entity seen in children. Embolization is the first choice of treatment for this disease.

In patients with vein of Galen malformations, high-flow shunting decreases cerebral perfusion. By reducing or eliminating these shunts, transarterial embolization can improve cerebral perfusion and clinical outcomes. Quantifying pre- and postembolization shunt blood flow may help determine the optimal timing and efficacy of embolization and may provide prognostic information. The authors used magnetic resonance imaging noninvasive optimal vessel analysis as a novel modality to measure volumetric blood flow through vein of Galen malformation shunts in a neonate and an infant before and after transarterial embolization

PURPOSE/OBJECTIVE:To identify MR spectroscopic changes in the rat hippocampus following proton radiosurgery. METHODS AND MATERIALS/METHODS:A group of 12 rats were treated with Bragg peak proton beam irradiation involving the right hippocampus. Single doses of 30 CGE, 50 CGE, 70 CGE, 90 CGE were delivered to groups of 3 animals using single fraction technique. Animals were imaged using a standard 3 T GE Signa MRI at 4 months following treatment. An untreated animal was also studied. A 3'' surface coil was employed to obtain T1 weighted coronal pre- and post-gadolinium images (TR 600 and TE 30) and dual echo T2 weighted coronal images (TR 3000, TE 30/90). Volumetric analysis with custom software was done to evaluate areas of increased signal on T2 weighted images and the development of hydrocephalus was examined. Animals were sacrificed and specimens of the treated hippocampus were harvested for High Resolution Magic Angle Spinning MR Spectroscopy (HRMAS) followed by histopathology of the tissue samples. Peak values of choline, creatine, N-acetyl aspartate and lipids were evaluated and compared. RESULTS:Peak tissue injury occurred in the surviving 90 CGE animal by both T2 weighted and post-gadolinium imaging. Gadolinium enhancement was seen in decreasing volumes of tissue at dosage levels from 90 to 50 CGE. Hydrocephalus was seen on the untreated side in the 90 CGE animal likely because of mass effect, while it was seen in small degrees in the side of treatment in the 70 and 50 CGE animals. Histopathology showed changes at 90 and 70 CGE, but not at 50 or 30 CGE at this time point using H and E stains. HRMAS showed spectroscopic changes in the surviving 90 and 70 CGE animals but not in the 50 and 30 CGE animals. Statistical significance was not reached because of the small sample size. CONCLUSIONS:Following single dose proton radiosurgery of rat hippocampus, HRMAS is able to identify metabolic changes induced by radiation. Studies built on these principles may help develop non-invasive MR spectroscopic methods to distinguish radiation changes from tumor recurrence.

OBJECTIVE: To study the incidence and clinical outcomes of intraoperative aneurysm rupture (IOR) during endovascular coil embolization at a single large volume center and to review the literature on this subject to determine whether IOR rupture rate and mortality correlate with volume of aneurysms treated at a given center and years since the institution of Guglielmi detachable coils as a treatment modality. METHODS: We reviewed the aneurysm database at the Center for Endovascular Surgery since its inception (1997-2003) and reviewed 600 consecutively treated intracranial aneurysms in which coiling was attempted. All patients who sustained an IOR were studied. Procedural and follow-up angiograms as well as clinical outcomes were retrospectively reviewed. A literature review was conducted. RESULTS: Six patients (1.0%) experienced IOR (1.4% in acutely ruptured lesions, 0% in unruptured). All six had presented with diffuse subarachnoid hemorrhage (Fisher Grade 3) and in good clinical grade (Hunt & Hess Grades 1-3). One patient was rendered permanently disabled secondary to delay in controlling the IOR. All others were neurologically unchanged. A review of the literature revealed a trend in correlation between volume of aneurysms treated and IOR rate; no statistically significant correlation was found between volume of aneurysms treated or years since the introduction of GDC technology and IOR rates or mortality. CONCLUSION: IOR remains a serious risk of endosaccular coiling of intracranial aneurysms, with aneurysms presenting with subarachnoid hemorrhage at greater risk for this complication. This risk can be minimized with very low associated morbidity and mortality (incidence 1%, 17% morbidity, 0% mortality at our institution).

While several cases of cancer metastatic to cranial meningiomas have been reported, metastasis to spinal meningioma has been reported only once, and a mechanism for such metastases has not been investigated. We report a case of breast carcinoma metastatic to an epidural cervical meningioma, summarize the literature on metastases to central nervous system meningiomas, and suggest a possible mechanism. Our patient, a 55-year-old woman, presented with difficulty walking, back pain, and quadriparesis. Magnetic resonance imaging revealed an enhancing C3-4 epidural lesion and an L4 compression fracture. Because of concern that the fracture and epidural lesion might represent metastases, we performed a metastatic work-up, which revealed a right breast mass. The patient underwent C3-C4 laminectomies and an epidural lesion was encountered. Intraoperative frozen section revealed mixed meningioma and breast adenocarcinoma. A gross total resection was achieved and the patient subsequently received spinal irradiation and hormonal therapy. Whereas a literature review revealed numerous reports of metastases to cranial meningiomas, this represents only the second reported case of such pathology in the spine. Mechanisms of this unusual process likely include meningiomas' vascularity, meningiomas' slow growth providing nutrient availability, and perhaps, as suggested by our analysis, E-cadherin expression by both meningiomas and breast cancer. Metastasis to meningioma must be considered in an epidural spinal lesion in all patients with a known malignancy, with surgical aggressiveness tailored to the intraoperative pathologic diagnosis.

OBJECT: The authors characterize the clinical presentation and imaging features of paraspinal nonvertebral arteriovenous fistulas (AVFs) along the segmental nerve and describe their endovascular treatment. METHODS: The authors undertook a retrospective review of medical records, imaging, and treatment of patients with endovascular problems spanning the period from 1985 to 2003. Five pediatric patients (2-3 years of age) received diagnoses of nonvertebral paraspinal AVFs along the segmental nerve. All patients presented with an incidentally discovered continuous murmur over the paraspinal or parasternal regions. All patients were neurologically intact; two patients had cardiomegaly. The AVF was found in the midthoracic level in four patients and at L-3 in one patient. All AVFs were high-flow single-hole fistulas at the neural foramen with venous drainage into paraspinal and epidural veins but without intradural reflux. All fistulas were endovascularly occluded in the same session as diagnostic angiography took place. The fistula was completely occluded, with detachable coils in one case and with N-butyl-cyanoacrylate (NBCA) in four cases. Before NBCA injection, the flow through the fistula was decreased either by placing coils distal to the fistula or by inflating a balloon proximally. No signs of recanalization appeared on short-term follow-up magnetic resonance imaging in all patients. All patients remained neurologically intact at the last available follow-up session (mean 6 years). CONCLUSIONS: Nonvertebral paraspinal AVFs along the segmental nerve are specific disease entities seen in children presenting with bruit and cardiomegaly. Endovascular embolization should be the treatment of choice for this rare disease.

OBJECTIVE:To study the hyperacute histological and immunohistochemical effects of stereotactic proton beam irradiation of the rat hippocampus. METHODS:Nine rats underwent proton beam radiosurgery of one hippocampus with nominal doses of cobalt-2, -12, and -60 Gray equivalents (n = 3 each). Control animals (n = 3) were not irradiated. Animals were killed 5 hours after irradiation and brain sections were stained for Nissl, silver degeneration, deoxyribonucleic acid (DNA) fragmentation (DNAF), and the activated form of two mitogen-activated protein kinases (MAPKs), phospho-Erk1/2 (P-Erk1/2) and p38. Stained cells in the hippocampus expressing DNAF and/or P-Erk1/2 were counted. Confocal microscopy with double immunofluorescent staining was used to examine cellular colocalization of DNAF and P-Erk1/2. RESULTS:Both DNAF and P-Erk1/2 showed quantitative dose-dependent increases in staining in the targeted hippocampus compared with the contralateral side and controls. This finding was restricted to the subgranular proliferative zone of the hippocampus. Both markers also were up-regulated on the contralateral side when compared with controls in a dose-dependent fashion. Simultaneous staining for DNAF and P-Erk1/2 was found in fewer than half of all cells. p38 was unchanged compared with controls. Although Nissl staining appeared normal, silver stain confirmed dose-dependent cellular degeneration. CONCLUSION/CONCLUSIONS:DNAF, a marker of cell death, was present in rat hippocampi within 5 hours of delivery of cobalt-2 Gray equivalents stereotactically focused irradiation, suggesting that even low-dose radiosurgery has hyperacute neurotoxic effects. Activated mitogen-activated protein kinase was incompletely colocalized with DNAF, suggesting that activation of this cascade is neither necessary nor sufficient to initiate acute cell death after irradiation.