Oculomotor nerve palsy in the setting of an anterior cerebral A2 segment aneurysm.

INTRODUCTION: A case is presented which highlights a rare cause of oculomotor nerve palsy (third nerve palsy) in the setting of subarachnoid hemorrhage secondary to an A2 segment anterior cerebral aneurysm. A third nerve palsy is most often associated with posterior communicating artery aneurysms which are explained by the anatomic proximity of nerve and artery. Third nerve palsies from remote aneurysms however are more difficult to understand. PRESENTATION: A patient presented to the emergency department with severe headache, dizziness, nausea and vomiting. Her examination was remarkable only for a partial left third nerve palsy manifest as a non-pupil sparing mild ptosis. A CT scan and digital subtraction cerebral angiography revealed subarachnoid hemorrhage secondary to a small ruptured aneurysm at the A2 segment of the anterior cerebral artery. The aneurysm was deemed treatable by endovascular coil embolization and the patient underwent successful placement of a detachable helical coil. At 1 month follow-up, the patient had no complaints and showed complete resolution of all oculomotor symptoms. CONCLUSION: While oculomotor nerve palsy is an incredibly rare sequelae of anterior cerebral artery aneurysm rupture, it is important that clinicians and researchers continue to report and study such cases. It has been hypothesized that mass effect, hemotoxicity and ischemia are all possible causes of third nerve injury in remote aneurysms, as in this case.

Angiographic reversed flow ratio as an indicator of high-grade internal carotid stenosis.

PURPOSE: To examine differential flow through internal carotid artery (ICA) and external carotid artery (ECA) circulations on digital subtraction angiography (DSA) as an indicator of carotid stenosis. MATERIALS AND METHODS: Carotid and cerebral angiograms (N = 148) were retrospectively evaluated, with flow through ICA and ECA circulations scored on a five-point flow scale ratio: a score of 1 indicated ICA flow arrived at the vertex at least 1 second before ECA flow, a score of 3 indicated ICA and ECA flow arrived at the same time, and a score of 5 indicated ECA flow reached the vertex at least 1 second before ICA flow. Sensitivities and specificities for ICA stenosis detection were determined for flow ratios. RESULTS: Sensitivity and specificity varied with stenosis severity and flow grade. In general, deranged flow was an insensitive marker for stenosis; however, flow ratio equalization or frank ratio reversal was a highly specific indicator of ICA stenosis. A flow grade of 3-5 was 88% specific (95% CI, 79%-94%) and 66% sensitive (95% CI, 53%-77%) for stenosis of 70% or greater. A grade of 4 or 5 was 99% specific (95% CI, 93%-99%) and 24% sensitive (95% CI, 15%-37%) and a grade of 5 was 100% specific (95% CI, 94%-100%) and 18% sensitive (95% CI, 9%-29%) for carotid stenosis of 70% or greater. CONCLUSIONS: Identification of deranged differential flow between the ICA and ECA circulations is an insensitive but highly specific marker for high-grade stenosis. Therefore, if flow reversal is identified but the apparent carotid stenosis is mild, further angiographic projections should be used to uncover a highly probable severe carotid stenosis.

Disseminated enterogenous cells at the cervicomedullary junction causing communicating hydrocephalus.

The authors present a unique case of a patient with communicating hydrocephalus and repeated ventriculoperitoneal shunt obstructions resulting from mucin-secreting enterogenous cell deposits at the cervicomedullary junction. Pathological examinations revealed that these cellular deposits lacked characteristic cystic architecture and the patient had no history of previous cyst with dissemination. Because of the repeated shunt obstructions and inability to surgically resect the lesion in its entirety, the authors elected radiation therapy to the cervicomedullary junction, encompassing the radiological abnormality. As of this writing, the patient has remained at neurological baseline and has not required further shunt revisions for obstruction.

Putative risk of substantial venous air embolism during vertebroplasty: a technical observation.

STUDY DESIGN: Technical report. OBJECTIVE: To convey the mechanism of venous air embolism (VAE) during percutaneous spinal procedures and its proper identification and management. SUMMARY OF BACKGROUND DATA: Percutaneous spinal procedures such as vertebroplasty and kyphoplasty are commonplace techniques employed to alleviate back pain for compression fractures. VAE is a real and likely underappreciated phenomenon that is important to recognize. METHODS: A case report is used to illustrate the clinical scenario of VAE during vertebroplasty performed for a T9 compression fracture. RESULTS: The rapid sumping of fluid and air was identified during the procedure and believed to be due to a large air/venous interface within the trabecular bone. The needle was capped and no undue harm occurred to the patient. CONCLUSION: VAE is a complication with associated morbidity and mortality from percutaneous procedures for the treatment of compression fractures. An understanding of the causes, prevention, identification, and management when it occurs will serve to improve patient care and reduce morbidity.

Spinal extradural arteriovenous malformations with parenchymal drainage: venous drainage variability and implications in clinical manifestations.

OBJECT: Although nontraumatic spinal arteriovenous malformations and fistulas (AVMs and AVFs) restricted to the epidural space are rare, they can lead to significant neurological morbidity. Careful diagnostic imaging is essential to their detection and the delineation of the pathological anatomy. Aggressive endovascular and open operative treatment can provide arrest and reversal of neurological deficits. METHODS: The authors report on 6 cases of extradural AVMs/AVFs causing progressive myelopathy. Clinical findings, diagnostic evaluation, treatment, and outcome are discussed. Special consideration is given to the anatomy of the lesions and the operative techniques used to treat them. A review of the literature concerning extradural vascular malformations is also presented. RESULTS: All 6 cases of extradural AVMs had an extradural fistulous location with intradural medullary venous drainage. These cases illustrate progressive myelopathy through cord venous congestion (hypertension) that can be caused by an extradural nidus or fistula. In 4 cases, a large epidural lake was identified on angiography. At surgery, the epidural lake was obliterated and medullary drainage interrupted. All patients had stabilization of their neurological deficits and successful obliteration of the AVM/AVF was obtained. CONCLUSIONS: Extradural AVMs and AVFs are a poorly described entity with published clinical experience limited to sporadic case reports and small series. Although these lesions have a purely extradural location of arteriovenous shunting and early venous drainage, they can be responsible for acute and progressive neurological symptoms similar to those caused by their dural-based intradural counterparts. With careful imaging recognition of the pathological anatomy, surgical and endovascular techniques can be used for the treatment of extradural AVMs affording effective and durable obliteration with stabilization or reversal of neurological symptoms. Venous drainage directly correlates the pathologic mechanisms of presentation. Specific attention must be paid intraoperatively to the epidural lake common to both variants so that recurrence is avoided.

Malplacement of ventricular catheters by neurosurgeons: a single institution experience.

INTRODUCTION: The placement of cerebrospinal fluid (CSF) diversion devices requires an appropriate technical expertise associated with proper surgical training in order to minimize undue complications. This study sought to review a single institution's experience with placement of external ventricular drains (EVD) and ventriculoperitoneal (VP) shunts as performed by neurosurgeons with procedure-specific training. METHODS: A retrospective database review was conducted for all patients who underwent intraventricular CSF diversion over a 5-year period from March 2003 to February 2008. Included in the analysis were ventriculostomy procedures that included EVDs, VP shunts, and ventriculoatrial shunts. RESULTS: A total of 138 patients underwent 212 ventriculostomy procedures. Seventy-one (51%) patients were male and sixty-seven (49%) were female. The median age was 50.1 years. A ventriculostomy-related hemorrhage was identified in 15 (7.1%) patients-4 of whom developed new symptoms. Twenty-six (12.3%) ventriculostomy catheters were malplaced as determined from post-procedural imaging. Ventriculostomy-related infections were identified in 7 (3.3%) patients, 4 of whom had EVDs and 3 of whom had VP shunts. CONCLUSION: The placement of intraventricular catheters by neurosurgeons remains a relatively safe and effective procedure that is associated with infrequent rates of symptomatic hemorrhage and infection.

Recurrence of dysembryoplastic neuroepithelial tumor following resection.

Dysembryoplastic neuroepithelial tumor (DNT) is an increasingly recognized surgically curable tumor that characteristically presents with seizures in children. We report a case of a patient who underwent resection of a histologically proven DNT at 6 years of age. The resection was thought to be total at the time of surgery, and this impression was confirmed on postoperative imaging. Following the initial resection, the patient underwent surveillance imaging at regular intervals. Six years following the initial surgery, surveillance imaging demonstrated an enlarging area of signal abnormality at the site of the prior resection. The patient underwent a second resection with pathological confirmation of DNT recurrence. Although recurrence of DNT following resection is rare, this case suggests that surveillance imaging may have a role in patients with DNT, even following resections that are thought to be complete.

Rate of spontaneous hemorrhage in histologically proven cases of pilocytic astrocytoma.

OBJECT: Spontaneous intracerebral hemorrhage is an uncommon but recognized initial presenting sign of both primary and metastatic brain tumors. The rate of tumor-related intracranial hemorrhage is variably reported from <1 to 14.6%. Hemorrhage in primary gliomas occurs in 3.7-7.2% of gliomas, mainly in glioblastoma muliforme and oligodendroglioma with low-grade astrocytomas accounting for <1%. Hemorrhage associated with pilocytic astrocytomas (PAs) is only sporadically reported. The authors report on a series of patients in whom PAs presenting as hemorrhages prompted them to examine the incidence of bleeding in these tumors. METHODS: Cases involving a confirmed tissue diagnosis of PA from 1994-2005 were reviewed retrospectively. The authors included only patients with evidence of hemorrhage on computed tomography and/or magnetic resonance imaging seen prior to biopsy or resection and in the absence of trauma or other vascular pathological entities. RESULTS: In 138 patients with histologically proven PAs, the mean age at diagnosis was 23 years. In 11 patients (8%; 5 male and 6 female) there was evidence of hemorrhage at presentation. There were no locations more susceptible to hemorrhage than any other, although no bleeding occurred within the cerebellum. All but 1 patient was treated with a gross-total resection. CONCLUSIONS: Hemorrhage in association with PAs likely results from the frequently observed abnormal vasculature in these tumors, occurs with a greater frequency than previously thought, and should be considered in the differential diagnosis of spontaneous intracerebral hemorrhage.

Utility of the "buddy" wire in intracranial procedures.

Patients undergoing neurointerventional procedures with excessively tortuous vascular anatomy often have limited treatment options. The ability to pass and maintain the stability of micro-guidewires, catheters, and interventional devices is often a product of guide catheter steadiness. A companion wire passed through the lumen of the guide catheter to increase the guide catheter's stiffness can overcome the challenges associated with tortuous anatomy; this companion wire is referred to as a "buddy" wire. We demonstrate the technical success of this system by presenting a patient whose endovascular treatment would have otherwise been impossible without a "buddy" wire.

Endovascular embolization of paragangliomas: A safe adjuvant to treatment.

BACKGROUND AND PURPOSE: Paragangliomas are tumors of neural crest origin commonly arising from the carotid body, vagal nerve, or jugular bulb. The definitive treatment for these tumors is surgical resection, often augmented with pre-operative embolization due their highly vascular nature. We present our experience examining the efficacy and safety of endovascular embolization of these rare tumors. METHODS: A review of patient's diagnosed with paragangliomas who underwent pre-operative embolization over a 5-year period (2002-2007) was conducted. The tumor subtype, efficacy of embolization, method of embolization, and rate of complication were noted. RESULTS: A total of 38 patients underwent selective arterial embolization of their paraganglioma using polyvinyl alcohol (PVA) particles ranging in size from 100-1000 microns. The tumor subtypes treated were carotid body (n = 20), glomus vagale (n = 10), and glomus jugulare (n = 8). The average age at presentation was 44 years (range, 15-81). Twenty-two patients were female and sixteen were male. The most common artery embolized was the ascending pharyngeal branch of the external carotid artery. Post-embolization angiography revealed an average decrease in blood flow to tumor of 75%. With the exception of transient facial pain documented in 1 patient, there were no known complications from embolization. CONCLUSIONS: The endovascular embolization of paragangliomas using PVA prior to surgical resection is a very safe and efficacious procedure that may reduce operative blood loss and associated morbidity.

Isolated third nerve palsy associated with a ruptured anterior communicating artery aneurysm.

INTRODUCTION: An oculomotor palsy in the setting of aneurysmal subarachnoid hemorrhage is often due to compression by a posterior communicating artery aneurysm. Anterior communicating artery (ACOM) aneurysms may produce ophthalmologic symptoms of the anterior visual pathways, but rarely ever lead to a 3rd nerve palsy. This report describes a rare case of an isolated oculomotor palsy in a patient who experienced subarachnoid hemorrhage from an ACOM aneurysm. CLINICAL PRESENTATION: A 46-year-old male presented to the emergency department with headache, emesis, and an isolated left third nerve palsy-the remainder of his exam was normal. A head CT showed diffuse subarachnoid hemorrhage that was later attributed to an ACOM aneurysm as determined by angiography. INTERVENTION: Due to the configuration of the aneurysm, it was not deemed treatable by endovascular means. Following a successful clipping, the patient experienced a delayed, transient, monocular visual loss. Upon follow-up, his oculomotor palsy had completely resolved. CONCLUSION: In very rare circumstances, an ACOM aneurysm may produce an isolated third nerve palsy. The etiology of the palsy is likely related to clot formation and/or irritating blood products.

Nonenhancing tumors of the spinal cord.

OBJECT: Enhancement of pathological entities in the central nervous system is a common finding when the blood-brain barrier has been compromised. In the brain, the presence or absence of gadolinium enhancement is often an indicator of tumor invasiveness and/or grade. In the spinal cord, however, contrast enhancement has been shown in all tumor types, regardless of grade. In this study the authors explore the incidence of nonenhancing tumors of the spinal cord and the clinical course of patients with these lesions. METHODS: A retrospective analysis was conducted in which investigators examined the patterns of enhancement of histologically proven intramedullary spinal cord tumors that had been evaluated at the Mayo Clinic between 1998 and 2002. The tumors that did not enhance were the subject of this report. RESULTS: A total of 130 patients with intramedullary tumors were evaluated. Of those, 11 patients (9%) had tumors that did not enhance. Histologically, a majority of tumors were astrocytomas (eight low-grade and two high-grade lesions); one tumor was a subependymoma. Morphologically, most of the tumors were diffuse and none had associated cysts. Tumors spanned from two to seven levels and were located throughout the spinal cord (four cervical, three cervicothoracic, one thoracic, and three thoracolumbar). Biopsy procedures were performed in eight patients, subtotal resection was performed in two, and gross-total resection in one. After a mean follow-up period of 19 months, tumors remained stable in eight patients but progressed in three, two of whom died. CONCLUSIONS: A number of intramedullary spinal cord tumors will not enhance after addition of contrast agents. The absence of enhancement does not imply the absence of tumor.

A case of infertility in a patient with a ventriculoperitoneal shunt.

OBJECTIVE AND IMPORTANCE: Complications arising from the placement of ventriculoperitoneal (VP) shunts are well documented. A case of infertility is presented that was thought to result from factors related to the distal end of a VP shunt residing within a patient's abdomen. CLINICAL PRESENTATION: A 30-year-old female with a 3-year history of infertility was referred for fallopian tube blockage. An exploratory laparoscopy revealed multiple adhesions adjoining the distal end of her fallopian tubes. The distal portion of a VP shunt placed at childhood (with subsequent revisions) was found entangled among grossly inflamed and densely adhesive pelvic viscera. INTERVENTION: Laparoscopic adhesiolysis was performed and the patient's fallopian tubes were reconstituted. The distal portion of the VP shunt was freed from the surrounding viscera and was not revised. CONCLUSION: VP shunts may produce adhesive disease and complicate fertility via mechanical, chemical, and/or infectious processes.

Balloon-assisted coiling through a 5-French system.

INTRODUCTION: We present a catheter technique that utilizes a 5F system for the purpose of balloon-assisted coiling in the setting of intracranial aneurysms. METHODS: A standard 5F short sheath is placed in the common femoral artery, and a 5F diagnostic catheter is placed through the sheath and used for selective vessel angiography. When endovascular intervention is pursued, the diagnostic catheter is placed in the appropriate vessel and systemic heparinization is ensured. Over an exchange length wire, the 5F vertebral catheter and 5F short sheath are exchanged for a 5F Shuttle (Cook) sheath. We then routinely place a 10, 14 or 18 microcatheter over an appropriately gauged microguidewire into the aneurysm. As needed, balloon catheters are then placed across the neck of the aneurysm for remodeling purposes. During the course of the procedure, control angiography is performed through the Shuttle sheath. Following the placement of coils, the microcatheter and balloon catheter are removed and a final biplane image is obtained via the 5F Shuttle sheath. RESULTS: This technique has been employed in 15 patients who required balloon-assisted coiling of an intracranial aneurysm. There were no technical difficulties or arterial access site complications from the procedures. Catheter mobility and torque were not affected, nor was the quality of our imaging. CONCLUSION: We conclude that this small-diameter system provides ample "room" for catheter placement and interventional treatment while reducing the known risks of postprocedural complications. Angiographic images remain excellent and are comparable to those obtained by larger catheters.

Expanding the treatment window with mechanical thrombectomy in acute ischemic stroke.

INTRODUCTION: Acute ischemic stroke is a common disease associated with high mortality and significant long-term disability. Treatment options for acute ischemic stroke continue to evolve and include pharmaceutical and mechanical therapies. With the recent US Food and Drug Administration approval of a new device for mechanical thrombectomy, the options available for treatment of acute ischemic stroke have been expanded. Thrombolytic therapy is generally given intravenously in the first 3 h and up to 6 h via the intraarterial route for pharmacological clot disruption. The maximum time-frame for mechanical thrombectomy devices has yet to be determined. METHODS: A 78-year-old female presented to the emergency room with a dense right hemiparesis, leftward gaze preference and dense global aphasia. Eight hours after symptom onset, left carotid angiography confirmed a left internal carotid artery terminus occlusion. A single pass was made through the clot with an X6 Merci Retriever device. RESULTS: After a single pass, the vessel was reopened and normal flow in the left internal carotid artery was demonstrated. At the time of discharge, her neurological deficits had improved significantly. Furthermore, the final infarct area, as demonstrated on magnetic resonance imaging, was probably much smaller than it would have been if the vessel had not been recanalized. CONCLUSION: We report the use of a new mechanical thrombectomy device 8 h after onset of ischemic symptoms, with substantial subsequent improvement in neurological outcome. In selected cases, use of the Merci Retriever can result in improved outcomes beyond the traditional 6-h window used for intraarterial pharmacological thrombolysis.

Long-term outcome of epilepsy surgery among 399 patients with nonlesional seizure foci including mesial temporal lobe sclerosis.

OBJECT: The authors reviewed the long-term outcome of focal resection in a large group of patients who had intractable partial nonlesional epilepsy, including mesial temporal lobe sclerosis (MTS), and who were treated consecutively at a single institution. The goal of this study was to evaluate the long-term efficacy of epilepsy surgery and the preoperative factors associated with seizure outcome. METHODS: This retrospective analysis included 399 consecutive patients who underwent epilepsy surgery at Mayo Clinic in Rochester, Minnesota, between 1988 and 1996. The mean age of the patients at surgery was 32 +/- 12 years (range 3-69 years), and the mean age at seizure onset was 12 +/- 11 years (range 0-55 years). There were 214 female (54%) and 185 male (46%) patients. The mean duration of epilepsy was 20 +/- 12 years (range 1-56 years). The preceding values are given as the mean +/- standard deviation. Of the 399 patients, 237 (59%) had a history of complex partial seizures, 119 (30%) had generalized seizures, 26 (6%) had simple partial seizures, and 17 (4%) had experienced a combination of these. Preoperative evaluation included a routine and video-electroencephalography recordings, magnetic resonance imaging of the head according to the seizure protocol, neuropsychological testing, and a sodium amobarbital study. Patients with an undefined epileptogenic focus and discordant preoperative studies underwent an intracranial study. The mean duration of follow up was 6.2 +/- 4.5 years (range 0.6-15.7 years). Seizure outcome was categorized based on the modified Engel classification. Time-to-event analysis was performed using Kaplan-Meier curves and Cox regression models to evaluate the risk factors associated with outcomes. Among these patients, 372 (93%) underwent temporal and 27 (7%) had extratemporal resection of their epileptogenic focus. Histopathological examination of the resected specimens revealed MTS in 113 patients (28%), gliosis in 237 (59%), and normal findings in 49 (12%). Based on the Kaplan-Meier analysis, the probability of an Engel Class I outcome (seizure free, auras, or seizures related only to medication withdrawal) for the overall patient group was 81% (95% confidence interval [CI] 77-85%) at 6 months, 78% (CI 74-82%) at 1 year, 76% (CI 72-80%) at 2 years, 74% (CI 69-78%) at 5 years, and 72% (CI 67-77%) at 10 years postoperatively. The rate of Class I outcomes remained 72% for 73 patients with more than 10 years of follow up. If a patient was in Class I at 1 year postoperatively, the probability of seizure remission at 10 years postoperatively was 92% (95% CI 89-96%); almost all seizures occurred during the 1st year after surgery. Factors predictive of poor outcome from surgery were normal pathological findings in resected tissue (p = 0.038), male sex (p = 0.035), previous surgery (p < 0.001), and an extratemporal origin of seizures (p < 0.001). CONCLUSIONS: The response to epilepsy surgery during the 1st follow-up year is a reliable indicator of the long-term Engel Class I postoperative outcome. This finding may have important implications for patient counseling and postoperative discontinuation of anticonvulsant medications.

Use of the Perclose ProGlide device with the 9 French Merci retrieval system.

INTRODUCTION: Closure devices are commonly used in neurointerventional procedures to achieve groin hemostasis. These devices are particularly useful in procedures requiring anticoagulation and larger catheters. The suture-mediated Perclose ProGlide device is intended for use with 5F to 8F sheaths. We describe the use of the ProGlide device with 9F sheaths in acute stroke treatment using the Merci retrieval device. METHODS: The ProGlide device is advanced over a wire until the wire exit port is at the skin surface. The wire is removed and the device is advanced until pulsatile blood flow is encountered. The footplates are opened and the stitch is deployed. The footplates are then closed and the device is removed. After advancing the suture to the vessel, it is locked and trimmed. Firm pressure is necessary during deployment to prevent oozing around the device. If continued bleeding is encountered, direct manual pressure is used to achieve hemostasis. RESULTS: We have successfully used the Perclose ProGlide device in four patients following the Merci retriever without groin or extremity complication. The Perclose ProGlide device can be successfully used after placement of a 9F system in patients who have undergone mechanical thrombectomy. CONCLUSION: This technique may be of interest to endovascular surgical neuroradiologists because it affords fast hemostasis in large access sites following mechanical thrombectomy with the Merci retrieval device. Compared to the "Preclose" technique, it saves valuable time at the beginning of the case.