Sean Lavine - Academia.edu (original) (raw)

Papers by Sean Lavine

Research paper thumbnail of Neuroanesthesia for Gamma Knife Radiosurgery: Technique, Outcome & Complications

Journal of Neurosurgical Anesthesiology, 1998

Research paper thumbnail of Neuropsychological Dysfunction in the Absence of Structural Evidence for Cerebral Ischemia after Uncomplicated Carotid Endarterectomy

Neurosurgery, 2006

OBJECTIVE-Neurocognitive dysfunction has been shown to occur in roughly 25% of patients undergoin... more OBJECTIVE-Neurocognitive dysfunction has been shown to occur in roughly 25% of patients undergoing carotid endarterectomy (CEA). Despite this, little is known about the mechanism of this injury. Recently, several groups have shown that new diffusion weighted imaging (DWI)-positive lesions are seen in 20% of patients undergoing CEA. We investigated to what degree neurocognitive dysfunction was associated with new DWI lesions. METHODS-Thirty-four consecutive patients undergoing CEA were subjected to preand postoperative cognitive evaluation with a battery of neuropsychological tests. Postoperative magnetic resonance imaging was performed in all patients within 24 hours of surgery. Lesions that showed high signal on DWI and restricted diffusion on apparent diffusion coefficient maps but no abnormal high signal on the fluid-attenuated inversion recovery images were considered hyperacute. RESULTS-Cognitive dysfunction was seen in eight (24%) patients. New hyperacute DWI lesions were seen in three (9%). Only one (13%) of the patients with cognitive dysfunction had a new DWI lesion. Two thirds of the new DWI lesions occurred in the absence of cognitive deterioration. Patients with cognitive dysfunction had significantly longer carotid cross-clamp times. CONCLUSION-Neurocognitive dysfunction after CEA does not seem to be associated with new DWI positive lesions.

Research paper thumbnail of Imaging of Subdural Hematomas

Neurosurgery Clinics of North America, 2017

The imaging of subdural hematoma has evolved significantly. Computed tomography and MRI have supp... more The imaging of subdural hematoma has evolved significantly. Computed tomography and MRI have supplanted other procedures and rendered most obsolete for the evaluation of intracranial pathology because of ease of use, tremendous soft tissue resolution, safety, and availability. Noncontrast computed tomography has become the accepted standard of care for the initial evaluation of patients with suspected subdural hematoma because of widespread availability, rapid acquisition time, and noninvasive nature. MRI offers important features in determining potential secondary causes of subdural hematoma, such as dural-based neoplasms.

Research paper thumbnail of Dobutamine versus Milrinone after Subarachnoid Hemorrhage

Neurosurgery, 2005

OBJECTIVE: Neurogenic stunned myocardium is a well-recognized complication of subarachnoid hemorr... more OBJECTIVE: Neurogenic stunned myocardium is a well-recognized complication of subarachnoid hemorrhage. Dobutamine and milrinone are both used for neurogenic stunned myocardium, but there are few data comparing them after subarachnoid hemorrhage. METHODS: We compared the physiological dose response of dobutamine and milrinone in patients with subarachnoid hemorrhage requiring a pulmonary artery catheter. We located 11 patients who received either inotrope. Physiological data were fitted to a mixed model accounting for drug, dose, and between-patient variation. RESULTS: There were 11 patients who had 152 pulmonary artery catheter measurements. Two received both inotropes (but not within 4 h of each other), 2 only milrinone, and 7 only dobutamine. The groups had similar clinical and physiological characteristics. After adjustment for vasopressin, milrinone was significantly more potent in increasing cardiac output (P < 0.0001) and stroke volume (P = 0.03), while decreasing vascular ...

Research paper thumbnail of Analysis of hemorrhage volumes after angiogram-negative subarachnoid hemorrhage

World neurosurgery, Jan 14, 2016

Antiplatelet medication use is associated with worsened outcome after angiogram-negative subarach... more Antiplatelet medication use is associated with worsened outcome after angiogram-negative subarachnoid hemorrhage (SAH). It has been hypothesized that these worsened outcomes may be the result of an association between antiplatelet medication use and increased hemorrhage volumes after angiogram-negative SAH. To test this hypothesis, we performed volumetric analysis of CT-defined hemorrhage after angiogram-negative SAH. A retrospective analysis of patients presenting with non-traumatic, angiogram-negative SAH in the Columbia University Subarachnoid Hemorrhage Outcomes database from 2000 to 2013 was performed. Subarachnoid hemorrhage volumes on admission head CT scans were measured using MIPAV software package (version 7.20; National Institutes of Health) in a semi-automated fashion. A total of 108 presenting CT scans from patients with angiogram-negative SAH were analyzed. In patients with a history of antiplatelet medication use, the mean hemorrhage volume was 14.3 mL. Patients who d...

Research paper thumbnail of Historical Account of Interventional Neuroradiology

Catheter-Based Cardiovascular Interventions, 2012

Although neurointervention shares common roots with other catheter-based interventions, the compl... more Although neurointervention shares common roots with other catheter-based interventions, the complexity of the cerebrovascular system and the diversity of illnesses that affect it have led to the development of special tools and approaches uniquely designed to address these challenges. This chapter reviews the major milestones in the evolution of what some may consider the youngest of the catheter-based cardiovascular disciplines.

Research paper thumbnail of The Role of Antiplatelet Medications in Angiogram-Negative Subarachnoid Hemorrhage

Neurosurgery, 2014

BACKGROUND: The use of antiplatelet medications has greatly expanded and this has been associated... more BACKGROUND: The use of antiplatelet medications has greatly expanded and this has been associated with an increased rate of complications after aneurysmal subarachnoid hemorrhage (SAH). The influence of antiplatelet medications on outcomes after non-aneurysmal SAH is unknown. OBJECTIVE: To analyze the frequency and impact on outcome of antiplatelet medication use among patients with angiogram-negative SAH. METHODS: An analysis of patients within the Columbia University SAH Outcomes Project database was performed. All patients who underwent catheter cerebral angiography after presenting with nontraumatic SAH between 1996 and 2013 were included. Outcomes were assessed by using the modified Rankin Scale. RESULTS: A total of 1351 patients underwent catheter angiography for evaluation of SAH. Of these, 173 (13%) were designated angiogram-negative. The fraction of patients presenting with angiogram-negative SAH as well as the frequency of antiplatelet use among these patients significantl...

Research paper thumbnail of Treating Stroke as a Medical Emergency: A Survey of Resident Physicians' Attitudes toward “Brain Attack” and Carotid Endarterectomy

Neurosurgery, 2001

OBJECTIVE: A major impetus of the "brain attack" campaign is the early recognition and treatment ... more OBJECTIVE: A major impetus of the "brain attack" campaign is the early recognition and treatment of acute stroke. Critical to this goal is the education of physicians during their residency training. METHODS: Resident physicians in Los Angeles who were in family practice (18%), internal medicine (51%), emergency medicine (20%), and neurology (11%) and had already completed their first year of training responded to a questionnaire on stroke and the treatment of carotid stenosis. RESULTS: Of the 266 respondents, 76% had heard of the "brain attack" campaign, 22% did not identify dysarthria as a symptom of stroke, and 21% did not identify obtundation as a presentation of stroke. Twenty-eight percent chose not to use tissue plasminogen activator for acute ischemic stroke, and 60% recognized the need to begin treatment within 3 hours. More than 90% of respondents were able to identify correct screening tests for patients with suspected carotid stenosis. However, 56% responded that they would not advocate operating on patients with asymptomatic severe stenosis (>70%) until stenosis reached a critical value (85%). Conversely, 45% would recommend operative treatment for symptomatic patients who had less than 60% stenosis. Sixty-eight percent would refer patients to vascular surgeons, 14% to neurosurgeons, and 17% to both for carotid endarterectomy. CONCLUSION: Recognition of stroke as a medical emergency is improving. However, significant progress can still be made in the recognition of stroke symptoms. Primary care and neurology residents remain skeptical about carotid endarterectomy for asymptomatic patients, whereas there is enthusiasm for treating stroke survivors. Education by members of the surgical community could promote the aggressive treatment of asymptomatic patients to prevent stroke.

Research paper thumbnail of Embolization as an Adjuvant in the Treatment of Cerebral Arteriovenous Malformations

Neurosurgery, 2008

Close Window. Close Window. Thank you for choosing to subscribe to the eTOC for Neurosurgery. Ent... more Close Window. Close Window. Thank you for choosing to subscribe to the eTOC for Neurosurgery. Enter your Email address: Wolters Kluwer Health may email you for journal alerts and information, but is committed to maintaining ...

Research paper thumbnail of 2-Hexyl Cyanoacrylate (Neuracryl M) Embolization of Cerebral Arteriovenous Malformations

Neurosurgery, 2006

Neuracryl M is a newly designed liquid embolic agent. In an attempt to verify the safety and effi... more Neuracryl M is a newly designed liquid embolic agent. In an attempt to verify the safety and efficacy of neuracryl M, we participated in the PROVASIS Trial, a pilot study using this agent in the preoperative treatment of cerebral arteriovenous malformations (AVMs). Because the trial was prematurely terminated by the sponsoring company because of financial considerations, we now present our data as a single center series. Between November 2002 and December 2003, six patients were enrolled in the PROVASIS trial at our institution, and four of these patients were randomized to treatment with neuracryl M. The patients were a 30-year-old man with a right frontal lobe AVM, a 20-year-old man with a right cerebellar AVM, a 26-year-old woman with a midline cerebellar AVM, and a 47-year-old man with a left parietotemporal lobe AVM. All patients underwent AVM embolization with neuracryl M, followed by definitive treatment, either open surgery or radiosurgery. In each case, there were no permanent complications, and blood loss was minimal. Follow-up imaging demonstrated either complete AVM obliteration (open surgery) or substantial diminution in AVM size (radiosurgery). Our data provide preliminary evidence supporting the thesis that neuracryl M is a safe and effective liquid embolic agent for the preoperative embolization of cerebral AVMs. Larger trials and continued experience using this novel liquid embolic agent are warranted.

Research paper thumbnail of Controversies in the Endovascular Management of Cerebral Vasospasm After Intracranial Aneurysm Rupture and Future Directions for Therapeutic Approaches

Neurosurgery, 2008

CEREBRAL VASOSPASM IS one of the leading causes of morbidity and mortality after aneurysmal subar... more CEREBRAL VASOSPASM IS one of the leading causes of morbidity and mortality after aneurysmal subarachnoid hemorrhage. Despite maximal medical therapy, however, up to 15% of patients surviving the ictus of subarachnoid hemorrhage experience stroke or death from vasospasm. For those cases of vasospasm that are refractory to medical treatment, endovascular techniques are frequently used, including balloon angioplasty with or without intra-arterial infusion of vasodilators, combined endovascular modalities, and aortic balloon devices. In this article, we review each of these therapies and their expanding role in the management of this condition. Moving forward, rigorous prospective outcome assessments after endovascular treatment of cerebral vasospasm are necessary to clearly delineate the efficacy and indications for these techniques.

Research paper thumbnail of Mechanical treatment of vasospasm

Neurological Research, 2009

Since cerebral vasospasm (CV) was first described nearly half a century ago, significant progress... more Since cerebral vasospasm (CV) was first described nearly half a century ago, significant progress has been made in understanding its underlying pathophysiology and developing treatment modalities. The purpose of this review is to discuss the rationale behind mechanical interventions for CV as well as the efficacy and complications associated with these treatment options. The authors summarize the pertinent literature on the mechanical treatment of CV, focusing first on balloon angioplasty, second on therapy combined with intra-arterial drug infusion, and concluding by briefly discussing intra-aortic balloon counterpulsation. The epidemiology, pathophysiology, technique, outcome, timing and complications are discussed for each treatment option. A review of the relevant medical literature reveals that in the last 20 years, endovascular techniques including transluminal balloon angioplasty, intra-arterial drug infusion and newer experimental strategies have provided an important supplement to the established medical therapy. Despite these developments, however, CV remains a major contributor to poor outcome following aSAH and continued efforts are necessary to improve and refine endovascular strategies as well as develop new treatment modalities.

Research paper thumbnail of Gunshot wounds to the head: Gang- and non-gang-related injuries and outcomes

Research paper thumbnail of The Hydrogel Endovascular Aneurysm Treatment Trial (HEAT): A Randomized Controlled Trial of the Second-Generation Hydrogel Coil

Neurosurgery, 2020

BACKGROUND Aneurysm recurrence after coiling has been associated with aneurysm growth, (re)hemorr... more BACKGROUND Aneurysm recurrence after coiling has been associated with aneurysm growth, (re)hemorrhage, and a greater need for follow-up. The second-generation HydroCoil Embolic System (HES; MicroVention, Inc) consists of a platinum core with integrated hydrogel and was developed to reduce recurrence through enhancing packing density and healing within the aneurysm. OBJECTIVE To compare recurrence between the second-generation HES and bare platinum coil (BPC) in the new-generation Hydrogel Endovascular Aneurysm Treatment Trial (HEAT). METHODS HEAT is a randomized, controlled trial that enrolled subjects with ruptured or unruptured 3- to 14-mm intracranial aneurysms amenable to coiling. The primary endpoint was aneurysm recurrence using the Raymond-Roy scale. Secondary endpoints included minor and major recurrence, packing density, adverse events related to the procedure and/or device, mortality, initial complete occlusion, aneurysm retreatment, hemorrhage from target aneurysm during ...

Research paper thumbnail of High-Dose Intra-arterial Verapamil for the Treatment of Cerebral Vasospasm After Subarachnoid Hemorrhage: Prolonged Effects on Hemodynamic Parameters and Brain Metabolism

Neurosurgery, 2011

Studies attempting to establish the safety and efficacy of standard and high-dose intra-arterial ... more Studies attempting to establish the safety and efficacy of standard and high-dose intra-arterial infusions of calcium channel blockers for treatment of cerebral vasospasm have focused on hemodynamic changes during the angiographic procedure. To evaluate longer-term drug effects over the hours following infusion and the effects on brain tissue oxygen tension or cerebral metabolism. We studied 11 patients with poor-grade aneurysmal subarachnoid hemorrhages who underwent multimodality brain monitoring and angiography with infusion of high-dose intra-arterial verapamil (≥15 mg total dose). Hourly intracerebral microdialysis measurements and continuously recorded mean arterial pressure (MAP), intracranial pressure (ICP), cerebral perfusion pressure (CPP), and Pbto₂ were analyzed for 6 hours before and 12 hours following treatment. A median dose of 23 mg (range, 15-55 mg) of intra-arterial verapamil was given. Compared with baseline values, reductions in CPP and MAP were maximal at 3 hours postangiography (from 105 ± 13 mm Hg to 95 ± 15 mm Hg and from 116 ± 12 mm Hg to 106 ± 16 mm Hg, P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .01) and persisted for up to 6 hours (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .04); increases in vasopressor therapy were required in 8 procedures (53%). ICP significantly increased during the first 3 hours post angiography (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .03). Brain glucose increased by 33% by hour 9 (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .001). There were no significant changes in Pbto₂ or the lactate/pyruvate ratio. High-dose intra-arterial verapamil causes increases in ICP and reductions in CPP, followed by an increase in brain glucose levels, without altering brain oxygen tension or oxidative metabolism. Patients undergoing high-dose intra-arterial verapamil therapy warrant close hemodynamic and ICP monitoring for at least 12 hours following treatment.

Research paper thumbnail of Treatment of spinal cord compression by epidural malignancy in childhood

Neurosurgery, 1991

Epidural spinal cord compression by a malignant tumor is a rare occurrence in children. Both the ... more Epidural spinal cord compression by a malignant tumor is a rare occurrence in children. Both the tumors involved and the extent of involvement of the vertebral column are different in children and adults. Often, the epidural tumor in a child is identified before significant spinal canal compromise has occurred, and these children frequently can be managed by radiation therapy and/or chemotherapy. There is a group of children, however, who have severe spinal canal encroachment by a tumor, as evidenced by a near complete or complete block on myelography. In this study, we report a group of patients with severe spinal cord compression, as documented by imaging studies. We compared the results of a decompressive laminectomy and subtotal tumor resection followed by adjuvant therapy with the results obtained with radiation therapy and/or chemotherapy alone. Thirty-three patients met the criteria for inclusion in the study. Twenty-six were treated with a laminectomy and adjuvant therapy, and 7 were treated without surgical intervention. With surgical therapy, 25 of 26 epidurals were either improved or stable, whereas 4 of 7 nonsurgical patients deteriorated. Especially notable was a decrease in pain in the operative patients immediately after their procedure. There was no surgical mortality or morbidity. The results of this study indicate that children with severe spinal cord compression as evidenced by a near complete or complete block on myelography or filling of 50% or more of the spinal canal on magnetic resonance imaging are best treated by a combination of surgical decompression and tumor removal followed by adjuvant therapy.

Research paper thumbnail of Outcome Prediction after Penetrating Craniocerebral Injury in a Civilian Population

Neurosurgery, 1994

In an attempt to evaluate the response of patients who have low admission Glasgow Coma Scale scor... more In an attempt to evaluate the response of patients who have low admission Glasgow Coma Scale scores (GCS) after a penetrating craniocerebral injury to aggressive management, we evaluated a series of 190 patients with penetrating injuries who presented with a GCS score of 3, 4, or 5 during a 6-year period. Entrance criteria required replicable neurological examinations that were not altered by the presence of hypotension, drugs/toxins, or systemic injury. The surgical patients included 21 patients with an admission GCS score of 3, 24 with an admission GCS score of 4, and 15 with an admission GCS score of 5. All patients underwent surgical intervention and aggressive perioperative management in the neurosurgical intensive care, including resuscitative protocols. Five of the patients with a GCS score of 3 survived, all with poor outcomes. Seven of the patients with a GCS score of 4 survived, although only one had a good outcome. Eleven of the patients with a GCS score of 5 survived. Five had a Glasgow Outcome Score of 2, five had a Glasgow Outcome Score of 3, and one had a Glasgow Outcome Score of 4. We have devised a prospective model of outcome based on our series in an attempt to predict nonsurvivors at admission (while overpredicting for survivors). The variables most predictive of mortality include admission GCS score and subarachnoid hemorrhage in one model and admission GCS score and pupillary changes in a second, when pupillary response was definitive at admission (P &lt; or = 0.00005).(ABSTRACT TRUNCATED AT 250 WORDS)

Research paper thumbnail of AUGMENTATION OF CEREBRAL BLOOD FLOW AND REVERSAL OF ENDOTHELIN-1-INDUCED VASOSPASM

Neurosurgery, 2007

Local intra-arterial infusions of verapamil and nicardipine have been used to treat human cerebra... more Local intra-arterial infusions of verapamil and nicardipine have been used to treat human cerebral vasospasm. Only a few reports of early clinical experience with these medications are currently available, and limited data are available regarding their cerebral physiological activity. We assessed the efficacy of intracarotid administration of verapamil and nicardipine on augmenting cerebral blood flow of New Zealand White rabbits and compared the ability of these drugs with reverse topical endothelin (ET)-1-triggered vasospasm. In the first group of New Zealand white rabbits, cerebral blood flow (laser Doppler) and systemic hemodynamic measurements were recorded at baseline and with increasing intracarotid doses of verapamil and nicardipine. In the second group, topical ET-1 (10(-4) mol/L) was applied in an acutely implanted cranial window. Dose responses to nonspecific reversal of ET-1-induced vasospasm were evaluated with intra-arterially administered nicardipine and verapamil. The dose-response studies revealed that intracarotid administration of nicardipine, compared with verapamil, was more effective in augmenting cerebral blood flow. Topical ET-1-induced vasospasm was completely reversed by nicardipine and partially reversed by verapamil. This study suggests that intra-arterially administered nicardipine is a more potent cerebral vasodilator and is superior to verapamil for treating ET-1-induced experimental cerebral vasospasm and supports further investigation of these agents in subarachnoid hemorrhage-induced vasospasm.

Research paper thumbnail of Gamma Knife Radiosurgery for Metastatic Melanoma: An Analysis of Survival, Outcome, and Complications

Neurosurgery, 1999

Although the mainstays for treatment of metastatic brain disease have been surgery and/or externa... more Although the mainstays for treatment of metastatic brain disease have been surgery and/or external beam radiation therapy, an increasing number of patients are being referred for stereotactic radiosurgery as the primary intervention for their intracranial pathological abnormalities. The lack of efficacy and cognitive and behavioral consequences of whole brain irradiation have prompted clinicians to select patients for alternative therapies. This study analyzes the effectiveness of Leksell gamma unit therapy for metastatic melanoma to the brain. We present our experience with 59 Leksell gamma unit treatment sessions in 45 consecutive patients who presented with metastatic melanoma to the brain. Five of these procedures were performed as salvage therapy for patients who needed second radiosurgical treatment for new lesions that were remote from the previous targets and were not included in the overall analyses. The population included 78% male patients. The mean patient age was 53 years (age range, 24-80 yr). The mean time from diagnosis of primary melanoma to discovery of brain metastasis was 43 months (median, 27.5 mo; range, 1-180 mo). At the time of diagnosis of brain disease, 35.5% of the patients (16 of 45 patients) had neurological symptoms, 77.7% (35 of 45 patients) had known visceral metastases, and 11.1% (5 of 45 patients) had seizure disorders. Eighty-six percent of the lesions (80 of 93 lesions) were cortical, 12% (11 of 93 lesions) were cerebellar, 1% (1 of 93 lesions) were pontine, and 1% (1 of 93 lesions) were thalamic. Fifty-seven percent of the sessions (31 of 54 sessions) were performed for a single lesion, 24.1% (13 of 54 sessions) for two lesions, 9.2% (5 of 54 sessions) for three lesions, 7.4% (4 of 54 sessions) for four lesions, and 1.8% (1 of 54 sessions) for five lesions. The mean treatment volume was 5.6 cc, with a mean prescription of 21.6 Gy to the 56.0% mean isodose line. The median survival time of the patients in our population, using Kaplan-Meier curves, was 43 months from the time of diagnosis of primary melanoma (range, 3-180 mo) and 8 months (range, 1-20 mo) from the time of gamma knife treatment. Complications included seizures within 24 hours of the procedure in four patients, with transient nausea and vomiting in three patients, transient worsening of preprocedure paresis responsive to steroids in three patients, and increased confusion in one patient. All 45 patients were located for follow-up (mean follow-up duration, 1 yr). After gamma knife treatment, 78% of the patients (35 of 45 patients) experienced either improved or stable neurological symptomatology before death or at the time of the latest follow-up examination. There were 26 deaths (58%). The cause of death was determined to be neurological in only 2 of 45 patients (7.7%). Follow-up magnetic resonance images revealed a 97% local tumor control rate of gamma knife-treated lesions, with 28% radiographic disappearance (9 of 32 cases). Six patients developed new lesions remote from radiosurgical targets and underwent second procedures. Although metastatic melanoma to the brain continues to have a foreboding prognosis for long-term survival, gamma knife radiosurgery seems to be a relatively safe, noninvasive, palliative therapy, halting or reversing neurological progression in 77.8% of treated patients (35 of 45 patients). The survival rate matches or exceeds those previously reported for surgery and other forms of radiotherapy. Only 7.7% of the patients in our study population who died as a result of metastatic melanoma (2 of 26 patients) died as a result of neurological disease. The routine use of therapeutic level antiseizure medication is emphasized, considering the findings of our review.

Research paper thumbnail of The Endoscopic Stylet

Neurosurgery, 1994

The use of a small-diameter, rigid ventriculoscope as a stylet to place a catheter optimally with... more The use of a small-diameter, rigid ventriculoscope as a stylet to place a catheter optimally within cerebrospinal fluid-containing spaces, is described.

Research paper thumbnail of Neuroanesthesia for Gamma Knife Radiosurgery: Technique, Outcome & Complications

Journal of Neurosurgical Anesthesiology, 1998

Research paper thumbnail of Neuropsychological Dysfunction in the Absence of Structural Evidence for Cerebral Ischemia after Uncomplicated Carotid Endarterectomy

Neurosurgery, 2006

OBJECTIVE-Neurocognitive dysfunction has been shown to occur in roughly 25% of patients undergoin... more OBJECTIVE-Neurocognitive dysfunction has been shown to occur in roughly 25% of patients undergoing carotid endarterectomy (CEA). Despite this, little is known about the mechanism of this injury. Recently, several groups have shown that new diffusion weighted imaging (DWI)-positive lesions are seen in 20% of patients undergoing CEA. We investigated to what degree neurocognitive dysfunction was associated with new DWI lesions. METHODS-Thirty-four consecutive patients undergoing CEA were subjected to preand postoperative cognitive evaluation with a battery of neuropsychological tests. Postoperative magnetic resonance imaging was performed in all patients within 24 hours of surgery. Lesions that showed high signal on DWI and restricted diffusion on apparent diffusion coefficient maps but no abnormal high signal on the fluid-attenuated inversion recovery images were considered hyperacute. RESULTS-Cognitive dysfunction was seen in eight (24%) patients. New hyperacute DWI lesions were seen in three (9%). Only one (13%) of the patients with cognitive dysfunction had a new DWI lesion. Two thirds of the new DWI lesions occurred in the absence of cognitive deterioration. Patients with cognitive dysfunction had significantly longer carotid cross-clamp times. CONCLUSION-Neurocognitive dysfunction after CEA does not seem to be associated with new DWI positive lesions.

Research paper thumbnail of Imaging of Subdural Hematomas

Neurosurgery Clinics of North America, 2017

The imaging of subdural hematoma has evolved significantly. Computed tomography and MRI have supp... more The imaging of subdural hematoma has evolved significantly. Computed tomography and MRI have supplanted other procedures and rendered most obsolete for the evaluation of intracranial pathology because of ease of use, tremendous soft tissue resolution, safety, and availability. Noncontrast computed tomography has become the accepted standard of care for the initial evaluation of patients with suspected subdural hematoma because of widespread availability, rapid acquisition time, and noninvasive nature. MRI offers important features in determining potential secondary causes of subdural hematoma, such as dural-based neoplasms.

Research paper thumbnail of Dobutamine versus Milrinone after Subarachnoid Hemorrhage

Neurosurgery, 2005

OBJECTIVE: Neurogenic stunned myocardium is a well-recognized complication of subarachnoid hemorr... more OBJECTIVE: Neurogenic stunned myocardium is a well-recognized complication of subarachnoid hemorrhage. Dobutamine and milrinone are both used for neurogenic stunned myocardium, but there are few data comparing them after subarachnoid hemorrhage. METHODS: We compared the physiological dose response of dobutamine and milrinone in patients with subarachnoid hemorrhage requiring a pulmonary artery catheter. We located 11 patients who received either inotrope. Physiological data were fitted to a mixed model accounting for drug, dose, and between-patient variation. RESULTS: There were 11 patients who had 152 pulmonary artery catheter measurements. Two received both inotropes (but not within 4 h of each other), 2 only milrinone, and 7 only dobutamine. The groups had similar clinical and physiological characteristics. After adjustment for vasopressin, milrinone was significantly more potent in increasing cardiac output (P < 0.0001) and stroke volume (P = 0.03), while decreasing vascular ...

Research paper thumbnail of Analysis of hemorrhage volumes after angiogram-negative subarachnoid hemorrhage

World neurosurgery, Jan 14, 2016

Antiplatelet medication use is associated with worsened outcome after angiogram-negative subarach... more Antiplatelet medication use is associated with worsened outcome after angiogram-negative subarachnoid hemorrhage (SAH). It has been hypothesized that these worsened outcomes may be the result of an association between antiplatelet medication use and increased hemorrhage volumes after angiogram-negative SAH. To test this hypothesis, we performed volumetric analysis of CT-defined hemorrhage after angiogram-negative SAH. A retrospective analysis of patients presenting with non-traumatic, angiogram-negative SAH in the Columbia University Subarachnoid Hemorrhage Outcomes database from 2000 to 2013 was performed. Subarachnoid hemorrhage volumes on admission head CT scans were measured using MIPAV software package (version 7.20; National Institutes of Health) in a semi-automated fashion. A total of 108 presenting CT scans from patients with angiogram-negative SAH were analyzed. In patients with a history of antiplatelet medication use, the mean hemorrhage volume was 14.3 mL. Patients who d...

Research paper thumbnail of Historical Account of Interventional Neuroradiology

Catheter-Based Cardiovascular Interventions, 2012

Although neurointervention shares common roots with other catheter-based interventions, the compl... more Although neurointervention shares common roots with other catheter-based interventions, the complexity of the cerebrovascular system and the diversity of illnesses that affect it have led to the development of special tools and approaches uniquely designed to address these challenges. This chapter reviews the major milestones in the evolution of what some may consider the youngest of the catheter-based cardiovascular disciplines.

Research paper thumbnail of The Role of Antiplatelet Medications in Angiogram-Negative Subarachnoid Hemorrhage

Neurosurgery, 2014

BACKGROUND: The use of antiplatelet medications has greatly expanded and this has been associated... more BACKGROUND: The use of antiplatelet medications has greatly expanded and this has been associated with an increased rate of complications after aneurysmal subarachnoid hemorrhage (SAH). The influence of antiplatelet medications on outcomes after non-aneurysmal SAH is unknown. OBJECTIVE: To analyze the frequency and impact on outcome of antiplatelet medication use among patients with angiogram-negative SAH. METHODS: An analysis of patients within the Columbia University SAH Outcomes Project database was performed. All patients who underwent catheter cerebral angiography after presenting with nontraumatic SAH between 1996 and 2013 were included. Outcomes were assessed by using the modified Rankin Scale. RESULTS: A total of 1351 patients underwent catheter angiography for evaluation of SAH. Of these, 173 (13%) were designated angiogram-negative. The fraction of patients presenting with angiogram-negative SAH as well as the frequency of antiplatelet use among these patients significantl...

Research paper thumbnail of Treating Stroke as a Medical Emergency: A Survey of Resident Physicians' Attitudes toward “Brain Attack” and Carotid Endarterectomy

Neurosurgery, 2001

OBJECTIVE: A major impetus of the "brain attack" campaign is the early recognition and treatment ... more OBJECTIVE: A major impetus of the "brain attack" campaign is the early recognition and treatment of acute stroke. Critical to this goal is the education of physicians during their residency training. METHODS: Resident physicians in Los Angeles who were in family practice (18%), internal medicine (51%), emergency medicine (20%), and neurology (11%) and had already completed their first year of training responded to a questionnaire on stroke and the treatment of carotid stenosis. RESULTS: Of the 266 respondents, 76% had heard of the "brain attack" campaign, 22% did not identify dysarthria as a symptom of stroke, and 21% did not identify obtundation as a presentation of stroke. Twenty-eight percent chose not to use tissue plasminogen activator for acute ischemic stroke, and 60% recognized the need to begin treatment within 3 hours. More than 90% of respondents were able to identify correct screening tests for patients with suspected carotid stenosis. However, 56% responded that they would not advocate operating on patients with asymptomatic severe stenosis (>70%) until stenosis reached a critical value (85%). Conversely, 45% would recommend operative treatment for symptomatic patients who had less than 60% stenosis. Sixty-eight percent would refer patients to vascular surgeons, 14% to neurosurgeons, and 17% to both for carotid endarterectomy. CONCLUSION: Recognition of stroke as a medical emergency is improving. However, significant progress can still be made in the recognition of stroke symptoms. Primary care and neurology residents remain skeptical about carotid endarterectomy for asymptomatic patients, whereas there is enthusiasm for treating stroke survivors. Education by members of the surgical community could promote the aggressive treatment of asymptomatic patients to prevent stroke.

Research paper thumbnail of Embolization as an Adjuvant in the Treatment of Cerebral Arteriovenous Malformations

Neurosurgery, 2008

Close Window. Close Window. Thank you for choosing to subscribe to the eTOC for Neurosurgery. Ent... more Close Window. Close Window. Thank you for choosing to subscribe to the eTOC for Neurosurgery. Enter your Email address: Wolters Kluwer Health may email you for journal alerts and information, but is committed to maintaining ...

Research paper thumbnail of 2-Hexyl Cyanoacrylate (Neuracryl M) Embolization of Cerebral Arteriovenous Malformations

Neurosurgery, 2006

Neuracryl M is a newly designed liquid embolic agent. In an attempt to verify the safety and effi... more Neuracryl M is a newly designed liquid embolic agent. In an attempt to verify the safety and efficacy of neuracryl M, we participated in the PROVASIS Trial, a pilot study using this agent in the preoperative treatment of cerebral arteriovenous malformations (AVMs). Because the trial was prematurely terminated by the sponsoring company because of financial considerations, we now present our data as a single center series. Between November 2002 and December 2003, six patients were enrolled in the PROVASIS trial at our institution, and four of these patients were randomized to treatment with neuracryl M. The patients were a 30-year-old man with a right frontal lobe AVM, a 20-year-old man with a right cerebellar AVM, a 26-year-old woman with a midline cerebellar AVM, and a 47-year-old man with a left parietotemporal lobe AVM. All patients underwent AVM embolization with neuracryl M, followed by definitive treatment, either open surgery or radiosurgery. In each case, there were no permanent complications, and blood loss was minimal. Follow-up imaging demonstrated either complete AVM obliteration (open surgery) or substantial diminution in AVM size (radiosurgery). Our data provide preliminary evidence supporting the thesis that neuracryl M is a safe and effective liquid embolic agent for the preoperative embolization of cerebral AVMs. Larger trials and continued experience using this novel liquid embolic agent are warranted.

Research paper thumbnail of Controversies in the Endovascular Management of Cerebral Vasospasm After Intracranial Aneurysm Rupture and Future Directions for Therapeutic Approaches

Neurosurgery, 2008

CEREBRAL VASOSPASM IS one of the leading causes of morbidity and mortality after aneurysmal subar... more CEREBRAL VASOSPASM IS one of the leading causes of morbidity and mortality after aneurysmal subarachnoid hemorrhage. Despite maximal medical therapy, however, up to 15% of patients surviving the ictus of subarachnoid hemorrhage experience stroke or death from vasospasm. For those cases of vasospasm that are refractory to medical treatment, endovascular techniques are frequently used, including balloon angioplasty with or without intra-arterial infusion of vasodilators, combined endovascular modalities, and aortic balloon devices. In this article, we review each of these therapies and their expanding role in the management of this condition. Moving forward, rigorous prospective outcome assessments after endovascular treatment of cerebral vasospasm are necessary to clearly delineate the efficacy and indications for these techniques.

Research paper thumbnail of Mechanical treatment of vasospasm

Neurological Research, 2009

Since cerebral vasospasm (CV) was first described nearly half a century ago, significant progress... more Since cerebral vasospasm (CV) was first described nearly half a century ago, significant progress has been made in understanding its underlying pathophysiology and developing treatment modalities. The purpose of this review is to discuss the rationale behind mechanical interventions for CV as well as the efficacy and complications associated with these treatment options. The authors summarize the pertinent literature on the mechanical treatment of CV, focusing first on balloon angioplasty, second on therapy combined with intra-arterial drug infusion, and concluding by briefly discussing intra-aortic balloon counterpulsation. The epidemiology, pathophysiology, technique, outcome, timing and complications are discussed for each treatment option. A review of the relevant medical literature reveals that in the last 20 years, endovascular techniques including transluminal balloon angioplasty, intra-arterial drug infusion and newer experimental strategies have provided an important supplement to the established medical therapy. Despite these developments, however, CV remains a major contributor to poor outcome following aSAH and continued efforts are necessary to improve and refine endovascular strategies as well as develop new treatment modalities.

Research paper thumbnail of Gunshot wounds to the head: Gang- and non-gang-related injuries and outcomes

Research paper thumbnail of The Hydrogel Endovascular Aneurysm Treatment Trial (HEAT): A Randomized Controlled Trial of the Second-Generation Hydrogel Coil

Neurosurgery, 2020

BACKGROUND Aneurysm recurrence after coiling has been associated with aneurysm growth, (re)hemorr... more BACKGROUND Aneurysm recurrence after coiling has been associated with aneurysm growth, (re)hemorrhage, and a greater need for follow-up. The second-generation HydroCoil Embolic System (HES; MicroVention, Inc) consists of a platinum core with integrated hydrogel and was developed to reduce recurrence through enhancing packing density and healing within the aneurysm. OBJECTIVE To compare recurrence between the second-generation HES and bare platinum coil (BPC) in the new-generation Hydrogel Endovascular Aneurysm Treatment Trial (HEAT). METHODS HEAT is a randomized, controlled trial that enrolled subjects with ruptured or unruptured 3- to 14-mm intracranial aneurysms amenable to coiling. The primary endpoint was aneurysm recurrence using the Raymond-Roy scale. Secondary endpoints included minor and major recurrence, packing density, adverse events related to the procedure and/or device, mortality, initial complete occlusion, aneurysm retreatment, hemorrhage from target aneurysm during ...

Research paper thumbnail of High-Dose Intra-arterial Verapamil for the Treatment of Cerebral Vasospasm After Subarachnoid Hemorrhage: Prolonged Effects on Hemodynamic Parameters and Brain Metabolism

Neurosurgery, 2011

Studies attempting to establish the safety and efficacy of standard and high-dose intra-arterial ... more Studies attempting to establish the safety and efficacy of standard and high-dose intra-arterial infusions of calcium channel blockers for treatment of cerebral vasospasm have focused on hemodynamic changes during the angiographic procedure. To evaluate longer-term drug effects over the hours following infusion and the effects on brain tissue oxygen tension or cerebral metabolism. We studied 11 patients with poor-grade aneurysmal subarachnoid hemorrhages who underwent multimodality brain monitoring and angiography with infusion of high-dose intra-arterial verapamil (≥15 mg total dose). Hourly intracerebral microdialysis measurements and continuously recorded mean arterial pressure (MAP), intracranial pressure (ICP), cerebral perfusion pressure (CPP), and Pbto₂ were analyzed for 6 hours before and 12 hours following treatment. A median dose of 23 mg (range, 15-55 mg) of intra-arterial verapamil was given. Compared with baseline values, reductions in CPP and MAP were maximal at 3 hours postangiography (from 105 ± 13 mm Hg to 95 ± 15 mm Hg and from 116 ± 12 mm Hg to 106 ± 16 mm Hg, P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .01) and persisted for up to 6 hours (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .04); increases in vasopressor therapy were required in 8 procedures (53%). ICP significantly increased during the first 3 hours post angiography (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .03). Brain glucose increased by 33% by hour 9 (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .001). There were no significant changes in Pbto₂ or the lactate/pyruvate ratio. High-dose intra-arterial verapamil causes increases in ICP and reductions in CPP, followed by an increase in brain glucose levels, without altering brain oxygen tension or oxidative metabolism. Patients undergoing high-dose intra-arterial verapamil therapy warrant close hemodynamic and ICP monitoring for at least 12 hours following treatment.

Research paper thumbnail of Treatment of spinal cord compression by epidural malignancy in childhood

Neurosurgery, 1991

Epidural spinal cord compression by a malignant tumor is a rare occurrence in children. Both the ... more Epidural spinal cord compression by a malignant tumor is a rare occurrence in children. Both the tumors involved and the extent of involvement of the vertebral column are different in children and adults. Often, the epidural tumor in a child is identified before significant spinal canal compromise has occurred, and these children frequently can be managed by radiation therapy and/or chemotherapy. There is a group of children, however, who have severe spinal canal encroachment by a tumor, as evidenced by a near complete or complete block on myelography. In this study, we report a group of patients with severe spinal cord compression, as documented by imaging studies. We compared the results of a decompressive laminectomy and subtotal tumor resection followed by adjuvant therapy with the results obtained with radiation therapy and/or chemotherapy alone. Thirty-three patients met the criteria for inclusion in the study. Twenty-six were treated with a laminectomy and adjuvant therapy, and 7 were treated without surgical intervention. With surgical therapy, 25 of 26 epidurals were either improved or stable, whereas 4 of 7 nonsurgical patients deteriorated. Especially notable was a decrease in pain in the operative patients immediately after their procedure. There was no surgical mortality or morbidity. The results of this study indicate that children with severe spinal cord compression as evidenced by a near complete or complete block on myelography or filling of 50% or more of the spinal canal on magnetic resonance imaging are best treated by a combination of surgical decompression and tumor removal followed by adjuvant therapy.

Research paper thumbnail of Outcome Prediction after Penetrating Craniocerebral Injury in a Civilian Population

Neurosurgery, 1994

In an attempt to evaluate the response of patients who have low admission Glasgow Coma Scale scor... more In an attempt to evaluate the response of patients who have low admission Glasgow Coma Scale scores (GCS) after a penetrating craniocerebral injury to aggressive management, we evaluated a series of 190 patients with penetrating injuries who presented with a GCS score of 3, 4, or 5 during a 6-year period. Entrance criteria required replicable neurological examinations that were not altered by the presence of hypotension, drugs/toxins, or systemic injury. The surgical patients included 21 patients with an admission GCS score of 3, 24 with an admission GCS score of 4, and 15 with an admission GCS score of 5. All patients underwent surgical intervention and aggressive perioperative management in the neurosurgical intensive care, including resuscitative protocols. Five of the patients with a GCS score of 3 survived, all with poor outcomes. Seven of the patients with a GCS score of 4 survived, although only one had a good outcome. Eleven of the patients with a GCS score of 5 survived. Five had a Glasgow Outcome Score of 2, five had a Glasgow Outcome Score of 3, and one had a Glasgow Outcome Score of 4. We have devised a prospective model of outcome based on our series in an attempt to predict nonsurvivors at admission (while overpredicting for survivors). The variables most predictive of mortality include admission GCS score and subarachnoid hemorrhage in one model and admission GCS score and pupillary changes in a second, when pupillary response was definitive at admission (P &lt; or = 0.00005).(ABSTRACT TRUNCATED AT 250 WORDS)

Research paper thumbnail of AUGMENTATION OF CEREBRAL BLOOD FLOW AND REVERSAL OF ENDOTHELIN-1-INDUCED VASOSPASM

Neurosurgery, 2007

Local intra-arterial infusions of verapamil and nicardipine have been used to treat human cerebra... more Local intra-arterial infusions of verapamil and nicardipine have been used to treat human cerebral vasospasm. Only a few reports of early clinical experience with these medications are currently available, and limited data are available regarding their cerebral physiological activity. We assessed the efficacy of intracarotid administration of verapamil and nicardipine on augmenting cerebral blood flow of New Zealand White rabbits and compared the ability of these drugs with reverse topical endothelin (ET)-1-triggered vasospasm. In the first group of New Zealand white rabbits, cerebral blood flow (laser Doppler) and systemic hemodynamic measurements were recorded at baseline and with increasing intracarotid doses of verapamil and nicardipine. In the second group, topical ET-1 (10(-4) mol/L) was applied in an acutely implanted cranial window. Dose responses to nonspecific reversal of ET-1-induced vasospasm were evaluated with intra-arterially administered nicardipine and verapamil. The dose-response studies revealed that intracarotid administration of nicardipine, compared with verapamil, was more effective in augmenting cerebral blood flow. Topical ET-1-induced vasospasm was completely reversed by nicardipine and partially reversed by verapamil. This study suggests that intra-arterially administered nicardipine is a more potent cerebral vasodilator and is superior to verapamil for treating ET-1-induced experimental cerebral vasospasm and supports further investigation of these agents in subarachnoid hemorrhage-induced vasospasm.

Research paper thumbnail of Gamma Knife Radiosurgery for Metastatic Melanoma: An Analysis of Survival, Outcome, and Complications

Neurosurgery, 1999

Although the mainstays for treatment of metastatic brain disease have been surgery and/or externa... more Although the mainstays for treatment of metastatic brain disease have been surgery and/or external beam radiation therapy, an increasing number of patients are being referred for stereotactic radiosurgery as the primary intervention for their intracranial pathological abnormalities. The lack of efficacy and cognitive and behavioral consequences of whole brain irradiation have prompted clinicians to select patients for alternative therapies. This study analyzes the effectiveness of Leksell gamma unit therapy for metastatic melanoma to the brain. We present our experience with 59 Leksell gamma unit treatment sessions in 45 consecutive patients who presented with metastatic melanoma to the brain. Five of these procedures were performed as salvage therapy for patients who needed second radiosurgical treatment for new lesions that were remote from the previous targets and were not included in the overall analyses. The population included 78% male patients. The mean patient age was 53 years (age range, 24-80 yr). The mean time from diagnosis of primary melanoma to discovery of brain metastasis was 43 months (median, 27.5 mo; range, 1-180 mo). At the time of diagnosis of brain disease, 35.5% of the patients (16 of 45 patients) had neurological symptoms, 77.7% (35 of 45 patients) had known visceral metastases, and 11.1% (5 of 45 patients) had seizure disorders. Eighty-six percent of the lesions (80 of 93 lesions) were cortical, 12% (11 of 93 lesions) were cerebellar, 1% (1 of 93 lesions) were pontine, and 1% (1 of 93 lesions) were thalamic. Fifty-seven percent of the sessions (31 of 54 sessions) were performed for a single lesion, 24.1% (13 of 54 sessions) for two lesions, 9.2% (5 of 54 sessions) for three lesions, 7.4% (4 of 54 sessions) for four lesions, and 1.8% (1 of 54 sessions) for five lesions. The mean treatment volume was 5.6 cc, with a mean prescription of 21.6 Gy to the 56.0% mean isodose line. The median survival time of the patients in our population, using Kaplan-Meier curves, was 43 months from the time of diagnosis of primary melanoma (range, 3-180 mo) and 8 months (range, 1-20 mo) from the time of gamma knife treatment. Complications included seizures within 24 hours of the procedure in four patients, with transient nausea and vomiting in three patients, transient worsening of preprocedure paresis responsive to steroids in three patients, and increased confusion in one patient. All 45 patients were located for follow-up (mean follow-up duration, 1 yr). After gamma knife treatment, 78% of the patients (35 of 45 patients) experienced either improved or stable neurological symptomatology before death or at the time of the latest follow-up examination. There were 26 deaths (58%). The cause of death was determined to be neurological in only 2 of 45 patients (7.7%). Follow-up magnetic resonance images revealed a 97% local tumor control rate of gamma knife-treated lesions, with 28% radiographic disappearance (9 of 32 cases). Six patients developed new lesions remote from radiosurgical targets and underwent second procedures. Although metastatic melanoma to the brain continues to have a foreboding prognosis for long-term survival, gamma knife radiosurgery seems to be a relatively safe, noninvasive, palliative therapy, halting or reversing neurological progression in 77.8% of treated patients (35 of 45 patients). The survival rate matches or exceeds those previously reported for surgery and other forms of radiotherapy. Only 7.7% of the patients in our study population who died as a result of metastatic melanoma (2 of 26 patients) died as a result of neurological disease. The routine use of therapeutic level antiseizure medication is emphasized, considering the findings of our review.

Research paper thumbnail of The Endoscopic Stylet

Neurosurgery, 1994

The use of a small-diameter, rigid ventriculoscope as a stylet to place a catheter optimally with... more The use of a small-diameter, rigid ventriculoscope as a stylet to place a catheter optimally within cerebrospinal fluid-containing spaces, is described.