David A Wilson

Barrow Neurological Institute, Phoenix, Arizona, United States

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Publications (21)43.32 Total impact

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    ABSTRACT: Object Cerebral vasospasm following subarachnoid hemorrhage (SAH) causes significant morbidity in a delayed fashion. The authors recently published a new scale that grades the maximum thickness of SAH on axial CT and is predictive of vasospasm incidence. In this study, the authors further investigate whether different aneurysm locations result in different SAH clot burdens and whether any concurrent differences in ruptured aneurysm location and maximum SAH clot burden affect vasospasm incidence. Methods Two hundred fifty patients who were part of a prospective randomized controlled trial were reviewed. Most outcome and demographic variables were included as part of the prospective randomized controlled trial. Additional variables were also collected at a later time, including vasospasm data and maximum clot thickness. Results Aneurysms were categorized into 1 of 6 groups: intradural internal carotid artery aneurysms, vertebral artery (VA) aneurysms (including the posterior inferior cerebellar artery), basilar trunk or basilar apex aneurysms, middle cerebral artery aneurysms, pericallosal aneurysms, and anterior communicating artery aneurysms. Twenty-nine patients with nonaneurysmal SAH were excluded. Patients with pericallosal aneurysms had the least average maximum clot burden (5.3 mm), compared with 6.4 mm for the group overall, but had the highest rate of symptomatic vasospasm (56% vs 22% overall, OR 4.9, RR 2.7, p = 0.026). Symptomatic vasospasm occurrence was tallied in patients with clinical deterioration attributable to delayed cerebral ischemia. There were no significant differences in maximum clot thickness between aneurysm sites. Middle cerebral artery aneurysms resulted in the thickest mean maximum clot (7.1 mm) but rates of symptomatic and radiographic vasospasm in this group were statistically no different compared with the overall group. Vertebral artery aneurysms had the worst 1-year modified Rankin scale (mRS) scores (3.0 vs 1.9 overall, respectively; p = 0.0249). A 1-year mRS score of 0-2 (good outcome) was found in 72% of patients overall, but in only 50% of those with pericallosal and VA aneurysms, and in 56% of those with basilar artery aneurysms (p = 0.0044). Patients with stroke from vasospasm had higher mean clot thickness (9.71 vs 6.15 mm, p = 0.004). Conclusions The location of a ruptured aneurysm minimally affects the maximum thickness of the SAH clot but is predictive of symptomatic vasospasm or clinical deterioration from delayed cerebral ischemia in pericallosal aneurysms. The worst 1-year mRS outcomes in this cohort of patients were noted in those with posterior circulation aneurysms or pericallosal artery aneurysms. Patients experiencing stroke had higher mean clot burden.
    Journal of Neurosurgery 12/2013; · 3.15 Impact Factor
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    ABSTRACT: Neurenteric cysts (NECs) are uncommonly encountered lesions of the central nervous system with heterogeneous imaging characteristics. The object of this study was to review the preoperative imaging findings represented among a cohort of surgically treated posterior-fossa NECs. These findings are considered in the context of surgical technique, and inform an understanding of aberrant neuroembryological development associated with NECs. A single-institution, multi-surgeon series of 7 consecutive patients (5 females, 2 males, mean age 36 years, range 19-57 years) treated surgically for histopathologically confirmed posterior fossa NECs was retrospectively reviewed. Lesion imaging and anatomic characteristics were noted on preoperative magnetic resonance imaging (MRI). Imaging comparisons were made against an additional cohort of 266 consecutive surgically treated posterior fossa masses to validate unique anatomic findings. T1 and T2 MRI signal characteristics were variable when compared across lesions. All NECs were found to be anteriorly located within the posterior fossa, but always situated between the brainstem pial surface and vertebrobasilar system, causing ventral displacement of vertebrobasilar vessels. Posterior fossa NECs display variable patterns of MRI signal and are commonly considered as part of a broad differential of cystic posterior fossa masses. We identified tumor insinuation between the ventral brainstem and vertebrobasilar system as a highly sensitive and specific radiographic sign for NECs. This finding was not observed among a large cohort of posterior fossa masses representative of multiple other pathologies.
    World Neurosurgery 10/2013; · 1.77 Impact Factor
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    ABSTRACT: Postoperative magnetic resonance imaging (MRI) is critical to the clinical decision making process for patients undergoing resection of intracranial tumors. The accuracy of immediate postoperative MRI in determining the presence of residual disease following intracranial tumor resection, however, has not been studied. A 57-year-old male underwent an uncomplicated retrosigmoid craniotomy for resection of a cystic vestibular schwannoma. Immediate gadolinium enhanced postoperative MRI, performed within 1.5 hours of surgery, was notable for a plaque-like, lobular, avidly enhancing collection with MRI characteristics consistent with fluid density extending from the porus acusticus into the cerebellopontine angle. This anomalous lesion disappeared upon repeat imaging 48 hours later, and the patient had no attributable clinical sequelae. He was discharged home without issues within 12 hours of repeat imaging. We demonstrate here that immediate postoperative, gadolinium enhanced MRI scans after tumor resection may result in avid enhancement in the region of surgical manipulation, likely due to leakage of gadolinium chelates into the subarachnoid space from residual compromise of the blood brain barrier immediately following surgical manipulation. Early imaging is no longer routinely performed at our institution unless otherwise clinically indicated.
    Neurosurgery 09/2013; · 2.53 Impact Factor
  • Journal of Neurosurgery 09/2013; 119(3):605. · 3.15 Impact Factor
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    ABSTRACT: Object Data regarding the time course of recovery after poor-grade subarachnoid hemorrhage (SAH) is lacking. Most SAH studies assess outcome at a single time point, often as early as 3 or 6 months following SAH. The authors hypothesized that recovery following poor-grade SAH is a dynamic process and that early outcomes may not always approximate long-term outcomes. To test this hypothesis, they analyzed long-term outcome data from a cohort of patients with poor-grade aneurysmal SAH to determine the incidence and predictors of early and delayed neurological improvement. Methods The authors reviewed outcome data from 88 poor-grade SAH patients enrolled in a prospective SAH treatment trial (the Barrow Ruptured Aneurysm Trial). They assessed modified Rankin Scale (mRS) scores at discharge, 6 months, 12 months, and 36 months after treatment to determine the incidence and predictors of neurological improvement during each interval. Results The mean aggregate mRS scores at 6 months (3.31 ± 2.1), 12 months (3.28 ± 2.2), and 36 months (3.17 ± 2.3) improved significantly compared with the mean score at hospital discharge (4.33 ± 1.3, p < 0.001), but they did not differ significantly among themselves. Between discharge and 6 months, 61% of patients improved on the mRS. The incidence of improvement between 6-12 months and 12-36 months was 18% and 19%, respectively. Hunt and Hess Grade IV versus V (OR 6.20, 95% CI 2.11-18.25, p < 0.001) and the absence of large (> 4 cm) (OR 2.76, 95% CI 1.02-7.55, p = 0.05) or eloquent (OR 5.17, 95% CI 1.89-14.10, p < 0.01) stroke were associated with improvement up to 6 months. Age ≤ 65 years (OR 5.56, 95% CI 1.17-26.42, p = 0.02), Hunt and Hess Grade IV versus V (OR 4.17, 95% CI 1.10-15.85, p = 0.03), and absence of a large (OR 8.97, 95% CI 2.65-30.40, p < 0.001) or eloquent (OR 4.54, 95% CI 1.46-14.08, p = 0.01) stroke were associated with improvement beyond 6 months. Improvement beyond 1 year was most strongly predicted by the absence of a large stroke (OR 7.62, 95% CI 1.55-37.30, p < 0.01). Conclusions A substantial minority of poor-grade SAH patients will experience delayed recovery beyond the point at which most studies assess outcome. Younger patients, those presenting in better clinical condition, and those without CT evidence of large or eloquent stroke demonstrated the highest capacity for delayed recovery.
    Journal of Neurosurgery 05/2013; · 3.15 Impact Factor
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    ABSTRACT: OBJECT: Surgical freedom and the angle of attack influence approach selection for open cranial base approaches, but these concepts have not been well studied in minimal access endoscopic approaches. We therefore developed a methodology to study surgical freedom and angle of attack in two endoscopic transmaxillary transpterygoid approaches, the endonasal ipsilateral uninostril medial maxillotomy and the sublabial Caldwell-Luc anterior maxillotomy. METHODS: Dissections were performed bilaterally in 3 formalin-fixed cadaver heads (6 sides). For each approach, 3 progressively lateral and posterior anatomic targets were identified. Utilizing frameless stereotaxy, surgical freedom using the vector crossproduct method was calculated for both approaches for each target. The mean and maximum possible angles of attack were calculated in the axial and sagittal planes. RESULTS: Compared to the endoscopic endonasal-transmaxillary approach, the endoscopic Caldwell-Luc approach offered significantly greater surgical freedom to the genu of the internal carotid artery (p=0.02), foramen rotundum (p=0.03), and foramen ovale (p=0.03). Mean and maximum possible angles of attack were also significantly different between the two approaches for each target. The Caldwell-Luc approach offered a more bottom-up approach in the sagittal plane and a more head-on approach in the axial plane to each target (p<0.05). CONCLUSIONS: We have successfully developed a model for comparing endoscopic skull base approaches. Both the endonasal medial maxillotomy approach and Caldwell-Luc approach provided endoscopic access to each target. However, the sublabial Caldwell-Luc approach offered greater surgical freedom and a more head-on approach than the endonasal medial maxillotomy. These differences in surgical freedom and angles of attack may be useful to consider when planning minimal access approaches.
    World Neurosurgery 02/2013; · 1.77 Impact Factor
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    ABSTRACT: The supraorbital eyebrow craniotomy provides minimally invasive access to a wide range of frontal fossa, parasellar and some middle and posterior fossae tumors. This approach is considered ideal for removal of many, if not most, planum and tuberculum sellae meningiomas, some olfactory groove meningiomas, as well as suprasellar craniopharyngiomas, particularly those with far lateral extensions. It is also ideal for many intra-axial tumors including metastases and gliomas arising from the orbito-frontal, frontal pole and medial temporal lobe regions. The use of endoscopy further extends the range and versatility of this keyhole approach and is considered an essential adjunct for allowing safe and maximal tumor removal. Herein we describe the indications, technical nuances and complication avoidance techniques for the supraorbital keyhole approach with endoscopic assistance.
    World Neurosurgery 02/2013; · 1.77 Impact Factor
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    ABSTRACT: BACKGROUND:: The absence of ventriculomegaly has been considered an overt or relative contraindication to the endoscopic resection of colloid cysts. In the past, endoscopic removal of colloid cysts in the absence of ventriculomegaly has been considered ill advised. Reports of successful endoscopic surgery in small ventricles are surfacing OBJECTIVE:: We examined the combined experience of 2 high-volume endoscopic centers to characterize the outcomes of patients undergoing endoscopic removal of colloid cysts in small ventricles. METHODS:: We retrospectively reviewed all endoscopic colloid cyst removal procedures by the 2 senior authors (PN, CT) performed at the Barrow Neurological Institute over an 8-year period. Radiographic, clinical, and interview data were recorded and analyzed. The age-adjusted relative bicaudate index was used to define "small ventricles." RESULTS:: Sixteen patients (8 females) underwent attempted endoscopic removal of a colloid cyst in the absence of ventriculomegaly. Surgery was technically successful in 15 cases. The cyst was removed completely in 13 of cases. Short-term memory loss was initially present in 3 cases and completely resolved in all but 1 patient who had presented with short-term memory loss. Temporary complications occurred in 2 patients. CONCLUSION:: Normal-sized ventricles are not a contraindication to endoscopic removal of third ventricular colloid cysts. Complication rates are at least comparable to those of patients with ventriculomegaly or to those undergoing open microsurgical resection.
    Neurosurgery 01/2013; · 2.53 Impact Factor
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    ABSTRACT: OBJECTIVE: Endoscopic approaches are increasingly utilized to treat third ventricular colloid cysts but have been associated with lower rates of complete cyst wall resection. Our objective was to assess the results of colloid cyst resection via an anterolateral endoscopic approach with a dual-instrument technique, with an emphasis on completeness of cyst wall resection. METHODS: A retrospective review of the senior author's experience with 22 colloid cysts treated with endoscopic resection since 2004 was performed. Initial cyst size, completeness of resection, postoperative radiographic residual, recurrence at follow-up, need for reoperation, and neurologic morbidity were assessed. All cysts were approached from an anterolateral trajectory with two instruments working in concert through a single endoscope. RESULTS: Of 22 patients, near-total resection was obtained in 95%. In 3 cases, a very small, radiographically occult residual was left. Complete cyst wall resection was therefore obtained in 18 (82%). There were no cases of recurrence at follow-up in any patient. No patients required craniotomy or underwent re-resection. Fifteen of 16 (94%) patients with long-term clinical follow-up remained stable or improved. CONCLUSION: High rates of complete colloid cyst resection, with low morbidity, are possible with an anterolateral endoscopic approach with dual-instrument technique. These results support the findings of other endoscopists that show how technical modifications to traditional endoscopic approaches can produce favorable results.
    World Neurosurgery 07/2012; · 1.77 Impact Factor
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    ABSTRACT: : Although the Fisher scale is commonly used to grade vasospasm risk in aneurysmal subarachnoid hemorrhage (aSAH) patients, it fails to account for increasing subarachnoid hemorrhage (SAH) thickness. : We developed a simple quantitative scale based on maximal SAH thickness and compared its reproducibility and ability to predict symptomatic vasospasm against the Fisher scale. : The incidence of radiographic and symptomatic vasospasm among 250 aSAH patients treated at our institution was investigated. Admission head computed tomography scans were graded according to the Fisher scale and the proposed scale, which assigns a score from 1 to 5 based on a single measurement of maximum SAH thickness. We calculated vasospasm risk per grade for the Fisher scale and the proposed scale, and compared inter- and intraobserver variability for both scales. : Forty-five patients (20.6%) developed symptomatic vasospasm. On the proposed scale, grade 5 patients were at highest risk, with an odds ratio for symptomatic vasospasm of 11 (95% confidence interval [CI] 2.27-53.37). Odds ratios for proposed grades 4 and 3 were 4.63 (95% CI 1.10-19.59) and 3.04 (95% CI 0.85-10.90), respectively. The odds ratio for Fisher grade 3 was 3.3 (0.96-11.30). Mean inter- and intraobserver agreement was greater for the proposed scale in comparison with the Fisher scale (κ0.65 and κ0.81 vs κ0.51 and κ0.35, respectively). : The new scale accounted for increasing SAH thickness and was superior to the Fisher scale in inter- and intraobserver agreement and in predicting symptomatic vasospasm, particularly among the highest-risk patients. : aSAH, aneurysmal subarachnoid hemorrhageBNI, Barrow Neurological InstituteCI, confidence intervalIVH, intraventricular hemorrhageSAH, subarachnoid hemorrhageTCD, transcranial Doppler.
    Neurosurgery 07/2012; 71(4):869-76. · 2.53 Impact Factor
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    ABSTRACT: The optimal management of pineocytomas remains controversial. Although the value of complete microsurgical removal is well accepted, gross-total resection is not always feasible. Data regarding the role of postoperative adjuvant stereotactic radiosurgery (SRS) for residual disease is limited and conflicting. Here, the authors review the largest single-institution experience with multimodal pineocytoma management in an effort to quantify the utility of adjuvant radiosurgical treatment of residual disease. The medical records and radiographic studies for all patients with histologically confirmed pineocytoma at the Barrow Neurological Institute between 1999 and 2011 were retrospectively reviewed. Clinical and radiographic data, including the volumetric extent of resection, were collected retrospectively, and Kaplan-Meier analysis was used to identify progression-free survival. Fourteen adults with newly diagnosed pineocytomas were surgically treated in the period from 1999 to 2011. The median clinical and radiographic follow-ups were 44 and 53 months, respectively. Twelve patients (86%) underwent microsurgical removal and 2 (14%) underwent endoscopic biopsy. Five patients (36%) had complete resections and 9 (64%) demonstrated residual disease. Three patients (21%) presented with radiographic recurrence at a median interval of 43 months after initial treatment (range 13-83 months). At the time of recurrence, the median preoperative tumor volume was 2.6 cm(3). Adjuvant SRS was used to treat 3 subtotally resected tumors (33%) following initial presentation and 2 (66%) at the time of recurrence. Among patients with subtotally resected tumors, progression-free survival was significantly longer (p < 0.05) for those who did as compared with those who did not undergo adjuvant radiosurgery. To date, no patient who underwent adjuvant radiosurgery has demonstrated radiographic or clinical evidence of disease progression. Microsurgical removal remains the definitive treatment for pineocytomas, yet residual disease can be effectively controlled using adjuvant SRS.
    Journal of Neurosurgery 06/2012; 117(2):212-7. · 3.15 Impact Factor
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    ABSTRACT: Conus medullaris arteriovenous malformations (AVMs) are rare, challenging spinal vascular lesions that cause progressive debilitating myeloradiculopathy. Only sporadic reports of conus AVMs have been published. To better define the presentation, prognosis, and optimal treatment of these lesions, we present the first case series of conus AVMs, reflecting over 2 decades of experience with a multimodality endovascular and surgical approach. We retrospectively reviewed the charts of 16 patients with a conus AVM evaluated at our institution from 1989 to 2010. For each patient, the following clinical data were collected: age, sex, symptoms, angiographic findings, type of treatment, complications, degree of angiographic obliteration, recurrence at follow-up, and need for re-treatment. Ambulatory status, Frankel Grade, motor function, and bladder/bowel function were assessed before treatment, at discharge, and at last follow-up. All 16 patients were treated. Eight (50%) patients underwent embolization followed by microsurgical resection, and 8 (50%) underwent microsurgical resection only. The rate of complete angiographic obliteration was 88%. At last follow-up (mean, 70 months), 43% of patients neurologically improved, 43% were stable, and 14% worsened in comparison with before treatment. During follow-up, 3 recurrences were detected, including the only 2 instances of long-term neurological decline. In the absence of recurrence, all patients ambulatory before treatment remained ambulatory at follow-up, whereas 75% of the initially nonambulatory patients regained the ability to walk. Although conus AVMs are challenging to treat, excellent long-term outcomes are possible with a multimodality approach. Recurrence is associated with long-term neurological decline and calls for close follow-up.
    Neurosurgery 04/2012; 71(1):100-8. · 2.53 Impact Factor
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    ABSTRACT: Many programs aimed at mitigating the problem of uncorrected refractive error and the resulting avoidable blindness use recycled (donated) spectacles as a seemingly inexpensive expedient. This article analyses the costs and benefits of recycled spectacles and compares them with alternative methodologies. Although well intentioned, it is argued that recycled spectacles will neither suit many of those affected by uncorrected refractive error nor provide a cost saving solution to the problem. Although this is not the first argument against the use of recycled spectacles, there has been no accurate costing of their delivery. This article assesses the real cost of delivery of recycled spectacles. The useable quantity of recycled spectacles was determined by examining two separate batches of donated spectacles. These data were used in the calculation of the cost of delivery. The metric used for comparison was only cost (i.e., it was a cost minimization analysis) because it was deemed that recycled spectacles and ready-made spectacles were the same mode of correction fundamentally. Only 7% of the 275 recycled spectacles analyzed were suitable for use. The relatively small proportion of useable spectacles contributed to the high societal cost of delivering recycled spectacles, which was found to be U.S.$20.49, more than twice the cost of supplying ready-made spectacles. Recycled spectacles are not a cost-saving method of correcting refractive error and should be discouraged as a strategy for eliminating uncorrected refractive error in developing countries.
    Optometry and vision science: official publication of the American Academy of Optometry 03/2012; 89(3):304-9. · 1.53 Impact Factor
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    ABSTRACT: Tanzania suffers from a severe lack of health practitioners trained in neurosurgical procedures. To address this problem, we have implemented an initiative, modeled after the experience of other pioneers in international neurosurgery, to establish cost-effective and sustainable neurosurgical care by teaching fundamental neurosurgical skills to local surgeons. In this report we describe our early experience in Northwest Tanzania and discuss the potential for this training model to improve neurosurgical care to a region in need. Between September 2009 and October 2010, three residents and two attendings from our institution spent a total of 15 weeks at Bugando Medical Centre in Mwanza, Tanzania. During this time, we focused on teaching neurosurgical techniques, intraoperative decision-making, and clinical management skills to two local surgeons. The emphasis of our presence was on teaching and providing sustainable neurosurgical care. During this period, we performed 41 neurosurgical procedures with one of two local surgeons. The most common procedures performed were ventriculoperitoneal shunts (22%), myelomeningocele repairs (22%), and cranial trauma cases (17%). Five (12%) cases required the placement of spinal instrumentation. Thirty-nine (95%) patients remained stable or improved at discharge. There were 2 (5%) perioperative deaths. Although numerous challenges remain, our experience demonstrates the potential of this teaching model in providing sustainable neurosurgical care in Northwest Tanzania.
    World Neurosurgery 11/2011; 77(1):32-8. · 1.77 Impact Factor
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    ABSTRACT: Intramedullary spinal cord metastasis (ISCM) is a rare manifestation of systemic cancer and data about the optimal management of these lesions are lacking. To clarify the role of surgery, we investigated survival and neurological outcomes after surgical resection of ISCMs. Between 2003 and 2010, we surgically treated 10 ISCMs in 9 patients. For each patient, we retrospectively collected the following data: demographic variables, history of prior cancer, site of primary cancer, extent of cancer on presentation, degree of resection, preoperative and postoperative spinal cord impairment (American Spinal Injury Association [ASIA] grade), and postoperative survival. We investigated the relationship between these variables, overall survival, and preservation of function. Eight ISCMs were treated with gross total resection and two were treated with subtotal resection. Overall postoperative survival was 6.4 ± 9.4 months (mean ± standard deviation), with one patient still alive at last follow-up. Patients with a diagnosis of melanoma had higher mean survival than those with nonmelanoma histology (20.5 ± 13.4 vs. 2.4 ± 1.7 months, P < 0.01). Degree of resection, number of organ systems affected, ambulatory status, and ASIA grade pre operatively or postoperatively, were not significantly associated with survival. Of the nine patients, seven (78%) demonstrated no change in ASIA grade postoperatively, one (11%) improved, and one patient (11%) deteriorated. All patients who were ambulatory preoperatively remained ambulatory postoperatively and at last follow-up. Although ISCM is associated with poor prognosis, survival appears to be greater in patients with melanoma. Surgical resection does not appear to significantly lengthen survival but may be indicated to preserve ambulatory status in symptomatic patients.
    World Neurosurgery 11/2011; 77(2):370-4. · 1.77 Impact Factor
  • David A Wilson, David J Fusco, Harold L Rekate
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    ABSTRACT: Complex syringomyelia is multifactorial, and treatment strategies are highly individualized. In refractory cases, sectioning of the filum terminale, also known as terminal ventriculostomy, has been described as a potential adjuvant treatment to alleviate syrinx progression. A 10-year-old boy with a history of arachnoiditis presented with complex syringomyelia, progressive lower extremity motor weakness, and spasticity. Previously, he had failed spinal cord detethering and direct syrinx shunting. Imaging studies demonstrated a holocord syrinx extending to the level of his conus medullaris and into the filum terminale. The patient underwent an uncomplicated lumbar laminectomy and transection of the filum terminale. Operative pathologic specimens demonstrated a dilated central canal within the filum. Postoperative imaging demonstrated significant reduction in the diameter of the syrinx. At follow-up, the patient's motor symptoms had improved. Terminal ventriculostomy may be a useful adjuvant in treating caudally placed syringes refractory to other treatments. This procedure carries low neurological risk and involves no hardware implantation. In select cases, terminal ventriculostomy may help preserve neurological function in the face of otherwise progressive syringomyelia.
    Acta Neurochirurgica 07/2011; 153(7):1449-53; discussion 1453. · 1.55 Impact Factor
  • David A Wilson, David J Fusco, Nicholas Theodore
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    ABSTRACT: Iatrogenic vascular injury is a rare but potentially devastating complication of cervical spine instrumentation. The authors report on a patient who developed an anterior spinal artery pseudoaneurysm associated with delayed subarachnoid hemorrhage after undergoing odontoid screw placement 14 months earlier. This 86-year-old man presented with spontaneous subarachnoid hemorrhage (Fisher Grade 4) and full motor strength on neurological examination. Imaging demonstrated pseudarthrosis of the odontoid process, extension of the odontoid screw beyond the posterior cortex of the dens, and a pseudoaneurysm arising from an adjacent branch of the anterior spinal artery. Due to the aneurysm's location and lack of active extravasation, endovascular treatment was not attempted. Posterior C1-2 fusion was performed to treat radiographic and clinical instability of the C1-2 joint. Postoperatively, the patient's motor function remained intact. Almost all cases of vascular injury related to cervical spine instrumentation are recognized at surgery. To the authors' knowledge, this is the first report of delayed vascular injury following an uncomplicated cervical fixation. This case further suggests that the risk of this phenomenon may be elevated in cases of failed fusion.
    Journal of neurosurgery. Spine 03/2011; 14(6):715-8. · 1.61 Impact Factor
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    ABSTRACT: This study aims to examine the outcomes of ten patients after orbitozygomatic (OZ) pterional surgery in cases of refractory epilepsy caused by hypothalamic hamartomas (HH). Ten patients with HH and treatment-resistant epilepsy (mean age 18.3 years, range 0.7 to 42.7) underwent HH resection with an OZ approach (n = 8) or an OZ approach combined with a transventricular endoscopic approach (n = 2). Follow-up for the patients ranged from 0.5 to 6.2 years (mean 3.1). Outcomes were prospectively monitored with the use of a proprietary database. Four patients (40%) are seizure-free, and four (40%) have had greater than 50% reduction in seizures. One patient had no significant change in seizure frequency, and one patient died unexpectedly 2.8 years after surgery. Six patients had total or near-total HH resection (98-100% of HH lesion volume). Of these, four of six (66%) were seizure-free, and two had at least greater than 50% reduction in seizures. Residual complications include diabetes insipidus (n = 1), poikilothermia (n = 1), visual field deficit (n = 1), and hemiparesis (n = 1). Eight families (80%) reported improved quality of life. Patients with treatment-resistant epilepsy and tumors with an inferior or horizontal plane of attachment to the hypothalamus should continue to be approached from below. Those with both intrahypothalamic and parahypothalamic components may require approaches from above and below, either simultaneously or staged. For appropriately selected patients, the success of controlling seizures with an OZ is comparable to results utilizing transcallosal or transventricular approaches. The likelihood of controlling seizures appears to correlate with extent of resection.
    Child s Nervous System 02/2011; 27(2):265-77. · 1.24 Impact Factor
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    ABSTRACT: Brainstem cavernous malformations (BSCMs) are believed to compose 9% to 35% of all cerebral cavernous malformations, but these lesions have been reported in children in very limited numbers. To review surgical outcomes of pediatric patients with BSCMs treated at 1 institution. We retrospectively analyzed the course of 40 pediatric patients (19 males, 21 females; age range, 10 months to 18.9 years; mean, 12.3 years) who underwent surgery between 1984 and 2009. Age, sex, presenting symptoms, location of lesion, surgical approach, new postoperative deficits, Glasgow Outcome Scale score, recurrences, and resolution of baseline symptoms were recorded. Thirty-nine patients experienced hemorrhage before surgery. Lesion locations included the pons (n=22), midbrain (n=4), midbrain and thalamus (n=4), pontomesencephalic junction (n=3), medulla (n=3), pontomedullary junction (n=3), and cervicomedullary junction (n=1). Mean lesion size was 2.3 cm. Mean length of hospital stay was 10.7 days. The average clinical follow-up was 31.9 months in 36 patients with follow-up after discharge. At last follow-up, 5 patients had experienced symptoms and/or imaging consistent with rehemorrhage, either from a residual that enlarged or true recurrence (5.25% annual rebleed risk per patient after surgery); 2 required reoperation for further resection of cavernoma. Mean Glasgow Outcome Scale score was 4.2 on admission, 4.05 at discharge, and 4.5 at latest follow-up. Preoperative symptoms and deficits improved in 16 patients (40%). New neurological deficits developed in 19 patients (48%) and resolved in 9, leaving 10 patients (25%) with new permanent deficit. Compared with adults, pediatric patients with BCSMs tend to have larger lesions and higher rates of recurrence (regrowth of residual lesion). Given the greater life expectancy of children, surgical treatment seems warranted in those with surgically accessible lesions that have bled. Outcomes were similar to those in our adult series of patients with BSCMs.
    Neurosurgery 12/2010; 67(6):1589-98; discussion 1598-9. · 2.53 Impact Factor
  • Acta Neurochirurgica 05/2010; 152(5):925-7. · 1.55 Impact Factor

Publication Stats

33 Citations
43.32 Total Impact Points


  • 2012–2013
    • Barrow Neurological Institute
      • Department of Neurosurgery
      Phoenix, Arizona, United States
    • University of New South Wales
      Kensington, New South Wales, Australia
  • 2011–2013
    • St. Joseph Medical Center
      Houston, Texas, United States