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Naylor, Ryan M.

https://orcid.org/0000-0003-3067-1000

Mayo Clinic

Mayo Clinic

Citations 38

Weathering the storm: a single-institution experience with paroxysmal sympathetic hyperactivity after brain tumor resection in pediatric patients
Bouchal, Samantha M. , Naylor, Ryan M. , Bouchal, Samantha M , Daniels, David J.

Journal of Neurosurgery: Pediatrics | January 6, 2023 | Volume: 31 | Issue: 4 | Pages: 282-289

10.3171/2022.12.peds22369 Get It

OBJECTIVE Paroxysmal sympathetic hyperactivity (PSH) is a complication of severe traumatic or hypoxic brain injury characterized by transient episodes of tachycardia, tachypnea, hypertension, hyperthermia, diaphoresis, and/or dystonic posturing. Posttraumatic "sympathetic storms" are associated with poor outcomes. PSH rarely occurs after brain tumor resection in pediatric patients; only 4 cases have been published since 1929. Thus, the authors sought to report their experience with postcraniotomy PSH in pediatric brain tumor patients. METHODS A retrospective study of patients younger than 18 years of age who underwent craniotomy for brain tumor resection at a single center by a single surgeon over a 7-year period was performed. A clinical diagnosis of postoperative PSH was recorded. Recorded outcomes included the interval between surgery and initiation of cytotoxic therapy, need for long-term CSF diversion, length of hospital stay, and survival. RESULTS Of the 150 patients who were included for analysis, 4 patients were diagnosed with postoperative PSH for an overall occurrence of 2.7%. PSH patients were younger than non-PSH patients (1.8 ± 0.4 years vs 9.2 ± 5.3 years, p = 0.010) and tended to have intraventricular tumors close to the thalamus, basal ganglia, and/or brainstem. PSH patients experienced longer hospital admissions (44.3 ± 23.4 days vs 6.8 ± 9.4 days, p = 0.001), a shorter interval between surgery and initiation of cytotoxic cancer-directed therapy (14.3 ± 8.0 days vs 90.7 days ± 232.9 days, p = 0.011), and increased need for long-term CSF diversion compared with non-PSH patients (75% vs 25%, p = 0.005). At the last follow-up, 50% of PSH patients had died compared with 13% of non-PSH patients (p = 0.094). CONCLUSIONS PSH is a rare postoperative complication that may affect young children with periventricular tumors and is associated with poorer clinical outcomes. Increasing awareness of this condition is vital to improving patient outcomes.
Microsurgical Obliteration of Craniocervical Junction Dural Arteriovenous Fistulas: Multicenter Experience
Salem, Mohamed M. , Srinivasan, Visish M. , Ravindran, Krishnan , Yang, Kaiyun , Karahalios, Katherine , Raygor, Kunal P. , Naylor, Ryan M. , Tavakoli, Samon , Abdelsalam, Ahmed , Chen, Stephanie H. , Jankowitz, Brian T. , Başkaya, Mustafa K. , Cherian, Jacob , Kim, Louis J. , Starke, Robert M., Kan, Peter , Dehdashti, Amir R. , Abla, Adib A. , Lawton, Michael T. , Burkhardt, Jan‐Karl , Abla, Adib , Burkhardt, Jan‐Karl , Tonetti, Daniel A. , Taussky, Philipp , Catapano, Joshua S , Grandhi, Ramesh , Mascitelli, Justin R , Gompel, Jamie J. Van , Couldwell, William T. , Kim, Louis J. , Cohen‐Gadol, Aaron

Neurosurgery | December 15, 2022 | Volume: 92 | Issue: 1 | Pages: 205-212

10.1227/neu.0000000000002196 Get It

BACKGROUND: Dural arteriovenous fistulas (dAVFs) located at craniocervical junction are extremely rare (1%-2% of intracranial/spinal dAVFs). Their angio-architectural complexity renders endovascular embolization to be challenging given multiple small feeders with risk of embolysate reflux into vertebral artery and limited transvenous access. The available literature discussing microsurgery for these lesions is limited to few case reports. OBJECTIVE: To report a multicenter experience assessing microsurgery safety/efficacy. METHODS: Prospectively maintained registries at 13 North American centers were queried to identify craniocervical junction dAVFs treated with microsurgery (2006-2021). RESULTS: Thirty-eight patients (median age 59.5 years, 44.7% female patients) were included. The most common presentation was subarachnoid/intracranial hemorrhage (47.4%) and myelopathy (36.8%) (92.1% of lesions Cognard type III-V). Direct meningeal branches from V3/4 vertebral artery segments supplied 84.2% of lesions. All lesions failed (n = 5, 13.2%) or were deemed inaccessible/unsafe to endovascular treatment. Far lateral craniotomy was the most used approach (94.7%). Intraoperative angiogram was performed in 39.5% of the cases, with angiographic cure in 94.7% of cases (median imaging follow-up of 9.2 months) and retreatment rate of 5.3%. Favorable last follow-up modified Rankin Scale of 0 to 2 was recorded in 81.6% of the patients with procedural complications of 2.6%. CONCLUSION: Craniocervical dAVFs represent rare entity of lesions presenting most commonly with hemorrhage or myelopathy because of venous congestion. Microsurgery using a far lateral approach provides robust exposure and visualization for these lesions and allows obliteration of the arterialized draining vein intradurally as close as possible to the fistula point. This approach was associated with a high rate of angiographic cure and favorable clinical outcomes.
Stereotactic radiosurgery for intermediate- and high-grade arteriovenous malformations: outcomes stratified by the supplemented Spetzler-Martin grading system
Naylor, Ryan M. , Graffeo, Christopher S. , Link, Michael J. , Brown, Paul D. , Stafford, Scott L., Laack, Nadia N., Pollock, Bruce E. , Nesvick, Cody L.

Journal of Neurosurgery | August 5, 2022 | Volume: 138 | Issue: 3 | Pages: 804-809

10.3171/2022.5.jns22761 Get It

OBJECTIVE The supplemented Spetzler-Martin (Supp-SM) grading system was developed to improve the predictive accuracy of surgical risk for patients with brain arteriovenous malformations (AVMs). The aim of this study was to apply the Supp-SM grading system to patients having stereotactic radiosurgery (SRS) for Spetzler-Martin (SM) intermediate- (grade III) or high-grade (grade IV–V) AVMs to enable comparison with published microsurgical series. METHODS In 219 patients who underwent SRS during the period from 1990 to 2016, the Supp-SM grade was calculated for SM grade III (n = 154) or SM grade IV–V (n = 65) AVMs. The Supp-SM grades in these patients were 4 (n = 14, 6%), 5 (n = 36, 16%), 6 (n = 67, 31%), 7 (n = 76, 35%), and 8–9 (n = 26, 12%). Sixty patients (27%) had deep AVMs (basal ganglia, thalamus, or brainstem). Thirty-nine patients (18%) had volume-staged SRS; 41 patients (19%) underwent repeat SRS. The median follow-up period was 69 months for SM grade III AVMs and 113 months for SM grade IV–V AVMs. RESULTS AVM obliteration was confirmed in 163 patients (74%) at a median of 38 months after initial SRS. The obliteration rates at 4 and 8 years were 59% and 76%, respectively. Thirty-one patients (14%) had post-SRS deficits from hemorrhage (n = 7, 3%) or radiation injury (n = 24, 11%). Six patients (3%) died after SRS (hemorrhage, n = 5; radiation injury, n = 1). The rates of neurological decline or death at 4 and 8 years were 11% and 18%, respectively. Factors predictive of nonobliteration were deep location (HR 0.57, 95% CI 0.39–0.82, p = 0.003) and increasing AVM volume (HR 0.96, 95% CI 0.93–0.99, p = 0.002). Increasing AVM volume was the only factor associated with neurological decline (HR 1.05, 95% CI 1.02–1.08, p = 0.002). The Supp-SM grading score did not correlate with either obliteration (HR 0.94, 95% CI 0.82–1.09, p = 0.43) or neurological decline (HR 1.15, 95% CI 0.84–1.56, p = 0.38). CONCLUSIONS The Supp-SM grading system was not predictive of outcomes after SRS of intermediate- or high-grade AVM. In a cohort that included a high percentage (47%) of "inoperable" AVMs according to Supp-SM grade (≥ 7), most patients had obliteration after SRS, although there was a high risk of neurological decline.
Right posterior petrosectomy for resection of petroclival meningioma
Vakharia, Kunal , Naylor, Ryan M. , Nassiri, Ashley M. , Driscoll, Colin L. W., Link, Michael J. , Vakharia, Kunal V., Hasegawa, Hirotaka

Neurosurgical Focus: Video | April 1, 2022 | Volume: 6 | Issue: 2 | Pages: V14

10.3171/2022.1.focvid21227 Get It

Petroclival meningiomas, which arise from the upper two-thirds of the clivus and are medial to the trigeminal nerve, carry significant surgical risk. Patients whose operations are tailored to maximize tumor resection while minimizing neurological morbidity have favorable outcomes. Subtotally resected tumors can be subsequently considered for radiosurgery in an attempt to limit recurrence. Here the authors report the case of a 40-year-old woman with postpartum trigeminal neuropathy secondary to a petroclival meningioma. The patient underwent an aggressive subtotal resection via a posterior petrosal approach with preservation of neurological function followed by adjuvant radiosurgery. The video can be found here: https://stream.cadmore.media/r10.3171/2022.1.FOCVID21227
Microsurgical Resection of a Petroclival Epidermoid Cyst Using an Anterior Petrosectomy Approach: 2-Dimensional Operative Video
Vakharia, Kunal , Naylor, Ryan M. , Nassiri, Ashley M. , Driscoll, Colin L. W., Link, Michael J., Vakharia, Kunal V., Link, Michael J.

Operative Neurosurgery | September 24, 2021 | Volume: 21 | Issue: 6 | Pages: E565-E565

10.1093/ons/opab364 Get It

Abstract Epidermoid cysts are rare, benign lesions that result from inclusion of ectodermal elements during neural tube closure. 1 Cysts are composed of desquamated epithelial cells and restrict diffusion on magnetic resonance imaging (MRI). 2,3 Symptoms are attributable to anatomic location. 4,5 In this video, we illustrate the surgical treatment of an epidermoid cyst located in the right cerebellopontine angle, petrous apex, and Meckel's cave. The patient, a 33-yr-old female with right-sided V1 trigeminal hypoesthesia, underwent surveillance imaging for 2 yr. However, she developed progressive V1 and V2 trigeminal hypoesthesia and imaging revealed enlargement of the lesion. Therefore, surgical resection was pursued. The patient consented to the procedure. The patient underwent a right middle fossa craniotomy and anterior petrosectomy. After identifying the greater superficial petrosal nerve and cutting the middle meningeal artery as it exited foramen spinosum, Kawase's triangle was drilled, and the dura over Meckel's cave and the subtemporal dura were opened. The lesion was resected, taking care to preserve the trigeminal nerve and the basilar artery. A retrosigmoid craniotomy was then fashioned. The cyst and its capsule were dissected off the brainstem and cranial nerves utilizing natural corridors between the trigeminal and vestibulocochlear nerves as well as between the facial and lower cranial nerves. Gross total resection was confirmed on postoperative MRI, and she was discharged home on postoperative day 5. Three months after surgery, she underwent formal pinprick testing, which revealed 95% loss of sensation in V1, 20% loss in V2, and normal sensation in V3. Three-month postoperative MRI showed no residual tumor.
Delayed-Onset Heparin-Induced Thrombocytopenia With Cerebral Venous Sinus Thrombosis Following Total Knee Arthroplasty: Case Report
Bauman, Megan M. J. , Naylor, Ryan M. , Santilli, Ashley R. , Wijdicks, Eelco F., Bauman, Megan , Wijdicks, Eelco F. M.

The Neurohospitalist | August 26, 2021 | Volume: 12 | Issue: 2 | Pages: 328-331

10.1177/19418744211042966 Get It

Heparin-induced thrombocytopenia (HIT) is a prothrombotic state caused by autoantibodies against platelet factor 4 (PF4)-heparin complexes. Although HIT typically presents 5-10 days after the initiation of heparin, thrombosis and thrombocytopenia may occur up to several weeks following heparin withdrawal, so-called delayed-onset HIT. Although rare, there have been isolated reports of HIT-induced cerebral venous sinus thrombosis (CVST), which carry high rates of morbidity and mortality. There is a need to further characterize the etiology, clinical presentation, treatment paradigms, and outcomes of patients with HIT-induced CVST. Here, we present the case of a 57-year old female who presented to the emergency department with a headache and seizure 11 days following a right total knee arthroplasty for which she received 3 post-operative doses of enoxaparin. Work-up demonstrated acute intracerebral hemorrhage (ICH), CVST, and thrombocytopenia. Intravenous heparin resulted in rapidly deteriorating platelet count and subsequent serologic testing confirmed the diagnosis of HIT. Treatment with bivalirudin was initiated, the HIT resolved, and the patient was discharged home on hospital day 19 with long-term anticoagulation mediated by warfarin. At 3-month follow up, the patient had mild upper motor neuron pattern weakness and was living independently. This case depicts a rare case of delayed-onset HIT and CVST, highlights the importance of establishing a fluid treatment plan for managing HIT-induced CVST, and illustrates the importance of employing rapid anticoagulation despite acute ICH to achieve a desirable clinical outcome.
Endoscope-Assisted Resection of Extra-Axial Premedullary Neurenteric Cyst via Far Lateral-Supracondylar Approach: 2-Dimensional Operative Video
Vakharia, Kunal , Naylor, Ryan M. , Vakharia, Kunal V., Gompel, Jamie J. Van

Operative Neurosurgery | August 25, 2021 | Volume: 21 | Issue: 6 | Pages: E544-E545

10.1093/ons/opab300 Get It

Abstract Neurenteric cysts are rare congenital lesions that may compress the ventral brainstem. 1-9 In this operative video, we illustrate the surgical treatment of an intradural extra-axial neurenteric cyst extending from the lower pons to the craniocervical junction. The patient, an asymptomatic 52-yr-old female, underwent surveillance imaging of the premedullary lesion for 14 yr without progression. However, after developing progressive strain-induced headaches, imaging revealed a significant enlargement of the lesion with brainstem compression and partial obstruction of the foramen magnum. Therefore, surgical resection was pursued. The patient consented to the procedure. The patient underwent a lateral suboccipital craniotomy and C1 laminectomy through a far lateral approach. The lesion was immediately visualized upon opening the dura. After identifying the cranial nerves, we resected the tumor while taking care to preserve the neurovascular elements of the cerebellopontine angle and foramen magnum. During the resection, we unexpectedly encountered a firm nodule that was adherent to the right posterior inferior cerebellar artery. This was meticulously dissected and removed en bloc using intraoperative indocyanine green (ICG) angiography. The cavity was inspected with 0-degree and 30-degree endoscopes to ensure complete resection of the lesion. Gross total resection was confirmed on postoperative magnetic resonance imaging. The patient was neurologically intact with no cranial nerve abnormalities and discharged home on postoperative day 3. This case demonstrates that the far lateral-supracondylar approach affords safe access to the ventral pontomedullary and craniocervical junctions and that intraoperative adjuncts, including ICG angiography and endoscopic visualization, can facilitate complete lesion resection with excellent clinical outcomes.
Teriparatide Treatment Increases Hounsfield Units in the Thoracic Spine, Lumbar Spine, Sacrum, and Ilium Out of Proportion to the Cervical Spine
Mikula, Anthony L. , Jeor, Jeffery D. St. , Naylor, Ryan M. , Bernatz, James T. , Patel, Nitesh P. , Fogelson, Jeremy L. , Sebastian, Arjun S. , Freedman, Brett A. , Currier, Bradford L. , Bydon, Mohamad , Kennel, Kurt A. , Yaszemski, Michael J. , Anderson, Paul A. , Elder, Benjamin D. , Bernatz, James T. , Larson, A. Noelle , Nassr, Ahmad

Clinical Spine Surgery | May 24, 2021 | Volume: 34 | Issue: 7 | Pages: E370-E376

10.1097/bsd.0000000000001203 Get It

Study Design: This was a retrospective chart review. Objective: The objective of this study was to compare the effect of teriparatide on Hounsfield Units (HU) in the cervical spine, thoracic spine, lumbar spine, sacrum, and pelvis. Second, to correlate HU changes at each spinal level with bone mineral density (BMD) on dual-energy x-ray absorptiometry (DXA). Summary of Background Data: HU represent a method to estimate BMD and can be used either separately or in conjunction with BMD from DXA. Materials and Methods: A retrospective chart review included patients who had been treated with at least 6 months of teriparatide. HU were measured in the vertebral bodies of the cervical, thoracic, and lumbosacral spine and iliac crests. Lumbar and femoral neck BMD as measured on DXA was collected when available. Results: One hundred twenty-five patients were identified for analysis with an average age of 67 years who underwent a mean (±SD) of 22±8 months of teriparatide therapy. HU improvement in the cervical spine was 11% (P=0.19), 25% in the thoracic spine (P=0.002), 23% in the lumbar spine (P=0.027), 17% in the sacrum (P=0.11), and 29% in the iliac crests (P=0.09). Lumbar HU correlated better than cervical HU with BMD as measured on DXA. Conclusions: Teriparatide increased average HU in the thoracolumbar spine to a proportionally greater extent than the cervical spine. The cervical spine had a higher baseline starting HU than the thoracolumbar spine. Lumbar HU correlated better than cervical and thoracic HU with BMD as measured on DXA.
Progressive Myelopathy From a Craniocervical Junction Dural Arteriovenous Fistula
Naylor, Ryan M. , Topinka, Britney, Rinaldo, Lorenzo , Jacobi, Jaclyn, Neth, Bryan J. , Flemming, Kelly D. , Neth, Bryan, Savastano, Luis E., Neth, Byran J. , Flemming, Kelly D , Savastano, Luis

Stroke | May 4, 2021 | Volume: 52 | Issue: 6 | Pages: No page available

10.1161/strokeaha.120.032552 Get It

1297: Thromboelastography Is a Marker for Progressive Hemorrhagic Injury in Severe Traumatic Brain Injury
Brown, Caitlin S. , Naylor, Ryan M. , Webb, Andrew , Rabinstein, Alejandro A. , Mara, Kristin C. , Nei, Andrea M.

Critical Care Medicine | December 18, 2020 | Volume: 49 | Issue: 1 | Pages: 654-654

10.1097/01.ccm.0000731076.63321.14 Get It