Publications by authors named "Allan D Levi"

149 Publications

Dose Adjustment Associated Complications of Bone Morphogenetic Protein: A Longitudinal Assessment.

World Neurosurg 2021 Sep 13. Epub 2021 Sep 13.

Department of Neurosurgery, University of Miami Miller School of Medicine, Miami, FL. Electronic address:

Objective: Bone morphogenetic protein (BMP) is a growth factor that aids in osteoinduction and promotes bone fusion. There is a lack of literature regarding rhBMP-2 dosage in different spine surgeries. This study aims to investigate the trends in rhBMP-2 dosage and the associated complications in spinal arthrodesis.

Methods: A retrospective study was conducted investigating spinal arthrodesis using rhBMP-2. Variables including age, procedure type, rhBMP-2 size, and complications were collected. Cases were grouped into the following surgical procedures: anterior lumbar interbody fusion/extreme lateral interbody fusion (ALIF/XLIF), posterior lumbar interbody fusion/transforaminal lumbar interbody fusion (PLIF/TLIF), posterolateral fusion (PLF), anterior cervical discectomy and fusion (ACDF), and posterior cervical fusion (PCF).

Results: 1209 patients who received rhBMP-2 from 2008 to 2020 were studied. Of these, 230 were categorized as ALIF/XLIF, 336 as PLIF/TLIF, 243 as PLF, 203 as ACDF, 197 as PCF. PCF (p < .001), PLIF/TLIF (p < .001), and PLF (p < .001) demonstrated a significant decrease in the rhBMP-2 dose used per level, with major transitions seen in 2018, 2011, and 2013, respectively. 120 complications following spinal arthrodesis were noted. A significant relation between rhBMP-2 size and complication rates (χ= 73.73, p = .0029) was noted. rhBMP-2 dosage per level was a predictor of complication following spinal arthrodesis (OR=1.212, p < .001).

Conclusion: BMP is an effective compound in fusing adjacent spine segments. However, it carries some regional complications. We demonstrate a decreasing trend in the dose/vertebral level. A decrease rhBMP-2 dose per level correlated with a decrease in complication rates.
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http://dx.doi.org/10.1016/j.wneu.2021.08.142DOI Listing
September 2021

Scalable culture techniques to generate large numbers of purified human Schwann cells for clinical trials in human spinal cord and peripheral nerve injuries.

J Neurosurg Spine 2021 Sep 3:1-10. Epub 2021 Sep 3.

1The Miami Project to Cure Paralysis.

Objective: Schwann cells (SCs) have been shown to play an essential role in axon regeneration in both peripheral nerve injuries (PNIs) and spinal cord injuries (SCIs). The transplantation of SCs as an adjunctive therapy is currently under investigation in human clinical trials due to their regenerative capacity. Therefore, a reliable method for procuring large quantities of SCs from peripheral nerves is necessary. This paper presents a well-developed, validated, and optimized manufacturing protocol for clinical-grade SCs that are compliant with Current Good Manufacturing Practices (CGMPs).

Methods: The authors evaluated the SC culture manufacturing data from 18 clinical trial participants who were recruited for autologous SC transplantation due to subacute SCI (n = 7), chronic SCI (n = 8), or PNIs (n = 3). To initiate autologous SC cultures, a mean nerve length of 11.8 ± 3.7 cm was harvested either from the sural nerve alone (n = 17) or with the sciatic nerve (n = 1). The nerves were digested with enzymes and SCs were isolated and further expanded in multiple passages to meet the dose requirements for transplantation.

Results: An average yield of 87.2 ± 89.2 million cells at P2 and 150.9 ± 129.9 million cells at P3 with high viability and purity was produced. Cell counts and rates of expansion increased with each subsequent passage from P0 to P3, with the largest rate of expansion between P2 and P3. Larger harvest nerve lengths correlated significantly with greater yields at P0 and P1 (p < 0.05). In addition, a viability and purity above 90% was sustained throughout all passages in nearly all cell products.

Conclusions: This study presents reliable CGMP-compliant manufacturing methods for autologous SC products that are suitable for regenerative treatment of patients with SCI, PNI, or other conditions.
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http://dx.doi.org/10.3171/2020.11.SPINE201433DOI Listing
September 2021

Challenges in Diagnosis and Management of Previously Embolized Spinal Dural Arteriovenous Fistulae.

World Neurosurg 2021 Aug 3. Epub 2021 Aug 3.

Department of Neurosurgery, University of Miami Miller School of Medicine, Miami, Florida, USA. Electronic address:

Background: Given the growing prevalence of initial endovascular treatment for type 1 spinal dural arteriovenous fistulae (dAVF), there are an increasing number of patients presenting with progressive symptoms related to recurrent previously embolized spinal dAVF. This study's goal was to identify demographic, clinical, and radiographic variables among patients who have failed embolization of type I spinal dAVF.

Methods: A retrospective review of 24 consecutive surgeries for type I spinal dAVF performed by the senior author (A.D.L.) identified 5 patients who underwent open surgery for failed embolization. These 5 cases were reviewed for location of fistula, time from embolization to recurrence, preoperative functional status, fistulous point encountered at surgery, and clinical outcome of the patient at 3-month follow-up. A representative example case is reviewed in detail.

Results: The median age at time of recurrence was 63 years (range 51-73 years). The median timing of embolization to recurrence of neurologic symptoms was 5 months (range 1-54) and to surgery 7 months (range 2-60 months). The level of the spinal dAVF was most frequently at T12-L1 (n = 3). Spinal magnetic resonance arteriography led to localization of the spinal dAVF in 2 patients and spinal catheter angiogram in 3 cases. All patients had definitive radiographic cure of the dAVF at last clinical follow-up.

Conclusions: The increased use of endovascular treatment of spinal dAVF has led to the treatment of refractory cases with a greater degree of surgical complexity. Open surgical ligation continues to provide the most definitive treatment outcomes for this complex spinal vascular entity.
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http://dx.doi.org/10.1016/j.wneu.2021.07.122DOI Listing
August 2021

Syrinx shunts for syringomyelia: a systematic review and meta-analysis of syringosubarachnoid, syringoperitoneal, and syringopleural shunting.

J Neurosurg Spine 2021 Jul 30:1-11. Epub 2021 Jul 30.

Objective: Syringomyelia is a debilitating, progressive disease process that can lead to loss of neurological function in patients already experiencing significant compromise. Syringosubarachnoid, syringoperitoneal, and syringopleural shunts are accepted treatment options for patients with persistent syringomyelia, but direct comparisons have been lacking to date. The authors conducted a systematic review of the literature and meta-analysis to compare clinical outcomes between these three syrinx shunt modalities.

Methods: Utilizing PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines for systematic reviews, Ovid Embase, PubMed, Scopus, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, American College of Physicians Journal Club, and Database of Abstracts of Review of Effectiveness were searched to identify all potentially relevant studies published from inception until July 2020. Data were extracted and analyzed using meta-analysis of proportions. The primary study outcome was the rate of reoperation based on the initial shunt modality. Secondary outcomes included clinical improvement, clinical deterioration, and complications following shunt placement.

Results: A total of 22 articles describing 27 distinct treatment cohorts published between 1984 and 2019 satisfied the inclusion criteria. This captured 473 syrinx shunt procedures, 193 (41%) by syringosubarachnoid shunt, 153 (32%) by syringoperitoneal shunt, and 127 (27%) by syringopleural shunt, with an overall median clinical follow-up of 44 months. The pooled incidences of revision surgery were estimated as 13% for syringosubarachnoid, 28% for syringoperitoneal, and 10% for syringopleural shunts, respectively (p-interaction = 0.27). The rate of clinical improvement was estimated as 61% for syringosubarachnoid, 64% for syringoperitoneal, and 71% for syringopleural shunts. The rate of clinical deterioration following placement was estimated as 13% for syringosubarachnoid, 13% for syringoperitoneal, and 10% for syringopleural shunts.

Conclusions: The preferred modality of syrinx shunting remains a controversial topic for symptomatic syringomyelia. This study suggests that while all three modalities offer similar rates of clinical improvement and deterioration after placement, syringoperitoneal shunts have a greater rate of malfunction requiring surgical revision. These data also suggest that syringopleural shunts may offer the best rate of clinical improvement with the lowest rate of reoperation.
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http://dx.doi.org/10.3171/2020.12.SPINE201826DOI Listing
July 2021

The Interdisciplinary Stem Cell Institute's Use of Food and Drug Administration-Expanded Access Guidelines to Provide Experimental Cell Therapy to Patients With Rare Serious Diseases.

Front Cell Dev Biol 2021 8;9:675738. Epub 2021 Jun 8.

Leonard M. Miller School of Medicine, The Interdisciplinary Stem Cell Institute, University of Miami, Miami, FL, United States.

The U.S. Food and Drug Administration (FDA) provides guidance for expanded access to experimental therapies, which in turn plays an important role in the Twenty-first Century Cures Act mandate to advance cell-based therapy. In cases of incurable diseases where there is a lack of alternative treatment options, many patients seek access to cell-based therapies for the possibility of treatment responses demonstrated in clinical trials. Here, we describe the use of the FDA's expanded access to investigational new drug (IND) to address rare and emergency conditions that include stiff-person syndrome, spinal cord injury, traumatic brain stem injury, complex congenital heart disease, ischemic stroke, and peripheral nerve injury. We have administered both allogeneic bone marrow-derived mesenchymal stem cell (MSC) and autologous Schwann cell (SC) therapy to patients upon emergency request using Single Patient Expanded Access (SPEA) INDs approved by the FDA. In this report, we present our experience with 10 completed SPEA protocols.
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http://dx.doi.org/10.3389/fcell.2021.675738DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8217825PMC
June 2021

Osteoporosis treatment in patients undergoing spinal fusion: a systematic review and meta-analysis.

Neurosurg Focus 2021 06;50(6):E9

Objective: Bisphosphonates and teriparatide are the most common therapies used in the treatment of osteoporosis. Their impact on fusion rates in osteoporotic patients following spinal fusion has yet to be concretely defined, with previous systematic reviews focusing heavily on bisphosphonates and lacking clinical insight on the utility of teriparatide. Herein the authors present an updated meta-analysis of the utility of both bisphosphonates and teriparatide in improving spinal fusion outcomes in osteoporotic patients.

Methods: After a comprehensive search of the English-language literature in the PubMed and Embase databases, 11 clinical studies were included in the final qualitative and quantitative analyses. Of these studies, 9 investigated bisphosphonates, 7 investigated teriparatide, and 1 investigated a combination of teriparatide and denosumab. Odds ratios and 95% confidence intervals were calculated where appropriate.

Results: A meta-analysis of the postoperative use of bisphosphonate demonstrated better odds of successful fusion as compared to that in controls during short-term monitoring (OR 3.33, 95% CI 1.72-6.42, p = 0.0003) but not long-term monitoring (p > 0.05). Bisphosphonate use was also shown to significantly reduce the likelihood of postoperative vertebral compression fracture (VCF; OR 0.07, 95% CI 0.01-0.59, p = 0.01) and significantly reduce Oswestry Disability Index scores (mean difference [MD] = -2.19, 95% CI -2.94 to -1.44, p < 0.00001) and visual analog scale pain scores (MD = -0.58, 95% CI -0.79 to -0.38, p < 0.00001). Teriparatide was found to significantly increase fusion rates at long-term postoperative periods as compared to rates after bisphosphonate therapy, with patients who received postoperative teriparatide therapy 2.05 times more likely to experience successful fusion (OR 2.05, 95% CI 1.17-3.59, p = 0.01).

Conclusions: The authors demonstrate the benefits of bisphosphonate and teriparatide therapy independently in accelerating fusion during the first 6 months after spinal fusion surgery in osteoporotic patients. In addition, they show that teriparatide may have superior benefits in spinal fusion during long-term monitoring as compared to those with bisphosphonates. Bisphosphonates may be better suited in preventing VCFs postoperatively in addition to minimizing postoperative disability and pain.
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http://dx.doi.org/10.3171/2021.3.FOCUS2175DOI Listing
June 2021

Introduction. Biologics in spine surgery.

Neurosurg Focus 2021 06;50(6):E1

6Department of Neurosurgery, University of Utah, Salt Lake City, Utah.

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http://dx.doi.org/10.3171/2021.3.FOCUS21171DOI Listing
June 2021

Preface.

Neurosurg Clin N Am 2021 07 11;32(3):ix-x. Epub 2021 May 11.

Division of Neurosurgery, Department of Surgery, University of Toronto, Division of Neurosurgery, Toronto Western Hospital, University Health Network, Toronto, ON, Canada.

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http://dx.doi.org/10.1016/j.nec.2021.04.002DOI Listing
July 2021

Hypothermia for Acute Spinal Cord Injury.

Neurosurg Clin N Am 2021 Jul;32(3):377-387

Department of Neurological Surgery, University of Miami MILLER School of Medicine, Lois Pope Life Center, 1095 Northwest 14th Terrace, Suite 2-24, Miami, FL 33136, USA. Electronic address:

Neuroprotection after acute spinal cord injury is an important strategy to limit secondary injury. Animal studies have shown that systemic hypothermia is an effective neuroprotective strategy that can be combined with other therapies. Systemic hypothermia affects several processes at the cellular level to reduce metabolic activity, oxidative stress, and apoptotic neuronal cell death. Modest systemic hypothermia has been shown to be safe and feasible in the acute phase after cervical spinal cord injury. These data have provided the impetus for an active multicenter randomized controlled trial for modest systemic hypothermia in acute cervical spinal cord injury.
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http://dx.doi.org/10.1016/j.nec.2021.03.009DOI Listing
July 2021

A single institution experience with proximal junctional kyphosis in the context of existing classification schemes - Systematic review.

J Clin Neurosci 2021 Jun 7;88:150-156. Epub 2021 Apr 7.

University of Miami Miller School of Medicine, Department of Neurological Surgery, Miami, FL, USA. Electronic address:

Background: Proximal junctional kyphosis is a kyphotic deformity following spine instrumentation, predominantly seen in scoliosis patients. There have been previous attempts to develop classification schema of PJK. We analyzed the factors contributing to PJK based upon our own clinical experience with the goal of developing a clinical guidance tool which took into account both etiology and mechanism of failure.

Methods: We performed a retrospective analysis of all re-operation thoracolumbar surgeries at a single institution over a 14-year period. Patients with PJK were identified and categorized based upon the etiology, mechanism of failure, and an indication of revision. Next, we conducted a systematic review on articles emphasizing a classification system for PJK.

Results: Fourteen PJK patients were identified out of 121 patients who required revision spine surgery. The average age was 64.9 ± 10.2 years, with 10 males (71%) and 4 females (29%). Three primary etiologies were identified: 6/14 (47%) overcorrection, 6/14 (47%) osteopenia, and 2/14 (14%) ligamentous disruption. The mechanism of failure was likewise divided into three categories: 9/14 (64%) compression fracture, 1/14 (7%) hardware failure, and 4/14 (29%) disc degeneration. The relationship between osteopenia and the development of a compression fracture leading to PJK was statistically significant (p = 0.031).

Conclusion: There are multiple current classification systems for PJK. Our study findings were in line with previously published literature and suggest the need for a future classification system combining both etiology, mechanism of failure, and severity of disease.
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http://dx.doi.org/10.1016/j.jocn.2021.03.031DOI Listing
June 2021

Vertebral multiple myeloma with pathological fracture: the most common etiology for emergency spine surgery in patients with no cancer diagnosis on admission.

Neurosurg Focus 2021 05;50(5):E2

Objective: Vertebral compression fractures are common in multiple myeloma (MM). Modern treatment paradigms place emphasis on treatment with radiation, with surgery reserved for cases involving frank instability or severe neural compression. However, experience at the authors' institution has led them to suspect a more prominent role for surgical intervention in some settings. The authors undertook the present study to better understand the incidence of MM in undiagnosed patients who require urgent surgery for pathological vertebral fracture.

Methods: The authors reviewed a prospectively collected database of all patients who underwent surgery with the senior author at their main hospital between June 1, 1998, and June 30, 2020. Patients admitted from the emergency room or after transfer from another hospital who then underwent surgery for pathological fracture during the same admission were included in the final analysis. Patients scheduled for elective surgery and those with previous cancer diagnoses were excluded.

Results: Forty-three patients were identified as having undergone urgent surgical decompression and/or stabilization for pathological fracture. Histopathology confirmed diagnosis of MM in 22 (51%) patients, lung metastasis in 5 (12%) patients, and breast metastasis in 4 (9%) patients. Twelve (28%) patients were diagnosed with other types of metastatic carcinoma or undifferentiated disease. Sixteen of 29 (55%) men and 6 of 14 (42%) women were diagnosed with MM (p = 0.02). Seventeen of 34 (50%) patients who underwent surgery for neurological deficit, 5 of 6 (83%) patients who underwent surgery for spinal instability, and 0 (0%) patients who underwent surgery for pain with impending spinal cord injury were diagnosed with MM (p = 0.12).

Conclusions: A majority of patients presenting to the authors' hospital with no history of malignancy who required urgent surgery for pathological compression fracture were found to have MM or plasmacytoma. This disease process may affect a significant portion of patients requiring decompressive or stabilizing surgery for compression fracture in academic medical centers.
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http://dx.doi.org/10.3171/2021.2.FOCUS201038DOI Listing
May 2021

The Focused Neurosurgical Examination During Telehealth Visits: Guidelines During the COVID-19 Pandemic and Beyond.

Cureus 2021 Feb 23;13(2):e13503. Epub 2021 Feb 23.

Neurological Surgery, University of Miami Miller School of Medicine, Miami, USA.

Objective:  To provide guidelines to healthcare workers for performing a focused neurological examination via telemedicine during the coronavirus disease-2019 (COVID-2019) pandemic.

Methods:  We reviewed our department's outpatient clinic visits after the implementation of a telemedicine protocol in response to the COVID-19 crisis. Crossover rates from telehealth to in-person visits were evaluated and guidelines for performing a telemedicine neurological exam were created based on the consensus of 16 neurosurgical attending providers over a four-month period.

Results:  From March 23, 2020 to July 20, 2020, some 2157 telehealth visits were performed in our department. Some 26 were converted to in-person visits by the provider request with the most cited reason for conversion being the need for a more detailed patient evaluation. Based on these experiences, we created a graphical tutorial to address the key components of the neurological exam with adaptations specific to the telehealth visit.

Conclusions:  In response to the global coronavirus pandemic, telemedicine has become an integral part of neurosurgeons' daily practice. Telemedicine failures remain low but primarily occur due to a need for more comprehensive evaluations. We provide guidelines for the neurosurgical exam during telehealth visits in an effort to assuage some of these issues.
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http://dx.doi.org/10.7759/cureus.13503DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7992292PMC
February 2021

Phase 1 Safety Trial of Autologous Human Schwann Cell Transplantation in Chronic Spinal Cord Injury.

J Neurotrauma 2021 May 3. Epub 2021 May 3.

The Miami Project to Cure Paralysis, Departments of University of Miami, Miami, Florida, USA.

A phase 1 open-label, non-randomized clinical trial was conducted to determine feasibility and safety of autologous human Schwann cell (ahSC) transplantation accompanied by rehabilitation in participants with chronic spinal cord injury (SCI). Magnetic resonance imaging (MRI) was used to screen eligible participants to estimate an individualized volume of cell suspension to be implanted. The trial incorporated standardized multi-modal rehabilitation before and after cell delivery. Participants underwent sural nerve harvest, and ahSCs were isolated and propagated in culture. The dose of culture-expanded ahSCs injected into the chronic spinal cord lesion of each individual followed a cavity-filling volume approach. Primary outcome measures for safety and trend-toward efficacy were assessed. Two participants with American Spinal Injury Association Impairment Scale (AIS) A and two participants with incomplete chronic SCI (AIS B, C) were each enrolled in cervical and thoracic SCI cohorts ( = 8 total). All participants completed the study per protocol, and no serious adverse events related to sural nerve harvest or ahSC transplantation were reported. Urinary tract infections and skin abrasions were the most common adverse events reported. One participant experienced a 4-point improvement in motor function, a 6-point improvement in sensory function, and a 1-level improvement in neurological level of injury. Follow-up MRI in the cervical (6 months) and thoracic (24 months) cohorts revealed a reduction in cyst volume after transplantation with reduced effect over time. This phase 1 trial demonstrated the feasibility and safety of ahSC transplantation combined with a multi-modal rehabilitation protocol for participants with chronic SCI.
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http://dx.doi.org/10.1089/neu.2020.7590DOI Listing
May 2021

Schwann cell delivery via a novel 3D collagen matrix conduit improves outcomes in critical length nerve gap repairs.

J Neurosurg 2021 Feb 19:1-11. Epub 2021 Feb 19.

1Department of Neurological Surgery and the Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, Florida; and.

Objective: The current clinical standard of harvesting a nerve autograft for repair of long-segment peripheral nerve injuries (PNIs) is associated with many potential complications. Guidance channels offer an alternative therapy. The authors investigate whether autologous Schwann cells (SCs) implanted within a novel collagen-glycosaminoglycan conduit will improve axonal regeneration in a long-segment PNI model.

Methods: Novel NeuraGen 3D collagen matrix conduits were implanted with autologous SCs to investigate axonal regeneration across a critical size defect (13 mm) in male Fischer rat sciatic nerve. Reversed sciatic nerve autografts served as positive controls, and conduits filled with serum only as negative controls. Electrophysiological assessments were made in vivo. Animals were killed at 4 or 16 weeks postinjury, muscle weights were measured, and grafts underwent immunohistochemical and morphometric analysis.

Results: SC survival was confirmed by the presence of green fluorescent protein-labeled SCs within regenerated fibers. Regeneration and elongation of myelinated axons in all segments of the graft were significantly enhanced at 16 weeks in the SC-filled conduits compared to the conduit alone and were statistically similar to those of the autograft. Nerves repaired with SC-filled conduits exhibited onset latencies and nerve conduction amplitudes similar to those of the contralateral controls and autograft (p < 0.05). Adding SCs to the conduit also significantly reduced muscle atrophy compared to conduit alone (p < 0.0001).

Conclusions: Repair of long-segment PNI of rat sciatic nerve is significantly enhanced by SC-filled NeuraGen 3D conduits. Improvements in the total number of myelinated axons, axon diameter, and myelin thickness throughout SC-filled conduits allow for significant recovery in nerve conduction and a decrease in muscle atrophy.
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http://dx.doi.org/10.3171/2020.8.JNS202349DOI Listing
February 2021

Neurophysiological Changes in the First Year After Cell Transplantation in Sub-acute Complete Paraplegia.

Front Neurol 2020 18;11:514181. Epub 2021 Jan 18.

The Miami Project to Cure Paralysis, Miller School of Medicine, The University of Miami, Miami, FL, United States.

Neurophysiological testing can provide quantitative information about motor, sensory, and autonomic system connectivity following spinal cord injury (SCI). The clinical examination may be insufficiently sensitive and specific to reveal evolving changes in neural circuits after severe injury. Neurophysiologic data may provide otherwise imperceptible circuit information that has rarely been acquired in biologics clinical trials in SCI. We reported a Phase 1 study of autologous purified Schwann cell suspension transplantation into the injury epicenter of participants with complete subacute thoracic SCI, observing no clinical improvements. Here, we report longitudinal electrophysiological assessments conducted during the trial. Six participants underwent neurophysiology screening pre-transplantation with three post-transplantation neurophysiological assessments, focused on the thoracoabdominal region and lower limbs, including MEPs, SSEPs, voluntarily triggered EMG, and changes in GSR. We found several notable signals not detectable by clinical exam. In all six participants, thoracoabdominal motor connectivity was detected below the clinically assigned neurological level defined by sensory preservation. Additionally, small voluntary activations of leg and foot muscles or positive lower extremity MEPs were detected in all participants. Voluntary EMG was most sensitive to detect leg motor function. The recorded MEP amplitudes and latencies indicated a more caudal thoracic level above which amplitude recovery over time was observed. In contrast, further below, amplitudes showed less improvement, and latencies were increased. Intercostal spasms observed with EMG may also indicate this thoracic "motor level." Galvanic skin testing revealed autonomic dysfunction in the hands above the injury levels. As an open-label study, we can establish no clear link between these observations and cell transplantation. This neurophysiological characterization may be of value to detect therapeutic effects in future controlled studies.
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http://dx.doi.org/10.3389/fneur.2020.514181DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7848788PMC
January 2021

Meralgia paresthetica treated by injection, decompression, and neurectomy: a systematic review and meta-analysis of pain and operative outcomes.

J Neurosurg 2021 Jan 15:1-11. Epub 2021 Jan 15.

1Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, Florida; and.

Objective: Meralgia paresthetica is caused by entrapment of the lateral femoral cutaneous nerve (LFCN) and often presents with pain. Multiple treatment options targeting the LFCN can be pursued to treat the pain should conservative measures fail, with the most common options being injection, neurolysis, and neurectomy. However, their efficacy in causing pain relief and their clinical outcomes have yet to be directly compared. The aim of this study was to interrogate the contemporary literature and quantitatively define how these options compare.

Methods: The electronic databases Ovid Embase, PubMed, SCOPUS, and the Cochrane Library were interrogated from inception to May 2020 following the PRISMA guidelines. Candidate articles were screened against prespecified criteria. Outcome data were abstracted and pooled by random-effects meta-analysis of proportions.

Results: There were 25 articles that satisfied all criteria, reporting outcomes for a total of 670 meralgia paresthetica patients, with 78 (12%) treated by injection, 496 (74%) by neurolysis, and 96 (14%) by neurectomy. The incidence of complete pain relief was 85% (95% CI 71%-96%) after neurectomy, 63% (95% CI 56%-71%) after neurolysis, and 22% (95% CI 13%-33%) after injection, which were all statistically different (p < 0.01). The incidence of revision procedures was 12% (95% CI 4%-22%) after neurolysis and 0% (95% CI 0%-2%) after neurectomy, which were significantly lower than 81% (95% CI 64%-94%) after injection (p < 0.01). The incidences of treatment complications were statistically comparable across all three treatments, ranging from 0% to 5% (p = 0.34).

Conclusions: There are multiple treatment options to target pain in meralgia paresthetica. The incidence of complete pain relief appears to be the greatest among the 3 interventions after neurectomy, accompanied by the lowest incidence of revision procedures. These findings should help inform patient preference and expectations. Greater exploration of the anatomical rationale for incomplete pain relief after surgical intervention will assist in optimizing further surgical treatment for meralgia paresthetica.
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http://dx.doi.org/10.3171/2020.7.JNS202191DOI Listing
January 2021

Posterior Surgical Approach for Ventral Cervical Spinal Cord Herniation: 2-Dimensional Operative Video.

Oper Neurosurg (Hagerstown) 2021 02;20(3):E215-E216

Spinal cord herniation (SCH) is a rare condition that is typically of idiopathic origin. Although SCH is mostly found in the thoracic region because of a dural defect, there are some reports of cervical SCH following surgery or trauma.1-3 Spinal cord tethering can be a result of SCH or as a standalone issue.4,5 These conditions can lead to progressive neurological deficits, including numbness, gait disturbances, and decreased muscle strength, requiring surgical correction. There are limited reports of surgical procedures for ventral SCHs. Several reports exist using a ventral approach for intradural tumors, but it is not commonly employed because of the inability to obtain adequate dural closure.6 Much of the literature on SCH comes from idiopathic and congenital cases in the thoracic spine.7,8 Posterior and posterolateral approaches for a ventral thoracic SCH have been described, as well as an anterior approach for a ventral cervical SCH.9-12 In this video, we describe a posterior approach for a ventral cervical SCH. A 38-yr-old male presented with progressive cervical myelopathy 9 yr after a C2-C3 schwannoma resection requiring an anterior approach and corpectomy of C3 with partial corpectomies of C2 and C4. A preoperative magnetic resonance imaging showed a ventrally herniated spinal cord at the top of the C3 vertebral body and below the C4 vertebral body. Informed consent was obtained. The posterior surgical approach involved a C1-C5 laminectomy, sectioning the dentate ligament, ventral cord untethering, removal of residual tumor, and placement of a ventral sling. A significant improvement in sensory and motor function was observed postoperatively.
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http://dx.doi.org/10.1093/ons/opaa340DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8133320PMC
February 2021

Commentary: Genetic Events and Signaling Mechanisms Underlying Schwann Cell Fate in Development and Cancer.

Neurosurgery 2021 01;88(2):E128-E129

Department of Neurological Surgery, Miller School of Medicine, University of Miami, Miami, Florida.

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http://dx.doi.org/10.1093/neuros/nyaa501DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7803429PMC
January 2021

Differences Between Neurosurgical Subspecialties in Telehealth Adoption.

World Neurosurg 2021 02 16;146:e323-e327. Epub 2020 Nov 16.

Department of Neurological Surgery, University of Miami, Miami, Florida, USA. Electronic address:

Objective: The health care field has been faced with unprecedented challenges during the COVID 19 pandemic. One such challenge was the implementation of enhanced telehealth capabilities to ensure continuity of care. In this study, we aim to understand differences between subspecialties with regard to patient consent and satisfaction following telehealth implementation.

Methods: A retrospective review of the electronic medical record was performed from March 2 to May 8, 2020 to evaluate surgical consents before and after telehealth implementation. Press Ganey survey results were also obtained both pre- and posttelehealth implementation and compared.

Results: There was no significant difference in the percentage of new patients consented for surgery (after being seen via telehealth only) between the cranial and spine services. For procedures in which >10 patients were consented for surgery, the highest proportion of patients seen only via telehealth was for ventriculoperitoneal shunt placement/endoscopic third ventriculostomy for the cranial service, and lumbar laminectomy and microdiscectomy for the spine service. Additionally, the spine service experienced marked improvement in Press Ganey scores posttelehealth implementation with overall doctor ranking improving from the 29th to the 93rd percentile, and likelihood to recommend increasing from the 24th to the 94th percentile.

Conclusions: There were clear trends with regard to which pathologies and procedures were most amenable to telehealth visits, which suggests a potential roadmap for future clinic planning. Additionally, the notable improvement in spine patient satisfaction following the implementation of a telehealth program suggests the need for long-term process changes.
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http://dx.doi.org/10.1016/j.wneu.2020.10.080DOI Listing
February 2021

Comparison of adverse events between cervical disc arthroplasty and anterior cervical discectomy and fusion: a 10-year follow-up.

Spine J 2021 02 17;21(2):253-264. Epub 2020 Oct 17.

Department of Orthopedic Surgery, SUNY Upstate Medical University, 750 E. Adams St, Syracuse, NY 13210 USA. Electronic address:

Background Context: Cervical disc arthroplasty (CDA) has been advocated as an alternative to anterior cervical discectomy and fusion (ACDF) with the added potential to reduce the risk of adjacent level disc degeneration and segmental instability. However, the long-term adverse events of arthroplasty have yet to be fully reported.

Purpose: To investigate the 10-year follow-up adverse events rates between CDA and ACDF.

Study Design/setting: The study was a randomized, prospective, multicenter Investigational Device Exemption (IDE) trial and its continued follow-up as a postapproval study (PAS). Single level surgeries were performed for cervical disc pathologies between May 2002 and October 2004.

Patient Sample: n=463 patients.

Outcome Measures: Adverse events comparison of CDA and ACDF from self-reported and physiologic measures.

Methods: At each evaluation time point, subjects were queried for adverse events since their last visit; and all adverse events were documented, regardless of whether or not they appeared related to the surgery or device. Adverse events were recorded, categorized, and assessed for severity and relationship to the study device and/or surgical procedure. The 10-year cumulative rates for each type of adverse events were summarized using a life-table method for the time-to-event analysis. A log-rank test was used to compare the two treatment groups.

Results: A total of 242 patients received CDA and 221 patients received ACDF. At 10-year follow-up, 54% (130/242) of CDA patients and 47% (104/221) of the ACDF subjects were evaluated. At up to 10-year follow-up, 231 patients in the CDA group (cumulative rate 98.4%) and 199 patients in the ACDF group (cumulative rate 98.7%) had at least one adverse event. Overall, the difference in the cumulative rate of all adverse events over 10 years was not statistically different (p=0.166). The cumulative rates of the following adverse events were not different between the two groups for cancer, cardiovascular, death, dysphonia/dysphagia, gastrointestinal, infection, urogenital, respiratory, implant displacement/loosening, implant malposition, neck and arm pain, neurological, other pain, spinal events, and intraoperative vascular injury. However, there were more adverse events in the CDA group resulting from trauma (p=.012) and more spinal events at the index level (p=.006). The ACDF group had significantly more nonunion events (p=.019), and nonunion outcome pending (p=.034), adjacent level spinal events (p=.033), and events that fell into the "other" category (p=.015).

Conclusions: The cumulative rates of patients who had any adverse events were not different between the artificial cervical disc and the anterior cervical arthrodesis groups. In addition, the cumulative rates were not different between the two groups for the majority of categories as well.
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http://dx.doi.org/10.1016/j.spinee.2020.10.013DOI Listing
February 2021

Ultrasound-Guided Needle Localization Wires in Peripheral Nerve Injuries With Long Segmental Defects: Technical Case Report.

Oper Neurosurg (Hagerstown) 2020 12;20(1):E60-E65

The Miami Project to Cure Paralysis, Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, Florida.

Background And Importance: In cases of severe nerve trauma with significant local soft tissue damage, identification and subsequent repair of nerve stumps can pose a technical challenge. Ultrasound (US) localization in peripheral nerve surgery has recently become popular. We present a case report illustrating the use of needle-wire localization systems to identify proximal and several distal branches of an injured femoral nerve with a large segmental defect in order to illustrate how such techniques can be used to make surgical repair more efficient, particularly with identifying the distal stump(s).

Clinical Presentation: We illustrate a case of a 16-yr-old female involved in a traumatic accident that lead to a severe injury of the femoral nerve and artery. The patient presented with a 7.3-cm defect between the proximal and distal aspect of the femoral nerve and its branches, respectively. High-resolution US was used to identify the proximal, large femoral nerve, and 3 distal stumps. By enlisting our musculoskeletal radiology team, we were able to trace distal branches of the femoral nerve and see their target muscles. Three separate US flexible needles were used to locate small muscular branches of the femoral nerve and 1 to locate the proximal stump. Intraoperatively, the localization wires allowed for safe and efficient dissection of proximal and distal nerve stumps in a significantly scarred and edematous plane.

Conclusion: US-guided needle-wire localization has shown promise in identifying the distal stumps and minimizing tissue dissection. Preoperative US guidance significantly aided in nerve repair for this severe injury without increasing morbidity.
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http://dx.doi.org/10.1093/ons/opaa297DOI Listing
December 2020

Early Changes to Neurosurgery Resident Training During the COVID-19 Pandemic at a Large U.S. Academic Medical Center.

World Neurosurg 2020 12 28;144:e926-e933. Epub 2020 Sep 28.

Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, Florida, USA.

Background: The coronavirus disease 2019 pandemic has led to sweeping changes in residency programs across the world, including cancellation of elective cases. The effects of safety measures on neurosurgical training remain unclear. To understand how neurosurgical residents have been affected, we analyzed the operative experience in the months leading up to and during the pandemic.

Methods: The resident and institutional case totals were tallied for a single residency program in Miami-Dade County from January 1, 2019 to June 30, 2020. A matched cohort analysis was performed before and during the pandemic to assess the effects on resident surgical training.

Results: The case totals for all levels of training were lower when restrictions were placed on elective surgeries. An average of 11 cases was logged in April 2020, a decrease from 26 cases in April 2019 (95% confidence interval, 8.7-22; P < 0.01). An average of 20 cases was logged in May 2020, a decrease from 25 cases in May 2019 (95% confidence interval, 1.2-8.8; P = 0.01). In April and May 2020, 299 (66%) and 148 (50%) fewer cases had been performed at our institution compared with April and May 2109.

Conclusions: Operative experience was reduced for residents during the months when the performance of elective cases was restricted. Our data suggest experience in some areas of neurosurgery were more affected than were others, and residents at different levels of training were also affected differently. However, the extent of the coronavirus disease 2019 pandemic on neurosurgical training is unlikely to be understood in the short term.
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http://dx.doi.org/10.1016/j.wneu.2020.09.125DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7521299PMC
December 2020

Telemedicine in Neurosurgery: Lessons Learned from a Systematic Review of the Literature for the COVID-19 Era and Beyond.

Neurosurgery 2020 12;88(1):E1-E12

University of Miami, Department of Neurosurgery, Miami, Florida.

Background: Evolving requirements for patient and physician safety and rapid regulatory changes have stimulated interest in neurosurgical telemedicine in the COVID-19 era.

Objective: To conduct a systematic literature review investigating treatment of neurosurgical patients via telemedicine, and to evaluate barriers and challenges. Additionally, we review recent regulatory changes that affect telemedicine in neurosurgery, and our institution's initial experience.

Methods: A systematic review was performed including all studies investigating success regarding treatment of neurosurgical patients via telemedicine. We reviewed our department's outpatient clinic billing records after telemedicine was implemented from 3/23/2020 to 4/6/2020 and reviewed modifier 95 inclusion to determine the number of face-to-face and telemedicine visits, as well as breakdown of weekly telemedicine clinic visits by subspecialty.

Results: A total of 52 studies (25 prospective and 27 retrospective) with 45 801 patients were analyzed. A total of 13 studies were conducted in the United States and 39 in foreign countries. Patient management was successful via telemedicine in 99.6% of cases. Telemedicine visits failed in 162 cases, 81.5% of which were due to technology failure, and 18.5% of which were due to patients requiring further face-to-face evaluation or treatment. A total of 16 studies compared telemedicine encounters to alternative patient encounter mediums; telemedicine was equivalent or superior in 15 studies. From 3/23/2020 to 4/6/2020, our department had 122 telemedicine visits (65.9%) and 63 face-to-face visits (34.1%). About 94.3% of telemedicine visits were billed using face-to-face procedural codes.

Conclusion: Neurosurgical telemedicine encounters appear promising in resource-scarce times, such as during global pandemics.
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http://dx.doi.org/10.1093/neuros/nyaa306DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7454774PMC
December 2020

Employment Status for the First Decade Following Randomization to Cervical Disc Arthroplasty Versus Fusion.

Spine (Phila Pa 1976) 2020 Oct;45(20):1411-1418

Department of Orthopedic Surgery, SUNY Upstate Medical University, Syracuse, NY.

Study Design: An analysis of employment status data up to 10 years following the Federal Drug Administration (FDA) Investigational Device Exemption (IDE) randomized trial and extension as post-approval study comparing BRYAN cervical disc (Medtronic, Minneapolis, MN) arthroplasty (CDA) versus single-level anterior cervical discectomy and fusion (ACDF) was performed.

Objective: Ten-year experience with the BRYAN disc arthroplasty trial provides opportunity to report patient employment data.

Summary Of Background Data: The long-term consequences of arthroplasty remain incomplete, including the occurrence of occupational compromise.

Methods: Patients' employment status were measured at regular intervals in both groups up to 10 years.

Results: The preoperative employment status proportion was comparable between investigational (BRYAN CDA) and control (ACDF) groups. In the investigational group, 49.2% returned to work at 6 weeks compared with 39.4% of the control group (P = 0.046). At 6 months and 2 years postoperatively, there was a similar likelihood of active employment in both groups. After 2 years at all time points, 10% drop-off seen in control group employment, but not in investigational group. At 10 years, 76.2% CDA patients were employed to 64.1% ACDF patients (P = 0.057). Preoperative variables influencing work status at 10 years following CDA included: preoperative work status, age, and SF-36 Mental Component Score (SF-36 MCS); whereas, no significant preoperative factor identified with ACDF. Time to return to work was influenced in both groups by preoperative work status; and in the ACDF group: reaching age 65 at 10-year visit, preoperative arm pain and NDI score had significant influences.

Conclusion: More patients returned to work at 6 weeks after CDA compared with ACDF, although there was no difference by 6 months. After 2 years, a nonsignificant trend toward higher employment rates in the arthroplasty group was evident, but this difference could not be validated due to the very high rate of loss of patients to the follow-up.

Level Of Evidence: 2.
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http://dx.doi.org/10.1097/BRS.0000000000003565DOI Listing
October 2020

Supraclavicular Resection of a Cervical Rib Causing Thoracic Outlet Syndrome: 2-Dimensional Operative Video.

Oper Neurosurg (Hagerstown) 2020 10;19(5):E520

Miami Project to Cure Paralysis, Department of Neurological Surgery, Miller School of Medicine, University of Miami, Miami, Florida.

Presence of a cervical rib results from overdevelopment of the seventh cervical vertebrae.1-3 The cervical rib along with scalene muscles can cause neurogenic thoracic outlet syndrome.4,5 Rib resection is typically done via anterior approach, using either supraclavicular or transaxillary route.6,7 We present an operative video detailing supraclavicular resection of a cervical rib causing neurogenic thoracic outlet syndrome with direct decompression of the lower trunk of the brachial plexus. The patient presented with severe symptoms including hand atrophy. We were able to directly visualize the rib and resect it, along with scalene musculature. We present 3-mo follow-up data noting clinical improvement in neuropathic symptoms.
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http://dx.doi.org/10.1093/ons/opaa139DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8133325PMC
October 2020

Commentary: A Porcine Model of Peripheral Nerve Injury Enabling Ultra-Long Regenerative Distances: Surgical Approach, Recovery Kinetics, and Clinical Relevance.

Neurosurgery 2020 09;87(4):E520-E521

Department of Neurological Surgery, University of Miami, Miami, Florida.

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http://dx.doi.org/10.1093/neuros/nyaa121DOI Listing
September 2020

Temperature Management in Neurological and Neurosurgical Intensive Care Unit.

Ther Hypothermia Temp Manag 2020 06 23;10(2):86-90. Epub 2020 Apr 23.

Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, Florida, USA.

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http://dx.doi.org/10.1089/ther.2020.29072.pjlDOI Listing
June 2020
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