Tej D Azad

Tej D Azad
Johns Hopkins Medicine | JHUSOM · Department of Neurosurgery

MD MS

About

176
Publications
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Publications

Publications (176)
Article
Background: Management of sporadic schwannomas is often dictated by a patient's clinical presentation and the tumor's behavior. For patients who are managed nonsurgically, there are little data available about the expected natural history. Objective: To evaluate the natural history and growth patterns of extracranial schwannomas including tumors...
Article
BACKGROUND CONTEXT Anterior lumbar interbody fusion (ALIF) is an effective procedure for spondylolisthesis and pseudarthrosis but is not without risks. Surgeons and patients would benefit from an easy to use shared decision-making tool that can accurately predict patients at risk for mortality after ALIF. PURPOSE We developed the ALFA score to pre...
Article
Full-text available
INTRODUCTION: Post-traumatic syringomyelia is an uncommon complication after traumatic spinal cord injury. This case study details our decision-making and surgical approach for a patient with symptomatic post-traumatic syringomyelia after sustaining a gunshot wound. CASE PRESENTATION: A 24-year-old man with past medical history of distant American...
Article
Background Research on the effects of substance use disorders (SUDs) on postoperative outcomes within neurosurgical oncology has been limited. Therefore, the present study sought to quantify the effect of having a SUD on hospital length of stay (LOS), postoperative complication incidence, discharge disposition, hospital charges, 90-day readmission...
Preprint
Lesions within the brain cavity pose critical challenges for diagnostics, particularly distinction between cancerous and non-cancerous lesions. We here introduce an analytic technique called Real-CSF to detect cancers of the central nervous system from evaluation of DNA in the cerebrospinal fluid (CSF). Short interspersed nuclear elements (SINEs) f...
Conference Paper
The ExcelsiusGPS (Globus Medical, Inc., Audubon, PA) robot received clearance from the United States Food and Drug Administration for clinical use in 2017 with the first in human use for lumbar spine instrumentation at Johns Hopkins Hospital the same year. The applications of the robot soon expanded with the first interbody cage placement in 2020 a...
Article
Objective While predictive analytic techniques have been used to analyze meningioma postoperative outcomes, to our knowledge, there have been no studies that have investigated the utility of machine learning (ML) models in prognosticating outcomes among skull base meningioma patients. The present study aimed to develop models for predicting postope...
Article
Full-text available
Diagnosis and longitudinal monitoring of neurological diseases are limited by the poor specificity and limited resolution of currently available techniques. Analysis of circulating cells in cerebrospinal fluid (CSF) has emerged as a promising strategy for the diagnosis, molecular characterization, and monitoring of neurological disease. In comparis...
Article
Objectives: The standard-of-care for postoperative care following elective craniotomy has historically been ICU admission. However, recent literature interrogating complications and interventions during this postoperative ICU stay suggests that all patients may not require this level of care. Thus, hospitals began implementing non-ICU postoperativ...
Article
Objective To summarize the clinical characteristics, histo-genomic profiles, management strategies, and survival outcomes of H3K27M-altered adult diffuse midline gliomas (aDMGs). Methods PubMed, Scopus, and Cochrane databases were used to identify relevant articles. Papers including H3K27M-altered aDMGs with sufficient clinical outcome data were i...
Article
Background Context Awake spine surgery is growing in popularity, and may facilitate earlier postoperative recovery, reduced cost, and fewer complications than spine surgery conducted under general anesthesia (GA). However, trends in adoption of awake (ie, non-GA) spine surgery have not been previously studied. Purpose To investigate temporal trend...
Article
Objective: Within the neurosurgical oncology literature, the effect of structural and socioeconomic factors on postoperative outcomes remains unclear. In this study, the authors quantified the effects of social determinant of health (SDOH) disparities on hospital complications, length of stay (LOS), nonroutine discharge, 90-day readmission, and 90...
Article
Heterogeneity is recognized as a major barrier in efforts to improve the care and outcomes of patients with traumatic brain injury (TBI). Even within the narrower stratum of moderate and severe TBI, current management approaches do not capture the complexity of this condition characterized by manifold clinical, anatomical, and pathophysiologic feat...
Article
Background: Interest in machine learning (ML)-based predictive modeling has led to the development of models predicting outcomes after aneurysmal subarachnoid hemorrhage (aSAH), including the Nijmegen acute subarachnoid hemorrhage calculator (Nutshell). Generalizability of such models to external data remains unclear. Objective: To externally va...
Chapter
The use of predictive models within neurosurgery is increasing and many models described in published journal articles are made available to readers in formats such as nomograms and online calculators. The present chapter details a step-by-step methodology with accompanying R code that may be used to implement models both in the form of traditional...
Chapter
The history of machine learning in neurosurgery spans three decades and continues to develop at a rapid pace. The earliest applications of machine learning within neurosurgery were first published in the 1990s as researchers began developing artificial neural networks to analyze structured datasets and supervised tasks. By the turn of the millenniu...
Chapter
A host of machine learning algorithms have been used to perform several different tasks in NLP and TSA. Prior to implementing these algorithms, some degree of data preprocessing is required. Deep learning approaches utilizing multilayer perceptrons, recurrent neural networks (RNNs), and convolutional neural networks (CNNs) represent commonly used t...
Article
Full-text available
Background: Intracranial deposits of fat droplets are an unusual presentation of a spinal dermoid cyst after spontaneous rupture and are even more uncommon after trauma. Here, the authors present a case with this rare clinical presentation, along with a systematic review of the literature to guide decision making in these patients. Observations:...
Article
Purpose There is a need to better understanding the prognostic factors that influence high-value care outcomes following meningioma surgery. The goal of this study was to develop predictive models to determine patients at risk for experiencing an extended hospital length of stay (LOS), non-routine discharge disposition, or a 90-day hospital readmis...
Article
BACKGROUND CONTEXT Existing literature demonstrates well-identified racial disparities in spine surgery outcomes. However, previous studies are of significant limitations. PURPOSE To investigate the association of race with 30-day perioperative complication rates of elective posterior spinal fusions (PSF) for adolescent idiopathic scoliosis (AIS)....
Article
Full-text available
Most circulating tumor DNA (ctDNA) assays are designed to detect recurrent mutations. Pediatric sarcomas share few recurrent mutations but rather are characterized by translocations and copy number changes. We applied CAncer Personalized Profiling by deep Sequencing (CAPP-Seq) for detection of translocations found in the most common pediatric sarco...
Presentation
Introduction Given the benign nature of extracranial schwannomas and the low rate of conversion to malignancy, management is often dictated by a patient's clinical presentation and the tumor's growth. For patients who are managed expectantly, there remains the question of what is the expected natural history of the lesion. This can help drive decis...
Article
Full-text available
Background Context Despite established guidelines, long-term management of surgically-treated low back pain (LBP) and lower extremity pain (LEP) remains heterogeneous. Understanding care heterogeneity could inform future approaches for standardization of practices. Purpose To describe treatment heterogeneity in surgically-managed LBP and LEP. Stu...
Article
Full-text available
Study design: Systematic review. Objectives: To review the existing literature of prediction models in degenerative spinal surgery. Methods: Review of PubMed/Medline and Embase databases was conducted to identify articles between January 1, 2000 and March 1, 2020 that reported prediction model performance for outcomes following elective degene...
Article
Objectives: To determine if a restrictive visitor policy inadvertently lengthened the decision-making process for dying inpatients without coronavirus disease 2019. Design: Regression discontinuity and time-to-event analysis. Setting: Two large academic hospitals in a unified health system. Patients or subjects: Adult decedents who received...
Article
Craniosynostosis (CS) is a congenital disease that arises due to premature ossification of single or multiple sutures, which results in skull deformities. The surgical management of single-suture CS continues to evolve and is driven by a robust body of clinical research; however, the molecular underpinnings of CS remain poorly understood. Despite l...
Article
Traumatic brain injury patients may be dependent on the decision-making of their families. Restrictive visitation policies implemented during the COVID-19 pandemic disproportionately affect these patients and their families. This narrative aims to illustrate this phenomenon and catalyze discussions regarding the need for careful evaluation of restr...
Article
Introduction: The recent COVID-19 pandemic has revealed important obstacles in our health care systems, including online specialist consultations. Amidst mass lockdowns and social distancing, we observed the importance of developing a consistent method of performing effective neurological examinations that yield accurate results in a time efficient...
Article
Objective To investigate the impact of race on 30-day postoperative complication rates of elective posterior spinal fusions (PSF) for adolescent idiopathic scoliosis (AIS). Methods Patients who underwent (PSF) between 2012-2018 were reviewed from the ACS-NSQIP pediatric database. Propensity score matching was utilized to evaluate whether race (i.e...
Article
OBJECTIVE The objective of this study was to evaluate the characteristics and performance of current prediction models in the fields of spine metastasis and degenerative spine disease to create a scoring system that allows direct comparison of the prediction models. METHODS A systematic search of PubMed and Embase was performed to identify relevan...
Article
As the use of machine learning algorithms in the development of clinical prediction models has increased, researchers are becoming more aware of the deleterious effects that stem from the lack of reporting standards. One of the most obvious consequences is the insufficient reproducibility found in current prediction models. In an attempt to charact...
Article
BACKGROUND CONTEXT Outpatient postoperative pain management in spine patients, specifically involving the use of opioids, demonstrates significant variability. PURPOSE Using preoperative risk factors and 30-day postoperative opioid prescribing patterns, we developed models for predicting long-term opioid use in patients after elective spine surger...
Article
Full-text available
Radiologic screening of high-risk adults reduces lung-cancer-related mortality1,2; however, a small minority of eligible individuals undergo such screening in the United States3,4. The availability of blood-based tests could increase screening uptake. Here we introduce improvements to cancer personalized profiling by deep sequencing (CAPP-Seq)⁵, a...
Article
Full-text available
Study Design Narrative review. Objectives Robotic systems in spinal surgery may offer potential benefits for both patients and surgeons. In this article, the authors explore the future prospects and current limitations of robotic systems in minimally invasive spine surgery. Methods We describe recent developments in robotic spine surgery and mini...
Article
Full-text available
Background: The setting of a randomized trial can determine whether its findings are generalizable and can therefore apply to different settings. The contribution of low- and middle-income countries (LMICs) to neurosurgical randomized trials has not been systematically described before. Objective: To perform a systematic analysis of design chara...
Article
Background: Pediatric pineoblastomas are highly aggressive tumors that portend poor outcomes despite multimodal management. Controversy remains regarding optimal disease management. Objective: To evaluate patterns of care and optimal clinical management of pediatric pineoblastoma. Methods: A total of 211 pediatric (age 0-17 yr) histologically...
Article
Background: Idiopathic intracranial hypertension results in increased intracranial pressure leading to headache and visual loss. This disease frequently requires surgical intervention through lumboperitoneal (LP) or ventriculoperitoneal (VP) shunting. Objective: To compare postoperative outcomes between LP and VP shunts, including failure and co...
Article
The optimal surgical management of gliomas requires a balance between surgical cytoreduction and preservation of neurological function. Preoperative functional neuroimaging, such as functional MRI (fMRI) and diffusion tensor imaging (DTI), has emerged as a possible tool to inform patient selection and surgical planning. However, evidence that preop...
Article
Objective: Rising patient demand for minimally invasive surgery and increased payer emphasis on quality-based payment schema have created a need for technologies that provide consistent, high-quality outcomes for patients undergoing spine surgery. Robotic assistance is one such technology. Here we report our early experience with a novel real-time...
Article
Background: Ventriculoperitoneal shunts are used to alleviate elevated intracranial pressure due to either hydrocephalus or idiopathic intracranial hypertension; however, shunt failure is a significant neurosurgical problem. Despite increases in intraoperative stereotactic navigation usage over the past decade, its effect on shunt survival remains...
Article
Full-text available
Diffuse midline glioma (DMG) is a highly malignant childhood tumor with an exceedingly poor prognosis and limited treatment options. The majority of these tumors harbor somatic mutations in genes encoding histone variants. These recurrent mutations correlate with treatment response and are forming the basis for molecularly guided clinical trials. T...
Article
Full-text available
Intramedullary spinal cord tumors (IMSCTs) are rare neoplasms that have limited treatment options and are associated with high rates of morbidity and mortality. To better understand the genetic basis of these tumors we performed whole exome sequencing on 45 tumors and matched germline DNA, including twenty-nine spinal cord ependymomas and sixteen a...
Article
Introduction: Randomized controlled trials (RCTs) have been critical in evaluating the safety and efficacy of functional neurosurgery interventions. Given this, we sought to systematically assess the quality of functional neurosurgery RCTs. Methods: We used a database of neurosurgical RCTs (trials published from 1961 to 2016) to identify studies...
Article
Full-text available
Study Design This was an epidemiological study using national administrative data from the MarketScan database. Objective To investigate the impact of early versus delayed adjuvant radiotherapy (RT) on wound healing following surgical resection for spinal metastatic disease. Methods We queried the MarketScan database (2007-2016), identifying pati...
Article
Background: The morbidity and mortality associated with opioid and benzodiazepine co-prescription is a pressing national concern. Little is known about patterns of opioid and benzodiazepine use in patients with acute low back pain or lower extremity pain. Objective: To characterize patterns of opioid and benzodiazepine prescribing among opioid-n...
Article
Background & aims: Biomarkers are needed to identify patients at risk of tumor progression following chemoradiotherapy for localized esophageal cancer. These could improve identification of patients at risk for cancer progression and selection of therapy. Methods: We performed deep sequencing (CAPP-Seq) analyses of plasma cell-free DNA collected...
Article
Robotic systems in surgery have developed rapidly. Installations of the da Vinci Surgical System® (Intuitive Surgical, Sunnyvale, CA, USA), widely used in urological and gynecological procedures, have nearly doubled in the United States from 2010 to 2017. Robotics systems in spine surgery have been adopted more slowly; however, users are enthusiast...
Poster
Introduction: Rising patient demand for minimally invasive surgery and increased payer emphasis on quality-based payment schema have created a need for technologies capable of providing consistent, high-quality outcomes for spine surgery patients. Robot-assistance is one such technology. Here we report our preliminary experience with a novel real-t...
Article
Background: Although the incidence of spinal fusions has increased significantly in the United States over the last quarter century, national trends of anterior lumbar interbody fusion (ALIF) utilization are not known. Purpose: The objective of this study was to characterize trends, clinical characteristics, risk factors associated with, and out...
Article
INTRODUCTION Intramedullary spinal cord tumors (IMSCTs) are a rare, heterogeneous group of neoplasms with limited treatment options and high rates of morbidity and mortality. Next-generation sequencing has revealed opportunities for targeted therapies of the intracranial counterparts of IMSCT, but little is known about the molecular features of IMS...
Article
INTRODUCTION Pediatric pineoblastomas are highly aggressive tumors that portend poor outcomes despite multimodal management. While treatment often utilizes a combination of surgical resection, radiotherapy, and chemotherapy, controversy remains regarding optimal disease management. METHODS A total of 211 pediatric (age 0-17 yr) histologically conf...
Article
INTRODUCTION The morbidity and mortality associated with opioid and benzodiazepine co-prescribing is a pressing national concern. The aim of this work was to characterize patterns of opioid and benzodiazepine prescribing among opioid-naïve, newly-diagnosed low back and lower extremity pain patients and to investigate the relationship between benzod...
Article
INTRODUCTION Low back pain (LBP) may affect up to 20% of the pediatric population. No specific guidelines exist regarding pharmacotherapy for acute LBP in the pediatric population. Given this observation and the lack of data available regarding pharmacotherapy for pediatric LBP, we sought to characterize patterns of opioid prescribing in the pediat...
Article
Study design: This was a retrospective study using national administrative data from the MarketScan database. Objective: To investigate the complication rates, quality outcomes, and costs in a nationwide cohort of patients with movement disorders (MD) who undergo spinal deformity surgery. Summary of background data: Patients with MD often pres...
Article
Background: The landmark Patchell trial established surgical decompression followed by adjuvant radiotherapy as standard-of-care for patients with spinal cord compression caused by metastatic cancer. However, little comparative evidence exists with regard to the choice of specific surgical approaches for these patients. We sought to conduct a comp...
Article
Background: Spinal arteriovenous malformations (AVM) are an abnormal interconnection of vasculature in the spine than can lead to significant neurologic deficit if left untreated. Objective: The objective of this study was to characterize how patients with spinal AVM initially presented, what treatment options were used, and their overall outcom...
Article
Full-text available
Background: Rates of adverse events following spine surgery vary widely by patient-, diagnosis-, and procedure-related factors. It is critical to understand the expected rates of complications and to be able to implement targeted efforts at limiting these events. Purpose: To develop and evaluate a set of predictive models for common adverse even...
Article
Full-text available
Importance Low back pain (LBP) with or without lower extremity pain (LEP) is one of the most common reasons for seeking medical care. Previous studies investigating costs in this population targeted patients receiving surgery. Little is known about health care utilization among patients who do not undergo surgery. Objectives To assess use of healt...
Article
Primary spinal tumors are rare lesions that require careful clinical management due to their intimate relationship with critical neurovascular structures and the significant associated risk of morbidity. While the advent of molecular and genomic profiling is beginning to impact the management of the cranial counterparts, translation for spinal tumo...
Article
Full-text available
Circulating tumor DNA (ctDNA) is a component of cell-free DNA that is shed by malignant tumors into the bloodstream and other bodily fluids. Levels of ctDNA are typically low, particularly in patients with localized disease, requiring highly sophisticated methods for detection and quantification. Multiple liquid biopsy methods have been developed f...
Article
Background: There is a lack of literature guiding treatment of giant cell glioblastoma (gcGBM), a rare subtype of glioblastoma (GBM). We used a national hospital-based registry to explore treatment patterns and outcomes associated with gcGBM. Methods: Adult patients (age ≥18 years) diagnosed with gcGBM or GBM between 2004 and 2014 were identifie...
Article
Background: Traditional moyamoya disease (MMD) classification relies on morphological digital subtraction angiography (DSA) assessment, which do not reflect hemodynamic status, clinical symptoms, or surgical treatment outcome. Objective: To (1) validate the new Berlin MMD preoperative symptomatology grading system and (2) determine the clinical...
Article
Full-text available
Recent advances in stem cell biology present significant opportunities to advance clinical applications of stem cell–based therapies for spinal cord injury (SCI). In this review, the authors critically analyze the basic science and translational evidence that supports the use of various stem cell sources, including induced pluripotent stem cells, o...
Article
Odontoid fractures are the most common cervical spine fracture in the elderly. There is considerable controversy regarding the optimal management of type II odontoid fractures in this population. We present the case of an 89-year-old woman presented with neck pain after a mechanical fall. She was neurologically intact. Computed tomography (CT) of t...
Article
Full-text available
Glioblastoma multiforme (GBM) is a highly aggressive malignant brain tumor with fatal outcome. Tumor-associated macrophages and microglia (TAMs) have been found to be major tumor-promoting immune cells in the tumor microenvironment. Hence, modulation and reeducation of tumor-associated macrophages and microglia in GBM is considered a promising anti...
Article
OBJECTIVE Revascularization surgery is a safe and effective surgical treatment for symptomatic moyamoya disease (MMD) and has been shown to reduce the frequency of future ischemic events and improve quality of life in affected patients. The authors sought to investigate the occurrence of acute perioperative occlusion of the contralateral internal c...
Article
Full-text available
In silico quantification of cell proportions from mixed-cell transcriptomics data (deconvolution) requires a reference expression matrix, called basis matrix. We hypothesize that matrices created using only healthy samples from a single microarray platform would introduce biological and technical biases in deconvolution. We show presence of such bi...