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38 citation(s) found for "Rahul, Kumar".

Evaluating longitudinal changes of gait parameters following shunt placement in patients with idiopathic normal pressure hydrocephalus
Pennington, Zach , Potes, Maria Astudillo , Hallak, Hana , Rezaei, Asghar , Jusué-Torres, Ignacio , Graff-Radford, Jonathan, Cutsforth‐Gregory, Jeremy K. , Ali, Farwa, Elder, Benjamin D. , Pennington, Zach , Jusue-Torres, Ignacio , Kumar, Rahul , Hamouda, Abdelrahman M. , Shafi, Mahnoor , Bhat, Sandesh G. , Graff‐Radford, Jonathan , Jones, David , Botha, Hugo , Ali, Farwa , Cogswell, Petrice M. , Kaufman, Kenton R.

Journal of Neurosurgery | June 27, 2025 | Volume: 143 | Issue: 5 | Pages: 1254-1261

10.3171/2025.3.jns241416 | PMID 40513237 Get It

OBJECTIVE Idiopathic normal pressure hydrocephalus (iNPH) is characterized by gait deterioration, cognitive disturbances, and urinary incontinence. Gait deficits pose safety hazards due to frequent falls, yet objective investigations of gait improvement following ventriculoperitoneal shunt (VPS) placement are limited. Therefore, the aim of this study was to assess objective improvement in gait parameters for patients with iNPH after VPS placement. METHODS All patients treated with a VPS for iNPH by the senior author at a single tertiary care center from December 2017 to January 2023 were retrospectively reviewed. Patients who underwent detailed motion analysis testing before surgery with > 1 follow-up assessment were included. Analyzed parameters included gait velocity, gait cadence, stride length, stride width, gait stability ratio, total support, and single support. Time-dependent linear mixed-effects models and generalized additive mixed-effects models (GAMMs) were used to model short-term and longitudinal gait parameter changes, respectively. RESULTS A total of 212 patients (137 male, median age was 75.2 years) who underwent VPS placement for iNPH were included, with a total of 747 gait analyses performed at a median last-gait analysis follow-up duration of 12.0 months. Statistically significant changes in all gait parameter values were seen between the preoperative time point and first postoperative follow-up (within 3 months) time point (paired Wilcoxon p < 0.001), with a statistically significant majority of patients experiencing improvement (binominal p < 0.0001). Longitudinal analyses using a GAMM showed increased gait velocity, single support, and stride length, with decreased stability ratio, step width, and total support at early time points, while a plateau was achieved around 6 months. CONCLUSIONS A detailed gait analysis demonstrated significant improvements in objective ambulation metrics, particularly in the gait velocity, stride length, and gait stability ratio, following VPS placement in patients with iNPH. Most patients maintained marked improvement from baseline to the last follow-up assessment, although a plateau of the benefit was experienced over longer follow-up.
Single-Fraction Stereotactic Radiosurgery as Primary Management of Sporadic Meningiomas: A 25-Year Cohort Study
Kumar, Rahul , Carlstrom, Lucas P. , Morshed, Ramin A. , Brown, Paul D. , Mahajan, Anita , Graffeo, Christopher S. , Link, Michael J. , Pollock, Bruce E. , Morshed, Ramin , Graffeo, Christopher Salvatore , Kumar, Rahul , Laack, Nadia N.

Neurosurgery | June 6, 2025 | Volume: 97 | Issue: 6 | Pages: 1267-1274

10.1227/neu.0000000000003528 | PMID 40476726 Get It

BACKGROUND AND OBJECTIVES: Stereotactic radiosurgery (SRS) is increasingly used as a primary treatment modality for intracranial meningiomas. We aim to describe clinical outcomes after single-fraction SRS for sporadic intracranial meningiomas. METHODS: A prospectively maintained database was reviewed for patients with sporadic meningiomas who underwent SRS (Gamma Knife) as primary treatment modality from April 1997 to February 2022. Primary outcomes included progression-free survival (PFS) and treatment-related complications. RESULTS: Six hundred sixteen patients (653 tumors) underwent SRS with median follow-up of 6.3 years (interquartile range [IQR] 3.1-10.5 years). The median tumor volume was 4.5 cm 3 (IQR 2.0-8.0 cm 3 ). The median margin dose was 15.0 Gy (IQR 14.0-16.0). In-field progression was noted in 7 tumors (1.1%) and marginal progression in 2 tumors (0.3%) for a raw failure rate of 1.4%. PFS estimates at 5, 10, and 15 years were 99.8%, 99.0%, and 93.2%, respectively. Factors associated with reduced PFS on univariable analysis included older age (hazards ratio [HR] 1.14, 95% CI, 1.05-1.22, P < .001), male sex (HR 5.44, 95% CI, 1.45-20.4, P = .010), increasing tumor volume (HR 1.06, 95% CI, 0.99-1.13, P = .028), and lower tumor margin dose (HR 0.65, 95% CI, 0.43-0.97, P = .006). Treatment-related complications were noted in 56 patients (9.1%), of which 45 (7.3%) were temporary, 5 (0.8%) were minor, and 6 (1.0%) were permanent and/or required intervention. Radiosurgical parameters associated with treatment-related complications included increased number of isocenters (odds ratio [OR] 1.09, 95% CI, 1.04-1.14, P < .001), higher 12-Gy volume (OR 1.06, 95% CI, 1.03-1.09, P < .001), larger tumor volume (OR 1.06, 95% CI, 1.02-1.10, P < .001), and lower maximal dose (OR 0.90, 95% CI, 0.82-0.98, P = .11). CONCLUSION: SRS is effective as a primary treatment modality for sporadic, small-volume to medium-volume intracranial meningiomas. Pre-emptive SRS should be discussed as a safe management strategy compared with observation alone for incidentally discovered meningiomas.
A survival analysis for predictors of implant subsidence following 1- or 2-level transforaminal lumbar interbody fusion
Pennington, Zach , Mikula, Anthony L. , Potes, Maria Astudillo , Bydon, Mohamad , Krauss, William E. , Freedman, Brett A. , Sebastian, Arjun S. , Fogelson, Jeremy L. , Elder, Benjamin D. , Pennington, Zach , Kumar, Rahul , Hamouda, Abdelrahman M. , Martini, Michael L. , Clarke, Michelle J. , Nassr, Ahmad , Freedman, Brett A.

Journal of Neurosurgery: Spine | May 9, 2025 | Volume: 43 | Issue: 1 | Pages: 42-51

10.3171/2025.1.spine24923 | PMID 40344766 Get It

OBJECTIVE Transforaminal lumbar interbody fusion (TLIF) offers both indirect decompression and segmental correction through restoration of disc height. However, stresses exerted on the vertebral endplates by the interbody device can result in implant subsidence and loss of correction. The present time-to-event analysis aimed to identify predictors of interbody subsidence. METHODS Patients who underwent 1- or 2-level TLIF were identified. Data on demographics, surgical details, preoperative bone quality using CT-based Hounsfield units (HU), and pre- and postoperative lumbopelvic parameters were collected. Univariable analyses were conducted to identify predictors of subsidence (≥ 2-mm intrusion of interbody into cranial or caudal vertebrae) and significant subsidence (≥ 4-mm intrusion). Multivariable Cox regression was performed to identify independent predictors of subsidence, expressed as hazard ratios with 95% confidence intervals. RESULTS A total of 198 patients treated at 241 levels were included (median age 66.6 years, IQR 59.5, 73.7 years; 56.6% were women). In 92 levels (38.2%) there was some subsidence and in 25 (10.4%) there was significant subsidence. Implanted levels demonstrating subsidence (≥ 2 mm) were associated with lower HU in cranial and caudal vertebrae; had interbodies positioned farther from the anterior apophyseal ring; were implanted with taller, more lordotic interbodies; and underwent greater disc height restoration. Those showing significant subsidence (≥ 4 mm) were similarly associated with lower HU in the cranial and caudal vertebrae; had interbodies positioned farther from the anterior apophyseal ring of the caudal vertebrae; and underwent greater disc height restoration. Multivariable Cox regression showed that time to subsidence was predicted by greater implant height (HR 1.20/mm, 95% CI 1.05–1.38; p = 0.009), greater postoperative disc height (HR 1.21/mm, 95% CI 1.09–1.34; p < 0.001), and greater disc height restoration (HR 1.11/mm, 95% CI 1.04–1.19; p = 0.002). The time-to-subsidence analysis for significant (≥ 4 mm) subsidence showed that it was predicted by lower HU in the cranial vertebrae (HR 0.98/unit, 95% CI 0.97–0.99; p = 0.001); increasing number of levels instrumented (HR 1.26, 95% CI 1.04–1.52; p = 0.016); and greater disc height restoration (HR 1.33/mm, 95% CI 1.18–1.51; p < 0.001). CONCLUSIONS This time-to-event analysis suggests that interbody subsidence following TLIF is best predicted by implantation of a taller interbody and aggressive disc height restoration. Significant subsidence is similarly predicted by aggressive disc height restoration along with poor baseline bone quality. The results suggest the need to balance aggressive correction at the time of surgery against the increased risk of subsequent interbody subsidence.
Impact of Frailty and Other Factors as Estimated by HU to Predict Response to Anabolic Bone Medications
Hamouda, Abdelrahman M. , Pennington, Zach , Kumar, Rahul , Obiri‐Yeboah, Derrick, Potes, Maria Astudillo , Kendall, Nicholas , Mikula, Anthony L. , Clarke, Michelle J. , Krauss, William E. , Freedman, Brett A. , Sebastian, Arjun S. , Helgeson, Melvin D. , Kennel, Kurt A. , Fogelson, Jeremy L. , Elder, Benjamin D. , Astudillo Potes, Maria , Clarke, Michelle J , Helgeson, Melvin D , Kennel, Kurt A , Pennington, Zach , Hamouda, Abdelrahman , Kumar, Rahul , Martini, Michael L. , Nassr, Ahmad

Journal of Clinical Medicine | May 7, 2025 | Volume: 14 | Issue: 9 | Pages: 3247

10.3390/jcm14093247 | PMID 40364278 Get It

Introduction: Bone health optimization is a key component of the preoperative management of spine surgery patients, as poor bone quality increases the odds of mechanical complications. The present study aimed to achieve the following: (1) compare the relative efficacy of current osteoporosis medications in improving bone quality; (2) identify factors influencing treatment response in preoperative spine surgery patients. Methods: Patients treated at a single, multisite institution who received osteoporosis treatment were identified. Data were gathered on pre- and post-treatment lumbar spine Hounsfield Unit (HU) measurements, patient demographics, frailty scores (modified Frailty Index/mFI, risk analysis index/RAI), and pharmacologic treatment details. The primary outcome was a ≥7 point improvement in lumbar HU, and baseline and logistic regression models were utilized to identify factors associated with this improvement. Medications were grouped as anabolic (teriparatide, romosozumab) and antiresorptive (denosumab, alendronate) therapies. Results: A total of 267 patients were included (median age: 74 years; IQR [66–81]; 67.3% female), with 127 (47.6%) improving by ≥7 HU. The treatment agents used were alendronate (95), denosumab (113), romosozumab (31), and teriparatide (28). Univariable comparisons revealed significant differences across medication groups in age (p < 0.001), sex (p < 0.001), mFI (p < 0.001), RAI (p = 0.004), BMI (p < 0.001), pre-treatment HU (p = 0.022), and treatment duration (p < 0.001). The highest HU improvement rates (ΔHU ≥ 7) were observed in patients receiving the anabolic medications romosozumab (67.7%) and teriparatide (60.7%). Univariable logistic regression identified male sex (OR 0.54, p = 0.019), higher pre-treatment HU (OR 0.99, p = 0.006), and longer treatment duration (OR 0.97, p = 0.003) as factors associated with lower odds of HU improvement. Only romosozumab was associated with significantly higher odds of HU improvement relative to alendronate (OR 3.02, p = 0.012). In our multivariable analysis, male sex (OR 0.53, p = 0.028) and higher pre-treatment HU (OR 0.99, p = 0.002) remained significant predictors of HU improvement. However, medication type was not significant in the multivariable analysis. Conclusions: Our study highlights that male sex and higher pre-treatment HU were independently associated with lower odds of HU improvement, while medication type was not a significant predictor. Additionally, anabolic agents offered superior improvement relative to antiresorptive therapies.
Comparison of Sagittal Plane Correction With “Bullet” Versus “Banana” Type Transforaminal Lumbar Interbody Fusion Devices
Pennington, Zach , Hamouda, Abdelrahman M. , Martini, Michael L. , Kumar, Rahul , Mikula, Anthony L. , Potes, Maria Astudillo , Bydon, Mohamad , Clarke, Michelle J. , Krauss, William E. , Nassr, Ahmad , Freedman, Brett A. , Sebastian, Arjun S. , Fogelson, Jeremy L. , Elder, Benjamin D. , Hamouda, Abdelrahman , Martini, Michael , Pennington, Zach , Nassr, Ahmad N , Clarke, Michelle J , Kumar, Rahul , Freedman, Brett A.

Operative Neurosurgery | February 20, 2025 | Volume: 29 | Issue: 5 | Pages: 624-632

10.1227/ons.0000000000001518 | PMID 39976442 Get It

BACKGROUND AND OBJECTIVES: Transforaminal lumbar interbody fusion (TLIF) allows for direct and indirect decompression and segmental lordosis in sagittal plane correction. This study compares the effectiveness of “Bullet” type and “Banana” type devices for sagittal plane correction. METHODS: Patients who underwent 1-level or 2-level TLIF for degenerative pathology at a single tertiary care center were identified. Details were extracted on demographics, interbody dimensions, and preoperative and postoperative lumbopelvic parameters from upright radiographs. Cages were categorized as “Bullet” or “Banana” type based on morphology and manufacturer description of optimal position. Univariable comparisons between levels treated with “Bullet” and “Banana” type interbodies were performed. Multivariable linear regression was performed to identify independent predictors of postoperative segmental lordosis and change in segmental lordosis. RESULTS: One hundred and ninety eight unique patients (median 66.6 years; [IQR 59.5, 73.7]; 56.6% female) were included with 241 levels treated, of which 114 (52.7%) were treated with “Banana” type interbodies and 127 (47.3%) with “Bullet” type. “Banana” type interbodies afforded both greater postoperative segmental lordosis (8.1 [6.2, 10.7] vs 7.5 [5.2, 9.6]; P = .048) and greater increase in segmental lordosis (3.3 [0.7, 7.0] vs 2.3 [0.1, 4.2]; P = .015). On multivariable linear regression, only preoperative segmental lordosis (β = 0.322 per degree; [0.244, 0.399]; P < .001), implant listed lordosis (β = 0.146 per degree; 95% CI [0.048, 0.244]; P = .004), preoperative pelvic incidence (0.072 per degree; [0.034, 0.111]; P < .001), and use of bilateral TLIF windows (β = 3.133; [1.213, 5.053]; P = .001) were predictive of postoperative segmental lordosis. CONCLUSION: The present analysis suggests that baseline lumbopelvic anatomy, interbody lordosis, and the use of bilateral TLIF windows are the most important predictors of postoperative segmental lordosis. Use of “Banana” vs “Bullet” type interbodies was not predictive of segmental lordosis achieved on immediate postoperative upright radiographs. Further work is merited to determine whether the 2 interbody types demonstrate differences regarding subsidence risk or maintenance of correction.
Comparison of Two Surgical Approaches and Outcomes for Petroclival Meningiomas: A Single-Surgeon Series of Consecutive Cases
Cohen-Cohen, Salomón , Link, Michael J., Kumar, Rahul

Journal of Neurological Surgery Part B: Skull Base | February 7, 2025 | Volume: 86 | Issue: No issue available | Pages: No page available

10.1055/s-0045-1803226 Get It

Long-Term Outcomes and Complication Prediction after Stereotactic Radiosurgery for Previously Untreated Meningiomas
Brown, Paul D. , Graffeo, Christopher S. , Link, Michael J. , Pollock, Bruce E. , Kumar, Rahul , Carlstrom, Lucas P. , Morshed, Ramin A.

Journal of Neurological Surgery Part B: Skull Base | February 7, 2025 | Volume: 86 | Issue: No issue available | Pages: No page available

10.1055/s-0045-1803210 Get It

A Narrative Review of Prognostic Gene Signatures in Oral Squamous Cell Carcinoma Using LASSO Cox Regression
Faizal, Nur Fatinazwa Mohd, Shai, Saptarsi , Savaliya, Bansi, Karen‐Ng, Lee Peng , Kumari, Rupa, Kumar, Rahul , Vincent–Chong, Vui King , Mohd Faizal, Nur Fatinazwa , Savaliya, Bansi P, Kumari, Rupa

Biomedicines | January 8, 2025 | Volume: 13 | Issue: 1 | Pages: 134

10.3390/biomedicines13010134 | PMID 39857718 Get It

Oral squamous cell carcinoma (OSCC) is one of the most common malignancies of the head and neck squamous cell carcinoma (HNSCC). HNSCC is recognized as the eighth most commonly occurring cancer globally in men. It is essential to distinguish between cancers arising in the head and neck regions due to significant differences in their etiologies, treatment approaches, and prognoses. As the Cancer Genome Atlas (TCGA) dataset is available in HNSCC, the survival analysis prognosis of OSCC patients based on the TCGA dataset for discovering gene expression-based prognostic biomarkers is limited. To address this paucity, we aimed to provide comprehensive evidence by recruiting studies that have reported new biomarkers/signatures to establish a prognostic model to predict the survival of OSCC patients. Using PubMed search, we have identified 34 studies that have been using the least absolute shrinkage and selection operator (LASSO)-based Cox regression analyses to establish signature prognosis that related to different pathways in OSCC from the past 4 years. Our review was focused on summarizing these signatures and implications for targeted therapy using FDA-approved drugs. Furthermore, we conducted an analysis of the LASSO Cox regression gene signatures. Our findings revealed 13 studies that correlated a greater number of regulatory T cells (Tregs) cells in protective gene signatures with increased recurrence-free and overall survival rates. Conversely, two studies displayed an opposing trend in cases of OSCC. We will also explore how the dysregulation of these signatures impacts immune status, promoting tumor immune evasion or, conversely, enhancing immune surveillance. Overall, this review will provide new insight for future anti-cancer therapies based on the potential gene that is associated with poor prognosis in OSCC.
A hitchhiker’s guide to cerebrospinal fluid biomarkers for neuro-oncology
Riviere-Cazaux, Cécile , Keough, Michael B. , Schulz, Sebastian C, Warrington, Arthur E. , Ruff, Michael W. , Sanai, Nader , Campian, Jian , Kizilbash, Sani H. , Zadeh, Gelareh , Khasraw, Mustafa , Kessler, Tobias , Cahill, Daniel P. , Mansouri, Alireza , Kizilbash, Sani H , Zuccato, Jeffrey , Kumar, Rahul Robaish , Schulz, Sebastian C, Ellingson, Benjamin M. , Parney, Ian F. , Khasraw, Mustafa , Sener, Uğur , Mansouri, Alireza , Burns, Terry C.

Neuro-Oncology | December 27, 2024 | Volume: 27 | Issue: 5 | Pages: 1165-1179

10.1093/neuonc/noae276 | PMID 39786477 Get It

Abstract Cerebrospinal fluid (CSF) has emerged as a valuable liquid biopsy source for glioma biomarker discovery and validation. CSF produced within the ventricles circulates through the subarachnoid space, where the composition of glioma-derived analytes is influenced by the proximity and anatomical location of sampling relative to tumor, in addition to underlying tumor biology. The substantial gradients observed between lumbar and intracranial CSF compartments for tumor-derived analytes underscore the importance of sampling site selection. Moreover, radiographic features, such as tumor-CSF contact and blood-brain barrier disruption, are critical covariates that may affect biomarker detection and the abundance of plasma-derived analytes in CSF, respectively. Longitudinal intracranial CSF sampling, enabled by access devices like Ommaya reservoirs, may offer a window into treatment response and disease progression, though variability in analyte yield, sample volumes, and the dynamic effects of surgical resection pose challenges. This review critically evaluates the anatomic, radiographic, and longitudinal factors, or “time-space continuum,” that impact glioma CSF biomarker abundance. Practical considerations for longitudinal CSF biobanking, including access device placement and collection, are also reviewed. Key takeaways and recommendations for CSF glioma biomarker discovery and validation are provided as a “hitchhiker’s guide” based on our collective experience, along with resources for investigators aiming to develop CSF biobanking at their institutions.
Longitudinal Glioma Monitoring via Cerebrospinal Fluid Cell-Free DNA
Riviere-Cazaux, Cécile , Dong, Xiaoxi , Mo, Wei , Kumar, Rahul , Dai, Chao , Carlstrom, Lucas P. , Munoz-Casabella, Amanda , Nesvick, Cody L. , Andersen, Katherine M., Hoplin, Matthew D. , Canaday, Nicholas, Jusué-Torres, Ignacio , Malik, Noor , Campian, Jian L., Ruff, Michael W. , Uhm, Joon H. , Eckel‐Passow, Jeanette E. , Kizilbash, Sani H. , Warrington, Arthur E. , Jenkins, Robert B. , Du, Pan , Jia, Shidong , Ghadimi, Keyvan , Nesvick, Cody L , Andersen, Katherine M , Hoplin, Matthew D , Canaday, Nicholas , Jusue-Torres, Ignacio , Malik, Noor , Campian, Jian L , Ruff, Michael W , Uhm, Joon H , Eckel-Passow, Jeanette E , Kaufmann, Timothy J , Routman, David M , Kizilbash, Sani H , Sener, Ugur , Warrington, Arthur E , Jenkins, RB , Du, Pan , Jia, Shidong , Burns, Terry C , Kumar, Rahul , Kaufmann, Timothy J. , Routman, David M. , Sener, Uğur , Burns, Terry C.

Clinical Cancer Research | December 23, 2024 | Volume: 31 | Issue: 5 | Pages: 881-889

10.1158/1078-0432.ccr-24-1814 | PMID 39715486 Get It

Abstract Purpose: Current methods for glioma response assessment are limited. This study aimed to assess the technical and clinical feasibility of molecular profiling using longitudinal intracranial cerebrospinal fluid (CSF) from patients with gliomas. Experimental Design: Adults with gliomas underwent longitudinal intracranial CSF collection via Ommaya reservoirs or ventriculoperitoneal shunts. Cell-free DNA (cfDNA) was extracted and analyzed using PredicineCARE for cancer variant profiling and/or PredicineSCORE for low-pass whole-genome sequencing. Results: Five patients (two females and three males; median age, 40 years; range, 32–64 years) underwent longitudinal intracranial CSF collection via Ommaya reservoirs (n = 4) or ventriculoperitoneal shunts (n = 1). In total, 47 CSF samples were obtained (median volume, 4.00 mL; 0.5–5 mL). Forty-one samples (87.2%) yielded sufficient cfDNA for testing. Patient-specific tumor-associated variant allelic frequencies (VAF), and thus tumor fraction, decreased in pre- versus postchemoradiation samples, including through pseudoprogression. These also increased with radiographic progression in three patients, although identifying the time of definitive disease progression from MRIs was a significant limitation. In two patients with isocitrate dehydrogenase (IDH)–mutant gliomas, decreasing IDH1 VAF after resection and chemoradiation correlated with decreased CSF D-2-hydroxyglutarate levels (0.64× and 0.62×, respectively, for the first patient and 0.01× and 0.07× for the other patient), although D-2-hydroxyglutarate and IDH1 VAF were not concordant in one patient thereafter. Moreover, the copy-number burden decreased below the limit of quantification during treatment and increased above the limit at progression. Conclusions: Longitudinal intracranial CSF cfDNA can be obtained in patients with gliomas during their disease course. However, before deploying this technique, numerous questions and challenges should be answered.