Noojan Kazemi | University of Michigan (original) (raw)

Papers by Noojan Kazemi

Alzheimers & Dementia, Jul 1, 2008

World Neurosurgery, Jul 1, 2016

Contributorship Statement BAL and JKH were involved in the design and conception of this manuscri... more Contributorship Statement BAL and JKH were involved in the design and conception of this manuscript. AVP, NA, and DL performed the literature search. BAL, VC, and AVP compiled the primary manuscript. AVP compiled the figures. NA and MT critically revised the manuscript. All authors have approved the manuscript as it is written. Data Sharing All data pertaining to this research article are included within the manuscript as written. Disclaimer: The American College of Surgeons National Surgical Quality Improvement Program and the hospitals participating in the ACS NSQIP are the source of the data used herein; they have not verified and are not responsible for the statistical validity of the data analysis or the conclusions derived by the authors.

Neurology, Dec 28, 2009

Objective: Although subtraction ictal SPECT coregistered to MRI (SISCOM) is clinically useful in ... more Objective: Although subtraction ictal SPECT coregistered to MRI (SISCOM) is clinically useful in epilepsy surgery evaluation, it does not determine whether the ictal-interictal subtraction difference is statistically different from the expected random variation between 2 SPECT studies. We developed a statistical parametric mapping and MRI voxel-based method of analyzing ictalinterictal SPECT difference data (statistical ictal SPECT coregistered to MRI [STATISCOM]) and compared it with SISCOM. Methods: Two serial SPECT studies were performed in 11 healthy volunteers without epilepsy (control subjects) to measure random variation between serial studies from individuals. STATISCOM and SISCOM images from 87 consecutive patients who had ictal SPECT studies and subsequent temporal lobectomy were assessed by reviewers blinded to clinical data and outcome. Results: Interobserver agreement between blinded reviewers was higher for STATISCOM images than for SISCOM images (ϭ 0.81 vs ϭ 0.36). STATISCOM identified a hyperperfusion focus in 84% of patients, SISCOM in 66% (p Ͻ 0.05). STATISCOM correctly localized the temporal lobe epilepsy (TLE) subtypes (mesial vs lateral neocortical) in 68% of patients compared with 24% by SISCOM (p ϭ 0.02); subgroup analysis of patients without lesions (as determined by MRI) showed superiority of STATISCOM (80% vs 47%; p ϭ 0.04). Moreover, the probability of seizure-free outcome was higher when STATISCOM correctly localized the TLE subtype than when it was indeterminate (81% vs 53%; p ϭ 0.03). Conclusion: Statistical ictal SPECT coregistered to MRI (STATISCOM) was superior to subtraction ictal SPECT coregistered to MRI for seizure localization before temporal lobe epilepsy (TLE) surgery. STATISCOM localization to the correct TLE subtype was prognostically important for postsurgical seizure freedom. Neurology ® 2010;74:70-76 GLOSSARY CI ϭ confidence interval; ECD ϭ ethyl cysteinate dimer; HMPAO ϭ hexamethyl propylene-amine-oxime; SISCOM ϭ subtraction ictal SPECT coregistered to MRI; SPM ϭ statistical parametric mapping; STATISCOM ϭ statistical ictal SPECT coregistered to MRI; TLE ϭ temporal lobe epilepsy. Early methods of ictal SPECT interpretation relied on a visual comparison of ictal and interictal SPECT images to detect focal hyperperfusion changes (these represented potential sites of ictal hyperperfusion). 1 SPECT imaging subsequently was improved by subtraction ictal SPECT with coregistration on MRI (SISCOM). 2-5 With SISCOM, ictal SPECT data are subtracted from interictal SPECT data, 6,7 and the "difference image," which shows the focus of altered perfusion, is coregistered with the patient's MRI for anatomic correlation. A recent study that compared several functional imaging modalities showed that positive SISCOM has the greatest association with seizure-free outcome after focal epilepsy surgery. 8 Despite the validation of its clinical usefulness, SISCOM detection of abnormal perfusion is based a priori on a defined threshold of perfusion changes, and it does not account for the expected variability in voxel intensities between 2 serial images from an individual. To account for this random variation between images, our group developed a method that used statistical

Archives of neurology, Oct 1, 2008

Background: Reinitiating warfarin sodium therapy in a patient with a recent warfarin-related intr... more Background: Reinitiating warfarin sodium therapy in a patient with a recent warfarin-related intracerebral hemorrhage (WAICH) is a difficult clinical decision. Therefore, it is important to assess the outcome of resumption or discontinuation of warfarin therapy after WAICH. Objective: To compare patients who survived an episode of WAICH and restarted warfarin therapy with a group of WAICH patients who did not resume warfarin therapy. Design, Setting, and Patients: We conducted a follow-up study from November 1, 2001, through December 31, 2005, in a cohort from a single center. Longterm outcome was assessed at last clinical follow-up or via questionnaire. Main Outcome Measures: Recurrent WAICH and thromboembolic events. Results: Fifty-two patients were discharged from the hospital after a diagnosis of WAICH. Four patients were lost to follow-up. Mean follow-up among all patients was 43 (range, 1-108) months. Of the 23 patients who restarted warfarin therapy, 1 had a recurrent nontraumatic WAICH, 2 had traumatic intracerebral hemorrhages, and 2 had major extracranial hemorrhages. Of the 25 patients who did not restart warfarin therapy, 3 had a thromboembolic stroke, 1 had a pulmonary embolus, and 1 had a distal arterial embolus. Conclusions: Restarting warfarin therapy in patients with a recent WAICH is associated with a low risk of recurrence, but patients are subjected to known, substantial risks of warfarin use. Withholding warfarin therapy is associated with a risk of thromboembolization.

Journal of neurosurgery, Feb 1, 2020

The authors report an unusual case of an odontoid synchondrosis fracture causing chronic translat... more The authors report an unusual case of an odontoid synchondrosis fracture causing chronic translational anterior atlanto-axial subluxation and present a discussion of the unique management of this case. Traumatic translational anterior atlanto-axial subluxation is a rare manifestation within pediatrics. Patients with preexisting abnormalities in ligamentous or bony structures may present with unusual symptomatology, which could result in delay of treatment. A 6-year-old male patient with autism who presented with acute respiratory arrest was noted to have an odontoid synchondrosis fracture and severe anterior translational atlanto-axial subluxation. Initial attempts at reduction with halo traction were tried for first-line treatment. However, because of concern regarding possible inadvertent worsening of the impingement, the presence of comorbid macrocephaly, and possible instability with only C1–2 fusion, a posterior C1 laminectomy was performed. Further release of the C1–2 complex and odontoid peg from extensive fibrous tissue allowed for complete reduction. Acute injuries of the C1–2 complex may not present as expected, and the presence of pain is not a reliable symptom. Halo traction is an appropriate initial treatment, but some patients may require surgical realignment and stabilization.

Evidence-based spine-care journal, Feb 21, 2013

Study design: Retrospective case review. Introduction: Ischemic insults from blunt cerebrovascula... more Study design: Retrospective case review. Introduction: Ischemic insults from blunt cerebrovascular injuries (BCVI) can lead to significant cranial and spinal injury. Specific spine fracture patterns have been identified as more predictive of BCVI, such as vertebral subluxation, fractures through the foramen transversarium, and C1 through C3 fractures. Adequate screening and early treatment has led to a decrease in devastating neurological deficits from associated strokes [1]. However, BCVI in association with injuries of the craniocervical junction have been anecdotally reported but their true incidence is still unknown. We hypothesized that craniocervical dissociation (CCD), due to its distractive nature, is also associated with a high incidence of BCVI. Objective: To evaluate the incidence of BCVI in a large series of patients with CCD admitted to a singlelevel 1 trauma institution. Methods: A retrospective review of all consecutive patients diagnosed with unstable craniocervical distraction injuries (defined as abnormal widening of the C0-C1 and/or C1-2 joints) that were surgically treated from 2003-2009 was performed. All patients with CCD injuries who had a screening catheter angiogram or computed tomographic angiography (CTA) of the neck to exclude BCVI entered the study.

World Neurosurgery, Feb 1, 2019

Surgical Neurology International, 2017

Background: Currarino syndrome (CS) is a rare genetic condition that presents with the defining t... more Background: Currarino syndrome (CS) is a rare genetic condition that presents with the defining triad of anorectal malformations, sacral bone deformations, and presacral masses, which may include teratoma. Neurosurgeons are involved in the surgical treatment of anterior meningoceles, which are often associated with this condition. The accepted surgical treatment is a staged anterior-posterior resection of the presacral mass and obliteration of the anterior meningocele. Case Description: This case involved a 36-year-old female who presented with late onset of symptoms attributed to CS (e.g., presacral mass, anterior sacral meningocele, and sacral agenesis). She successfully underwent multidisciplinary single-stage approach for treatment of the anterior sacral meningocele and resection of the presacral mass. This required obliteration of the meningocele and closure of the dural defect. One year later, her meningocele had fully resolved. Conclusion: While late presentations with CS are rare, early detection and multidisciplinary treatment including single-state anterior may be successful for managing these patients.

Neurosurgery, Dec 1, 2020

Journal of Clinical Neuroscience, Jul 1, 2006

Epilepsia, Jun 1, 1997

Because focal encephalomalacia is an important cause of medically intractable partial epilepsy an... more Because focal encephalomalacia is an important cause of medically intractable partial epilepsy and few studies have evaluated the efficacy and the safety of resecting focal encephalomalacias to improve seizure control, we studied a cohort of 17 consecutive patients who underwent resection of encephalomalacias in the frontal lobes as a treatment of their intractable epilepsy. Methods: We evaluated several factors for their value in predicting postsurgical seizure control. Pre-and postsurgical magnetic resonance imaging (MRI) scans were reviewed independently by 2 blinded investigators. Results: At a median of 3 years of follow-up (range 0.6-7.5 years), 12 patients (70%) were seizure-free or had only rare seizures. The presence of a focal fast frequency discharge (focal ictal p pattern) at the beginning of seizures on scalp EEG was predictive of seizure-free outcome (p = 0.017), even among patients who had complete resection of their encephalomalacias (p = 0.016). There was no significant differences in outcome with regard to age at the time of the injury that caused encephalomalacia, interval between injury and onset of seizures, duration of presurgical seizure history, presurgical seizure frequency, age at surgery, or the completeness of encephalomalacia resection. The analysis regarding completeness of encephalomalacia resection almost reached significance, suggesting that it may also be an important predictive factor (p = 0.051). Conclusions: We conclude that surgery is a very effective treatment for intractable frontal lobe epilepsy (FLE) secondary to encephalomalacias. Patients are more likely to become seizure-free if they have a focal ictal / 3 discharge on their scalp EEG. Complete resection of the encephalomalacia should be attempted, since our results suggest that this may be a favorable predictive factor. Moreover, the operative strategy for our patients entailed, whenever possible, complete resection of the encephalomalacias and of the adjacent electrophysiologically abnormal tissues.

Alzheimers & Dementia, Jul 1, 2008

Journal of neurosurgery, May 1, 2022

A ccurAte localization in the thoracic spine remains a significant challenge in surgery. Sixty-ei... more A ccurAte localization in the thoracic spine remains a significant challenge in surgery. Sixty-eight percent of spine surgeons surveyed have admitted to wrong-level localization, although some of the wrong-level exposures were rectified intraoperatively. 1 Furthermore, approximately 1 of every 2 spine surgeons has performed a wrong-level surgery. 2 Wrong-level surgery falls under the broader term "wrong-site surgery" and is considered a sentinel event that exposes the patient to additional risks and unnecessary procedures, harms the doctor-patient relationship, and may even lead to medicolegal action. 3 Correct localization is usually most problematic in the midthoracic spine where the pathology is difficult to localize radiographically. Unless there is an osseous lesion that permits ease of level identification, intraoperative fluoroscopy use alone may predispose one to wrong-level surgery. Often, due to anatomical constraints and improved image quality, anteroposterior (AP) projection on fluoroscopy is the most effective way of visualizing the thoracic spine. However, AP projections can be very technique-dependent and require extensive knowledge of anatomy and experience using fluoroscopy to count spinal levels. Several factors, especially in the thoracic spine, make accurate localization difficult, including morbid obesity, previous spine surgery, infections, osteoporosis, anatomical variations including transitional vertebrae, scapular shadowing (in the upper-to midthoracic levels), variation in the number of rib-bearing vertebrae, hemivertebrae, and fused vertebrae. 4,5 Despite the growing concern for wrong-level surgery and advances in spinal surgery, there is tremendous variability as to how surgeons perform level localization. Even in traditional level counting with fluoroscopy, there is vari-ABBREVIATIONS AP = anteroposterior; PMMA = polymethylmethacrylate; PRISMA = Preferred Reporting Items for Systematic Reviews and Meta-Analyses.

Journal of Clinical Neuroscience, Aug 1, 2016

Schwannomatosis is characterized by multiple non-intradermal schwannomas with patients often pres... more Schwannomatosis is characterized by multiple non-intradermal schwannomas with patients often presenting with a painful mass in their extremities. In this syndrome malignant transformation of schwannomas is rare in spite of their large size at presentation. Non-invasive measures of assessing the biological behavior of plexiform neurofibromas in neurofibromatosis type 1 such as positron emission tomography (PET), CT scanning and MRI are well characterized but little information has been published on the use of PET imaging in schwannomatosis. We report a unique clinical presentation portraying the use of PET imaging in schwannomatosis. A 27-year-old woman presented with multiple, rapidly growing, large and painful schwannomas confirmed to be related to a constitutional mutation in the SMARCB1 complex. Whole body PET/MRI revealed numerous PET-avid tumors suggestive of malignant peripheral nerve sheath tumors. Surgery was performed on multiple tumors and none of them had histologic evidence of malignant transformation. Overall, PET imaging may not be a reliable predictor of malignant transformation in schwannomatosis, tempering enthusiasm for surgical interventions for tumors not producing significant clinical signs or symptoms.

World Neurosurgery, May 1, 2016

Surgical-site infections (SSIs) are a major cause of morbidity and mortality, increasing the leng... more Surgical-site infections (SSIs) are a major cause of morbidity and mortality, increasing the length and cost of hospitalization. In patients undergoing spine surgery, there is limited large-scale data on patient-specific risk factors for SSIs. The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was reviewed for all spinal operations between 2006 and 2012. The rates of 30 day surgical site infections were calculated, and univariate analysis of selected preoperative risk factors was performed. Multivariate analysis was then used to identify independent predictors of SSIs. 1110 of the 60179 patients (1.84%) had a postoperative wound infection. There were 527 (0.87%) deep and 590 (0.98%) superficial infections. Patients with infections had greater rates of sepsis, longer lengths of stay and more return visits to the operating room. Independent predictors of infection were female gender, inpatient status, insulin dependent diabetes, preoperative steroid use greater than 10 days, hematocrit less than 35, body mass index (BMI) greater than 30, wound class, ASA class, and operative duration. Analysis of a large national patient database revealed many independent risk factors for SSIs after spinal surgery. Some of these risk factors can be modified preoperatively to reduce the risk of postoperative infection.

World Neurosurgery, May 30, 2018

Surgical Neurology International, 2019

Background: Neurofibromatosis is an autosomal dominant disorder of the nerves, resulting in café-... more Background: Neurofibromatosis is an autosomal dominant disorder of the nerves, resulting in café-au-lait spots, axillary freckling, macules, and neurofibromas throughout the nervous system. Diagnosis of this condition has in the past been mainly clinical, but the usage of magnetic resonance imaging neurography (MRN) is a new diagnostic modality. Here, we report on a case of neurofibromatosis type I (NF-1) that was diagnosed using MRN after a protracted clinical course. Case Description: A 23-year-old female presented with several months of worsening right upper and lower quadrant abdominal pain. The patient underwent computed tomography (CT) of the abdomen and pelvis demonstrating multiple neurofibromas involving the psoas muscle and mesentery of the lower abdomen. Subsequent total neuronal axis magnetic resonance imaging (MRI) using the neurography protocol (MRN) showed multiple neurofibromas in both the right brachial plexus and lumbar plexus. Conclusion: We present a case of NF-1 that was diagnosed using MRN following a protracted clinical course. MRN is a diagnostic modality for NF-1 and other peripheral nerve disorders.

Publisher Summary This chapter summarizes the epidemiology of the double lesion and discusses the... more Publisher Summary This chapter summarizes the epidemiology of the double lesion and discusses the implications of coexistent temporal lobe pathology in the selection of surgical candidates, the preoperative evaluation, and operative strategy. The occurrence of the double lesion in patients with temporal lobe lesional epilepsy has ranged from 8 to 30% in clinical studies. Mesial temporal sclerosis (MTS) in patients with the double lesion must be differentiated from the mild decrease in hippocampal neuronal cell density that is present in most patients with temporal lobe epileptogenic lesions. The excitotoxic model based on the experimental observation that recurrent seizures result in progressive hippocampal neuronal loss and hippocampal formation atrophy is analyzed. The localization of the lesional pathology has been shown to be intimately associated with the epileptic brain tissue in most patients. Magnetic resonance imaging demonstrates the appropriate structural abnormalities in most patients with coexistent MTS and extra-hippocampal pathology. It is found that a worthwhile seizure reduction was achieved in more than 80% of patients with identified MTS undergoing anterior temporal lobectomy in one series.

Surgical Neurology International, 2013

Background and Methods: As with any evolving surgical discipline, it is diffi cult to predict the... more Background and Methods: As with any evolving surgical discipline, it is diffi cult to predict the future of the practice and science of spine surgery. In the last decade, there have been dramatic developments in both the techniques as well as the tools employed in the delivery of better outcomes to patients undergoing such surgery. In this article, we explore four specifi c areas in spine surgery: namely the role of minimally invasive spine surgery; motion preservation; robotic-aided surgery and neuro-navigation; and the use of biological substances to reduce the number of traditional and revision spine surgeries. Results: Minimally invasive spine surgery has fl ourished in the last decade with an increasing amount of surgeries being performed for a wide variety of degenerative, traumatic, and neoplastic processes. Particular progress in the development of a direct lateral approach as well as improvement of tubular retractors has been achieved. Improvements in motion preservation techniques have led to a signifi cant number of patients achieving arthroplasty where fusion was the only option previously. Important caveats to the indications for arthroplasty are discussed. Both robotics and neuro-navigation have become further refi ned as tools to assist in spine surgery and have been demonstrated to increase accuracy in spinal instrumentation placement. There has much debate and refi nement in the use of biologically active agents to aid and augment function in spine surgery. Biological agents targeted to the intervertebral disc space could increase function and halt degeneration in this anatomical region. Conclusions: Great improvements have been achieved in developing better techniques and tools in spine surgery. It is envisaged that progress in the four focus areas discussed will lead to better outcomes and reduced burdens on the future of both our patients and the health care system.

World Neurosurgery, 2018

Objective Spontaneous cervical intradural disc herniation (IDH) is a rare occurrence with limited... more Objective Spontaneous cervical intradural disc herniation (IDH) is a rare occurrence with limited and disparate information available regarding its presentation, diagnosis, and treatment. However, its accurate detection is vital for planning surgical treatment. In this review of the literature, we collected data from all cervical intradural disc herniations described to date. Particular attention is paid to diagnostic findings, surgical approach and causation for cervical IDH, especially at the cervicothoracic junction. Methods A review for cases of cervical IDH was performed utilizing the search criteria: ("neck"[MeSH Terms] OR "neck"[All Fields] OR "cervical"[All Fields]) AND intradural[All Fields] AND disc[All Fields]. Thirty seven cases of cervical disc herniation were identified. Demographic variables identified include age, gender, cervical level of herniation, history of associated cervical trauma, presence of Brown-Sequard Syndrome (BSS), Horner Syndrome (HS), and other neurological findings, radiographic findings, direction of surgical approach and postoperative outcomes. Results A total of 37 cases of cervical IDH were identified. Most of the cases occurred at the lower levels of the cervical spine, with 35.1% at the C5/6 level, followed by 24.3% at C6/7, and lower still at other levels. Of the patients reviewed, 44.4% had a prior history of trauma before manifestation of symptom with the majority being spontaneous IDH with no previous history of trauma or spine surgery. BSS was present in 43.2% of the patients, while 10.8% of patients experienced HS. The most common presentations of IDH include quadriplegia, finger/gait ataxia, radiculopathy and nuchal pain. The degree of neurological recovery was not associated with patient age. Most of the cervical IDH in literature were treated surgically via an anterior approach, but a larger portion of patients who underwent a posterior approach had improved recovery. Conclusion Cervical intradural disc herniation is a rare event, with this review of the literature outlining the clinical and radiographic parameters of its presentation as well as comparing common surgical strategies for treatment. We outline theories underlying the development of cervical IDH and argue for a posterior surgical approach where the disc herniation is sequestrated with migration.

Alzheimers & Dementia, Jul 1, 2008

World Neurosurgery, Jul 1, 2016

Contributorship Statement BAL and JKH were involved in the design and conception of this manuscri... more Contributorship Statement BAL and JKH were involved in the design and conception of this manuscript. AVP, NA, and DL performed the literature search. BAL, VC, and AVP compiled the primary manuscript. AVP compiled the figures. NA and MT critically revised the manuscript. All authors have approved the manuscript as it is written. Data Sharing All data pertaining to this research article are included within the manuscript as written. Disclaimer: The American College of Surgeons National Surgical Quality Improvement Program and the hospitals participating in the ACS NSQIP are the source of the data used herein; they have not verified and are not responsible for the statistical validity of the data analysis or the conclusions derived by the authors.

Neurology, Dec 28, 2009

Objective: Although subtraction ictal SPECT coregistered to MRI (SISCOM) is clinically useful in ... more Objective: Although subtraction ictal SPECT coregistered to MRI (SISCOM) is clinically useful in epilepsy surgery evaluation, it does not determine whether the ictal-interictal subtraction difference is statistically different from the expected random variation between 2 SPECT studies. We developed a statistical parametric mapping and MRI voxel-based method of analyzing ictalinterictal SPECT difference data (statistical ictal SPECT coregistered to MRI [STATISCOM]) and compared it with SISCOM. Methods: Two serial SPECT studies were performed in 11 healthy volunteers without epilepsy (control subjects) to measure random variation between serial studies from individuals. STATISCOM and SISCOM images from 87 consecutive patients who had ictal SPECT studies and subsequent temporal lobectomy were assessed by reviewers blinded to clinical data and outcome. Results: Interobserver agreement between blinded reviewers was higher for STATISCOM images than for SISCOM images (ϭ 0.81 vs ϭ 0.36). STATISCOM identified a hyperperfusion focus in 84% of patients, SISCOM in 66% (p Ͻ 0.05). STATISCOM correctly localized the temporal lobe epilepsy (TLE) subtypes (mesial vs lateral neocortical) in 68% of patients compared with 24% by SISCOM (p ϭ 0.02); subgroup analysis of patients without lesions (as determined by MRI) showed superiority of STATISCOM (80% vs 47%; p ϭ 0.04). Moreover, the probability of seizure-free outcome was higher when STATISCOM correctly localized the TLE subtype than when it was indeterminate (81% vs 53%; p ϭ 0.03). Conclusion: Statistical ictal SPECT coregistered to MRI (STATISCOM) was superior to subtraction ictal SPECT coregistered to MRI for seizure localization before temporal lobe epilepsy (TLE) surgery. STATISCOM localization to the correct TLE subtype was prognostically important for postsurgical seizure freedom. Neurology ® 2010;74:70-76 GLOSSARY CI ϭ confidence interval; ECD ϭ ethyl cysteinate dimer; HMPAO ϭ hexamethyl propylene-amine-oxime; SISCOM ϭ subtraction ictal SPECT coregistered to MRI; SPM ϭ statistical parametric mapping; STATISCOM ϭ statistical ictal SPECT coregistered to MRI; TLE ϭ temporal lobe epilepsy. Early methods of ictal SPECT interpretation relied on a visual comparison of ictal and interictal SPECT images to detect focal hyperperfusion changes (these represented potential sites of ictal hyperperfusion). 1 SPECT imaging subsequently was improved by subtraction ictal SPECT with coregistration on MRI (SISCOM). 2-5 With SISCOM, ictal SPECT data are subtracted from interictal SPECT data, 6,7 and the "difference image," which shows the focus of altered perfusion, is coregistered with the patient's MRI for anatomic correlation. A recent study that compared several functional imaging modalities showed that positive SISCOM has the greatest association with seizure-free outcome after focal epilepsy surgery. 8 Despite the validation of its clinical usefulness, SISCOM detection of abnormal perfusion is based a priori on a defined threshold of perfusion changes, and it does not account for the expected variability in voxel intensities between 2 serial images from an individual. To account for this random variation between images, our group developed a method that used statistical

Archives of neurology, Oct 1, 2008

Background: Reinitiating warfarin sodium therapy in a patient with a recent warfarin-related intr... more Background: Reinitiating warfarin sodium therapy in a patient with a recent warfarin-related intracerebral hemorrhage (WAICH) is a difficult clinical decision. Therefore, it is important to assess the outcome of resumption or discontinuation of warfarin therapy after WAICH. Objective: To compare patients who survived an episode of WAICH and restarted warfarin therapy with a group of WAICH patients who did not resume warfarin therapy. Design, Setting, and Patients: We conducted a follow-up study from November 1, 2001, through December 31, 2005, in a cohort from a single center. Longterm outcome was assessed at last clinical follow-up or via questionnaire. Main Outcome Measures: Recurrent WAICH and thromboembolic events. Results: Fifty-two patients were discharged from the hospital after a diagnosis of WAICH. Four patients were lost to follow-up. Mean follow-up among all patients was 43 (range, 1-108) months. Of the 23 patients who restarted warfarin therapy, 1 had a recurrent nontraumatic WAICH, 2 had traumatic intracerebral hemorrhages, and 2 had major extracranial hemorrhages. Of the 25 patients who did not restart warfarin therapy, 3 had a thromboembolic stroke, 1 had a pulmonary embolus, and 1 had a distal arterial embolus. Conclusions: Restarting warfarin therapy in patients with a recent WAICH is associated with a low risk of recurrence, but patients are subjected to known, substantial risks of warfarin use. Withholding warfarin therapy is associated with a risk of thromboembolization.

Journal of neurosurgery, Feb 1, 2020

The authors report an unusual case of an odontoid synchondrosis fracture causing chronic translat... more The authors report an unusual case of an odontoid synchondrosis fracture causing chronic translational anterior atlanto-axial subluxation and present a discussion of the unique management of this case. Traumatic translational anterior atlanto-axial subluxation is a rare manifestation within pediatrics. Patients with preexisting abnormalities in ligamentous or bony structures may present with unusual symptomatology, which could result in delay of treatment. A 6-year-old male patient with autism who presented with acute respiratory arrest was noted to have an odontoid synchondrosis fracture and severe anterior translational atlanto-axial subluxation. Initial attempts at reduction with halo traction were tried for first-line treatment. However, because of concern regarding possible inadvertent worsening of the impingement, the presence of comorbid macrocephaly, and possible instability with only C1–2 fusion, a posterior C1 laminectomy was performed. Further release of the C1–2 complex and odontoid peg from extensive fibrous tissue allowed for complete reduction. Acute injuries of the C1–2 complex may not present as expected, and the presence of pain is not a reliable symptom. Halo traction is an appropriate initial treatment, but some patients may require surgical realignment and stabilization.

Evidence-based spine-care journal, Feb 21, 2013

Study design: Retrospective case review. Introduction: Ischemic insults from blunt cerebrovascula... more Study design: Retrospective case review. Introduction: Ischemic insults from blunt cerebrovascular injuries (BCVI) can lead to significant cranial and spinal injury. Specific spine fracture patterns have been identified as more predictive of BCVI, such as vertebral subluxation, fractures through the foramen transversarium, and C1 through C3 fractures. Adequate screening and early treatment has led to a decrease in devastating neurological deficits from associated strokes [1]. However, BCVI in association with injuries of the craniocervical junction have been anecdotally reported but their true incidence is still unknown. We hypothesized that craniocervical dissociation (CCD), due to its distractive nature, is also associated with a high incidence of BCVI. Objective: To evaluate the incidence of BCVI in a large series of patients with CCD admitted to a singlelevel 1 trauma institution. Methods: A retrospective review of all consecutive patients diagnosed with unstable craniocervical distraction injuries (defined as abnormal widening of the C0-C1 and/or C1-2 joints) that were surgically treated from 2003-2009 was performed. All patients with CCD injuries who had a screening catheter angiogram or computed tomographic angiography (CTA) of the neck to exclude BCVI entered the study.

World Neurosurgery, Feb 1, 2019

Surgical Neurology International, 2017

Background: Currarino syndrome (CS) is a rare genetic condition that presents with the defining t... more Background: Currarino syndrome (CS) is a rare genetic condition that presents with the defining triad of anorectal malformations, sacral bone deformations, and presacral masses, which may include teratoma. Neurosurgeons are involved in the surgical treatment of anterior meningoceles, which are often associated with this condition. The accepted surgical treatment is a staged anterior-posterior resection of the presacral mass and obliteration of the anterior meningocele. Case Description: This case involved a 36-year-old female who presented with late onset of symptoms attributed to CS (e.g., presacral mass, anterior sacral meningocele, and sacral agenesis). She successfully underwent multidisciplinary single-stage approach for treatment of the anterior sacral meningocele and resection of the presacral mass. This required obliteration of the meningocele and closure of the dural defect. One year later, her meningocele had fully resolved. Conclusion: While late presentations with CS are rare, early detection and multidisciplinary treatment including single-state anterior may be successful for managing these patients.

Neurosurgery, Dec 1, 2020

Journal of Clinical Neuroscience, Jul 1, 2006

Epilepsia, Jun 1, 1997

Because focal encephalomalacia is an important cause of medically intractable partial epilepsy an... more Because focal encephalomalacia is an important cause of medically intractable partial epilepsy and few studies have evaluated the efficacy and the safety of resecting focal encephalomalacias to improve seizure control, we studied a cohort of 17 consecutive patients who underwent resection of encephalomalacias in the frontal lobes as a treatment of their intractable epilepsy. Methods: We evaluated several factors for their value in predicting postsurgical seizure control. Pre-and postsurgical magnetic resonance imaging (MRI) scans were reviewed independently by 2 blinded investigators. Results: At a median of 3 years of follow-up (range 0.6-7.5 years), 12 patients (70%) were seizure-free or had only rare seizures. The presence of a focal fast frequency discharge (focal ictal p pattern) at the beginning of seizures on scalp EEG was predictive of seizure-free outcome (p = 0.017), even among patients who had complete resection of their encephalomalacias (p = 0.016). There was no significant differences in outcome with regard to age at the time of the injury that caused encephalomalacia, interval between injury and onset of seizures, duration of presurgical seizure history, presurgical seizure frequency, age at surgery, or the completeness of encephalomalacia resection. The analysis regarding completeness of encephalomalacia resection almost reached significance, suggesting that it may also be an important predictive factor (p = 0.051). Conclusions: We conclude that surgery is a very effective treatment for intractable frontal lobe epilepsy (FLE) secondary to encephalomalacias. Patients are more likely to become seizure-free if they have a focal ictal / 3 discharge on their scalp EEG. Complete resection of the encephalomalacia should be attempted, since our results suggest that this may be a favorable predictive factor. Moreover, the operative strategy for our patients entailed, whenever possible, complete resection of the encephalomalacias and of the adjacent electrophysiologically abnormal tissues.

Alzheimers & Dementia, Jul 1, 2008

Journal of neurosurgery, May 1, 2022

A ccurAte localization in the thoracic spine remains a significant challenge in surgery. Sixty-ei... more A ccurAte localization in the thoracic spine remains a significant challenge in surgery. Sixty-eight percent of spine surgeons surveyed have admitted to wrong-level localization, although some of the wrong-level exposures were rectified intraoperatively. 1 Furthermore, approximately 1 of every 2 spine surgeons has performed a wrong-level surgery. 2 Wrong-level surgery falls under the broader term "wrong-site surgery" and is considered a sentinel event that exposes the patient to additional risks and unnecessary procedures, harms the doctor-patient relationship, and may even lead to medicolegal action. 3 Correct localization is usually most problematic in the midthoracic spine where the pathology is difficult to localize radiographically. Unless there is an osseous lesion that permits ease of level identification, intraoperative fluoroscopy use alone may predispose one to wrong-level surgery. Often, due to anatomical constraints and improved image quality, anteroposterior (AP) projection on fluoroscopy is the most effective way of visualizing the thoracic spine. However, AP projections can be very technique-dependent and require extensive knowledge of anatomy and experience using fluoroscopy to count spinal levels. Several factors, especially in the thoracic spine, make accurate localization difficult, including morbid obesity, previous spine surgery, infections, osteoporosis, anatomical variations including transitional vertebrae, scapular shadowing (in the upper-to midthoracic levels), variation in the number of rib-bearing vertebrae, hemivertebrae, and fused vertebrae. 4,5 Despite the growing concern for wrong-level surgery and advances in spinal surgery, there is tremendous variability as to how surgeons perform level localization. Even in traditional level counting with fluoroscopy, there is vari-ABBREVIATIONS AP = anteroposterior; PMMA = polymethylmethacrylate; PRISMA = Preferred Reporting Items for Systematic Reviews and Meta-Analyses.

Journal of Clinical Neuroscience, Aug 1, 2016

Schwannomatosis is characterized by multiple non-intradermal schwannomas with patients often pres... more Schwannomatosis is characterized by multiple non-intradermal schwannomas with patients often presenting with a painful mass in their extremities. In this syndrome malignant transformation of schwannomas is rare in spite of their large size at presentation. Non-invasive measures of assessing the biological behavior of plexiform neurofibromas in neurofibromatosis type 1 such as positron emission tomography (PET), CT scanning and MRI are well characterized but little information has been published on the use of PET imaging in schwannomatosis. We report a unique clinical presentation portraying the use of PET imaging in schwannomatosis. A 27-year-old woman presented with multiple, rapidly growing, large and painful schwannomas confirmed to be related to a constitutional mutation in the SMARCB1 complex. Whole body PET/MRI revealed numerous PET-avid tumors suggestive of malignant peripheral nerve sheath tumors. Surgery was performed on multiple tumors and none of them had histologic evidence of malignant transformation. Overall, PET imaging may not be a reliable predictor of malignant transformation in schwannomatosis, tempering enthusiasm for surgical interventions for tumors not producing significant clinical signs or symptoms.

World Neurosurgery, May 1, 2016

Surgical-site infections (SSIs) are a major cause of morbidity and mortality, increasing the leng... more Surgical-site infections (SSIs) are a major cause of morbidity and mortality, increasing the length and cost of hospitalization. In patients undergoing spine surgery, there is limited large-scale data on patient-specific risk factors for SSIs. The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was reviewed for all spinal operations between 2006 and 2012. The rates of 30 day surgical site infections were calculated, and univariate analysis of selected preoperative risk factors was performed. Multivariate analysis was then used to identify independent predictors of SSIs. 1110 of the 60179 patients (1.84%) had a postoperative wound infection. There were 527 (0.87%) deep and 590 (0.98%) superficial infections. Patients with infections had greater rates of sepsis, longer lengths of stay and more return visits to the operating room. Independent predictors of infection were female gender, inpatient status, insulin dependent diabetes, preoperative steroid use greater than 10 days, hematocrit less than 35, body mass index (BMI) greater than 30, wound class, ASA class, and operative duration. Analysis of a large national patient database revealed many independent risk factors for SSIs after spinal surgery. Some of these risk factors can be modified preoperatively to reduce the risk of postoperative infection.

World Neurosurgery, May 30, 2018

Surgical Neurology International, 2019

Background: Neurofibromatosis is an autosomal dominant disorder of the nerves, resulting in café-... more Background: Neurofibromatosis is an autosomal dominant disorder of the nerves, resulting in café-au-lait spots, axillary freckling, macules, and neurofibromas throughout the nervous system. Diagnosis of this condition has in the past been mainly clinical, but the usage of magnetic resonance imaging neurography (MRN) is a new diagnostic modality. Here, we report on a case of neurofibromatosis type I (NF-1) that was diagnosed using MRN after a protracted clinical course. Case Description: A 23-year-old female presented with several months of worsening right upper and lower quadrant abdominal pain. The patient underwent computed tomography (CT) of the abdomen and pelvis demonstrating multiple neurofibromas involving the psoas muscle and mesentery of the lower abdomen. Subsequent total neuronal axis magnetic resonance imaging (MRI) using the neurography protocol (MRN) showed multiple neurofibromas in both the right brachial plexus and lumbar plexus. Conclusion: We present a case of NF-1 that was diagnosed using MRN following a protracted clinical course. MRN is a diagnostic modality for NF-1 and other peripheral nerve disorders.

Publisher Summary This chapter summarizes the epidemiology of the double lesion and discusses the... more Publisher Summary This chapter summarizes the epidemiology of the double lesion and discusses the implications of coexistent temporal lobe pathology in the selection of surgical candidates, the preoperative evaluation, and operative strategy. The occurrence of the double lesion in patients with temporal lobe lesional epilepsy has ranged from 8 to 30% in clinical studies. Mesial temporal sclerosis (MTS) in patients with the double lesion must be differentiated from the mild decrease in hippocampal neuronal cell density that is present in most patients with temporal lobe epileptogenic lesions. The excitotoxic model based on the experimental observation that recurrent seizures result in progressive hippocampal neuronal loss and hippocampal formation atrophy is analyzed. The localization of the lesional pathology has been shown to be intimately associated with the epileptic brain tissue in most patients. Magnetic resonance imaging demonstrates the appropriate structural abnormalities in most patients with coexistent MTS and extra-hippocampal pathology. It is found that a worthwhile seizure reduction was achieved in more than 80% of patients with identified MTS undergoing anterior temporal lobectomy in one series.

Surgical Neurology International, 2013

Background and Methods: As with any evolving surgical discipline, it is diffi cult to predict the... more Background and Methods: As with any evolving surgical discipline, it is diffi cult to predict the future of the practice and science of spine surgery. In the last decade, there have been dramatic developments in both the techniques as well as the tools employed in the delivery of better outcomes to patients undergoing such surgery. In this article, we explore four specifi c areas in spine surgery: namely the role of minimally invasive spine surgery; motion preservation; robotic-aided surgery and neuro-navigation; and the use of biological substances to reduce the number of traditional and revision spine surgeries. Results: Minimally invasive spine surgery has fl ourished in the last decade with an increasing amount of surgeries being performed for a wide variety of degenerative, traumatic, and neoplastic processes. Particular progress in the development of a direct lateral approach as well as improvement of tubular retractors has been achieved. Improvements in motion preservation techniques have led to a signifi cant number of patients achieving arthroplasty where fusion was the only option previously. Important caveats to the indications for arthroplasty are discussed. Both robotics and neuro-navigation have become further refi ned as tools to assist in spine surgery and have been demonstrated to increase accuracy in spinal instrumentation placement. There has much debate and refi nement in the use of biologically active agents to aid and augment function in spine surgery. Biological agents targeted to the intervertebral disc space could increase function and halt degeneration in this anatomical region. Conclusions: Great improvements have been achieved in developing better techniques and tools in spine surgery. It is envisaged that progress in the four focus areas discussed will lead to better outcomes and reduced burdens on the future of both our patients and the health care system.

World Neurosurgery, 2018

Objective Spontaneous cervical intradural disc herniation (IDH) is a rare occurrence with limited... more Objective Spontaneous cervical intradural disc herniation (IDH) is a rare occurrence with limited and disparate information available regarding its presentation, diagnosis, and treatment. However, its accurate detection is vital for planning surgical treatment. In this review of the literature, we collected data from all cervical intradural disc herniations described to date. Particular attention is paid to diagnostic findings, surgical approach and causation for cervical IDH, especially at the cervicothoracic junction. Methods A review for cases of cervical IDH was performed utilizing the search criteria: ("neck"[MeSH Terms] OR "neck"[All Fields] OR "cervical"[All Fields]) AND intradural[All Fields] AND disc[All Fields]. Thirty seven cases of cervical disc herniation were identified. Demographic variables identified include age, gender, cervical level of herniation, history of associated cervical trauma, presence of Brown-Sequard Syndrome (BSS), Horner Syndrome (HS), and other neurological findings, radiographic findings, direction of surgical approach and postoperative outcomes. Results A total of 37 cases of cervical IDH were identified. Most of the cases occurred at the lower levels of the cervical spine, with 35.1% at the C5/6 level, followed by 24.3% at C6/7, and lower still at other levels. Of the patients reviewed, 44.4% had a prior history of trauma before manifestation of symptom with the majority being spontaneous IDH with no previous history of trauma or spine surgery. BSS was present in 43.2% of the patients, while 10.8% of patients experienced HS. The most common presentations of IDH include quadriplegia, finger/gait ataxia, radiculopathy and nuchal pain. The degree of neurological recovery was not associated with patient age. Most of the cervical IDH in literature were treated surgically via an anterior approach, but a larger portion of patients who underwent a posterior approach had improved recovery. Conclusion Cervical intradural disc herniation is a rare event, with this review of the literature outlining the clinical and radiographic parameters of its presentation as well as comparing common surgical strategies for treatment. We outline theories underlying the development of cervical IDH and argue for a posterior surgical approach where the disc herniation is sequestrated with migration.