IU Indianapolis ScholarWorks :: Browsing by Author "Witten, Andrew J."

Browsing by Author "Witten, Andrew J."

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Cerebellopontine Angle Primary Choroid Plexus Carcinoma Present in an Adult: Case Report and Literature Review
(Cureus, 2021-02-10) Witten, Andrew J.; Mendenhall, Stephen K.; DeWitt, Logan S.; Vortmeyer, Alexander; Cohen-Gadol, Aaron; Neurological Surgery, School of Medicine
Choroid plexus tumors (CPTs) are rare intraventricular neoplasms that primarily occur in children and are rare in adults. Of the CPT subtypes, choroid plexus carcinomas (CPC) are highly aggressive and malignant and of World Health Organization (WHO) Grade III. Dissemination through the cerebrospinal fluid space is the inevitable natural course of the disease. In this case report, we present a 33-year-old female with a past medical history notable for schizophrenia and bipolar disease who suffered from left-sided acute vision loss and hearing loss. Magnetic resonance imaging (MRI) demonstrated multiple enhancing masses found in the left cerebellopontine angle (CPA), right internal auditory canal, the atrium of the left ventricle, and the left foramen of Monroe. After surgical decompression of the CPA tumor, the permanent final pathology was consistent with CPC. To our knowledge, this is the first reported case of a primary CPC occurring within the CPA in an adult. The unique presentation and progression of this rare adult-onset CPC provide insight for the diagnosis and treatment of other rare instances of CPTs.
Cytomegalovirus reactivation and acute and chronic complications in children with cerebral malaria: a prospective cohort study
(Springer Nature, 2025-02-17) Mayhew, Jonathan A.; Witten, Andrew J.; Bond, Caitlin A.; Opoka, Robert O.; Bangirana, Paul; Conroy, Andrea L.; Hernandez‑Alvarado, Nelmary; Schleiss, Mark R.; John, Chandy C.; Pediatrics, School of Medicine
Background: Virus co-infection or reactivation may modify the host response during cerebral malaria. Cytomegalovirus (CMV) DNAemia has been associated with increased morbidity and mortality in adults with sepsis; however, the impact of CMV DNAemia on adverse outcomes in children with cerebral malaria is unknown. Methods: Clinical, physiological, and neurocognitive outcomes were compared in children aged 18 months to 12 years with cerebral malaria (N = 242) based on the presence or absence of CMV DNAemia 24 h after admission. The primary study outcome was subsequent in-hospital mortality. Secondary outcomes included the presence of acute kidney injury, neurocognitive impairment over a 2-year follow-up, and chronic kidney disease at the 1-year follow-up. Markers of platelet and endothelial cell activation and oxidative and nitrosative stress were measured to characterize the mechanisms by which CMV DNAemia might contribute to pathogenesis. Results: CMV DNAemia was present in 33 children with cerebral malaria (13.6%) 24 h after admission. CMV DNAemia was not significantly associated with mortality in this study. Children with CMV-DNAemia had a higher prevalence of acute kidney injury than those without CMV-DNAemia (59.4% vs. 38.6%, p = 0.03). There was no difference in the prevalence of chronic kidney disease or long-term neurocognitive impairment based on the presence of DNAemia. CMV DNAemia was associated with elevated plasma levels of P-selectin, angiopoietin-1, asymmetric dimethylarginine, and platelet counts. Conclusions: In children with cerebral malaria, CMV DNAemia is associated with acute kidney injury but not in-hospital mortality, chronic kidney disease, or long-term neurocognitive impairment.
Diffuse leptomeningeal glioneuronal tumor with distinct neuronal and glial components but identical diagnostic molecular and genetic features
(Wiley, 2024) Witten, Andrew J.; Dougherty, Carson; Hao, Chunhai; Neurological Surgery, School of Medicine
The 2021 World Health Organization (WHO) classification of the central nervous system (CNS) tumors has classified diffuse leptomeningeal glioneuronal tumor (DLGNT) as a mixed neuronal and glial tumor. Here, we report a DLGNT with two distinct morphological tumor components but identical molecular features. A four-year-old female child presented with progressive right upper extremity weakness. Magnetic resonance imaging (MRI) revealed the leptomeningeal enhancement over the brain stem and cervicothoracic spine. The histological examination of surgical specimens revealed two distinct tumor components: approximately half of the tumor is composed of oligodendroglioma-like tumor intermingled with nodules of ganglioglioma-like tumor. Immunohistochemistry confirmed the oligodendroglioma and ganglioglioma features. The molecular genetic studies demonstrated the features of DLGNT, including fusion of KIAA1549::BRAF, deletion of chromosome 1p, and absence of isocitrate dehydrogenase 1/2 (IDH1/2) mutation in both tumor components. Interestingly, the genetic studies also revealed the distinct chromosomal abnormalities of the loss of chromosome 4 only in oligodendroglioma-like tumor and copy neutral loss of heterozygosity of 7Q34Q36.3 in the ganglioglioma-like tumor component. This case highlights the critical role of molecular testing in the diagnosis of rare cases of DLGNT with diverse morphological components as well as in the identification of unique molecular alternations responsible for morphological phenotypes of the distinct tumors in DLGNT.
Image Segmentation of Operative Neuroanatomy Into Tissue Categories Using a Machine Learning Construct and Its Role in Neurosurgical Training
(Wolters Kluwer, 2022) Witten, Andrew J.; Patel, Neal; Cohen-Gadol, Aaron; Neurological Surgery, School of Medicine
Background: The complexity of the relationships among the structures within the brain makes efficient mastery of neuroanatomy difficult for medical students and neurosurgical residents. Therefore, there is a need to provide real-time segmentation of neuroanatomic images taken from various perspectives to assist with training. Objective: To develop the initial foundation of a neuroanatomic image segmentation algorithm using artificial intelligence for education. Methods: A pyramidal scene-parsing network with a convolutional residual neural network backbone was assessed for its ability to accurately segment neuroanatomy images. A data set of 879 images derived from The Neurosurgical Atlas was used to train, validate, and test the network. Quantitative assessment of the segmentation was performed using pixel accuracy, intersection-over-union, the Dice similarity coefficient, precision, recall, and the boundary F1 score. Results: The network was trained, and performance was assessed class wise. Compared with the ground truth annotations, the ensembled results for our artificial intelligence framework for the pyramidal scene-parsing network during testing generated a total pixel accuracy of 91.8%. Conclusion: Using the presented methods, we show that a convolutional neural network can accurately segment gross neuroanatomy images, which represents an initial foundation in artificial intelligence gross neuroanatomy that will aid future neurosurgical training. These results also suggest that our network is sufficiently robust, to an unprecedented level, for performing anatomic category recognition in a clinical setting.
Intracranial Vasospasm After Evacuation of Acute Spontaneous Subdural Hematoma
(Cureus, 2021-05-27) Witten, Andrew J.; Ordaz, Josue D.; Alentado, Vincent J.; Bohnstedt, Bradley; Neurological Surgery, School of Medicine
Cerebral vasospasm is a well-known entity following aneurysmal subarachnoid hemorrhage. While it has been described in trauma, it has been much less studied. There have been no previous reports of cerebral vasospasm following spontaneous subdural hematoma or after subdural hematoma evacuation. In this case report, we present a 38-year-old otherwise healthy female who suffered an acute spontaneous subdural hematoma. After surgical evacuation of her hematoma, she developed neurologic decline. Computer tomography angiography demonstrated intracranial vasospasm. She was treated with blood pressure augmentation and nimodipine. She went on to make a full neurologic recovery.To our knowledge, this is the first reported case of cerebral vasospasm after acute spontaneous subdural hematoma or after subdural hematoma evacuation, and the patient recovered without sequelae. The promising outcome of this case may provide a framework for future similar cases. Neurosurgeons and intensivists should keep cerebral vasospasm in their differentials for patients who have neurologic decline after craniotomy for acute subdural hematoma and have an otherwise negative scan for new acute abnormality.
Management of Type III Occipital Condyle Fractures
(MDPI, 2024-12-15) Kwon, Jae Hyun; Chinthala, Anoop Sai; Arnold, Jonathan C.; Witten, Andrew J.; Bohnstedt, Bradley N.; Neurological Surgery, School of Medicine
Background/Objectives: Occipital condyle fractures (OCFs) can be seen in around 4-19% of patients who suffer from cervical spine trauma. Anderson and Montesano system type III OCFs, which are avulsion fractures, are potentially unstable and operative. This study evaluates the management of type III OCFs at our institution over a 22-year period. Methods: This retrospective study reviewed all cases of type III OCFs at our institution from July 2001 to March 2023, identified via imaging reports. Using the in-house radiology imaging informatics system "Doris" (Dig Our Radiology Information System), reports containing the terms subluxation, avulsion, unstable, or type 3/III with occipital condyle, occipital condylar, occipital fx, or occipital fracture were collected. We also searched for Montesano type III/3 fracture. Electronic medical records were used to collect clinical and demographic data. Patients evaluated by the neurosurgical team with at least 1 month of follow-up were included in the analysis. Results: A total of 563 patients were identified with type III OCFs. A total of 56 patients met the inclusion criteria. The majority (91%, 51/56) were treated conservatively with cervical orthosis. A small subset (8.9%, 5/56) underwent occipito-cervical fusion. Three had concomitant unstable C1 fractures, while the other two had significant coronal deformity associated with their type III OCF. Conclusions: At our institution, type III OCFs are predominantly managed with cervical orthosis. Only those with an associated malalignment of the occipito-cervical joint underwent fusion. These findings suggest that most type III OCFs can be treated conservatively with orthosis once stability is confirmed with an upright radiograph.
Pediatric Prostatic Alveolar Rhabdomyosarcoma Presenting with Metastatic Spinal Cord Compression in the Thoracic Spine: A Case Report and Review of the Literature
(Springer Nature, 2024-03-20) Perry, Matthew T.; Witten, Andrew J.; Marwan, Majeed; Vortmeyer, Alexander; Tailor, Jignesh; Neurological Surgery, School of Medicine
Rhabdomyosarcoma (RMS) is a pediatric malignancy with a variable prognosis depending on tumor stage and genotype. There has been a significant improvement in survival rates over the past decades. However, aggressive variants can metastasize to locations that are difficult to treat. We report a case of prostatic alveolar rhabdomyosarcoma with metastases to the bone marrow and thoracic spine in a child. The patient was treated with a multimodal approach that included surgical resection of the epidural mass; the administration of vincristine, dactinomycin, and cyclophosphamide; and radiotherapy. Unfortunately, after six months, the patient showed disease progression and was started on secondary-line treatment. This case illustrates the difficulties in managing end-stage metastatic rhabdomyosarcoma and is the first report of prostatic rhabdomyosarcoma presenting with spinal cord compression in a child.
Resection of a Pineal Region Papillary Tumor Using Robotic Exoscope: Improved Visualization and Ergonomics for Deep Seeded Tumor
(American Association of Neurological Surgeons, 2021-07-01) Huff, Wei X.; Witten, Andrew J.; Shah, Mitesh V.; Neurological Surgery, School of Medicine
Surgery for pineal region tumors is technically challenging due to their deep location and close proximity to critical deep venous structures, midbrain, and thalamus. A high-definition video exoscope was recently proposed as an alternative to the operating microscope. The authors illustrate a case of the midline supracerebellar infratentorial approach to resect a pineal region tumor using the Modus V exoscope and demonstrate the improved visualization of critical structures in this deep location. Additionally, the marked improvement in surgeon comfort suggests that this system may have significant advantages over traditional microscope-based surgery for tumors of the pineal region. The video can be found here: https://stream.cadmore.media/r10.3171/2021.4.FOCVID2127.
Virtual Exploration of Safe Entry Zones in the Brainstem: Comprehensive Definition and Analysis of the Operative Approach
(Elsevier, 2020) Meybodi, Ali Tayebi; Hendricks, Benjamin K.; Witten, Andrew J.; Hartman, Jerome; Tomlinson, Samuel B.; Cohen-Gadol, Aaron A.; Neurological Surgery, School of Medicine
Background Detailed and accurate understanding of intrinsic brainstem anatomy and the inter-relationship between its internal tracts and nuclei and external landmarks is of paramount importance for safe and effective brainstem surgery. Using anatomical models can be an important step in sharpening such understanding. Objective To show the applicability of our developed virtual 3D model in depicting the safe entry zones (SEZs) to the brainstem. Methods Accurate 3D virtual models of brainstem elements were created using high-resolution magnetic resonance imaging and computed tomography to depict brainstem SEZs. Results All the described SEZs to different aspects of the brainstem were successfully depicted using our 3D virtual models. Conclusions The virtual models provide an immersive experience of brainstem anatomy, allowing users to understand the intricacies of the microdissection that is necessary to appropriately traverse the brainstem nuclei and tracts toward a particular target. The models provide an unparalleled learning environment for illustrating SEZs into the brainstem that can be used for training and research.

Browsing by Author "Witten, Andrew J."

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