Prolactinoma extension as a contributing factor in dopamine agonist-induced CSF rhinorrhea: a systematic review of the literature.

BACKGROUND: Dopamine agonist-induced cerebrospinal fluid (CSF) rhinorrhea is an uncommon treatment-related complication arising in 6.1% of prolactinoma patients treated with dopamine agonists. Locally invasive prolactinomas may create CSF fistulae through formation of dural and osseous skull base defects. Tumor shrinkage secondary to dopamine agonist therapy unmasks skull base defects, thus inducing CSF rhinorrhea. In these cases, repair of the leak may be achieved through collaborative surgical intervention by rhinologists and neurosurgeons. Multiple variables have been investigated as potential contributors to the risk of CSF rhinorrhea development in medically treated prolactinoma patients, with little consensus. OBJECTIVE: The primary aim of our study was the characterization of risk factors for CSF rhinorrhea development following dopamine agonist treatment. METHODS: A systematic review of the literature was conducted to identify cases of CSF rhinorrhea following dopamine agonist treatment of prolactinoma. The clinical history, radiographic findings and treatment outcomes are discussed. RESULTS: Fifty-four patients with dopamine agonist-induced CSF rhinorrhea were identified across 23 articles published from 1979 to 2019. Description of diagnostic imaging [computed tomography (CT)/magnetic resonance imaging (MRI)] was not provided for 18/54 subjects. For the 36 cases that described prolactinoma appearance on CT or MRI, invasion of the cavernous sinuses was reported in 13 (36.1%) and invasion of the sphenoid sinus was reported in 18 (50%). CONCLUSION: Based on our systematic review, we propose that CT findings of osseous erosion of the sella or the anterior skull base may predict dopamine agonist-induced CSF rhinorrhea. We recommend obtaining a thin-slice CT of the sinuses in cases with MRI evidence of sphenoid involvement.

Anatomy and white matter connections of the lateral occipital cortex.

PURPOSE: White matter tracts link different regions of the brain, and the known functions of those interconnected regions may offer clues about the roles that white matter tracts play in information relay. The authors of this report discuss the structure and function of the lateral occipital lobe and how the lateral occipital lobe communicates with other regions via white matter tracts. METHODS: The authors used generalized q-sampling imaging and cadaveric brain dissections to uncover the subcortical white matter connections of the lateral occipital lobe. The authors created GQI of ten healthy controls and dissected ten cadaveric brains. RESULTS: The middle longitudinal fasciculus, vertical occipital fasciculus, inferior fronto-occipital fasciculus, inferior longitudinal fasciculus, optic radiations, and a diverse array of U-shaped fibers connect the lateral occipital lobe to itself, parts of the temporal, parietal, and medial occipital cortices. The complex functional processes attributed to the lateral occipital lobe, including object recognition, facial recognition, and motion perception are likely related to the subcortical white matter tracts described within this study. CONCLUSIONS: There was good concordance between the white matter tracts generated using GQI and the white matter tracts that were found after dissection of the cadaveric brains. This article presents the anatomic connections of the lateral occipital lobe and discusses the associated functions.

Functional connectivity of hippocampus in temporal lobe epilepsy depends on hippocampal dominance: a systematic review of the literature.

BACKGROUND: Lateralized alterations in hippocampal function in the resting-state have been demonstrated for patients with temporal lobe epilepsy (TLE). However, resting-state fMRI of the hippocampus has yet to be substantiated as an adjunct to standard pre-operative assessments of the seizure focus. OBJECTIVE: Here we report the results of a systematic review of resting-state fMRI studies investigating laterality of hippocampal network connectivity in TLE patients. METHODS: A search of the PubMed, SCOPUS, Web of Science, and Embase databases for full-length articles written in English was conducted through June 2020 using the following terms: 'resting state fMRI,' 'hippocampus,' 'epilepsy,' and 'laterality.' RESULTS: Our literature search yielded a total of 42 papers. After excluding studies that did not include patients with epilepsy, utilize resting-state fMRI, or explore the relationship between functional connectivity and disease lateralization, 20 publications were selected for inclusion. From these studies, a total of 528 patients, 258 with left TLE and 270 with right TLE, and 447 healthy controls were included. Of the 20 studies included, 18 found that patients with TLE demonstrated decreased hippocampal functional connectivity ipsilateral to the epileptogenic focus and 10 additionally reported increased hippocampal functional connectivity contralateral to the epileptogenic focus. Several studies demonstrated that the duration of disease was correlated with these changes in functional connectivity. This implies that a compensatory mechanism may be present in patients with treatment-refractory TLE. CONCLUSION: The consistency of this hippocampal connectivity pattern across multiple studies suggests resting-state fMRI may be useful as a non-invasive diagnostic tool for preoperative evaluation of TLE patients.

Boomer Sooner: neurosurgery at the University of Oklahoma.

Neurosurgery at the University of Oklahoma has played a pivotal role in the development of the specialty in the state. Its history spans nearly 90 years, beginning in 1931 when Dr. Harry Wilkins established the first neurosurgical practice in the state at the University of Oklahoma. Together with his first trainee, Dr. Jess Herrmann, Wilkins established the Division of Neurosurgery and its training program in 1946. Through their tireless work, the division and its residency program gained renown for its patient care and teaching, and this tradition was carried forward by its subsequent leaders. The Department of Neurosurgery was established in 1993. From humble beginnings, neurosurgery at the University of Oklahoma has grown a comprehensive residency program with an intensive curriculum, leveraging the clinical and academic breadth afforded by relationships with the College of Medicine, the University of Oklahoma Health Sciences Center, and allied clinical and research partners. Here, the authors recount the history of neurosurgery at the University of Oklahoma, the flagship academic neurosurgical program in the state.

Primary Dural Repair Using Titanium Microclips Following Lateral Skull Base Surgery.

Objective Standard techniques for primary dural repair following lateral skull base surgery are both technically challenging and time consuming without the potential for primary dural repair. Inadequate closure may result in postoperative cerebrospinal fluid (CSF) leak infectious sequalae. Traditional methods of dural repair rely on secondary obliteration of the CSF fistula. We hypothesized that the use of nonpenetrating titanium microclips may serve as a useful adjunct in primary dural repair or the establishment of an immobile repair layer following lateral skull base surgery. Methods Here, we report a novel technique for primary dural repair using nonpenetrating titanium microclips as an adjunct to standard techniques in a series of six patients with lateral skull base pathologies. Results A total of six consecutive lateral skull base tumor patients with titanium microclip dural reconstruction were included in our case series. Lateral skull base pathologies represented in this group included two jugular foramen schwannomas, one vestibular schwannoma, one petroclival meningioma, one glomus jugulare paraganglioma, and one jugular foramen chordoid meningioma. Conclusion To our knowledge, this is the first report on the use of microclips in repairing dural defects following lateral skull base surgery. Surgical outcomes for this small case series suggest that dural repair of the later skull base with nonpenetrating titanium microclips is a useful adjunct in dural repair following lateral skull base surgery.

Primary Repair of Posteriorly Located Anterior Skull Base Dural Defects Using Nonpenetrating Titanium Clips in Cranial Trauma.

Objective Primary repair of posteriorly located anterior skull base (ASB) dural defects following cranial trauma is made difficult by narrow operative corridors and adherent dura mater. Inadequate closure may result in continued cerebrospinal fluid (CSF) leak and infectious sequelae. Here, we report surgical outcomes following the use of nonpenetrating titanium microclips as an adjunctive repair technique in traumatic anterior skull base dural defects extending from the olfactory groove to the tuberculum sellae. Methods All trauma patients who underwent a bifrontal craniotomy from January 2013 to October 2019 were retrospectively reviewed. Patients with ASB defects located at posterior to the olfactory groove were analyzed. Patients with isolated frontal sinus fractures were excluded. All patients presented with CSF leak or radiographic signs of dural compromise. Patients were divided according to posterior extent of injury. Patient characteristics, imaging, surgical technique, and outcomes are reported. Results A total of 19 patients who underwent a bifrontal craniotomy for repair of posteriorly located ASB dural defects using nonpenetrating titanium microclips were included. Defects were divided by location: olfactory groove (10/19), planum sphenoidale (6/19), and tuberculum sellae (3/19). No patients demonstrated a postoperative CSF leak. No complications related to the microclip technique was observed. Clip artifact did not compromise postoperative imaging interpretation. Conclusion Primary repair of posteriorly located ASB dural defects is challenging due to narrow working angles and thin dura mater. Use of nonpenetrating titanium microclips for primary repair of posteriorly located dural defects is a reasonable adjunctive repair technique and was associated with no postoperative CSF leaks in this cohort.

Conductive and injectable hyaluronic acid/gelatin/gold nanorod hydrogels for enhanced surgical translation and bioprinting.

There is growing evidence indicating the need to combine the rehabilitation and regenerative medicine fields to maximize functional recovery after spinal cord injury (SCI), but there are limited methods to synergistically combine the fields. Conductive biomaterials may enable synergistic combination of biomaterials with electric stimulation (ES), which may enable direct ES of neurons to enhance axon regeneration and reorganization for better functional recovery; however, there are three major challenges in developing conductive biomaterials: (1) low conductivity of conductive composites, (2) many conductive components are cytotoxic, and (3) many conductive biomaterials are pre-formed scaffolds and are not injectable. Pre-formed, noninjectable scaffolds may hinder clinical translation in a surgical context for the most common contusion-type of SCI. Alternatively, an injectable biomaterial, inspired by lessons from bioinks in the bioprinting field, may be more translational for contusion SCIs. Therefore, in the current study, a conductive hydrogel was developed by incorporating high aspect ratio citrate-gold nanorods (GNRs) into a hyaluronic acid and gelatin hydrogel. To fabricate nontoxic citrate-GNRs, a robust synthesis for high aspect ratio GNRs was combined with an indirect ligand exchange to exchange a cytotoxic surfactant for nontoxic citrate. For enhanced surgical placement, the hydrogel precursor solution (i.e., before crosslinking) was paste-like, injectable/bioprintable, and fast-crosslinking (i.e., 4 min). Finally, the crosslinked hydrogel supported the adhesion/viability of seeded rat neural stem cells in vitro. The current study developed and characterized a GNR conductive hydrogel/bioink that provided a refinable and translational platform for future synergistic combination with ES to improve functional recovery after SCI.

Cerebral venous thrombosis of the sphenoparietal sinus: A case report.

BACKGROUND: Cerebral venous thrombosis (CVT) is a rare cause of stroke that preferentially affects reproductive aged females and patients with hereditary or acquired thrombotic risk factors. The superior sagittal sinus and transverse sinus are the two most common sites for thrombus formation. CASE DESCRIPTION: We report a case of CVT arising in a very rare location, the sphenoparietal sinus. A 32-year-old woman with a history of factor V Leiden mutation and multiple prior episodes of venous thromboembolism presented with a new-onset seizure, headache, and emesis. CT angiography ultimately revealed thrombosis of the left sphenoparietal sinus. The patient received anticoagulation with apixaban with resolution of symptoms and without complications. CONCLUSION: This case serves as an uncommon example of sphenoparietal sinus thrombosis managed with novel oral anticoagulant treatment.

A rare giant mixed germ cell tumor of the pineal region with immature elements: Case report and review of the literature.

The diagnosis and management of mixed intracranial germ cell tumors may be complicated by the diversity present within this tumor category. Mixed germ cell tumors demonstrate variable natural histories which may be altered by the inclusion of even the most minute immature histological components. We report the case of an 18-year-old male who presented with a 3-month history of progressive headache and nausea leading to lethargy. Imaging revealed a giant pineal region mass extending superiorly from the roof of the fourth ventricle into the lateral ventricle, with resultant obstructive hydrocephalus. No spinal lesions were noted. Following gross total resection, the patient experienced marked improvement. Pathologic analysis identified an uncommon tumor composition: mature teratoma (96%), immature teratoma (2%), and germinoma (2%). Guided by the immature component, chemotherapy and radiation were added post-operatively to provide this patient with the greatest chance of long-term survival. Intracranial pathology, including germ cell tumors, should be included in the differential for any young patient presenting with new and progressive headache and nausea. This case emphasizes the benefit of a multimodal approach to mixed germ cell tumors of the pineal region and the importance of careful pathologic review of all submitted material.

Dynamic Occlusion of Distal Ventriculoperitoneal Shunt Catheter after Infusion Port Placement: A New Shunt Malfunction.

Shunt failure requiring reintervention remains a common complication of hydrocephalus treatment. Here, we report a novel cause of mechanical shunt obstruction in an adult patient: position-dependent intermittent occlusion via an infusion port catheter. A 51-year-old woman with a grade II oligodendroglioma presented in a delayed fashion following surgery with a pseudomeningocele. She underwent ventriculoperitoneal shunt placement due to communicating hydrocephalus, resolving her pseudomeningocele. Shortly thereafter, she underwent placement of a subclavian infusion port at an outside institution. Her pseudomeningocele returned. Imaging demonstrated close proximity of her port catheter to the shunt catheter overlying the clavicle. Her shunt was tapped demonstrating a patent ventricular catheter with normal pressure. She underwent shunt exploration after her pseudomeningocele did not respond to valve adjustment. Intraoperative manometry demonstrated head position-dependent distal catheter obstruction. Repeat manometry following distal catheter revision demonstrated normal runoff independent of position. Her pseudomeningocele was resolved on follow-up. To our knowledge, this is the only reported case of intermittent, position-dependent distal catheter obstruction. Shunted patients with concern for malfunction following subclavian infusion port placement should be evaluated for possible dynamic obstruction of their distal catheter when the two catheters are in close proximity along the clavicle.

Occipital condyle screw fixation after posterior decompression for Chiari malformation: Technical report and application.

BACKGROUND: Surgical techniques for stabilization of the occipital cervical junction have traditionally consisted of screw-based techniques applied in conjunction with occipital plating and rods connected to subaxial instrumentation in the form of pars, pedicle, or lateral mass screws. In patients with type 1 Chiari malformation (CM-1) and evidence of occipital cervical junction instability who have undergone posterior decompression, the occipital condyle (OC) represents a potential alternative cranial fixation point. To date, this technique has only been described in pediatric case reports and morphometric cadaver studies. METHODS: Patients underwent posterior fossa decompression for treatment of CM. Subsequently, patients received occipital cervical stabilization using OC screws. RESULTS: Patients were successfully treated with no post-operative morbidity. Patient 2 was found to have pseudoarthrosis and underwent revision. Both patients continue to do well at 1-year follow-up. CONCLUSION: Placement of the OC screw offers advantages over traditional plate-based occipital fixation in that bone removal for suboccipital decompression is not compromised by the need for hardware placement, screws are hidden underneath ample soft tissue in patients with thin skin which prevents erosion, and the OC consists of primarily cortical bone which provides for robust tricortical fixation. These cases demonstrate the novel application of the OC screw fixation technique to the treatment of occipital cervical junction instability in adult patients undergoing simultaneous posterior fossa decompression.

Parcellation-based anatomic model of the semantic network.

INTRODUCTION: The semantic network is an important mediator of language, enabling both speech production and the comprehension of multimodal stimuli. A major challenge in the field of neurosurgery is preventing semantic deficits. Multiple cortical areas have been linked to semantic processing, though knowledge of network connectivity has lacked anatomic specificity. Using attentional task-based fMRI studies, we built a neuroanatomical model of this network. METHODS: One hundred and fifty-five task-based fMRI studies related to categorization of visual words and objects, and auditory words and stories were used to generate an activation likelihood estimation (ALE). Cortical parcellations overlapping the ALE were used to construct a preliminary model of the semantic network based on the cortical parcellation scheme previously published under the Human Connectome Project. Deterministic fiber tractography was performed on 25 randomly chosen subjects from the Human Connectome Project, to determine the connectivity of the cortical parcellations comprising the network. RESULTS: The ALE analysis demonstrated fourteen left hemisphere cortical regions to be a part of the semantic network: 44, 45, 55b, IFJa, 8C, p32pr, SFL, SCEF, 8BM, STSdp, STSvp, TE1p, PHT, and PBelt. These regions showed consistent interconnections between parcellations. Notably, the anterior temporal pole, a region often implicated in semantic function, was absent from our model. CONCLUSIONS: We describe a preliminary cortical model for the underlying structural connectivity of the semantic network. Future studies will further characterize the neurotractographic details of the semantic network in the context of medical application.

Headache outcomes after surgery for pineal cyst without hydrocephalus: A systematic review.

BACKGROUND: Pineal cysts are common entities, with a reported prevalence between 10 and 54%. Management of pineal cysts has historically been expectant, with surgical treatment of these lesions usually reserved for patients with a symptomatic presentation secondary to mass effect. The appropriate management of pineal cysts in patients presenting with headache in the absence of hydrocephalus - often the most common clinical scenario - has been more ambiguous. Here, we report the results of a comprehensive systematic review of headache outcomes for surgically treated, non-hydrocephalic pineal cyst patients without signs of increased intracranial pressure (ICP). METHODS: Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed to construct a systematic review. A comprehensive search of the PubMed, Embase, Scopus, and Web of Science databases was conducted from through June 2020. Relevant English-language articles were identified using the search terms "pineal cyst" and "headache." The following eligibility criteria were applied: the inclusion of at least one surgically-treated, non-hydrocephalic pineal cyst patient presenting with headache in the absence of hemorrhage or signs and symptoms of increased ICP. Patient demographics and post-operative headache outcomes for the included studies were extracted and summarized. RESULTS: A total of 24 pineal cyst cases meeting our selection criteria were identified across 11 included studies. Postoperative improvement or resolution of headaches was reported for 23/24 patients. Our systematic review of the literature demonstrates that non-hydrocephalic patients with pineal cysts have a high rate of headache improvement following surgical intervention. CONCLUSION: The results indicate a need for further investigation of the link between headache and pineal cysts in the non-hydrocephalic patient.

Flat-Detector CT to Quantify Response to Intra-Arterial Spasmolytic Therapy for Cerebral Vasospasm.

BACKGROUND AND PURPOSE: Cerebral vasospasm in the setting of subarachnoid hemorrhage causes morbidity and mortality due to delayed cerebral ischemia and permanent neurological deficits. Vasospasm treatment includes intra-arterial injection of a spasmolytic during cerebral angiography. To evaluate effectiveness, neurointerventionalists subjectively examine a posttreatment cerebral angiogram to determine change in vessel diameter or increase in microvascular perfusion. Flat-detector computed tomography (FDCT) scanner has the ability to quantitatively measure cerebral blood volume (CBV) within the parenchyma and detect a quantitative change following treatment. METHODS: This is a prospective study at a single institution between October 5, 2017 and June 3, 2019 that examines CBV studies from the Artis Q biplane (Siemens). Regions of interest were made in various territories to measure the CBV within the parenchyma before and after treatment with the spasmolytic verapamil. All instances of vasospasm involved vasculature within the left middle cerebral artery or internal carotid artery. The Wilcoxon signed-rank test was used to determine significance before and after treatment. RESULTS: Our cohort consists of 6 patients who underwent Digital Subtraction Angiography (DSA) and FDCT scans for cerebral vasospasm within the left hemisphere. After intra-arterial injection of 20 mg of verapamil, average increases in blood volume were 59%, 22%, and 24% for the temporal, frontal, and parietal lobes, respectively. P-values associated were .03. We also observed decrease in the mean arterial blood pressure and transcranial Doppler values after treatment. CONCLUSION: In conclusion, FDCT could measure the effectiveness of a change in CBV from infusion of verapamil in the setting of cerebral vasospasm. The authors believe quantifying the change allows for reassurance of improvement of cerebral vasospasm.

Cryptococcal Choroid Plexitis and Non-Communicating Hydrocephalus.

Cryptococcus neoformans is a fungus that commonly invades the central nervous system. While the choroid plexus, the site of the blood-cerebrospinal fluid barrier, serves as one potential entry point for the pathogen, disease involvement of the choroid plexus itself remains a very rare manifestation of Cryptococcus infection. In cases in which choroid plexus involvement blocks cerebrospinal fluid flow, obstructive hydrocephalus may occur. Here we report the case of a 63-year-old woman who presented with choroid plexitis causing obstructive hydrocephalus at the foramen of Monro. Endoscopic biopsy confirmed Cryptococcus neoformans, and the patient was successfully treated with amphotericin, flucytosine, and fluconazole. With proper recognition and treatment of this pathology, patients can fully recover from this condition.

Solitary osteochondroma of the cervical spine presenting with quadriparesis and hand contracture.

BACKGROUND: Spinal osteochondromas are rare, benign tumors arising from the cartilaginous elements of the spine that may appear as solitary lesions versus multiple lesions in patients with hereditary multiple exostoses. Here, we present a 15-year-old female with a solitary C3-C4 osteochondroma who presented with a progressive quadriparesis and hand contracture successfully managed with a laminectomy/posterior spinal fusion. CASE DESCRIPTION: A 15-year-old female presented with a 3-month history of progressive quadriparesis and hand contracture secondary to a magnetic resonance (MR) documented C3-C4 cervical spine osteochondroma. The MR imaging revealed a solitary osseous extramedullary outgrowth arising from the left laminar cortex of the C-3 vertebral body extending to C-4. Due to the marked resultant canal stenosis, the patient underwent a cervical laminectomy of C3- C4 with posterior spinal fusion. Gross total resection was achieved, and the pathology confirmed an osteochondroma. The patient's myelopathy resolved, and 2 years later, she demonstrated no residual deficits or tumor recurrence. CONCLUSION: Here, we report the successful management of a 15-year-old female with a C3-C4 osteochondroma and progressive quadriparesis through cervical laminectomy/fusion.

Embolization and Open Decompression of a Giant Aneurysm Involving the P2 Segment of the Posterior Cerebral Artery.

A 5-year-old girl was brought to the clinic because of chronic intermittent left-sided headaches. The patient underwent computed tomographic angiography, which demonstrated a giant aneurysm that involved the P2 segment of the left posterior cerebral artery. Before treatment proceeded, consent was obtained from the patient's legal guardian. A trapping-evacuation technique was used for proximal control and decompression so that a clip could be placed on the proximal inflow artery of the aneurysm. First, embolization was performed for aneurysm trapping and for sacrifice of the parent vessel. Two days later, the patient was taken to the operating room for open surgical decompression, clipping, and reconstruction. Heparin was administered during the embolization stage of the operation. The patient did well postoperatively and was discharged home. The 3-month follow-up evaluation demonstrated a right superior homonymous quadrantanopia and no other neurologic deficits. The patient's clinical course is summarized in Video 1.

Laser Interstitial Thermal Therapy Case Series: Choosing the Correct Number of Fibers Depending on Lesion Size.

BACKGROUND: Laser interstitial thermal therapy (LITT) is being used for the treatment of recurrent glioblastoma multiforme (GBM). Lesions can be treated using 1 or multiple LITT fibers depending on the preference of surgeons. Usually, more fibers are needed for coverage of larger tumors. OBJECTIVE: To investigate and analyze how tumor size affected the number of LITT fibers used. METHODS: This is a retrospective review of patients undergoing treatment of recurrent GBM. Patients were treated with up to 4 LITT fibers for adequate tumor coverage. Patient demographics, tumor characteristics, length of stay, complications, and biopsy results were recorded. RESULTS: A total of 43 cases were treated using LITT, and of these cases, 31 consisted of contiguous lesions. We used more fibers to treat larger tumor volumes. On average, for each 5 cc of tumor volume, a fiber was added for proper coverage (P = .554). Complications and length of stay were similar across the groups (P = .378, P = .941). CONCLUSION: LITT can be used for the treatment of recurrent GBM. For each 5 cc of tumor volume, a LITT fiber can be added to the treatment plan.

Anatomy and white matter connections of the fusiform gyrus.

The fusiform gyrus is understood to be involved in the processing of high-order visual information, particularly related to faces, bodies, and stimuli characterized by high spatial frequencies. A detailed understanding of the exact location and nature of associated white-tracts could significantly improve post-operative morbidity related to declining capacity. Through generalized q-sampling imaging (GQI) validated by gross dissection as a direct anatomical method of identifying white matter tracts, we have characterized these connections based on relationships to other well-known structures. We created the white matter tracts using GQI and confirmed the tracts using gross dissection. These dissections demonstrated connections to the occipital lobe from the fusiform gyrus along with longer association fibers that course through this gyrus. The fusiform gyrus is an important region implicated in such tasks as the visual processing of human faces and bodies, as well as the perception of stimuli with high spatial frequencies. Post-surgical outcomes related to this region may be better understood in the context of the fiber-bundle anatomy highlighted by this study.

Rosette-forming glioneuronal tumor: an illustrative case and a systematic review.

BACKGROUND: Rosette-forming glioneuronal tumors (RGNTs) are rare, low-grade, primary CNS tumors first described in 2002 by Komori et al. RGNTs were initially characterized as a World Health Organization (WHO) grade I tumors typically localized to the fourth ventricle. Although commonly associated with an indolent course, RGNTs have the potential for aggressive behavior. METHODS: A comprehensive search of PubMed and Web of Science was performed through November 2019 using the search term "rosette-forming glioneuronal tumor." Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. English, full-text case reports and series with histopathological confirmation were included. Patient demographics, presentations, MRI features, tumor location, treatment, and follow-up of all 130 cases were extracted. RESULTS: A 19-year-old man with a history of epilepsy and autism presented with acute hydrocephalus. MRI scans from 2013 to 2016 demonstrated unchanged abnormal areas of cortex in the left temporal lobe with extension into the deep gray-white matter. On presentation to our clinic in 2019, the lesion demonstrated significant progression. The patient's tumor was identified as RGNT, WHO grade I. One hundred thirty patients were identified across 80 studies. CONCLUSION: RGNT has potential to transform from an indolent tumor to a tumor with more aggressive behavior. The results of our systematic review provide insight into the natural history and treatment outcomes of these rare tumors.