Sex differences in reporting of concussion symptoms in adults.

Objective: To examine differences in concussion symptom reporting between female and male adults considering current psychological symptoms such as anxiety and depression and pre-injury factors in order to identify sex differences which may guide treatment efforts. Method: This prospective study is part of the North Texas Concussion Registry (ConTex). Subjects (N = 132) age 19 to 78 years had sustained a concussion within 30 days of clinic visit. The independent variable was sex and covariates included age, ethnicity, current anxiety and depression ratings, history of attention deficit disorder, history of headache/migraine, and time to clinic. The dependent variables were 22 post-concussion symptoms as measured by the Sport Concussion Assessment Tool-5 Post-Concussion Symptom Scale. Results: Analysis of covariance and ordinal logistic regression results both revealed that females had a greater likelihood of reporting increased symptom severity for 15/22 concussion symptoms. The largest risk ratios (effect size) in symptom reporting between sexes (higher symptoms in females) included: feeling more emotional 4.05 (0.72), fatigue or low energy 4.05 (0.72), sensitivity to light 3.74 (0.69), headache 3.65 (0.57), balance problems 3.31 (0.53), pressure in head 3.06 (0.51), and neck pain 2.97 (0.60). Conclusions: Adult females in our sample reported higher levels of many concussion symptoms than males and showed an increased risk of developing these same symptoms following concussion. Examination of the magnitude of sex difference in concussion symptom reporting will better inform medical staff to anticipate and address symptoms that may present greater challenges for adult females.

Resilience and recovery from sports related concussion in adolescents and young adults.

INTRODUCTION: Recovery and return to play are important milestones for athletes who sustain sport-related concussions (SRC). Several factors have been shown to influence resolution of post-concussion related symptoms (PCS), but resilience, a trait that reflects the ability to overcome adversity, is another factor that may influence recovery. The aim of this study was to determine the relationship of resilience with resolution of symptoms during recovery in adolescents and young adults following SRC. METHOD: This prospective study is part of the North Texas Concussion Registry (ConTex). Subjects (N = 332) aged 13 to 25 years who sustained a SRC within 10 days of presenting to clinic were evaluated at two time points: initial clinical visit and three-month follow-up. Resilience was measured by the self-report Brief Resilience Survey (BRS) and PCS by the Sport Concussion Assessment Tool-5 Symptom Evaluation Post-Concussion Symptom Scale (PCSS). Recovery was determined by self-reported return to sports/physical activity and percent back to normal. RESULTS: Repeated measures ANCOVA and linear regression models showed that lower resilience ratings at initial visit were associated with a greater number and severity of PCSS symptoms along with higher levels of anxiety and depression symptoms during recovery from SRC. At three months, subjects with lower initial resilience ratings were less likely to report feeling back to normal and had greater aggravation of symptoms from physical and cognitive activity even when they had returned to sports/physical activity. CONCLUSIONS: Lower resilience was associated with greater symptoms and delayed recovery from SRC. Results suggest that resilience may be another important factor to address in recovery from SRC. Future research is needed to examine the extent to which resilience measured after SRC reflects pre-injury characteristics and to better inform the development of interventions to promote resilience during recovery.

Sex Differences and Reporting of SCAT-5 Concussion Symptoms in Adolescent Athletes.

OBJECTIVE: To elucidate specific symptoms that may differ between adolescent female and male athletes after a sports-related concussion (SRC) and identify symptoms that may require greater clinical attention by medical and athletic staff. DESIGN: Prospective. SETTING: This study is part of a larger research project conducted at clinics in the North Texas Concussion Network (ConTex) Registry. PARTICIPANTS: Subjects (N = 491) aged 12 to 18 years who sustained a diagnosed SRC within 30 days of clinic visit. INDEPENDENT VARIABLES: Sex (female vs male). Covariates included age, race, current mood (anxiety and depression), learning disability/ADHD, and time to clinic. MAIN OUTCOME MEASURES: Twenty-two individual postconcussion symptoms as measured by the Post-Concussion Symptom Scale from the Sport Concussion Assessment Tool-5 (SCAT-5). RESULTS: Girls endorsed higher levels of anxiety and depression symptoms at initial clinic visit. analysis of covariance results revealed that girls had significantly greater symptom severity of headache, dizziness, sensitivity to light, sensitivity to noise, pressure in the head, feeling slowed down, fatigue, and drowsiness than boys. Ordinal logistic regression results also revealed that girls had significantly greater predicted odds of higher symptom severity on these 8 symptoms and in trouble concentrating than boys. CONCLUSIONS: Closer examination of specific symptoms with attention to patients' current levels of anxiety and depression symptoms may better inform medical and athletic staff to anticipate and address symptoms that may present greater challenges for adolescent girls than boys.

Seizure outcome in patients with cavernous malformation after early surgery.

OBJECTIVE: To describe seizure outcome and complications in patients with cavernous malformations (CM) undergoing early versus late surgery. METHODS: A database was created for all CM patients who presented with seizure referred to the neurosurgical clinic at an academic center. A telephone survey and chart review were conducted to evaluate for preoperative and postoperative seizure frequency. Postoperative seizure-free outcome of patients who had ≤2 preoperative seizures versus those that had >2 preoperative seizures was compared. RESULTS: A total of 35 CM patients were included for analysis. Nineteen patients had ≤2 preoperative seizures and 16 patients had >2 preoperative seizures, six of them drug resistant for over two years. Among the ≤2 seizure group, 15 had only a single seizure before surgical resection. 94.7% of patients with ≤2 preoperative seizures and 62.5% of patients with >2 preoperative seizures were seizure free one year following surgical resection (p = 0.019). 78.9% of patients with ≤2 preoperative seizures and 25% of patients with >2 preoperative seizures were able to wean off AEDs (p < 0.001). Among those patients who had a single preoperative seizure, 100% of patients were seizure free at one year. CONCLUSIONS: Early surgical resection for CM patients who present after a CM-related seizure is an effective, well tolerated treatment and has good chance to offer seizure freedom without the need for long-term antiepileptic medications. Outcome for patients operated with only one or two preoperative seizures may lead to better results than patients who delay the procedure.

Differences in Adolescent Symptom Reporting Following Motor Vehicle Accident Versus Sport-Related Concussion.

OBJECTIVE: To characterize potential differences in youth concussion sustained in motor vehicle accident (MVA) versus sport-related concussion (SRC), hypothesizing that youth who sustain concussion in a MVA would endorse higher initial and persistent symptom scores compared to those with SRC, despite similar injury severity levels. METHODS: Participants age 12-18 who sustained a concussion (i.e., Glasgow Coma Scale = 13-15) in a MVA (n = 35) were matched with SRC participants (n = 35) by sex, age, and days since injury. ANCOVA comparing initial postconcussion total symptom scores between the MVA and SRC groups were performed. Chi-square analysis with injury group by recovery time was used to determine whether youth who sustained concussion from MVA were more likely to endorse symptoms persisting >30 days at 3 months postinjury, and ANCOVA compared 3-month total symptom scores. RESULTS: On average, the MVA group reported significantly higher initial postconcussion and more frequent persistent symptom scores compared to the SRC group. CONCLUSIONS: This is the first known study to examine context of injury in youth concussion while matching for injury severity, age, sex, and days since injury. Findings suggest the context of injury is an important clinical variable related to initial reporting of symptoms and endorsement of symptoms lasting more than 30 days. Tailored interventions that consider the context of injury may facilitate symptom resolution.

Inchoate guidelines of endoscopic resection of colloid cysts.

Colloid cyst are cystic lesions in the third ventricle and could render patients asymptomatic. However, there is an inherent risk of symptomatic progression, acute decompensation, and sudden death. Therefore, there is no clear consensus as how to observe or when to treat a newly diagnosed patient with a colloid cyst. The authors' objective is to identify the risk factors and then develop a risk stratification score to guide neurosurgeons during acute or chronic presentation. Radiological imaging characteristics have been outlined for the risk stratification as well preoperative evaluation. A baseline neuropsychological evaluation is helpful to obtain during an incidental presentation because history and neurological examination could be inconclusive in these cases. Radiological imaging with an MRI brain scan plays a vital role for the initial screening (determination of the cyst size, exact location, and the imaging characteristics) as well as for the preoperative planning. Stereotactic guidance is a high yield, followed by neuroendoscopic resection of the colloid cyst has been an established approach to resect these lesions. Modified colloid cyst risk scoring (mCCRS) system is robust and detailed for the optimal risk stratification of colloid cyst presentation. Stereotactic guided neuroendoscopic resection of the colloid cyst is a safe and efficacious approach to manage these lesions. The intended use, crucial steps involved, and the limitations of the technique have been discussed especially with a focus on the recurrence. Moreover, a comprehensive treatment algorithm has been presented.

Diffuse intrinsic pontine gliomas: Diagnostic approach and treatment strategies.

Diffuse intrinsic pontine gliomas (DIPG) are high grade gliomas of the brainstem with fatal outcomes. Radiation is known to be partially effective to control the immediate flare but relapse is frequent. There has been ongoing research to study the role of molecular subgroups and identification of specific targets but this is not possible with histopathological diagnosis alone. The authors' objective is to highlight the need for and discuss ongoing molecular research. There is an inherent need for the availability of tumor tissue to be able to conduct research studies. The authors advocate the use of neuronavigation assisted stereotactic technique for tumor biopsy. The technique is feasible with a predefined surgical trajectory. After obtaining tissue diagnosis further work can be performed to isolate and identify histone protein genetic mutations and methylation changes responsible for DIPG molecular subgrouping. Moreover, convection enhanced delivery of therapeutic agents is being developed for better instillation of future drug agents. Despite identification of genetic/epigenetic mutations, growth factors, receptors, and tissue biomarkers, the oncogenesis of DIPG remains elusive. The authors' effort to provide a comprehensive review on DIPG to better understand the disease, need for tissue diagnosis, described surgical technique, and need for pre-clinical and clinical future research is novel.

Tulip Giant Aneurysm Amputation and "Shingle Clip Cut Clip" Technique for Microsurgical Reconstruction of a Giant Thrombosed Middle Cerebral Artery Aneurysm.

In this video, we present the case of a 61-year-old female who was brought to the emergency department after she had partial complex seizures. Computed tomography and magnetic resonance imaging of the brain revealed a right temporal lobe mass, which was initially thought to be a tumor. The patient was therefore referred to us for further management. The round nature of the lesion raised suspicion for an aneurysm. Computed tomography angiography was performed, followed by a diagnostic conventional cerebral angiogram, and confirmed the presence of a giant thrombosed aneurysm. Giant aneurysms represent 3%-5% of all cerebral aneurysms.1 They are more common in females with a ratio of 2:1 to 3:1.1 They have a high risk of rupture up to 50% in the posterior circulation and 40% in the anterior circulation over 5 years according to the International Study of Unruptured Intracranial Aneurysms Investigators.2,3 Their treatment can be complex and treacherous. Treatment options vary widely from parent artery sacrifice in select cases to clip reconstruction to an array of endovascular approaches such as flow diversion. In some cases a combination of both open and endovascular approaches might be necessary.4-8 In our case, we opted for an open surgical clip reconstruction. A superior temporal artery-middle cerebral artery bypass was attempted to allow for trapping of the aneurysm without risking ischemic complication distal to it. Unfortunately, the patient's vessels were too atherosclerotic to maintain patency. A strategy was then devised, which consisted of cutting the dome of the aneurysm and clearing the distal two thirds of the clot ("tulip technique") and then completing thrombus resection under temporary occlusion. Once clot removal was completed, the aneurysm was clipped using the "shingle clip cut clip" technique (Video 1). The patient's postoperative course was uneventful, and the patient remained seizure free.

Traumatic Brain Injury and Risk of Long-Term Brain Changes, Accumulation of Pathological Markers, and Developing Dementia: A Review.

Traumatic brain injuries (TBI) have received widespread media attention in recent years as being a risk factor for the development of dementia and chronic traumatic encephalopathy (CTE). This has sparked fears about the potential long-term effects of TBI of any severity on cognitive aging, leading to a public health concern. This article reviews the evidence surrounding TBI as a risk factor for the later development of changes in brain structure and function, and an increased risk of neurodegenerative disorders. A number of studies have shown evidence of long-term brain changes and accumulation of pathological biomarkers (e.g., amyloid and tau proteins) related to a history of moderate-to-severe TBI, and research has also demonstrated that individuals with moderate-to-severe injuries have an increased risk of dementia. While milder injuries have been found to be associated with an increased risk for dementia in some recent studies, reports on long-term brain changes have been mixed and often are complicated by factors related to injury exposure (i.e., number of injuries) and severity/complications, psychiatric conditions, and opioid use disorder. CTE, although often described as a neurodegenerative disorder, remains a neuropathological condition that is poorly understood. Future research is needed to clarify the significance of CTE pathology and determine whether that can explain any clinical symptoms. Overall, it is clear that most individuals who sustain a TBI (particularly milder injuries) do not experience worse outcomes with aging, as the incidence for dementia is found to be less than 7% across the literature.

Ventriculoperitoneal Shunt Outcomes of Normal Pressure Hydrocephalus: A Case Series of 116 Patients.

Background Permanent cerebrospinal fluid (CSF) diversion with a ventriculoperitoneal shunt (VPS) is a treatment option for patients with normal pressure hydrocephalus (NPH). Objectives Herein, we examine the outcomes, complication rates, and associations between predictors and outcomes after VPS in patients with NPH. Methods This was a retrospective review of 116 patients (68 males, 48 females) with NPH who underwent VPS placement from March 2008 to September 2017 after demonstrating objective and/or subjective improvement after a lumbar drain trial. The Chi-square test of independence was used to examine associations between predictors and clinical improvement after shunting. Complications associated with the VPS procedure were recorded. Results The mean age was 77 years (range 52-93). The mean duration of disturbance in gait, cognition, and continence were 29, 32, and 28 months, respectively. Of the 116 patients, 111 followed up at two weeks; of these, improvement in gait, incontinence, and cognition were reported in 72, 20, and 23 patients, respectively. Gait improved more than incontinence or cognition. A shorter duration of gait disturbance predicted an improvement in gait after shunting (p<0.01). Being on a cognition-enhancing medication predicted an improvement in cognition and/or incontinence after shunting (p<0.05). Complications included misplaced proximal catheters (n=6), asymptomatic catheter tract hemorrhages (n=3), bilateral hygromas (n=7), subdural hematomas (SDH) (n=5), and CSF leak (n=1). Conclusion VPS placement in patients with NPH is well-tolerated and associated with improved outcomes at least in the short-term follow-up (<6 months). A shorter duration of gait disturbance and being on a cognition-enhancing medication are associated with greater improvement after VPS.

Current State of the Literature on Psychological and Social Sequelae of Sports-Related Concussion in School-Aged Children and Adolescents.

Considerably less attention has been paid to psychological and social sequelae of concussion in youth athletes compared with neurocognitive outcomes. This narrative review consolidates the literature on postconcussive emotional and psychosocial functioning in school-aged children and adolescents, highlighting athlete-specific findings. MEDLINE and PsycINFO databases were queried for pediatric concussion studies examining psychological and/or social outcomes, and 604 studies met search criteria (11 of those specific to sport). Results were organized into domains: emotional and social dysfunction, behavioral problems, academic difficulties, sleep disturbance, headache, and quality of life. The small body of literature regarding psychological and social issues following pediatric concussion suggests behavioral disturbances at least temporarily disrupt daily life. Extrapolation from samples of athletes and nonathletes indicates postconcussive anxiety and depressive symptoms appear, although levels may be subclinical. Social and academic findings were less clear. Future well-controlled and adequately powered research will be essential to anticipate concussed athletes' psychosocial needs.

Objective Pupillometry as an Adjunct to Prediction and Assessment for Oculomotor Nerve Injury and Recovery: Potential for Practical Applications.

BACKGROUND: Pupillary light reflex examinations are intrinsic to any good neurological examination. Consistent evidence has shown that automated pupillometry assessments provide superior accuracy and interrater correlation compared with bedside eye examinations. Pupillary indexes such as the neurological pupil index (NPI) can also provide several hours of warning before the advent of herniation syndromes or third nerve palsy. METHODS: We determined the unique temporal relationship between NPI changes and third nerve palsy occurrence and recovery in an initially neurologically intact hospitalized patient. A 53-year-old woman presented with aneurysmal subarachnoid hemorrhage and headaches. Her aneurysm was treated surgically without complications. After lumbar drainage for hydrocephalus, she developed isolated left third nerve palsy that slowly recovered over the following weeks. Pupilometer data were obtained throughout her hospital stay. RESULTS: A total of 121 pupillary measurement sets were obtained. The NPI had decreased to an abnormal level (<3) 12 hours before she became symptomatic. The NPI also started improving 24 hours before improvement in her clinical examination. The patient did not display signs of neurological dysfunction related to vasospasm during her stay. CONCLUSION: The NPI seems to reliably correlate with third nerve function and appears to possess predictive temporal properties that could allow practitioners to anticipate neurological injury and recovery. These findings could affect the fields of neurosciences, trauma, military medicine, critical care, and ophthalmology.

Transcavernous Approach to the Basilar Apex: A Cadaveric Prosection.

The transcavernous approach to the basilar artery, as initially described by Dolenc, is one of the most common and elegant approaches to the region. It affords a generous working and viewing angle, but it can be technically challenging and requires attention to detail at each step. We investigate this approach in this report via a cadaveric prosection with a focus on the value of each of the component steps in improving surgical view and exposure. The transcavernous approach steps are divided into extradural stages: orbitozygomatic osteotomy (a modern adjunct to Dolenc's original description), drilling of the lesser sphenoid wing, and anterior clinoidectomy; and intradural stages: wide splitting of the Sylvian fissure, unroofing of the oculomotor and trochlear nerves, and posterior clinoidectomy. The surgical windows afforded by each step in the approach are illustrated using microscopic images taken during the cadaveric prosection of a donor who happened to harbor a basilar apex aneurysm. An illustrative case and artist illustrations are used to emphasize the relative value of each step of the transcavernous exposure.

National Football League Head, Neck and Spine Committee's Concussion Diagnosis and Management Protocol: 2017-18 season.

One of the National Football League's (NFL) Head, Neck and Spine Committee's principal goals is to create a 'best practice' protocol for concussion diagnosis and management for its players. The science related to concussion diagnosis and management continues to evolve, thus the protocol has evolved contemporaneously. The Fifth International Conference on Concussion in Sport was held in Berlin in 2016, and guidelines for sports concussion diagnosis and management were revised and refined. The NFL Head, Neck and Spine Committee has synthesised the most recent empirical evidence for sports concussion diagnosis and management including the Berlin consensus statement and tailored it to the game played in the NFL. One of the goals of the Committee is to provide a standardised, reliable, efficient and evidence-based protocol for concussion diagnosis and management that can be applied in this professional sport during practice and game day. In this article, the end-of-season version of the 2017-18 NFL Concussion Diagnosis and Management Protocol is described along with its clinical rationale. Immediate actions for concussion programme enhancement and research are reviewed. It is the Committee's expectation that the protocol will undergo refinement and revision over time as the science and clinical practice related to concussion in sports crystallise.

Consistency of traumatic brain injury reporting in older adults with and without cognitive impairment.

OBJECTIVE: Medical history information regarding prior traumatic brain injury (TBI) usually relies on self-report, although little is known about the reliability of this information with regard to injuries sustained years or decades earlier. Even less is known about the reliability of self-reported medical history information in older individuals with cognitive impairment. To this end, we assessed the test-retest reliability of self-reported TBI history in a large, national sample. METHODS: Participants (n = 4309) were older adults with intact cognition, mild cognitive impairment (MCI) and Alzheimer's disease (AD) from the National Alzheimer's Coordinating Center. Subjects provided TBI history information at baseline and one annual follow-up visit. Consistency of self-reported history of TBI with <5 minutes loss of consciousness (mLOC) and TBI with ≥5 mLOC reported at time 1 and 2 was analyzed across diagnostic groups. RESULTS: Overall, subjects provided reports of TBI history at follow-up that were highly consistent with baseline reports (97.8-99.6% agreement), and Cohen's kappa coefficients were all larger than .80 and statistically significant, maximum p < .001. Furthermore, level of cognitive impairment was not a significant predictor of consistency in reporting. CONCLUSIONS: These data are some of the first to suggest that self-report may be a consistent method of obtaining remote TBI history in the absence of medical records for older individuals, regardless of cognitive impairment.

Use of a harvested radial artery graft with preservation of the vena comitantes to reduce spasm risk and improve graft patency for extracranial to intracranial bypass: Technical note.

BACKGROUND AND SIGNIFICANCE: The vessels of choice for cerebrovascular high-flow direct bypass procedures are the radial artery and the saphenous vein. Radial artery grafts have become favored over saphenous vein grafts because of higher patency rates and better size matching to appropriate recipient vessels. Radial grafts are prone to spasm however, and this may be seen in 4-10% of cases and can be associated with ischemic sequelae. The standard technique for radial artery harvest calls for complete separation of the artery from its adventitial attachments and associated venous network. There is reason to believe that this could contribute to spasm risk and possibly even thrombosis. Radial graft outcomes appear to be improved when the vena comitantes is preserved in cardiac and peripheral applications. We report the novel use of a harvested radial artery graft with preservation of its venae comitantes for extracranial to intracranial bypass. CLINICAL PRESENTATION: The patient is a 59-year-old male who had a blunt head trauma with associated loss of consciousness and who was led to the incidental discovery of a large fusiform middle cerebral artery (MCA) aneurysm. CONCLUSION: Preservation of the vena comitantes when harvesting a radial arterial graft for bypass, along with dual (arterial and venous) anastomoses, and concomitant use of intra-operative vaso-dilatory maneuvers to prevent spasm, may improve overall graft patency and patient outcome.

Evidence of increased brain amyloid in severe TBI survivors at 1, 12, and 24 months after injury: report of 2 cases.

Traumatic brain injury (TBI) is a major risk factor for Alzheimer's disease. With respect to amyloid deposition, there are no published serial data regarding the deposition rate of amyloid throughout the brain after TBI. The authors conducted serial (18)F-AV-45 (florbetapir F18) positron emission tomography (PET) imaging in 2 patients with severe TBI at 1, 12, and 24 months after injury. A total of 12 brain regions were surveyed for changes in amyloid levels. Case 1 involved a 50-year-old man who experienced a severe TBI. Compared with the 1-month time point, of the 12 brain regions that were surveyed, a decrease in amyloid (as indicated by standard uptake value ratios) was only observed in the hippocampus (-16%, left; -12%, right) and caudate nucleus (-18%, left; -18%, right), suggesting that initial amyloid accumulation in the brain was cleared between time points 1 and 12 months after injury. Compared to the scan at 1 year, a greater increase in amyloid (+15%) was observed in the right hippocampus at the 24-month time point. The patient in Case 2 was a 37-year-old man who suffered severe trauma to the head and a subsequent stroke; he had poor cognitive/functional outcomes and underwent 1.5 years of rehabilitation. Due to a large infarct area on the injured side of the brain (right side), the authors focused primarily on brain regions affected within the left hemisphere. Compared with the 1-month scan, they only found an increase in brain amyloid within the left anterior putamen (+11%) at 12 months after injury. In contrast, decreased amyloid burden was detected in the left caudate nucleus (-48%), occipital cortex (-21%), and precuneus (-19%) brain regions at the 12-month time point, which is indicative of early accumulation and subsequent clearance. In comparison with 12-month values, more clearance was observed, since a reduction in amyloid was found at 24 months after trauma within the left anterior putamen (-12%) and occipital cortex (-15%). Also, by 24 months, most of the amyloid had been cleared and the patient demonstrated improved results on the Rivermead symptom questionnaire, Glasgow Outcome Scale-Extended, and Disability Rating Scale. With respect to APOE status, the patient in Case 1 had two ε3 alleles and the patient in Case 2 had one ε2 and one ε3 allele. In comparison to the findings of the initial scan at 1 month after TBI, by 12 and 24 months after injury amyloid was cleared in some brain regions and increased in others. Serial imaging conducted here suggests that florbetapir F18 PET imaging may be useful in monitoring amyloid dynamics within specific brain regions following severe TBI and may be predictive of cognitive deficits.

Snapshot MR technique to measure OEF using rapid frequency mapping.

Magnetic resonance (MR)-based oxygen extraction fraction (OEF) measurement techniques that use blood oxygen level-dependent (BOLD)-based approaches require the measurement of the R2' decay rate and deoxygenated blood volume to derive the local oxygen saturation in vivo. We describe here a novel approach to measure OEF using rapid local frequency mapping. By modeling the MR decay process in the static dephasing regime as two separate dissipative and oscillatory effects, we calculate the OEF from local frequencies measured across the brain by assuming that the biophysical mechanisms causing OEF-related frequency changes can be determined from the oscillatory effects. The Parameter Assessment by Retrieval from Signal Encoding (PARSE) technique was used to acquire the local frequency change maps. The PARSE images were taken on 11 normal volunteers, and 1 patient exhibiting hemodynamic stress. The mean MR-OEF in 11 normal subjects was 36.66±7.82%, in agreement with positron emission tomography (PET) literature. In regions of hemodynamic stress induced by vascular steal, OEF exhibits the predicted focal increases. These preliminary results show that it is possible to measure OEF using a rapid frequency mapping technique. Such a technique has numerous advantages including speed of acquisition, is noninvasive, and has sufficient spatial and temporal resolution.

Three-dimensional hemodynamics in intracranial aneurysms: influence of size and morphology.

PURPOSE: To use four-dimensional (4D)-flow MRI for the comprehensive in vivo analysis of hemodynamics and its relationship to size and morphology of different intracranial aneurysms (IA). We hypothesize that different IA groups, defined by size and morphology, exhibit different velocity fields, wall shear stress, and vorticity. MATERIALS AND METHODS: The 4D-flow MRI (spatial resolution = 0.99-1.8 × 0.78-1.46 × 1.2-1.4 mm(3) , temporal resolution = 44-48 ms) was performed in 19 IAs (18 patients, age = 55.4 ± 13.8 years) with saccular (n = 16) and fusiform (n = 3) morphology and different sizes ranging from small (n = 8; largest dimension = 6.2 ± 0.4 mm) to large and giant (n = 11; 25 ± 7 mm). Analysis included quantification of volumetric spatial-temporal velocity distribution, vorticity, and wall shear stress (WSS) along the aneurysm's 3D surface. RESULTS: The 4D-flow MRI revealed distinct hemodynamic patterns for large/giant saccular aneurysms (Group 1), small saccular aneurysms (Group 2), and large/giant fusiform aneurysms (Group 3). Saccular IA (Groups 1, 2) demonstrated significantly higher peak velocities (P < 0.002) and WSS (P < 0.001) compared with fusiform aneurysms. Although intra-aneurysmal 3D velocity distributions were similar for Group 1 and 2, vorticity and WSS was significantly (P < 0.001) different (increased in Group 1 by 54%) indicating a relationship between IA size and hemodynamics. Group 3 showed reduced velocities (P < 0.001) and WSS (P < 0.001). CONCLUSION: The 4D-flow MRI demonstrated the influence of lesion size and morphology on aneurysm hemodynamics suggesting the potential of 4D-flow MRI to assist in the classification of individual aneurysms.