Efficacy of transvenous embolization of CSF-venous fistula in spontaneous intracranial hypotension: Case-series.

BACKGROUND: Spontaneous intracranial hypotension is a debilitating neurological condition which can be caused by a cerebrospinal fluid-venous fistula. Transvenous embolization is a promising technique to provide minimally invasive yet durable treatment. METHODS: A retrospective single-center case series was performed on all patients who underwent transvenous embolization of a cerebrospinal fluid (CSF)-venous fistula. Clinical and radiographic parameters, including Bern score, were reported preoperatively and at 3-month follow-up. RESULTS: Six patients underwent embolization of a CSF-venous fistula. All fistulae were located in the thoracic spine and technical success was achieved in all cases. Three patients had symptom resolution, two had significant improvement, and one had stable symptoms on follow-up. The mean Bern score was 6.83 (SD = 1.47) preoperatively and 1.83 (SD = 1.64) postoperatively with a mean improvement in Bern score of 5.0 (SD = 1.9, p = 0.0013). CONCLUSIONS: CSF-venous fistulas are an increasingly recognized clinical entity which may be treated with transvenous embolization. This case series serves to further validate this technique and suggests it can be performed with similar outcomes in lower volume centers.

Middle meningeal artery pseudoaneurysm and pterygoid plexus fistula following percutaneous radiofrequency rhizotomy: illustrative case.

BACKGROUND: Percutaneous treatment for trigeminal neuralgia is a safe and effective therapeutic methodology and can be accomplished in the form of balloon compression, glycerol rhizotomy, and radiofrequency thermocoagulation. These procedures are generally well tolerated and demonstrate minimal associated morbidity. Moreover, vascular complications of these procedures are exceedingly rare. OBSERVATIONS: We present the case of a 64-year-old female with prior microvascular decompression and balloon rhizotomy who presented after symptom recurrence and underwent a second balloon rhizotomy at our institution. Soon thereafter, she presented with pulsatile tinnitus and a right preauricular bruit on physical examination. Subsequent imaging revealed a middle meningeal artery (MMA) to pterygoid plexus fistula and an MMA pseudoaneurysm. Coil and Onxy embolization were used to manage the pseudoaneurysm and fistula. LESSONS: This case illustrates the potential for MMA pseudoaneurysm formation as a complication of percutaneous trigeminal balloon rhizotomy, which has not been seen in the literature. Concurrent MMA-pterygoid plexus fistula is also a rarity demonstrated in this case.

Prevalence of SLEC-negative spontaneous intracranial hypotension in patients with spinal nerve root sleeve diverticula on MRI.

PURPOSE: While there is thought to be an association between spinal nerve root diverticula (NRD) and spontaneous intracranial hypotension (SIH) without a spinal longitudinal epidural collection (SLEC), it remains unclear what the overall prevalence of SLEC-negative SIH is in patients with NRD on MRI. METHODS: Spine MRI imaging reports from our single institution were electronically screened for instances of NRD over a 9-year period (2016-2023). From these cases, patients with brain MRIs consistent with SIH were also identified. Subsequently, the overall proportion of SLEC-negative SIH was determined as a function of total cases with NRD based on spinal level. RESULTS: In total, 83,843 patients with spinal MRIs were screened which identified 4174 (4.97%) with NRD. From these, there were 1203 cervical, 622 thoracic, and 2979 lumbosacral spine MRIs. In total, 16 patients (0.38%; Standard Error [SE]: 0.48%-0.28%) had a brain MRI compatible with SLEC-negative SIH and met ICHD-3 criteria. Patients with cervical NRD had SIH in 2 cases (0.16%; SE: 0.27%-0.05%). SLEC-negative SIH was present in 11 patients with lumbosacral NRD (0.34%; SE: 0.44%-0.24%). In patients with diverticula in the thoracic spine, 14 (2.3%; SE: 2.8%-1.8%) had SLEC-negative SIH. SLEC-negative SIH was significantly more prevalent in patients with thoracic diverticula compared to those with cervical (p<.0001) or lumbosacral NRD (p<.0001). CONCLUSION: In patients with spinal NRD, concurrent SLEC-negative SIH is present in approximately 0.38% of patients, suggesting that in the vast majority of cases, they are an incidental finding. However, SIH is present in approximately 2.3% of patients with thoracic NRD and may be more specific for leak localization.

Direct percutaneous puncture versus transarterial embolization for head and neck paragangliomas: A systematic review and meta-analysis.

INTRODUCTION: Embolization of head and neck paragangliomas (HNPs) is a well-established treatment strategy and adjunctive therapy. However, the optimal mode of intervention, whether by direct percutaneous puncture (DP) or via transarterial embolization (TAE), remains unclear. METHODS: The aim of this study was to complete a systematic literature review and meta-analysis to compare the safety and efficacy of DP versus TAE for HNP embolization. The Cochrane Library and MEDLINE databases were used to identify studies describing the clinical outcomes of either DP or TAE for HNP embolization. Outcome measures included: complete angiographic devascularization, major complications, and minor complications. Pooled rates were calculated for each variable which were then compared with meta-regression using a random effects model. RESULTS: Thirty-one retrospective studies met inclusion criteria, detailing 394 patients with 411 HNPs. Overall, DP was associated with a higher rate of complete devascularization (91.5%, 95% confidence interval [CI]: 85.6% to 97.4%; I2 = 0%) when compared to TAE technique (40.1%, CI: 27.2% to 58.9%; I2 = 93%). However, there was no difference regarding major complication rates between DP (6%, CI:1.3% to 10.8%; I2 = 0%) and TAE for HNP embolization (3.3%, CI: 1.4% to 5.3%; I2 = 0%) (p = 0.370), nor in minor complications between the techniques (p = 0.211). Subgroup analysis of TAE embolic agents revealed that particle embolics were associated with a significantly lower rate of major complications (2.5%; 0.4% to 4.6%; I2 = 0%) when compared to liquid embolics (10.6%, CI:4% to 17.3%; I2 = 48%; p = 0.022). CONCLUSIONS: A DP approach for HNP embolization results in a higher rate of complete devascularization and with a similar complication profile when compared to TAE. These findings also suggest that particle embolics are associated with fewer major complications compared to liquid embolics when TAE is utilized.

A case of spontaneous basal ganglia hemorrhage with contralateral extension utilizing the canal of Gratiolet.

BACKGROUND: Intracranial hemorrhage accounts for 10-20% of stroke etiologies annually. Basal ganglia is the most common site for intracranial hemorrhage accounting for 50% of all cases. Bilateral spontaneous basal ganglia hemorrhages (BGH) are rare with few reported cases. CASE PRESENTATION: We report an unusual case of a 69-year-old female who presented with a spontaneous bilateral basal ganglia hemorrhage secondary to a right BGH with contralateral extension through the anterior commissure (AC) utilizing the Canal of Gratiolet. Clinical course and imaging findings are discussed. CONCLUSIONS: To our knowledge, this is the first case to specifically detail the extension of spontaneous hemorrhage across the AC via the Canal of Gratiolet, and imaging findings provide a novel depiction of AC anatomy and fiber distribution in a clinical context. These findings may explain the mechanism behind this rare clinical entity.

A pictorial review of imaging findings associated with upper cervical trauma.

The diagnosis of cervical spine injury in the emergency department remains a critical skill of emergency room physicians as well as radiologists. Such diagnoses are often associated with high morbidity and mortality unless readily identified and treated appropriately. Both computed tomography (CT) and magnetic resonance imaging (MRI) often are crucial in the workup of spinal injury and play a key role in arriving at a diagnosis. Unfortunately, missed cervical spine injuries are not necessarily uncommon and often precede detrimental neurologic sequalae. With the increase in whole-body imaging ordered from the emergency department, it is critical for radiologists to be acutely aware of key imaging features associated with upper cervical trauma, possible mimics, and radiographic clues suggesting potential high-risk patient populations. This pictorial review will cover key imaging features from several different imaging modalities associated with upper cervical spine trauma, explore patient epidemiology, mechanism, and presentation, as well as identify confounding radiographic signs to aid in confident and accurate diagnoses.

Confirmation of Intracranial Neuroendocrine Metastasis Using 68Ga-DOTATATE PET/CT.

Neuroendocrine tumors (NETs) are rare neoplasms with an exceedingly low incidence of intracranial metastasis. We present a 79-y-old woman with a biopsy-proven pulmonary neuroendocrine tumor who presented with an intracranial mass in the posterior fossa that was avid on 68Ga-DOTATATE PET/CT, facilitating the rare diagnosis of intracranial NET metastasis. The case highlights the utility of advanced imaging techniques in differentiating intracranial NET metastasis from other etiologies.

Management of postoperative cervical pseudomeningocele with percutaneous aspiration and epidural blood patch.

INTRODUCTION: While epidural blood patch can be an effective management option in lumbar pseudomeningoceles in certain clinical settings, its utility in the cervical spine is unclear. The aim of this study was to evaluate the safety and effectiveness of percutaneous aspiration and autologous blood patch for post-operative durotomy related pseudomeningoceles within the cervical spine. METHODS: A single institution retrospective review detailing 3 patients with durotomy related pseudomeningocele following posterior cervical spine surgery was completed. RESULTS: In all three cases, aspiration with subsequent injection of autologous epidural blood patch successfully treated each pseudomeningocele. One patient required more than one intervention, while the other two were successfully treated after one procedure. All three patients improved clinically without need for additional surgery. CONCLUSION: Percutaneous aspiration and epidural blood patch can be used to safely manage post-operative pseudomeningoceles within the posterior cervical spine.

Effect of Age on Cerebral Arteriovenous Malformation Draining Vein Stenosis.

OBJECTIVE: The pathogenesis of venous intimal hyperplasia and venous outflow stenosis associated with cerebral arteriovenous malformation (AVM) draining veins is poorly understood. We sought to determine the relationship between venous stenosis and age. METHODS: All patients with an AVM seen at our institution between 1990 and 2016 who underwent a diagnostic cerebral angiogram were retrospectively reviewed. Draining vein stenosis was measured from angiograms before any treatment. The relationship between venous stenosis and age was assessed. RESULTS: We included 281 patients (mean age 39 years, age range 3-83 years, 55% male). Venous stenosis measuring ≥50% was present in 59 patients (21% of cohort). Peak age at presentation was 25-29 years, whereas peak frequency of venous stenosis ≥50% was 50-54 years. Venous stenosis was present in a significantly higher proportion of patients ≥50 years versus <50 years (P = 0.03). Mean percentage stenosis was significantly higher in patients ≥50 years versus <50 years (32% vs. 22%, P = 0.001). CONCLUSIONS: Clinically significant cerebral AVM draining vein stenosis appears to be associated with older age, suggesting that venous stenosis is a progressive disease that occurs by the same process that leads to intimal hyperplasia. These results should be confirmed with a population-based longitudinal study.

Correlation Between Contrast Time-Density Time on Digital Subtraction Angiography and Flow: An in Vitro Study.

BACKGROUND AND PURPOSE: Digital subtraction angiography (DSA) provides an excellent anatomic characterization of cerebral vasculature, but hemodynamic assessment is often qualitative and subjective. Various clinical algorithms have been produced to semiquantify flow from the data obtained from DSA, but few have tested them against reliable flow values. METHODS: An arched flow model was created and injected with contrast material. Seventeen injections were acquired in anterior-posterior and lateral DSA projections, and 4 injections were acquired in oblique projection. Image intensity change over the angiogram cycle of each DSA run was analyzed through a custom MATLAB code. Time-density plots obtained were divided into 3 components (time-density times, TDTs): TDT10%-100% (time needed for contrast material to change image intensity from 10% to 100%), TDT100%-10% (time needed for contrast material to change image intensity from 100% to 10%), and TDT25%-25% (time needed for contrast material to change from 25% image intensity to 25%). Time-density index (TDI) was defined as model cross-sectional area to TDT ratio, and it was measured against different flow rates. RESULTS: TDI10%-100%, TDI100%-10%, and TDI25%-25% all correlated significantly with flow (P < 0.001). TDI10%-100%, TDI100%-10%, and TDI25%-25% showed, respectively, a correlation coefficient of 0.91, 0.91, and 0.97 in the anterior-posterior DSA projections (P < 0.001). In the lateral DSA projection, TDI100%-10% showed a weaker correlation (r = 0.57; P = 0.03). Also in the oblique DSA projection, TDIs correlated significantly with flow. CONCLUSIONS: TDI on DSA correlates significantly with flow. Although in vitro studies might overlook conditions that occur in patients, this method appears to correlate with the flow and could offer a semiquantitative method to evaluate the cerebral blood flow.

Cerebral Aneurysm Size and Distal Intracranial Hemodynamics: An Assessment of Flow and Pulsatility Index Using Quantitative Magnetic Resonance Angiography.

BACKGROUND: The relationship between cerebral aneurysm size and risk of rupture is well documented, but the impact of aneurysms on distal intracranial hemodynamics is unknown. OBJECTIVE: To examine the relationship between aneurysm size and distal intracranial hemodynamics prior to treatment. METHODS: Patients seen at our institution between 2006 and 2015 with cerebral aneurysms within the internal carotid artery (ICA) segments (proximal to ICA terminus) were retrospectively reviewed. Patients were included if the aneurysm was unruptured, and were excluded if a contralateral aneurysm was present. Flows within bilateral ICAs and middle cerebral arteries (MCA) were measured prior to any treatment using quantitative magnetic resonance angiography. Pulsatility index (PI = [systolic - diastolic flow velocity]/mean flow velocity) within each vessel was then calculated. Hemodynamic parameters were analyzed with respect to aneurysm size. RESULTS: Forty-two patients were included. Mean aneurysm size was 13.5 mm (range 2-40 mm). There was a significant correlation between aneurysm size and ipsilateral MCA PI (P = .006; r = 0.441), MCAipsilateral/ICAipsilateral PI ratio (P = .003; r = 0.57), and MCAipsilateral/MCAcontralateral PI ratio (P = .008; r = 0.43). Mean PI in the ipsilateral ICA was 0.38 (range 0.17-0.77) and ipsilateral MCA was 0.31 (range 0.08-0.83), and mean PI in contralateral ICA was 0.35 (range 0.19-0.57) and MCA was 0.30 (range 0.07-0.89). CONCLUSION: Larger aneurysm size correlates with higher ipsilateral MCA PI, demonstrating that aneurysms affect distal intracranial hemodynamics.

Evaluating Student Attitudes: Perceptions of Interprofessional Experiences Following Participation in a Student-Run Free Clinic.

It is increasingly evident that patient health outcomes are improved when they are treated by an effective interdisciplinary healthcare team. Many also endorse that learning to function collaboratively in interdisciplinary settings should start at the onset of one's medical education. Student-run free clinics, such as the University of Central Florida College of Medicine's (UCF COM) KNIGHTS (Keeping Neighbors In Good Health Through Service) Clinic, provide opportunities for students to work in concert with other healthcare professionals. This study aimed to discern whether volunteering in this setting had a positive impact on medical students' perception of working within an interdisciplinary team. A single survey was distributed via Qualtrics to all first and second-year medical students (N = 248) at the UCF COM. The items of interest examined in this study were part of a larger study described elsewhere. The mean responses on a 5-point Likert-like scale to these survey items were recorded and compared between two cohorts: KNIGHTS volunteers and non-volunteers. One hundred twenty-three (49.6%) students responded to the survey and most items showed no statistically significant difference between the two groups (p-value > 0.05). However, there were a few items of interest that did show a significant difference. These included KNIGHTS volunteers being much more likely to have worked with other healthcare professionals (p < 0.001) as well as believing themselves to have a better understanding of the role of medicine within an interprofessional team (p = 0.016). Additionally, KNIGHTS volunteers were more likely to feel like they understood the role of patient education (p = 0.031) and pharmacy (p = 0.040) within an interprofessional team. Interestingly, KNIGHTS volunteers were also more likely to believe that problem-solving skills should be learned with students within their own discipline (p = 0.009) as well as that there is little overlap between the roles of medical students and students from other healthcare disciplines (p = 0.044). Still, overall results showed that both volunteers and non-volunteers had an overall positive perception of interdisciplinary teams and working with other healthcare professionals.

The Effect of Volunteering at a Student-Run Free Healthcare Clinic on Medical Students' Self-Efficacy, Comfortableness, Attitude, and Interest in Working with the Underserved Population and Interest in Primary Care.

INTRODUCTION: The number of primary care physicians in the United States continues to lag behind the number of uninsured people. There has been a growing demand for medical students to improve their self-efficacy, comfortableness, attitude, and interest in working with the underserved and in primary care. This study aims to discern whether volunteering at a student-run, free healthcare clinic has a positive impact on these five variables of interest or not. METHODS: A 95-item survey was distributed through Qualtrics Survey Software (Qualtrics, Provo, UT, USA) to medical students from the Class of 2018 and Class of 2019 at the University of Central Florida College of Medicine. They were recruited via emails, Facebook, and in-classroom announcements. Mean responses on a Likert-like scale to different survey items were collected and compared between two study cohorts: Keeping Neighbors In Good Health Through Service (KNIGHTS) Clinic volunteers and non-volunteers. RESULTS: Results from 128 students showed no significant differences in the means between the two cohorts (p-values were not significant). When volunteers were asked the survey item, "KNIGHTS Clinic positively influenced my attitude towards working with underserved patients," 62% strongly agreed, 26% agreed, 10% were neutral, and 2% disagreed. DISCUSSION: Based on the results, volunteering at KNIGHTS Clinic may not have a positive impact on the five variables of interest. However, the lack of significance may also be due to certain limitations of this study addressed elsewhere in this paper. With the majority of KNIGHTS Clinic volunteers agreeing that "KNIGHTS Clinic positively influenced […their] attitude towards working with underserved patients," there may be a positive impact of volunteering on volunteers' attitude towards working with the underserved.

The Effect of Medical Student Volunteering in a Student-Run Clinic on Specialty Choice for Residency.

INTRODUCTION:  Student-run free clinics (SRFCs) are a recent popular addition to medical school education, and a subset of studies has looked at the influence of SRFC volunteering on the medical student's career development. The majority of the research done in this area has focused on understanding if these SRFCs produce physicians who are more likely to practice medicine in underserved communities, caring for the uninsured. The remainder of the research has investigated if volunteering in an SRFC influences the specialty choice of medical school students. The results of these specialty choice studies give no definitive answer as to whether medical students chose primary or specialty care residencies as a result of their SRFC experience. Keeping Neighbors in Good Health through Service (KNIGHTS) is the SRFC of the University of Central Florida College of Medicine (UCF COM). Both primary and specialty care is offered at the clinic. It is the goal of this study to determine if volunteering in the KNIGHTS SRFC influences UCF COM medical students to choose primary care, thereby helping to meet the rising need for primary care physicians in the United States. METHODS:  A survey was distributed to first, second, and third-year medical students at the UCF COM to collect data on demographics, prior volunteering experience, and specialty choice for residency. Responses were then combined with records of volunteer hours from the KNIGHTS Clinic and analyzed for correlations. We analyzed the frequency and Pearson's chi-squared values. A p value of less than 0.05 was considered statistically significant. RESULTS:  Our survey had a total response rate of 39.8%. We found that neither the act of becoming a KNIGHTS Clinic volunteer nor the hours volunteered at the KNIGHTS Clinic influenced the UCF COM student's choice to enter a primary care specialty (p = NS). Additionally, prior volunteering/clinical experience or the gender of the medical school student did not influence a student's choice to volunteer at the KNIGHTS Clinic. DISCUSSION:  Volunteering at KNIGHTS Clinic did not increase student choice to enter primary care, with students choosing other specialties at equal rates, probably due to the variety of specialties present at the KNIGHTS Clinic. This suggests that the volunteer attending physicians present at an SRFC may influence the choice of residency for students. It also suggests that SFRCs are not a viable tool to increase the number of primary care doctors in the United States.

Role of Gamma Knife® Radiosurgery for the Treatment of Brain Metastases from Gynecological Cancers.

OBJECTIVE: Gamma Knife® (GK) (Elekta Instruments, Stockholm, Sweden) radiosurgery is well established for treatment of brain metastases. There are limited data on patients treated with GK from gynecological cancers. The authors sought to determine the effectiveness of the GK in patients with brain metastases from gynecological cancers. METHODS: An IRB-approved database was queried for patients with gynecologic cancers treated with GK between June 1996 and May 2016. Imaging studies were reviewed post-SRS (stereotactic radiosurgery) to evaluate local control (LC) and distant brain control (DC). Overall survival (OS), local control, and distant brain control were calculated using the Kaplan-Meier (KM) method and log-rank test.  Results: Thirty-three patients underwent SRS for 73 separate cranial lesions. The median age was -58.5 years, and 17 (52%) also had extracranial metastases. Ten (30%) patients had previously received whole brain radiotherapy (WBRT), and 11 (33%) underwent concurrent WBRT. The median tumor volume was 0.96 cm3. Median radiographic follow-up was 11 months. At the time of treatment, 39% of patients were categorized as recursive partitioning analysis (RPA) Class I, 55% as RPA Class II, and 6% as RPA Class III. The local failure rate was 8%. Five patients (15%) developed new brain lesions outside the radiation field with a median progression-free survival (PFS) of seven (range: 3-9) months. Median OS was 15 months from GK treatment. One-year OS was 72.9% from GK treatment. Primary cancer histology was a significant predictor of OS, favoring ovarian and endometrial cancer (p = 0.03). CONCLUSIONS: Gamma Knife stereotactic radiosurgery for gynecologic brain metastases leads to excellent control rates of treated lesions. Primary histology may have a significant impact on OS following GK, with improved survival seen with ovarian and cervical cancer following Gamma Knife radiosurgery (p = 0.03).