Effects of the presence and absence of amino acids on translation, signaling, and long-term depression in hippocampal slices from Fmr1 knockout mice.

Fragile X syndrome (FXS) is caused by silencing of the FMR1 gene and consequent absence of its protein product, fragile X mental retardation protein (FMRP). FMRP is an RNA-binding protein that can suppress translation. The absence of FMRP leads to symptoms of FXS including intellectual disability and has been proposed to lead to abnormalities in synaptic plasticity. Synaptic plasticity, protein synthesis, and cellular growth pathways have been studied extensively in hippocampal slices from a mouse model of FXS (Fmr1 KO). Enhanced metabotropic glutamate receptor 5 (mGluR5)-dependent long-term depression (LTD), increased rates of protein synthesis, and effects on signaling molecules have been reported. These phenotypes were found under amino acid starvation, a condition that has widespread, powerful effects on activation and translation of proteins involved in regulating protein synthesis. We asked if this non-physiological condition could have effects on Fmr1 KO phenotypes reported in hippocampal slices. We performed hippocampal slice experiments in the presence and absence of amino acids. We measured rates of incorporation of a radiolabeled amino acid into protein to determine protein synthesis rates. By means of western blots, we assessed relative levels of total and phosphorylated forms of proteins involved in signaling pathways regulating translation. We measured evoked field potentials in area CA1 to assess the strength of the long-term depression response to mGluR activation. In the absence of amino acids, we replicate many of the reported findings in Fmr1 KO hippocampal slices, but in the more physiological condition of inclusion of amino acids in the medium, we did not find evidence of enhanced mGluR5-dependent LTD. Activation of mGluR5 increased protein synthesis in both wild type and Fmr1 KO. Moreover, mGluR5 activation increased eIF2α phosphorylation and decreased phosphorylation of p70S6k in slices from Fmr1 KO. We propose that the eIF2α response is a cellular attempt to compensate for the lack of regulation of translation by FMRP. Our findings call for a re-examination of the mGluR theory of FXS.

Complications in Patients Undergoing Microsurgical Clipping of Intracranial Aneurysms with Pre-existing Ventriculoperitoneal Shunts Following a Cranial Procedure.

INTRODUCTION: Patients with ventriculoperitoneal/pleural (VP) shunts occasionally must undergo subsequent craniotomy, craniectomy, or cranioplasty. Due to changes in pressure dynamics following shunt placement, we hypothesized that such patients may have an increased risk of developing symptomatic collections of extra-axial blood, fluid, and/or air postoperatively, leading to longer stays and worse outcomes compared to those undergoing cranial operations without a VP shunt. METHODS: From a retrospective cohort of patients who underwent cranial operations for management of cerebral aneurysms in 2005-2014, we identified patients who previously had a VP shunt placed, determined the temporal relationship between shunt placement and cranial operation, and investigated outcomes in those with and without a shunt. RESULTS: Of 818 patients who underwent cranial operations, 28 (3.4%) had a VP shunt. Four of these 28 (14.3%, 95% confidence interval [CI] 4.0%-32.7%) developed postoperative complications, compared to 42 of 790 (5.3%, 95% CI 4.0%-7.1%) without a history of VP shunt (P = .07). In addition, patients with a shunt were more likely to have longer cranial procedures (P = .04), longer hospital stays (P = .05), and more computed tomography scans during their craniotomy-associated admission (P = .002). Multivariate analysis, though not significant, demonstrated that the presence of a shunt contributed to the development of complications (odds ratio [OR] 2.24, 95% CI .70-7.13, P = .17). Length of surgery (OR 1.17, 95% CI 1.04-1.31, P = .01) and length of stay (OR 1.04, 95% CI 1.01-1.07, P = .01) were significantly longer in those with a postoperative complication. CONCLUSION: We found a nonsignificant trend toward increased postoperative complications in patients with a VP shunt who underwent a subsequent cranial operation.

Identification of fragile X syndrome specific molecular markers in human fibroblasts: a useful model to test the efficacy of therapeutic drugs.

Fragile X syndrome (FXS) is the most frequent cause of inherited intellectual disability and autism. It is caused by the absence of the fragile X mental retardation 1 (FMR1) gene product, fragile X mental retardation protein (FMRP), an RNA-binding protein involved in the regulation of translation of a subset of brain mRNAs. In Fmr1 knockout mice, the absence of FMRP results in elevated protein synthesis in the brain as well as increased signaling of many translational regulators. Whether protein synthesis is also dysregulated in FXS patients is not firmly established. Here, we demonstrate that fibroblasts from FXS patients have significantly elevated rates of basal protein synthesis along with increased levels of phosphorylated mechanistic target of rapamycin (p-mTOR), phosphorylated extracellular signal regulated kinase 1/2, and phosphorylated p70 ribosomal S6 kinase 1 (p-S6K1). The treatment with small molecules that inhibit S6K1 and a known FMRP target, phosphoinositide 3-kinase (PI3K) catalytic subunit p110ß, lowered the rates of protein synthesis in both control and patient fibroblasts. Our data thus demonstrate that fibroblasts from FXS patients may be a useful in vitro model to test the efficacy and toxicity of potential therapeutics prior to clinical trials, as well as for drug screening and designing personalized treatment approaches.

Incidence and risk factors for cognitive impairment in rural elderly populations in Costa Rica.

Risk factors for the onset of cognitive impairment in Costa Rica are not well understood, despite a substantial elderly population stemming from a higher than average life expectancy for the western hemisphere. To investigate the risk factors that predict the onset of cognitive impairment in the rural elderly of Costa Rica, a modified version of the Mini Mental State Exam-designed for illiterate populations-was administered to 90 elderly inhabitants of San Carlos, Alajuela, Costa Rica between April and May of 2011. Subsequently, each participant took a structured interview assessing viability of risk factors and behaviors potentially contributing to a diagnosis of cognitive impairment. Results showed strong dependencies between age (p = 0.0001), education level (p = 0.0095), the ability to read (p = 0.0001) and write (p = 0.0153), frequency of reading (p = 0.0011), use of puzzles and mind games (p < 0.0001), vocation (p = 0.0225), area of residence (p < 0.0001), comorbid mental dis- eases (p = 0.0005), history of stroke or brain trauma (p = 0.0104), urinary or renal problems (p = 0.0443), consistent cooking practices (p = 0.0262) and number of living companions (p = 0.0299) in susceptibility for developing cognitive impairment. The study concluded that high intellectual use, or lack thereof, during the lifetime of a person was a predictor for cognitive status later in life. In addition, comorbid mental disorders, including neu- rological trauma due to stroke, impeded normal cognitive function. Future research should examine incidence and risk factors of cognitive impairment in urban, more educated populations.

Trans-lamina Terminalis Approach for Resection of Third Ventricular Tumor.

Granular cell tumors are rare vascular neoplastic lesions of the sellar and suprasellar region that usually arise from the pituitary stalk but can originate as low as the posterior pituitary or as high as the tuber cinereum.1 Complete resection, although ideal, can yield high rates of endocrine or visual morbidity.1,2 On headache workup, a 66-year-old woman was found to have a 1.2 × 1.1 × 1.3-cm contrast-enhancing lesion in the anterior-inferior third ventricle, posterior to the infundibulum. Endocrine testing was unremarkable, and a lumbar puncture was nondiagnostic. An open biopsy and possible resection were selected by the patient over short-interval imaging. A translamina terminalis approach was selected over a transsphenoidal approach to preserve the third ventricular floor (Video 1). A right frontotemporal craniotomy was performed, including flattening of the lesser sphenoid wing. The optic chiasm was exposed via subfrontal microsurgical dissection, and the lamina terminalis was opened sharply. A firm, vascular tumor was identified extending into the anterior-inferior aspect of the third ventricle. Frozen pathologic analysis was nondiagnostic. Given the proximity of the optic chiasm, a complete piecemeal microsurgical resection was performed, preserving the floor and lateral walls of the third ventricle and optic apparatus. Final pathology was a granular cell tumor. Postoperatively, the patient had transient diabetes insipidus, with preserved vision and normal endocrine function on follow-up. The trans-lamina terminalis approach can be used for safe resection of anterior third ventricular tumors. Preservation of the floor and walls of the third ventricle is critical to avoid morbidity.

Superficial abdominal reflex in syringomyelia: Associations with Chiari I malformation.

An abnormal or absent superficial abdominal reflex (SAR) may be associated with an underlying spinal cord syrinx. The sensitivity of an abnormal or absent SAR and the relationship to Chiari malformation type I (CM-I) or syrinx morphology has not been studied. We aimed to describe the relationship between SAR abnormalities and syrinx size, location, and etiology. Children who underwent brain or c-spine MRI over 11 years were reviewed in this retrospective cohort study. Patients with idiopathic and CM-I-associated syringes (axial diameter ≥ 3 mm) were included. Clinical examination findings (including SAR) and imaging characteristics were analyzed. Of 271 patients with spinal cord syrinx, 200 had either CM-I-associated or idiopathic syrinx, and 128 of these patients had SAR-evaluation documentation. Forty-eight percent (62/128) had an abnormal or absent reflex. Abnormal/absent SAR was more common in patients with CM-I-associated syrinx (61%) compared with idiopathic syrinx (22%) (P < 0.0001). Abnormal/absent SAR was associated with wider syringes (P < 0.001), longer syringes (P < 0.05), and a more cranial location of the syrinx (P < 0.0001). Controlling for CM-I, scoliosis, age, sex, cranial extent of syrinx, and syrinx dimensions, CM-I was independently associated with abnormal or absent SAR (OR 4.2, 95% CI 1.4-14, P < 0.01). Finally, the sensitivity of SAR for identifying a patient with syrinx was 48.1%. An abnormal/absent SAR was present in most patients with CM-I-associated syrinx but in a minority of patients with idiopathic syrinx. This has implications for pathophysiology of CM-I-associated syrinx and in guiding clinical care of patients presenting with syrinx.

Case Series and Systematic Review of Electronic Scooter Crashes and Severe Traumatic Brain Injury.

OBJECTIVE: Electric scooters (e-scooters) are an increasingly popular form of transportation, but their use has also resulted in increased incidence of traumatic brain injury (TBI). Previous reports have predominantly described mild TBI with limited attention to other injury patterns. Our objective was to evaluate the impact of e-scooter use on rates of severe TBI. METHODS: We performed a multicenter retrospective case review of patients who presented with severe TBI (Glasgow Coma Scale score 3-8) related to e-scooter use and undertook a systematic literature review to identify other reports of severe TBI related to e-scooter use. RESULTS: Of the 19 patients (mean age, 38 ± 16 years; 73.7% male) included in the case series, 13 (68.4%) experienced a fall and 6 (31.6%) were involved in a collision. Various cerebral injury patterns, associated craniofacial fractures, and cervical spine injuries were also seen. Twelve patients (63.2%) underwent intracranial pressure monitor placement and 6 (31.6%) underwent a decompressive hemicraniectomy. Most patients (n = 12; 63.2%) were discharged to acute rehabilitation, with a median modified Rankin Scale score of 2 at 4.9 ± 7.7 months follow-up (52.6% had a good outcome of modified Rankin Scale score ≤2), but 4 patients died of primary injuries. The systematic review identified 18 studies with 77,069 patients between 2019 and 2021, with 37 patients who required intensive care and 6 patients who had neurosurgical intervention. CONCLUSIONS: Severe TBI after e-scooter use is associated with high morbidity and is likely underdiagnosed in the literature. Awareness and public policies may be helpful to reduce the impact of injury.

Emerging Utility of Applied Magnetic Resonance Imaging in the Management of Traumatic Brain Injury.

Traumatic brain injury (TBI) is a widespread and expensive problem globally. The standard diagnostic workup for new TBI includes obtaining a noncontrast computed tomography image of the head, which provides quick information on operative pathologies. However, given the limited sensitivity of computed tomography for identifying subtle but meaningful changes in the brain, magnetic resonance imaging (MRI) has shown better utility for ongoing management and prognostication after TBI. In recent years, advanced applications of MRI have been further studied and are being implemented as clinical tools to help guide care. These include functional MRI, diffusion tensor imaging, MR perfusion, and MR spectroscopy. In this review, we discuss the scientific basis of each of the above techniques, the literature supporting their use in TBI, and how they may be clinically implemented to improve the care of TBI patients.

Abdominal aortic aneurysm is associated with subarachnoid hemorrhage.

BACKGROUND: Although intracranial aneurysms (IA) and abdominal aortic aneurysms (AAA) share similar risk factors, little is known about the relationship between them. Previous studies have shown an increased incidence of IA in patients with AAA, though the rate of subarachnoid hemorrhage (SAH) in patients with AAA has not been described. OBJECTIVE: To use claims data with longitudinal follow-up, to evaluate the incidence of aneurysmal SAH in patients diagnosed with AAA. METHODS: We examined longitudinally linked medical claims data from a large private insurer to determine rates of aneurysmal SAH (aSAH) and secured aSAH (saSAH) in 2004-2014 among patients with previously diagnosed AAA. RESULTS: We identified 62 910 patients diagnosed with AAA and compared them 5:1 with age- and sex-matched controls. Both populations were predominantly male (70.9%), with an average age of 70.8 years. Rates of hypertension (69.7% vs 50.6%) and smoking (12.8% vs 4.1%) were higher in the AAA group (p<0.0001) than in controls. Fifty admissions for aSAH were identified in patients with AAA (26/100 000 patient-years, 95% CI 19 to 44) and 115 admissions for aSAH in controls (7/100 000 years, 95% CI 6 to 9), giving an incidence rate ratio (IRR) of 3.6 (95% CI 2.6 to 5.0, p<0.0001) and a comorbidity-adjusted incidence rate ratio (IRR) of 2.8 (95% CI 1.9 to 3.9) for patients with AAA. The incidence of secured aneurysmal SAH was proportionally even higher in patients with AAA, 7 vs 2/100 000 years, IRR 4.5 (95% CI 3.2 to 6.3, p<0.0001). CONCLUSION: SAH rate was elevated in patients with AAA, even after adjustment for comorbidities. Among risk factors evaluated, AAA was the strongest predictor for SAH. The relative contributions of common genetic and environmental risk factors to both diseases should be investigated.

Longitudinal scoliosis behavior in Chiari malformation with and without syringomyelia.

OBJECTIVE: The objective of this study was to understand the natural history of scoliosis in patients with Chiari malformation type I (CM-I) with and without syringomyelia. METHODS: A retrospective review of data was conducted. Patients with CM-I were identified from a cohort of 14,118 individuals age 18 years or younger who had undergone MRI over an 11-year period at the University of Michigan. Patients eligible for study inclusion had a coronal curve ≥ 10° on radiography, associated CM-I with or without syringomyelia, and at least 1 year of clinical follow-up prior to any surgery. Curve magnitude at initial diagnosis, prior to posterior fossa decompression (PFD; if applicable), and at the last follow-up (prior to any surgical correction of scoliosis) was recorded, and clinical and radiographic characteristics were noted. The change in curve magnitude by 10° was defined as curve progression (increase by 10°) or regression (decrease by 10°). RESULTS: Forty-three patients met the study inclusion criteria and were analyzed. About one-third (35%) of the patients presented with symptoms attributed to their CM-I. The mean degree of scoliosis at presentation was 32.6° ± 17.7°. Twenty-one patients (49%) had an associated syrinx. The mean tonsil position below the level of the foramen magnum was 9.8 ± 5.8 mm. Patients with a syrinx were more likely to have a curve > 20° (86% vs 41%, p = 0.002). Curve magnitude remained stable (≤ ±10°) in 77% of patients (33/43), progressed in 16% (7/43), and regressed in 7% (3/43). Mean age was higher (14.8 ± 0.59 years) among patients with regressed curves (p = 0.026). All regressed curves initially measured ≤ 20° (mean 14° ± 5.3°), and none of the patients with regressed curves had a syrinx. The change in curve magnitude was statistically similar in patients with (7.32° ± 17.7°) and without (5.32° ± 15.8°) a syrinx (p = 0.67). After a mean follow-up of 3.13 ± 2.04 years prior to surgery, 27 patients (63%) ultimately underwent posterior fossa or scoliosis correction surgery. For those who eventually underwent PFD only, the rate of change in curve magnitude prior to surgery was 0.054° ± 0.79°. The rate of change in curve magnitude was statistically similar before (0.054° ± 0.79°) and after (0.042° ± 0.33°) surgery (p = 0.45) for patients who underwent PFD surgery only. CONCLUSIONS: The natural history of scoliosis in the presence of CM-I is variable, though most curves remained stable. All curves that regressed were ≤ 20° at initial diagnosis, and most patients in such cases were older at scoliosis diagnosis. Patients who underwent no surgery or PFD only had similar profiles for the change in curve magnitude, which remained relatively stable overall, as compared to patients who underwent PFD and subsequent fusion, who demonstrated curve progression. Among the patients with a syrinx, no curves regressed, most remained stable, and some progressed. Understanding this variability is a first step toward building a prediction model for outcomes for these patients.

Management of Water and Sodium Disturbances after Transsphenoidal Resection of Pituitary Tumors.

Patients with pituitary masses who undergo transsphenoidal resection are at risk for a number of medical complications postoperatively. Among these are disturbances in fluid and sodium homeostasis, including diabetes insipidus (DI) and syndrome of inappropriate secretion of antidiuretic hormone (SIADH). It is believed that these pathologic states are a result of damage to the hypothalamic-pituitary axis from surgery, as are the downstream consequences, such as the triple phase response. The triple-phase response describes the pattern of initial acute DI, subsequent rebound SIADH, and eventual chronic DI, the pathophysiology of which is described. Given the medical complexity of managing postoperative pituitary patients, it is essential to develop dedicated postoperative management protocols. Here, we describe the University of Utah's postoperative pituitary management protocol that includes immediate postoperative monitoring, treatment of DI, surveillance for the triple-phase response after discharge with outpatient serum sodium checks, and involvement of the endocrinology service for assistance with management of hypopituitarism. A complete understanding of the relevant anatomy, physiology, and development of standardized protocols for postoperative management can aid with minimizing medical complications after pituitary surgery.

Obstetric Management and Maternal Outcomes of Childbirth Among Patients With Chiari Malformation Type I.

BACKGROUND: A range of opinions exist in the literature regarding obstetric management of pregnant women with Chiari malformation type I (CM-I). OBJECTIVE: To examine obstetrical practices and outcomes with childbirth of women with CM-I. METHODS: We examined insurance claims data from a large, privately insured health care network and identified admissions for childbirth from 2004 to 2014. Women with a diagnosis of CM-I as well as normal controls were analyzed for demographic characteristics, type of obstetric management, and complications of childbirth. RESULTS: We identified 866 patients with CM-I diagnosis who had 1048 hospitalizations for delivery, including 103 deliveries to 83 patients who underwent performance of CM-I decompression (CMD) either before or after childbirth. Among 400 births that occurred after CM-I diagnosis, rates of caesarean section (C-section) were higher (42.3% vs 36.2%, OR 1.29, 95% CI 1.00-1.66, P = .05) and rates of epidural analgesia were lower (45.3% vs 55.4%, OR 0.67, 95% CI 0.52-0.85, P = .001) compared to 648 births before CM-I diagnosis. The rate of serious maternal morbidity was similar among deliveries to women with CM-I diagnosis (both before and after delivery) compared to 11 000 normal controls. CONCLUSION: A diagnosis of CM-I prior to delivery is associated with a higher rate of C-section and a lower rate of epidural analgesia. Rates of serious maternal morbidity among women with CM-I were similar to those for normal controls. The data suggest a predelivery diagnosis of CM-I may influence obstetric decisions despite no evidence of substantially increased delivery risk in this group.

Validation of the LACE Index (Length of Stay, Acuity of Admission, Comorbidities, Emergency Department Use) in the Adult Neurosurgical Patient Population.

BACKGROUND: The LACE index (Length of stay, Acuity of admission, Comorbidities, Emergency department use) quantifies the risk of mortality or unplanned readmission within 30 d after hospital discharge. The index was validated originally in a large, general population and, subsequently, in several specialties, not including neurosurgery. OBJECTIVE: To determine if the LACE index accurately predicts mortality and unplanned readmission of neurosurgery patients within 30 d of discharge. METHODS: We performed a retrospective, cohort study of consecutive neurosurgical procedures between January 1 and September 29, 2017 at our institution. The LACE index and other clinical data were abstracted. Data analysis included univariate and multivariate logistic regressions. RESULTS: Of the 1,054 procedures on 974 patients, 52.7% were performed on females. Mean age was 54.2 ± 15.4 yr. At time of discharge, the LACE index was low (1-4) in 58.3% of patients, moderate (5-9) in 32.4%, and high (10-19) in 9.3%. Rates of readmission and mortality within 30 d were 7.0, 11.4, and 14.3% in the low-, moderate-, and high-risk groups, respectively. Moderate-risk (odds ratio [OR] 1.62, 95% CI 1.02-2.56, P = .04) and high-risk LACE indexes (OR 2.20, 95% CI 1.15-4.19, P = .02) were associated with greater odds of readmission or mortality, adjusting for all variables. Additionally, longer operations (OR 1.11, 95% CI 1.02-1.21, P = .02) had greater odds of readmission. Specificity of the high-risk score to predict 30-d readmission or mortality was 91.2%. CONCLUSION: A moderate- or high-risk LACE index can be applied to neurosurgical populations to predict 30-d readmission and mortality. Longer operations are potential predictors of readmission or mortality.

Thirty-Day Hospital Readmission and Surgical Complication Rates for Shunting in Normal Pressure Hydrocephalus: A Large National Database Analysis.

BACKGROUND: Research on age-related complications secondary to shunts in normal pressure hydrocephalus (NPH) is primarily limited to single-center studies and small cohorts. OBJECTIVE: To determine the rates of hospital readmission and surgical complications, and factors that predict them, following shunt surgery for NPH in a large healthcare network. METHODS: Surgical procedures, complications, and readmissions for adults undergoing ventricular shunting for NPH were determined using de-identified claims from a privately insured United States healthcare network in years 2007-2014. Univariate and multivariate statistics were used to determine factors that predict poor surgical outcomes. The primary outcome variable was surgical complications or readmissions (composite variable for any major perioperative complication or 30-d readmission). RESULTS: The 30-d readmission rate for 974 patients with NPH who underwent ventricular shunting was 7.29%; the most common reasons for readmission were shunt-related complications, infection, hemorrhage, altered mental status, and cardiopulmonary and musculoskeletal problems. The perioperative complication rate was 21.15%, including intraparenchymal hemorrhage (5.85%) and extra-axial (subdural or epidural) hematoma (5.54%). The overall rate of having a surgical complication or 30-d readmission was 25.15%. Age did not predict surgical complication or 30-d readmission. Preoperative comorbidities independently associated with poor outcome were myocardial infarction within 1 yr (OR = 3.984, 95% CI = 1.105-14.368); existing cerebrovascular disease (odds ratio [OR] = 2.206, 95% CI = 1.544-3.152); and moderate/severe renal disease (OR = 2.000, 95% CI = 1.155-3.464). CONCLUSION: The rate of complications or readmission within 30 d of ventricular shunting for NPH is 25.15%. Preoperative comorbidities of myocardial infarction within 1 yr, cerebrovascular disease, and moderate/severe renal disease are independent risk factors for poor outcome.

Recent trends in North American pediatric neurosurgical fellowship training.

OBJECTIVE The goal of this study was to evaluate trends in pediatric neurosurgical fellowship training in North America. METHODS From a database maintained by the Accreditation Council for Pediatric Neurosurgery Fellowships (ACPNF), all graduates of ACPNF-accredited pediatric neurosurgery fellowships were identified, and an Internet search was conducted to determine sex, undergraduate and graduate degrees, location and dates of residency and fellowship training, current practice/employment environment, American Board of Neurological Surgery (ABNS) or Fellowship of the Royal College of Surgeons certification status, American Board of Pediatric Neurological Surgery (ABPNS) certification status, and extent of current pediatric-focused practice. The graduates were further studied to determine whether they had completed a neurosurgical residency at a program with an affiliated ACPNF-accredited pediatric neurosurgery fellowship program, and their residency training programs were further classified by whether the program was ranked in the top 50 by NIH funding awards. Each fellowship graduate's current practice was also ranked in a similar fashion. RESULTS There were 391 graduates of ACPNF-accredited pediatric neurosurgery fellowship programs from 1993 to 2018. The number of graduates per year has grown steadily over time, as has the percentage of women, now over 40% compared to zero in the first 3 years of fellowship accreditation in the mid-1990s. Approximately 71% of graduating fellows have a pediatric-focused practice, but only 63% went on to attain ABPNS certification. Of all graduates practicing in the United States, 68% practice in academic settings. Ninety-five percent of graduating fellows who were ABNS board eligible were ABNS certified. CONCLUSIONS A study of the graduates of accredited pediatric neurosurgical fellowships from 1993 to 2018 has revealed a growth in the number of graduates from ACPNF-accredited fellowship programs over time. A substantial portion of graduates will practice at least some adult neurosurgery and not go on to obtain ABPNS board certification.

A Large Database Analysis of Rates of Aneurysm Screening, Elective Treatment, and Subarachnoid Hemorrhage in Patients With Polycystic Kidney Disease.

BACKGROUND: Professional societies provide conflicting guidelines on aneurysm screening in patients with polycystic kidney disease (PKD), and the rate of subarachnoid hemorrhage (SAH) is poorly understood. OBJECTIVE: To evaluate screening, elective treatment, and the rate of SAH in patients with known PKD. METHODS: We examined longitudinally linked claims data from a large private insurer, identifying screening, elective treatment, aneurysmal subarachnoid hemorrhage (aSAH) and secured aneurysmal SAH (saSAH) in 2004 to 2014 amongst patients with known PKD. RESULTS: We identified 20 704 patients diagnosed with PKD. Among patients with an initial PKD diagnosis, 51/446 (15.9%) underwent angiographic screening within 2 yr. Forty aneurysms were treated electively in 48 868 yr at risk in PKD patients (82/100K patient yr, 95% confidence interval [CI] 60-112) vs 24 elective treatments in 349 861 yr at risk in age- and sex-matched controls (7/100K patient yr, 95% CI 5-10, P < .0001). Eleven admissions for aSAH were identified in PKD patients (23/100K patient yr, 95% CI 13-41) and 22 admissions for aSAH in controls (6/100K patient yr, 95% CI 4-10), giving an incidence rate ratio (IRR) of 3.6 (95% CI 1.7-7.4, P < .0001) and a comorbidity-adjusted IRR of 3.1 (95% CI 1.4-6.9). The incidence of saSAH was proportionally even higher in PKD patients than controls, 16 vs 2/100K patient years, IRR 9.5 (95% CI 3.3-27.5, P < .0001). CONCLUSION: Screening in PKD is performed only selectively, though resulting rates of elective treatment were over 10× those of controls. Despite screening and treatment, the rate of SAH remains significantly elevated over that of controls.