Automated translation accurately translates recorded pediatric neurosurgery clinic conversations between Spanish and English.

OBJECTIVE: The purpose of this study is to analyze an automated voice to text translation device by reporting the translation accuracy for recorded pediatric neurosurgery clinic conversations, classifying errors in translation according to their impact on overall understanding, and comparing the incidence of these errors in English to Spanish vs. Spanish to English conversations. METHODS: English and Spanish speaking patients at a single academic health system's outpatient pediatric neurosurgery clinic had their conversations recorded. These recordings were played back to a Google Pixel handheld smartphone with Live Translate voice to text translation software. A certified medical interpreter evaluated recordings for incidence of minor errors, errors impacting understanding, and catastrophic errors affecting patient-provider relationship or care. Two proportion t-testing was used to compare these outcomes. RESULTS: 50 patient visits were recorded: 40 English recordings translated to Spanish and 10 Spanish recordings translated to English. The mean transcript length was 4244 ± 992 words. The overall accuracy was 98.2% ± 0.5%. On average, 46 words were missed in translation (1.09% error rate), 31 understanding-altering translation errors (0.73% error rate), and 0 catastrophic errors were made. There was no significant difference in English to Spanish or vice versa. CONCLUSION: Voice to text translation devices using automatic speech recognition accurately translate recorded clinic conversations between Spanish and English with high accuracy and low incidence of errors impacting medical care or understanding. Further study should investigate additional languages, assess patient preferences and potential concerns with respect to device use, and compare these devices directly to medical interpreters in live clinic settings.

Synthetic interpolated DSA for radiation exposure reduction via gamma variate contrast flow modeling: a retrospective cohort study.

BACKGROUND: Digital subtraction angiography (DSA) yields high cumulative radiation dosages (RD) delivered to patients. We present a temporal interpolation of low frame rate angiograms as a method to reduce cumulative RDs. METHODS: Patients undergoing interventional evaluation and treatment of cerebrovascular vasospasm following subarachnoid hemorrhage were retrospectively identified. DSAs containing pre- and post-intervention runs capturing the full arterial, capillary, and venous phases with at least 16 frames each were selected. Frame rate reduction (FRR) of the original DSAs was performed to 50%, 66%, and 75% of the original frame rate. Missing frames were regenerated by sampling a gamma variate model (GVM) fit to the contrast response curves to the reduced data. A formal reader study was performed to assess the diagnostic accuracy of the "synthetic" studies (sDSA) compared to the original DSA. RESULTS: Thirty-eight studies met inclusion criteria (average RD 1,361.9 mGy). Seven were excluded for differing views, magnifications, or motion. GVMs fit to 50%, 66%, and 75% FRR studies demonstrated average voxel errors of 2.0 ± 2.5% (mean ± standard deviation), 6.5 ± 1.5%, and 27 ± 2%, respectively for anteroposterior projections, 2.0 ± 2.2%, 15.0 ± 3.1%, and 14.8 ± 13.0% for lateral projections, respectively. Reconstructions took 0.51 s/study. Reader studies demonstrated an average rating of 12.8 (95% CI 12.3-13.3) for 75% FRR, 12.7 (12.2-13.2) for 66% FRR and 12.0 (11.5-12.5) for 50% FRR using Subjective Image Grading Scale. Kendall's coefficient of concordance resulted in W = 0.506. CONCLUSION: FRR by 75% combined with GVM reconstruction does not compromise diagnostic quality for the assessment of cerebral vasculature. RELEVANCE STATEMENT: Using this novel algorithm, it is possible to reduce the frame rate of DSA by as much as 75%, with a proportional reduction in radiation exposure, without degrading imaging quality. KEY POINTS: • DSA delivers some of the highest doses of radiation to patients. • Frame rate reduction (FRR) was combined with bolus tracking to interpolate intermediate frames. • This technique provided a 75% FRR with preservation of diagnostic utility as graded by a formal reader study for cerebral angiography performed for the evaluation of cerebral vasospasm. • This approach can be applied to other types of angiography studies.

Surgical instruments and catheter damage during ventriculoperitoneal shunt assembly.

OBJECTIVE: Current surgical techniques use common surgical instruments for sterile shunt assembly. This study investigated the impact of using these techniques and surgical instruments on the mechanical integrity of the ventriculoperitoneal shunt system, specifically shunt catheters. METHODS: The authors conducted failure testing on 85 rifampin-coated catheters and 85 barium-impregnated catheters using 5 different surgical instruments and 2 different surgical techniques. In technique A, the distal end of the catheter was pushed onto the shunt valve inlet connector with the surgical instrument. In technique B, the catheter was pulled over the inlet connector. One hundred sixty catheters underwent 10-repetition-maximum testing, in which the catheter either failed before completion of 10 consecutive assembly/disassembly repetitions or the catheter completed 10 consecutive repetitions. The authors also conducted 100-repetition-maximum tests on 5 barium-impregnated and 5 rifampin-coated catheters using technique A. RESULTS: Catheter failure rates were significantly different among the different instruments used in assembly (p ≤ 0.001). Post hoc analysis showed that using mosquito forceps with shods resulted in a significantly lower catheter failure rate than the other instruments (p < 0.0005). The catheter failure rate of technique A was significantly lower than that of technique B (5% vs 81%, p < 0.001). There was no statistical difference between the failure rates of the barium and rifampin catheters (42% vs 44%, p = 0.9), but the barium catheters outperformed the rifampin catheters in the 100-repetition-maximum trials (p = 0.02). Instrument type (p = 0.0232) and catheter type (p = 0.0096) were both significant factors in determining the number of assembly/disassembly repetitions needed to cause catheter failure. It took an average of 2.79 repetitions of assembly/disassembly to cause catheter failure. DeBakey forceps had significantly lower mean repetitions to failure (mean 1.38) than the Gerald forceps without teeth (mean 2.73, p = 0.05) and bayonet (mean 3.25, p = 0.02). CONCLUSIONS: This study was the first of its kind to analyze how physical manipulation affects the mechanical integrity of ventriculoperitoneal shunt components. The authors demonstrated a significantly lower shunt catheter failure rate when mosquito forceps with shods and technique A were used in assembly. Moreover, the authors established that use of DeBakey forceps resulted in failure with fewer assembly/disassembly repetitions than use of the Gerald and bayonet forceps, suggesting that DeBakey forceps are the most damaging instrument.

Postoperative seizures following endoscopic third ventriculostomy and choroid plexus cauterization: a case series.

OBJECTIVE: In this study, the authors sought to investigate variables associated with postoperative seizures following endoscopic third ventriculostomy and choroid plexus cauterization (ETV/CPC) for treatment of pediatric hydrocephalus. METHODS: A retrospective analysis of 37 patients who underwent ETV/CPC for treatment of hydrocephalus at an academic medical center from September 2016 to March 2021 was conducted. Demographics, etiology of hydrocephalus, operative details, electroencephalography (EEG) data, MRI findings, need for subsequent procedures, perioperative laboratory tests, medical history, and presence of clinical postoperative seizures were collected. Postoperative seizures were defined as clinical seizures within 24 hours of surgery. Eighteen patients received levetiracetam intraoperatively as well as over the next 7 days postoperatively for seizure prophylaxis. RESULTS: Of 37 included patients, 9 (24%) developed clinical seizures within 24 hours after surgery, 5 of whom subsequently had electroclinical seizures captured on video-EEG. The clinical seizures in 4 of those 5 patients (80%) may have been associated with the hemisphere of the brain through which the endoscope was introduced. The median corrected age of the cohort was 3.4 months. The median corrected age of patients who did not develop postoperative seizures was 2.3 months compared with 0.7 months for patients who did develop postoperative seizures (p > 0.99). Postoperative seizures occurred in 43% (3/7) of prenatally repaired myelomeningocele patients versus 29% (2/7) of postnatally repaired myelomeningocele patients. Of the 18 patients who received prophylactic levetiracetam, none (0%) developed postoperative seizures compared with 9 of the 19 patients (47%) who did not receive prophylactic levetiracetam (p = 0.014). CONCLUSIONS: Postoperative seizures were recorded in 24% of the pediatric patients who underwent ETV/CPC for hydrocephalus, which is higher than previously reported rates in the literature of 5%. Since 80% of the postoperative electrographic seizures may have been associated with the hemisphere through which the endoscope was introduced, the surgical entry site may contribute to postoperative seizure development. In patients who received prophylactic perioperative levetiracetam, the postoperative seizure incidence dropped to 0% compared with 47% in those who did not receive prophylactic perioperative levetiracetam. This finding indicates that the use of prophylactic perioperative levetiracetam may be efficacious in the prevention of clinical seizures in this patient population.

Pediatric Neurosurgery in Primary Care: Masses of the Scalp and Skull in Children.

There are a wide variety of scalp and skull lesions that can affect the pediatric population, many of which are first encountered by primary care physicians. The differential consists of a broad range of more common congenital lesions, sequelae of trauma, and vascular anomalies, to very rare neoplastic processes. It is important to understand signs and symptoms that may indicate whether a lesion may be benign versus life threatening, what imaging studies are appropriate and how to interpret them, and when to seek referrals to specialists.

Neonatal Hydrocephalus Treatment with Ultrasmall Valve Implantation.

OBJECTIVE: Neonatal hydrocephalus remains a difficult condition to manage, due to high failure rates among all management strategies. Neurosurgeons commonly manage hydrocephalus with ventriculoperitoneal shunt (VPS) implantation, and valves of variable sizes and profiles are available for implantation. This study examines primary ventricular shunt valve implantation complication rates based on valve profiles in pediatric patients with hydrocephalus. METHODS: This study retrospectively reviews pediatric patients younger than 1 year of age who underwent ventricular shunt placement at a single institution from January 2001 to January 2017. Patients were classified by valve profile and categorized as either ultrasmall valves or regular-sized valves. Time until complication and type of complication were studied. RESULTS: A total of 156 patients met the inclusion criteria. Forty-eight (31%) patients received an ultrasmall shunt valve, while 108 patients received a regular valve. On average, patients undergoing ultrasmall valve placement were younger (2.1 months) than patients undergoing placement of regular valves (3.1 months) (P = 0.03). The overall complication rate within 2 years of VPS placement was 37.5% in patients with the ultrasmall valve and 41.7% in the regular valve population. There was no difference in 1-year shunt survival rate between the 2 cohorts. CONCLUSION: Our review did not find a significant difference in complication rates between ultrasmall and regular valves in patients under 1 year of age. However, the etiology of shunt malfunction did differ between the groups. This work further supports evidence suggesting a surgeon's preference for shunt hardware alone does not significantly impact outcome.

Long-term Efficacy of Single-agent Vemurafenib for Pleomorphic Xanthoastrocytoma.

Pleomorphic xanthoastrocytoma is a malignant brain tumor that has a good prognosis with complete resection but does not respond well to chemotherapy if there is residual tumor. BRAF V600E mutations are common in pleomorphic xanthoastrocytomas and provide an additional means for treatment when excision is not possible. Monotherapy with the BRAF V600E inhibitor vemurafenib has only been reported in a small number of cases and mostly in adults. We present the case of a 16-year-old male who responded to vemurafenib monotherapy initially and had an additional response to vemurafenib following progression after a brief time off the medication.

Wound Healing Complications After Cranial Vault Reconstruction for Craniosynostosis.

Craniosynostosis is a congenital cranial malformation involving premature fusion of cranial sutures. Indications for surgical repair of craniosynostosis include elevation of intracranial pressure, which can result in impaired vision and mental disability, as well as correction of abnormal skull shape. Resorbable plating systems have become the preferred technique for bony fixation in the repair of craniosynostosis. Multiple studies demonstrate the safety and low complication rate of resorbable plating systems.However, there is no consensus on which plating system is superior for patient outcomes. This study aims to investigate how the polymer composition of resorbable plating systems utilized in cranial vault reconstruction contributes to wound healing complications. A retrospective chart review was performed at the institution between January 1, 2005 and December 31, 2015. About 202 patients who underwent surgical repair of craniosynostosis were identified. The results showed that patients receiving the Biomet Lactosorb plating system were over twice as likely to have a wound complication within a year of surgery compared to other plating systems used at the institution. Wound complications continued to occur in the Biomet Lactosorb group at ≥180 days after surgery, whereas complications among the other plating systems occurred ≤80 days postoperatively. Half of all patients with wound complications had to undergo reoperation. These data demonstrate the effect of unique polymer compositions on wound healing, and will help to guide future clinical practice and industry development of resorbable plating systems.

Targeted head CT reduction for pediatric patients with hydrocephalus and traumatic brain injury: academic center institutional experience as an example of opportunities for further improvement.

PURPOSE: Recent studies aim to reduce radiation exposure associated with computed tomography (CT) using rapid-sequence magnetic resonance imaging (MRI). We evaluated imaging modalities used for hydrocephalus and traumatic brain injury (TBI) to identify opportunities for further radiation exposure reduction. METHODS: Pediatric (≤ 18 years) patients, with either hydrocephalus or TBI receiving a head CT or head MRI from 2009 to 2017, were quantified using ICD9, ICD10, and CPT codes at a large university hospital. The odds ratios of receiving each imaging modality year-to-year and receiving a MRI or CT in a given year with each diagnosis were calculated. RESULTS: Beginning in 2015, hydrocephalus patients were more likely to receive a MRI vs CT (p < 0.0001), with likelihood increasing in the following 2 years. TBI patients were more likely to receive a CT than an MRI from 2009 to 2017. There was a smaller overall decrease in CT scans in TBI patients (p < 0.05) than hydrocephalus patients (p < 0.0001) and a larger increase in MRI use in hydrocephalus patients (p < 0.05) than TBI patients (p < 0.05) from 2009 to 2017. CONCLUSIONS: Use of CT to evaluate hydrocephalus significantly decreased over the last 3-year time period. However, CT use for TBI patients was inconsistent and did not decrease proportionally, potentially representing a belief that CT is more effective than MRI for detecting hemorrhage. There was greater use of MRI as an alternate imaging method in hydrocephalus patients than TBI patients. Head injury remains an area of improvement to decrease pediatric radiation exposure at our institution and may be an area in need of attention more broadly.

Thirty-day medical and surgical readmission following prenatal versus postnatal myelomeningocele repair.

OBJECTIVE: Hospital readmission is an important quality metric that has not been evaluated in prenatal versus postnatal myelomeningocele (MMC) repair. This study compares hospital readmission outcomes between these two groups as well as their etiologies. METHODS: The medical records of patients who had undergone MMC repair in the period from 2011 to 2017 at a single academic medical center were retrospectively reviewed. Collected clinical data included surgery and defect details, neonatal intensive care unit (NICU) stay, and any readmissions or surgical procedures up to 1 year after surgery. Patient and defect characteristics, readmission outcomes at 30 and 60 days and 1 year after discharge from the NICU, and cerebrospinal fluid (CSF) diversion surgery rates were analyzed with the two-tailed t-test and/or k-sample test on the equality of medians. RESULTS: A total of 24 prenatal and 34 postnatal MMC repairs were completed during the study period. Prenatally repaired patients were born more prematurely (p < 0.001) and with lower birth weights (p < 0.001), although the NICU stay was similar between the two groups (p = 0.59). Fewer prenatally repaired patients were readmitted at 30 days (p = 0.005), 90 days (p = 0.004), and 1 year (p = 0.007) than the postnatal repair group. Hydrocephalus was the most common readmission etiology, and 29% of prenatal repair patients required CSF diversion at 1 year versus 81% of the postnatal repair group (p < 0.01). Prenatal patients who required CSF diversion had a higher body weight (p = 0.02) and an older age (p = 0.01) at the time of CSF diversion surgery than the postnatal group. CONCLUSIONS: Patients with prenatal MMC repair had fewer hospital readmissions at 30 days, 60 days, and 1 year than the postnatal repair group, despite similar NICU lengths of stay. The prenatal repair group had lower requirements for CSF diversion at 1 year and was older with greater body weights at the time of CSF diversion surgery, compared to those of the postnatal repair group. Future study of hospital quality metrics such as readmissions should be performed to better understand outcomes of these two procedures.

Cost of prenatal versus postnatal myelomeningocele closure for both mother and child at 1 year of life.

OBJECTIVE: Prenatal myelomeningocele (MMC) closure has been performed in the United States for 2 decades. While prior work has focused on clinical outcomes of prenatal MMC closure, the cost of this procedure in comparison with that of postnatal MMC closure is unclear. The authors' aim was to compare the cost of prenatal versus postnatal MMC closure for both the child and mother at 1 year. METHODS: A prospective database of patients undergoing prenatal and postnatal MMC closure between 2011 and 2018 with 1-year follow-up was retrospectively reviewed. Charge data for relevant admissions were converted to a cost estimate using the authors' institution's Medicare hospital-specific cost-to-charge ratio. Children, mothers, and mother/child pairs were considered separately. The primary outcome was cost. Secondary outcomes included the need for hydrocephalus treatment, length of stay (LOS), and readmissions. Other covariates included gestational age at birth, MMC lesion level, and obstetric complications. RESULTS: The median cost of care for children in the prenatal group was greater, although not significantly so, at $58,406.71 (IQR $16,900.24-$88,951.01) compared with $49,889.95 (IQR $38,425.18-$115,163.86) for children in the postnatal group (p = 0.204). The median cost for mothers in the prenatal group was significantly greater at $24,548.29 (IQR $20,231.55-$36,862.31) compared with $5087.30 (IQR $4430.72-$5362.56) (p < 0.001). The median cost for mother/child pairs in the prenatal group was $102,377.75 (IQR $37,384.30-$118,527.74) compared with $55,667.82 (IQR $42,840.78-$120,058.06) (p = 0.45). Children in the prenatal group had a lower gestational age at birth (235.81 days vs 265.77 days, p < 0.001) and fewer readmissions (33.3% vs 72.7%, p < 0.001), and hydrocephalus treatment was less common (33.3% vs 90.9%, p < 0.001). Index LOS did not differ between children in the prenatal and postnatal groups (26.8 days vs 23.5 days, p = 0.63). Mothers in the prenatal group had longer LOS (15.92 days vs 4.68 days, p < 0.001) and more readmissions (18.5% vs 0.0%, p = 0.06). CONCLUSIONS: The median cost of prenatal versus postnatal MMC closure did not significantly differ from a hospital perspective at 1 year, although variability in cost was high for both groups. When considering the mother alone, prenatal MMC closure was costlier. Future work is needed to assess cost from a patient and societal perspective both at 1 year and beyond.

Pediatric nonoperative skull fractures: delayed complications and factors associated with clinic and imaging utilization.

OBJECTIVE: Skull fractures represent a common source of morbidity in the pediatric trauma population. This study characterizes the type of follow-up that these patients receive and discusses predictive factors for follow-up. METHODS: The authors reviewed cases of nonoperative pediatric skull fractures at a single academic hospital between 2007 and 2017. Clinical patient and radiological fractures were recorded. Recommended neurosurgical follow-up, follow-up appointments, imaging studies, and fracture-related complications were recorded. Statistical analyses were performed to identify predictors for outpatient follow-up and imaging. RESULTS: The study included 414 patients, whose mean age was 5.2 years; 37.2% were female, and the median length of stay was 1 day (IQR 0.9-4 days). During 438 clinic visits and a median follow-up period of 8 weeks (IQR 4-12, range 1-144 weeks), 231 imaging studies were obtained, mostly head CT scans (55%). A total of 283 patients were given recommendations to attend follow-up in the clinic, and 86% were seen. Only 12 complications were detected, including 7 growing skull fractures, 2 traumatic encephaloceles, and 3 cases of hearing loss. Primary care physician (PCP) status and insurance status were associated with a recommendation of follow-up, actual follow-up compliance, and the decision to order outpatient imaging in patients both with and without intracranial hemorrhage. PCP status remained an independent predictor in each of these analyses. Follow-up compliance was not associated with a patient's distance from home. Among patients without intracranial hemorrhage, a follow-up recommendation and actual follow-up compliance were associated with pneumocephalus and other polytraumatic injuries, and outpatient imaging was associated with a bilateral fracture. No complications were found in patients with linear fractures above the skull base in those without an intracranial hemorrhage. CONCLUSIONS: Pediatric nonoperative skull fractures drive a large expenditure of clinic and imaging resources to detect a relatively small profile of complications. Understanding the factors underlying the decision for clinic follow-up and additional imaging can decrease future costs, resource utilization, and radiation exposure. Factors related to injury severity and socioeconomic indicators were associated with outpatient imaging, the decision to follow up patients in the clinic, and patients' subsequent attendance. Socioeconomic status (PCP and insurance) may affect access to appropriate neurosurgical follow-up and deserves future research attention. Patients with no intracranial hemorrhage and with a linear fracture above the skull base do not appear to be at risk for delayed complications and could be candidates for reduced follow-up and imaging.

Septal dysembryoplastic neuroepithelial tumor: a comprehensive clinical, imaging, histopathologic, and molecular analysis.

BACKGROUND: Dysembryoplastic neuroepithelial tumors (DNETs) are uncommon neural tumors presenting most often in children and young adults and associated with intractable seizures. Rare midline neoplasms with similar histological features to those found in DNETs have been described near the septum pellucidum and termed "DNET-like neoplasms of the septum pellucidum." Due to their rarity, these tumors have been described in just a few reports and their genetic alterations sought only in small series. METHODS: We collected 20 of these tumors for a comprehensive study of their clinical, radiological, and pathological features. RNA sequencing or targeted DNA sequencing was undertaken on 18 tumors, and genome-wide DNA methylation profiling was possible with 11 tumors. Published cases (n = 22) were also reviewed for comparative purposes. RESULTS: The commonest presenting symptoms and signs were related to raised intracranial pressure; 40% of cases required cerebrospinal fluid diversion. Epilepsy was seen in approximately one third of cases. All patients had an indolent disease course, despite metastasis within the neuraxis in a few cases. Radiologically, the septum verum/septal nuclei were involved in all cases and are the proposed site of origin for septal DNET (sDNET). Septal DNET showed a high frequency (~80%) of mutations of platelet derived growth factor receptor A (PDGFRA), and alterations in fibroblast growth factor receptor 1 (FGFR1) and neurofibromatosis type 1 (NF1) were also identified. In a genomic DNA methylation analysis alongside other neural tumors, sDNETs formed a separate molecular group. CONCLUSIONS: Genetic alterations that are different from those of cerebral DNETs and a distinct methylome profile support the proposal that sDNET is a distinct disease entity.

Intra-cavity stem cell therapy inhibits tumor progression in a novel murine model of medulloblastoma surgical resection.

BACKGROUND: Cytotoxic neural stem cells (NSCs) have emerged as a promising treatment for Medulloblastoma (MB), the most common malignant primary pediatric brain tumor. The lack of accurate pre-clinical models incorporating surgical resection and tumor recurrence limits advancement in post-surgical MB treatments. Using cell lines from two of the 5 distinct MB molecular sub-groups, in this study, we developed an image-guided mouse model of MB surgical resection and investigate intra-cavity NSC therapy for post-operative MB. METHODS: Using D283 and Daoy human MB cells engineered to express multi-modality optical reporters, we created the first image-guided resection model of orthotopic MB. Brain-derived NSCs and novel induced NSCs (iNSCs) generated from pediatric skin were engineered to express the pro-drug/enzyme therapy thymidine kinase/ganciclovir, seeded into the post-operative cavity, and used to investigate intra-cavity therapy for post-surgical MB. RESULTS: We found that surgery reduced MB volumes by 92%, and the rate of post-operative MB regrowth increased 3-fold compared to pre-resection growth. Real-time imaging showed NSCs rapidly homed to MB, migrating 1.6-fold faster and 2-fold farther in the presence of tumors, and co-localized with MB present in the contra-lateral hemisphere. Seeding of cytotoxic NSCs into the post-operative surgical cavity decreased MB volumes 15-fold and extended median survival 133%. As an initial step towards novel autologous therapy in human MB patients, we found skin-derived iNSCs homed to MB cells, while intra-cavity iNSC therapy suppressed post-surgical tumor growth and prolonged survival of MB-bearing mice by 123%. CONCLUSIONS: We report a novel image-guided model of MB resection/recurrence and provide new evidence of cytotoxic NSCs/iNSCs delivered into the surgical cavity effectively target residual MB foci.

Co-occurrence of frameshift mutations in SMAD6 and TCF12 in a child with complex craniosynostosis.

Non-syndromic craniosynostosis (CS) affects 1 in 2350 live births. Recent studies have shown that a significant fraction of cases are caused by de novo or rare transmitted mutations that promote premature osteoblast differentiation in cranial sutures. Rare heterozygous loss-of-function (LOF) mutations in SMAD6 and TCF12 are highly enriched in patients with non-syndromic sagittal and coronal CS, respectively. Interestingly, both mutations show striking incomplete penetrance, suggesting a role for modifying alleles; in the case of SMAD6, a common variant near BMP2 drastically increases penetrance of sagittal CS. Here, we report a proband presenting with both sagittal and coronal craniosynostosis with the highly unusual recurrence of CS within two months of initial surgery, requiring a second operation to re-establish suture patency at six months of age. Exome sequencing revealed a rare transmitted frameshift mutation in SMAD6 (p. 152 fs*27) inherited from an unaffected parent, absence of the common BMP2 risk variant, and a de novo frameshift mutation in TCF12 (p.E548fs*14). SMAD6 and TCF12 independently inhibit transcriptional targets of BMP signaling. The findings are consistent with epistasis of these mutations, increasing penetrance and severity of CS in this proband. They also add to the list of composite phenotypes resulting from two Mendelian mutations, and support the utility of exome sequencing in atypical CS cases.

Chiari decompression outcomes using ligamentum nuchae harvest and duraplasty in pediatric patients with Chiari malformation type I.

OBJECTIVE The choice of graft material for duraplasty in decompressions of Chiari malformations remains a matter of debate. The authors present a detailed technique for harvesting ligamenta nuchae, as well as the clinical and radiographic outcomes of this technique, in a case series. METHODS The authors conducted a retrospective study evaluating the outcomes of Chiari malformation type I decompression and duraplasty in children aged 0-18 years at a single institution from 2013 to 2016. They collected both intraoperative and postoperative variables and compared them qualitatively to published data. RESULTS During the study period, the authors performed 25 Chiari malformation decompressions with ligamentum nuchae graft duraplasties. Of the 25 patients, 10 were females, and the mean age at surgery was 8.6 years (range 13 months to 18 years). The median operative time was 163 minutes (IQR 152-187 minutes), with approximately 10 minutes needed by a resident surgeon to harvest the graft. The mean length of stay was 3 nights (range 2-6 nights), and the mean follow-up was 12.6 months (range 0.5-43.5 months). One patient (4%) developed a CSF leak that was repaired using an oversewing patch. There were no postoperative pseudomeningoceles or infections. Of the 19 patients presenting with a syrinx, imaging showed improvement in 10 (53%) and 8 (42%) had stable syrinx size on imaging. Of 16 patients presenting with a symptomatic Chiari malformation, 14 (87.5%) experienced resolution of symptoms and in 1 (4%) symptoms remained the same. One patient (4%) presented with worsening syrinx and symptoms 1.5 months after initial surgery and underwent repeat decompression. CONCLUSIONS The authors describe a series of clinical and imaging outcomes of patients who underwent Chiari malformation decompression and duraplasty with a harvested ligamentum nuchae. The rates of postoperative CSF leak are similar to established techniques of autologous and artificial grafts, with similarly successful outcomes. Further study will be needed with larger patient cohorts to more directly compare duraplasty graft outcomes.