Posterior Vault Distraction in the Acute Setting.

ABSTRACT: Posterior vault distraction osteogenesis (PVDO) has been shown to resolve acute intracranial hypertension (AIH) while carrying an acceptable perioperative morbidity profile. PVDO has been associated with symptomatic improvement and fewer surgeries in those requiring ventriculoperitoneal shunts. The authors' experience using PVDO as an acute intervention is presented, demonstrating its safety and efficacy for management of AIH. Four cases of children with craniosynostosis that underwent PVDO in the acute setting are outlined. All patients presented with papilledema and symptoms of AIH. One patient with slit ventricle syndrome (SVS) presented with a nonfunctioning shunt following multiple shunt revisions. No intraoperative complications during distractor placement or removal were reported. Distraction protocol for all patients began on postoperative day 1 at 1-2 mm per day, resulting in an average total distraction of 30.25 mm. For the 3 cases with no shunt, the average length of stay was 7 days. As part of the planned treatment course, the patient with SVS required externalization of the shunt during distraction followed by early distractor removal and planned shunt replacement. One case of surgical site infection (in an immunocompromised patient) required premature distractor removal during the consolidation period. Computed tomography (CT) in all patients indicated increased intracranial volume following distraction, and symptomatic improvement was reported. Six-month follow-up showed resolution of papilledema in all patients. The authors' experience using PVDO in the acute setting is reported, alongside a review of current literature, in order to provide supporting evidence for the efficacy of PVDO as a tool for resolving AIH.

Squamosal Craniosynostosis Associated with Rickets.

Rickets results from defective bone mineralization, leading to skeletal deformities. Among those deformities, rickets has been associated with craniosynostosis, the premature closure of cranial sutures. Most of these patients have fusion of major sutures. Rarely, squamosal craniosynostosis in association with rickets has been described. Squamosal craniosynostosis is noted as lacking a definitive head abnormality and difficult visualization on standard imaging modalities, leading to poor recognition. Careful attention should be given to rickets patients to monitor for these unusual suture closures. Additionally, craniosynostosis could be a presenting feature of rickets, and further rickets evaluation of the patient is indicated.

Does Obesity Affect Preoperative Shoulder Balance in Adolescent Idiopathic Scoliosis?

BACKGROUND: Obese patients with adolescent idiopathic scoliosis (AIS) have been shown to present with larger curve magnitudes preoperatively. However, the effect of obesity on shoulder balance in AIS remains unknown. The purpose of our study was to determine if overweight and obese patients with AIS have worse radiographic shoulder balance on initial presentation when compared with normal weight patients. METHODS: AIS patients <18 years old, with Lenke 1 or 2 curves, who underwent a posterior spinal fusion between March 2013 and December 2018 were retrospectively evaluated. BMI-for-age percentiles as defined by the Center for Disease Control and Prevention were used: obese (≥95th percentile), overweight (85th to <95th percentile), and normal weight (5th to <85th percentile). Shoulder height was measured via the radiographic shoulder height (RSH) method, with an RSH ≤ 1 cm considered balanced. The primary outcome was preoperative shoulder balance. Secondary outcomes included postoperative shoulder balance, major curve correction, and UIV selection. RESULTS: One hundred eighty-four patients (116 [63%] normal weight and 68 [37%] overweight/obese) were included. The mean age at surgery was 13.1 ± 2 years, and mean follow-up was 17.4 ± 13 months. Preoperative shoulder imbalance was significantly greater in the overweight/obese group compared to the normal weight group (1.9 ± 1 cm vs. 1.5 ± 1 cm, p = 0.04). The odds ratio of presenting with unbalanced shoulders was 2.0 (95% CI: 1.02-3.83, p = 0.04) for the overweight/obese group. No significant differences were found for postoperative shoulder balance, UIV selection, or major curve correction. CONCLUSIONS: Overweight and obese patients with AIS are twice as likely to present with unbalanced shoulders preoperatively; however, this difference is not clinically relevant with a mean difference of 0.4 cm between cohorts. Finally, the preoperative BMI percentile did not show a significant effect on the chosen UIV or curve magnitude correction. LEVEL OF EVIDENCE: Level III: this is a retrospective case-control study.

Posterior cranial vault distraction osteogenesis in the immunocompromised patient.

PURPOSE: The treatment of patients with multisuture craniosynostosis is complex and patient-dependent. Cranial distraction osteogenesis is a relatively new procedure for treatment of these patients, with its use increasing in many centers. With this increased use comes an expanding range of indications. Surgical management of multisuture craniosynostosis in therapeutically immunosuppressed patients following a solid organ transplant presents unique challenges. We describe our experience with posterior cranial vault distraction in two patients with multisuture craniosynostosis that had previously undergone organ transplantation. METHODS: Two solid-organ transplant recipient patients with multisuture craniosynostosis were identified. A detailed examination of their medical/transplant history and perioperative details were recorded. RESULTS: The first patient was a 3-year-old girl who received a kidney transplantation in infancy and subsequently presented with a symptomatic Chiari malformation and papilledema. Imaging revealed pansynostosis. She underwent posterior cranial vault distraction extending into a Chiari decompression. Her postoperative course was complicated by distractor site infection at the beginning of consolidation, necessitating early removal of distractors. The second patient was a 2-year-old boy who received a heart transplantation at the age of 3 months and subsequently presented with head shape concerns. Imaging revealed bicoronal and sagittal craniosynostosis. He underwent a posterior cranial vault distraction without complication. Following removal of the distractors, he developed an infection at one of the distractor sites with associated fever and leukocytosis, necessitating washout and drain placement. Both patients achieved successful cranial vault expansion with distraction osteogenesis and at a 2-year follow-up do not have evidence of elevated intracranial pressure. CONCLUSIONS: Immunosuppressive therapy has the potential to inhibit wound healing and place patients at risk for wound infection. Although we have demonstrated successful cranial vault expansion with distraction in two immunosuppressed children, extra care must be taken with these patients when placing semi-buried hardware. Specifically, prompt identification and proactive management of potential infectious complications is critical to applying this technique safely in these patients.

Comparison of Follow-Up Length-Matched Single-Center Myelomeningocele Postnatal Closure Cohort to the Management of Myelomeningocele Study (MOMS) Trial Results.

OBJECTIVE: We sought to compare our large single-institution cohort of postnatal myelomeningocele closure to the 2 arms of the Management of Myelomeningocele Study (MOMS) trial at the designated trial time points, as well as assess outcomes at long-term follow-up among our postnatal cohort. METHODS: A single-institutional retrospective review of myelomeningocele cases presenting from 1995 to 2015 at Children's Hospital of Pittsburgh was performed. We compared outcomes at 12 and 30 months to both arms of the MOMS trial and compared our cohort's outcomes at those designated time points to our long-term outcomes. Univariate statistical analysis was performed as appropriate. RESULTS: One-hundred sixty-three patients were included in this study. All patients had at least 2-year follow-up, with a mean follow-up of 10 years (range 2-20 years). There was no difference in the overall distribution of anatomic level of defect. Compared to our cohort, the prenatal cohort had a higher rate of tethering at 12 months of age, 8 versus 1.8%. Conversely, the Chiari II decompression rate was higher in our cohort (10.4 vs. 1.0%). At 30 months, the prenatal cohort had a higher rate of independent ambulation, but our cohort demonstrated the highest rate of ambulation with or without assistive devices among the 3 groups. When comparing our cohort at these early time points to our long-term follow-up data, our cohort's ambulatory function decreased from 84 to 66%, and the rate of detethering surgery increased almost 10-fold. CONCLUSIONS: This study demonstrated that overall ambulation and anatomic-functional level were significantly better among our large postnatal cohort, as well as having significantly fewer complications to both fetus and mother, when compared to the postnatal cohort of the MOMS trial. Our finding that ambulatory ability declined significantly with age in this patient population is worrisome for the long-term outcomes of the MOMS cohorts, especially given the high rates of cord tethering at early ages within the prenatal cohort. These findings suggest that the perceived benefits of prenatal closure over postnatal closure may not be as substantial as presented in the original trial, with the durability of results still remaining a concern.

Brainstem angiocentric glioma: report of 2 cases.

Angiocentric glioma is a rare tumor that was recognized by the WHO Classification of Tumours of the Central Nervous System as a distinct clinicopathological entity in 2007. Since this initial description, the vast majority of cases of angiocentric glioma reported in the literature have involved tumors of the cerebral hemispheres. To date, only 1 case of angiocentric glioma arising from the posterior midbrain has been reported. The authors present the cases of 2 pediatric patients who were found to have brainstem angiocentric gliomas. The clinical course, radiological and pathological features, treatment, and follow-up are described. The first case is one of a 5-year-old girl who presented with double vision, headache, and nausea and was found to have a midbrain lesion with pathological features consistent with angiocentric glioma. She was treated with resection and endoscopic third ventriculostomy (ETV), followed by close observation and serial neuroimaging. The second case is one of a 6-year-old boy who presented with progressive mouth drooping and problems with balance. He was found to have a pontine lesion with pathological features consistent with angiocentric glioma. This patient was treated with ETV, followed by close observation and serial neuroimaging. This report includes 6 and 1.5 years of follow-up of the patients, respectively. While there are limited data regarding the prognosis or long-term management of patients with brainstem angiocentric gliomas, the cases described in this report suggest an indolent course for this tumor, similar to the course of angiocentric gliomas located in the cerebral hemispheres.

Do tumor and ventricular volume predict the need for postresection shunting in colloid cyst patients?

OBJECTIVE Many colloid cyst patients present with obstructive hydrocephalus that resolves after resection of the cyst. However, a proportion of patients with these cysts will require cerebrospinal fluid shunting after tumor resection, despite resolution of the obstruction at the foramina of Monro. The goal of this study was to determine if colloid cyst size or preoperative ventricular volume predicted the need for postresection shunting. METHODS In a retrospective study design, ICD-9 codes 742.2 (colloid cyst) and 348.0 (brain cyst) were used to identify patients who had undergone resection of a colloid cyst at the University of Florida over the last 20 years. Preoperative imaging (CT or MRI) with a stereotactic software program developed at the University of Florida was used to measure volumes of the colloid cyst and the lateral ventricles. The relationships among ventricular volume, colloid cyst volume, and postoperative shunting were analyzed. RESULTS The number of patients included in the study was 67, and their mean age was 37.7 years. Forty percent of the patients were female. Overall, 49.2% of the patients had a transcallosal approach, 35.8% a transcortical approach, and 14.9% an endoscope-assisted surgery. Mean preoperative ventricular volume was 76.5 cc in patients who never received a ventriculoperitoneal shunt (VPS) and 98.1 cc in those who were eventually treated with a VPS (p = 0.305). Patients with a postoperative VPS had an initial mean colloid cyst volume of 1.8 cc compared with 0.9 cc in patients without a VPS postoperatively (p = 0.019). Patients with colloid cysts larger than 0.6 cc (1-cm diameter) had a 12.8 increased odds of needing a VPS postoperatively (95% CI 1.81-275). CONCLUSIONS Larger colloid cysts are associated with an increased need for postresection shunting independent of preoperative ventricular size. Prospective studies of patients with colloid cysts are necessary to further identify risks of permanent hydrocephalus.

Embryonal tumor with multilayered rosettes of the fourth ventricle: case report.

Embryonal tumor with multilayered rosettes (ETMR) is a recently described pathological entity. These primitive central nervous system tumors harbor amplification of the 19q13.42 locus and resultant overexpression of the LIN28A protein. Although the WHO currently recognizes 3 distinct histopathological entities-embryonal tumor with abundant neuropil and true rosettes (ETANTR), ependymoblastoma, and medulloepithelioma-recent studies indicate that these tumors have a common molecular profile and clinical course and that they are now classified as a single entity. Here the authors present a case of ETMR located in the fourth ventricle in a 12-month-old boy. The histopathology featured areas of neuropil-like stroma and highly cellular foci with characteristic multilayered rosettes. The authors discuss the clinical, radiological, and histopathological findings in this case and compare them with data in previously published cases in the literature. A review of studies assessing the molecular mechanisms underlying these tumors is also presented.

Decreased incidence of venous thromboembolism after spine surgery with early multimodal prophylaxis: Clinical article.

OBJECT: Venous thromboembolism (VTE) represents a significant complication after spine surgery, with reported rates as high as 2%-4%. Published institutional practices for VTE prophylaxis are highly variable. In 2008, the authors implemented a departmental protocol for early VTE prophylaxis consisting of combined compressive devices and subcutaneous heparin initiated either preoperatively or on the same day of surgery. In this study, the authors compared the incidence of VTE in spine surgery patients before and after implementing this protocol. METHODS: An institutional review board-approved retrospective review of outcomes in patients undergoing spine surgery 2 years before protocol implementation (representing the preprotocol group) and of outcomes in patients treated 2 years thereafter (the postprotocol group) was conducted. Inclusion criteria were that patients were 18 years or older and had been admitted for 1 or more days. Before 2008 (preprotocol), VTE prophylaxis was variable and provider dependent without any uniform protocol. Since 2008 (postprotocol), a new VTE-prophylaxis protocol was administered, starting either preoperatively or on the same day of surgery and continuing throughout hospitalization. The new protocol consisted of 5000 U heparin administered subcutaneously 3 times daily, except in patients older than 75 years or weighing less than 50 kg, who received this dose twice daily. All patients also received sequential compression devices (SCDs). The incidence of VTE in the 2 protocol phases was identified by codes of the International Classification of Diseases, Ninth Revision (ICD-9) codes for deep vein thrombosis (DVT) and pulmonary embolus (PE). Bleeding complications arising from anticoagulation treatments were evaluated by the Current Procedural Terminology (CPT) code for postoperative epidural hematoma (EDH) requiring evacuation. RESULTS: In total, 941 patients in the preprotocol group met the inclusion criteria: 25 had DVT (2.7%), 6 had PE (0.6%), and 6 had postoperative EDH (0.6%). In the postprotocol group, 992 patients met the criteria: 10 had DVT (1.0%), 5 had PE (0.5%), and 4 had postoperative EDH (0.4%). This reduction in DVT after the protocol's implementation was statistically significant (p = 0.009). Despite early aggressive prophylaxis, the incidence of postoperative EDH did not increase and compared favorably to the published literature. CONCLUSIONS: At a high-volume tertiary center, an aggressive protocol for early VTE prophylaxis after spine surgery decreases VTE incidence without increasing morbidity.

Differential distribution patterns from medial prefrontal cortex and dorsal raphe to the locus coeruleus in rats.

Locus coeruleus (LC) consists of a densely packed nuclear core and a surrounding plexus of dendritic zone, which is further divided into several subregions. Whereas many limbic-related structures topographically target specific subregions of the LC, the precise projections from two limbic areas, that is, medial prefrontal cortex (mPFC) and dorsal raphe (DR), have not been investigated. The goal of the present study is to identify and compare the distribution patterns of mPFC and DR afferent terminals to the LC nuclear core as opposed to specific pericoerulear dendritic regions (Peri-LC). To address these issues, anterograde tracer injections were combined with dopamine-ß-hydroxylase (DBH) immunofluorescent staining to reveal the distribution patterns around the LC nuclear complex. Our data suggest that both mPFC-LC and DR-LC projections exhibit selective afferent terminal patterns. More specifically, mPFC-LC projecting fibers mainly target the rostromedial Peri-LC, whereas DR-LC projecting fibers demonstrate a preference to the caudal juxtaependymal Peri-LC. Thus, our present findings provide further evidences that afferents to the LC are topographically organized. Understanding the relationship among different inputs to the LC may help to elucidate the organizing principle which likely governs the interactions between the broad afferent sources of the LC and its global efferent targets.

The "July phenomenon" for neurosurgical mortality and complications in teaching hospitals: an analysis of more than 850,000 neurosurgical patients in the nationwide inpatient sample database, 1998 to 2008.

BACKGROUND: The evidence of or against the presence of a 'July phenomenon' in resident teaching hospitals has been inconsistent. Moreover, there are limited data on the "July phenomenon" in the field of neurosurgery. OBJECTIVE: To determine whether a "July phenomenon" exists for neurosurgical mortality or complications. METHODS: A search of the National Inpatient Sample database from 1998 to 2008 was performed for all admissions for International Classification of Diseases, 9th Revision codes corresponding to nontraumatic hemorrhage, central nervous system (CNS) trauma, CNS tumor, and hydrocephalus. Generalized linear mixed-model analysis was performed, adjusted for patient demographics and hospital characteristics, for the outcomes of mortality and complications for the month of July compared with all other months in teaching hospitals. RESULTS: Generalized linear mixed-model analysis demonstrated that the risk of dying in the month of July vs any other month in a teaching hospital was not statistically different for any of the 4 diagnoses: nontraumatic hemorrhage (P = .071), CNS trauma category (P = .485), CNS tumor category (P = .578), hydrocephalus category (P = .1505). Moreover, the risk of any complication in the month of July vs any other month in a teaching hospital was not statistically different for any of the 4 diagnoses: nontraumatic hemorrhage (P = .529), CNS trauma category (P = .378), CNS tumor category (P = .461), and hydrocephalus category (P = .441). The same findings were true in an analysis of nonteaching hospitals performed as a control. CONCLUSION: No "July phenomenon" was found for neurosurgical mortality or complications in patients with nontraumatic hemorrhage, CNS trauma, CNS tumor, or hydrocephalus.

Perinatal antidepressant exposure alters cortical network function in rodents.

Serotonin (5-HT) plays a key role in early brain development, and manipulation of 5-HT levels during this period can have lasting neurobiological and behavioral consequences. It is unclear how perinatal exposure to drugs, such as selective serotonin reuptake inhibitors (SSRIs), impacts cortical neural network function and what mechanism(s) may elicit the disruption of normal neuronal connections/interactions. In this article, we report on cortical wiring organization after pre- and postnatal exposure to the SSRI citalopram. We show that manipulation of 5-HT during early development in both in vitro and in vivo models disturbs characteristic chemoarchitectural and electrophysiological brain features, including changes in raphe and callosal connections, sensory processing, and myelin sheath formation. Also, drug-exposed rat pups exhibit neophobia and disrupted juvenile play behavior. These findings indicate that 5-HT homeostasis is required for proper brain maturation and that fetal/infant exposure to SSRIs should be examined in humans, particularly those with developmental dysfunction, such as autism.

Neonatal exposure to citalopram selectively alters the expression of the serotonin transporter in the hippocampus: dose-dependent effects.

Infants born to mothers taking selective serotonin reuptake inhibitors (SSRIs) late in pregnancy have been reported to exhibit signs of antidepressant withdrawal. Such evidence suggests that these drugs access the fetal brain in utero at biologically significant levels. Recent studies in rodents have revealed that early exposure to antidepressants can lead to long lasting abnormalities in adult behaviors, and result in robust decreases in the expression of a major serotonin synthetic enzyme (tryptophan hydroxylase) along the raphe midline. In the present investigation, we injected rat pups with citalopram (CTM: 5 mg/kg, 10 mg/kg, and 20 mg/kg) from postnatal Days 8-21, and examined serotonin transporter (SERT) labeling in the hippocampus, ventrobasal thalamic complex, and caudate-putamen when the subjects reached adulthood. Our data support the idea, that forebrain targets in receipt of innervation from the raphe midline are particularly vulnerable to the effects of CTM. SERT-immunoreactive fiber density was preferentially decreased throughout all sectors of the hippocampal formation, whereas the subcortical structures, each supplied by more lateral and rostral aspects of the raphe complex, respectively, were not significantly affected. Reductions in SERT staining were also found to be dose-dependent. These findings suggest that SSRIs may not only interfere with the establishment of chemically balanced circuits in the neonate but also impose selective impairment on higher cortical function and cognitive processes via more circumscribed (i.e., regionally specific) deficits in 5-HT action.

Coexpression of serotonin and nitric oxide in the raphe complex: cortical versus subcortical circuit.

Several lines of evidence have implicated a direct reciprocal interaction between serotonin and nitric oxide (NO). The goal of this investigation was, therefore, to examine the coexpression of tryptophan hydroxylase (TPH; the rate limiting enzyme for the synthesis of serotonin) and neuronal NO synthase (nNOS) in the ascending cortical projecting raphe nuclei (B6-B9 subgroups), when compared with the descending spinal cord projecting raphe nuclei (B1-B3 subgroups). Our data demonstrated that: (1) a significant number of raphe-cortical projecting neurons was identified not only in the midline subgroup of dorsal raphe (B6, 7) but also in the median raphe (B8), as well as in the supralemniscal nucleus (B9); (2) serotonergic cortical projecting neurons from these three raphe nuclei exhibited a high (>80%) percentage of coexpression with nNOS immunoreactivity; (3) similarly, serotonin transporter immunoreactive fibers in the medial prefrontal cortex were also double-labeled with nNOS immunoreactivity; (4) in contrast, the descending spinal cord projecting raphe nuclei revealed only TPH but not nNOS immunoreactivity. Our present findings suggest the existence of a direct interaction between serotonin and NO in the ascending cortical projecting raphe system. In contrast, a different strategy appears to operate the descending spinal cord projecting raphe system.

Novel Brønsted acidic ionic liquids and their use as dual solvent-catalysts.

The reaction of triphenylphosphine or N-butylimidazole with cyclic sultones gives zwitterions that are subsequently converted into ionic liquids by reaction with trifluoromethane sulfonic acid or p-toluenesulfonic acid. The resulting ionic liquids have cations to which are tethered alkane sulfonic acid groups. These Brønsted acidic ionic liquids are useful solvent/catalysts for several organic reactions, including Fischer esterification, alcohol dehydrodimerization and the pinacol rearrangement. The new ionic liquids combine the low volatility and ease of separation from product normally associated with solid acid catalysts, with the higher activity and yields normally found using conventional liquid acids.