Upper lumbar spine far lateral disc herniations masquerading as peripheral nerve sheath tumors: illustrative cases.

BACKGROUND: Migratory disc herniations can mimic neoplasms clinically and on imaging. Far lateral lumbar disc herniations usually compress the exiting nerve root and can be challenging to distinguish from a nerve sheath tumor due to the proximity of the nerve and characteristics on magnetic resonance imaging (MRI). These lesions can occasionally present in the upper lumbar spine region at the L1-2 and L2-3 levels. OBSERVATIONS: The authors describe 2 extraforaminal lesions in the far lateral space at the L1-2 and L2-3 levels, respectively. On MRI, both lesions tracked along the corresponding exiting nerve roots with avid postcontrast rim enhancement and edema in the adjacent muscle tissue. Thus, they were initially concerning for peripheral nerve sheath tumors. One patient underwent fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET-CT) screening and demonstrated moderate FDG uptake on PET-CT scan. In both cases, intraoperative and postoperative pathology revealed fibrocartilage disc fragments. LESSONS: Differential diagnosis for lumbar far lateral lesions that are peripherally enhancing on MRI should include migratory disc herniation, regardless of the level of the disc herniations. Accurate preoperative diagnosis can aid in decision making for management, surgical approach, and resection.

Spinal Cord Drift Following Laminoplasty Versus Laminectomy and Fusion for Cervical Spondylotic Myelopathy.

BACKGROUND: Cervical laminoplasty and laminectomy and fusion (LF) are posterior-based surgical techniques for the surgical treatment of cervical spondylotic myelopathy (CSM). Interestingly, the comparative amount of spinal cord drift obtained from these procedures has not been extensively described. The purpose of this study is to compare spinal cord drift between cervical laminoplasty and LF in patients with CSM. METHODS: The laminoplasty group consisted of 22 patients, and the LF group consisted of 44 patients. Preoperative and postoperative alignment was measured using the Cobb angle (C2-C7). Spinal cord position was measured on axial T2-magnetic resonance imaging of the cervical spine preoperatively and postoperatively. Spinal cord drift was quantified by subtracting preoperative values from postoperative values. Functional improvement was assessed using the modified Japanese Orthopaedic Association (mJOA) score. RESULTS: Mean spinal cord drift was higher following LF compared to laminoplasty (2.70 vs 1.71 mm, P < .01). Using logistic regression analysis, there was no correlation between sagittal alignment and spinal cord drift. Both groups showed an improvement in mJOA scores postoperatively compared to their preoperative values (laminoplasty, +2.0, P = .012; LF, +2.4, P < .01). However, there was no difference in mJOA score improvement postoperatively between both groups (P = .482). CONCLUSIONS: This study demonstrates that patients who had LF for CSM achieved more spinal cord drift postoperatively compared to those who had laminoplasty. However, the increased drift did not translate into superior functional outcome as measured by the mJOA score. LEVEL OF EVIDENCE: 3. CLINICAL RELEVANCE: Spinal cord drift following LF may differ from laminoplasty in patients undergoing surgery for CSM. This finding should be considered when assessing CSM patients for surgical intervention.

Patient Safety Analysis in Radiation Burden of Head Computed Tomography Imaging in 1185 Neurosurgical Inpatients.

OBJECTIVE: We performed a retrospective analysis in a cohort of 1185 patients at our institution who were identified as undergoing ≥1 head computed tomography (CT) examinations during their inpatient stay on the neurosurgery service, to quantify the number, type, and associated radiation burden of head CT procedures performed by the neurosurgery service. METHODS: CT procedure records and radiology reports were obtained via database search and directly validated against records retrieved from manual chart review. Next, dosimetry data from the head CT procedures were extracted via automated text mining of electronic radiology reports. RESULTS: Among 4510 identified adult head CT procedures, 88% were standard head CT examinations. A total of 3.65 ± 3.60 head CT scans were performed during an average adult admission. The most common primary diagnoses were neoplasms, trauma, and other hemorrhage. The median cumulative effective dose per admission was 5.66 mSv (range, 1.06-84.5 mSv; mean, 8.56 ± 8.95 mSv). The median cumulative effective dose per patient was 6.4 mSv (range, 1.1-127 mSv; mean, 9.26 ± 10.0 mSv). CONCLUSIONS: The median cumulative radiation burden from head CT imaging in our cohort equates approximately to a single chest CT scan, well within accepted limits for safe CT imaging in adults. Refined methods are needed to characterize the safety profile of the few pediatric patients identified in our study.

Red Blood Cell Transfusions Following Resection of Skull Base Meningiomas: Risk Factors and Clinical Outcomes.

Objective This article identifies risk factors for and investigates clinical outcomes of postoperative red blood cell transfusion in patients with skull base meningiomas. Design Retrospective cohort study. Setting Single academic medical center. Participants The transfusion group included patients who had skull base meningiomas and who received packed red blood cell (RBC) transfusion within 7 days of surgery. The no transfusion group included patients who had skull base meningiomas but who did not have RBCs transfused within 7 days of surgery. Main Outcome Measures In-hospital complication rate, length of stay (LOS), and discharge disposition. Results One hundred and ninety-six patients had a craniotomy for resection of a meningioma at our institution from March 2013 to January 2017. Seven patients had skull base meningiomas and received RBC transfusion within 7 days of surgery (the transfusion group). The skull base was an independent risk factor for transfusion after we controlled for the effect of meningioma size (OR 3.89, 95% CI 1.34, 11.25). Operative time greater than 10 hours was an independent risk factor for prolonged hospital stay (OR 8.84, 95% CI 1.08, 72.10) once we controlled for the effect of transfusion. In contrast, transfusion did not independently impact LOS or discharge disposition once we controlled for the effect of operative time. Conclusions The skull base is an independent predictor of RBC transfusion. However, RBC transfusion alone cannot predict LOS or discharge disposition in patients who undergo surgical resection of a skull base meningioma.

Autonomous Trajectory Planning for External Ventricular Drain Placement.

BACKGROUND: External ventricular drain (EVD) placement is the most frequently performed neurosurgical procedure for management of various conditions including hydrocephalus, traumatic brain injury, and stroke. State-of-the-art computational pattern recognition techniques could improve the safety and accuracy of EVD placement. Placement of the Kocher's point EVD is the most common neurosurgical procedure which is often performed in urgent conditions. OBJECTIVE: To present the development of a novel computer algorithm identifying appropriate anatomy and autonomously plan EVD placement on clinical computed tomography (CT) scans. METHODS: The algorithm was tested on 2 data sets containing 5-mm slice noncontrast CT scans. The first contained images of 300 patients without significant intracranial pathology (normal), the second of 43 patients with significant acute intracranial hemorrhage. Automated planning was performed by custom 2-tiered heuristic with run-time template selection in combination with refinement using nonlinear image registration. RESULTS: Automated EVD planning was accurate in 297 of 300 normal and 41 of 43 patient cases. In the normal data set, mean distance between Kocher's point and the ipsilateral foramen of Monro was 63 ± 3.1 mm in women and 65 ± 6.5 mm in men (P = .0008). Trajectory angle with respect to the sagittal plane was 91 ± 6° in women and 90 ± 6° in men (obtuse posterior) (P = .15); to the coronal plane, 85 ± 6° and 86 ± 5° in women and men (P = .12), respectively (acute lateral). CONCLUSION: A combination of linear and nonlinear image registration techniques accurately planned EVD trajectory in 99% of normal scans and 95% of scans with significant intracranial hemorrhage.

Risk of Brain Tumor Induction from Pediatric Head CT Procedures: A Systematic Literature Review.

Head computed tomography (CT) is instrumental for managing patients of all ages. However, its low dose radiation may pose a low but non-zero risk of tumor induction in pediatric patients. Here, we present a systematic literature review on the estimated incidence of brain tumor induction from head CT exams performed on children and adolescents. MEDLINE was searched using an electronic protocol and bibliographic searches to identify articles related to CT, cancer, and epidemiology or risk assessment. Sixteen studies that predicted or measured head CT-related neoplasm incidence or mortality were identified and reviewed. Epidemiological studies consistently cited increased tumor incidence in pediatric patients (ages 0-18) exposed to head CTs. Excess relative risk of new brain tumor averaged 1.29 (95% confidence interval, 0.66-1.93) for pediatric patients exposed to one or more head CTs. Tumor incidence increased with number of pediatric head CTs in a dose-dependent manner, with measurable excess incidence even after a single scan. Converging evidence from epidemiological studies supported a small excess risk of brain tumor incidence after even a single CT exam in pediatric patients. However, refined epidemiological methods are needed to control for confounding variables that may contribute to reverse causation, such as patients with pre-existing cancer or cancer susceptibility. CT remains an invaluable technology that should be utilized so long as there is clinical indication for the study and the radiation dose is as small as reasonably achievable.

Next Generation Case Report: Supraorbital Craniotomy for Anterior Communicating Artery Aneurysm Clipping in Annotated Virtual Reality Environment.

BACKGROUND AND IMPORTANCE: Recent years have seen significant advancements in virtual reality. Implementation of this technology in combination with traditional learning methods is a powerful tool for medical teaching. CLINICAL PRESENTATION: This is a 60-yr-old woman who presented with a history of headaches and was found to have an unruptured 4-mm anterior communicating artery aneurysm. After discussion, the patient elected to have the aneurysm treated by surgical clipping. The aneurysm was completely occluded through a supraorbital craniotomy with a single clip. The patient was discharged home in good condition on postoperative day 2. This case was imported into a virtual reality environment with annotated slides and operative video for resident teaching. CONCLUSION: As virtual reality technology continues to grow, library of interactive case reports could revolutionize neurosurgical education.

Novel Method of Measuring Canal Dehiscence and Evaluation of its Potential as a Predictor of Symptom Outcomes After Middle Fossa Craniotomy.

BACKGROUND: Superior semicircular canal dehiscence (SSCD) is an osseous defect of the arcuate eminence of the petrous temporal bone. Strategies for measuring dehiscence size are variable, and the usefulness of such parameters remains in clinical equipoise. OBJECTIVE: To present a novel method of measuring dehiscence volume and to evaluate its potential as a predictor of symptom outcomes after surgical repair of SSCD. METHODS: High-resolution computed tomographic temporal bone images were imported into a freely available segmentation software. Dehiscence lengths and volumes were ascertained by independent authors. Inter-rater observer reliability was assessed using Cronbach's alpha. Correlation and regression analyses were performed to evaluate for relationships between dehiscence size and symptoms (pre- and post-operative). RESULTS: Thirty-seven dehiscences were segmented using the novel volumetric assessment. Cronbach's alpha for dehiscence lengths and volumes were 0.97 and 0.95, respectively. Dehiscence lengths were more variable as compared to dehiscence volumes (σ2 8.92 vs σ2 0.55, F = 1.74). The mean dehiscence volume was 2.22 mm3 (0.74, 0.64-0.53 mm3). Dehiscence volume and headache at presentation were positively correlated (Rpb = 0.67, P = .03). Dehiscence volume and vertigo improvement after surgery were positively correlated, although this did not reach statistical significance (Rpb = 0.46, P = .21). CONCLUSION: SSCD volumetry is a novel method of measuring dehiscence size that has excellent inter-rater reliability and is less variable compared to dehiscence length, but its potential as a predictor of symptom outcomes is not substantiated. However, the study is limited by low power.

The Etiology of Neuronal Development in Craniosynostosis: A Working Hypothesis.

Craniosynostosis is one of the most common craniofacial conditions treated by neurologic and plastic surgeons. In addition to disfigurement, children with craniosynostosis experience significant cognitive dysfunction later in life. Surgery is performed in infancy to correct skull deformity; however, the field is at a crossroads regarding the best approach for correction. Since the cause of brain dysfunction in these patients has remained uncertain, the role and type of surgery might have in attenuating the later-observed cognitive deficits through impact on the brain has been unclear. Recently, however, advances in imaging such as event-related potentials, diffusion tensor imaging, and functional MRI, in conjunction with more robust clinical studies, are providing important insight into the potential etiologies of brain dysfunction in syndromic and nonsyndromic craniosynostosis patients. This review aims to outline the cause(s) of such brain dysfunction including the role extrinsic vault constriction might have on brain development and the current evidence for an intrinsic modular developmental error in brain development. Illuminating the cause of brain dysfunction will identify the role of surgery can play in improving observed functional deficits and thus direct optimal primary and adjuvant treatment.

Multi-Parameter Ensemble Learning for Automated Vertebral Body Segmentation in Heterogeneously Acquired Clinical MR Images.

The development of quantitative imaging biomarkers in medicine requires automatic delineation of relevant anatomical structures using available imaging data. However, this task is complicated in clinical medicine due to the variation in scanning parameters and protocols, even within a single medical center. Existing literature on automatic image segmentation using MR data is based on the analysis of highly homogenous images obtained using a fixed set of pulse sequence parameters (TR/TE). Unfortunately, algorithms that operate on fixed scanning parameters do not avail themselves to real-world daily clinical use due to the existing variation in scanning parameters and protocols. Thus, it is necessary to develop algorithmic techniques that can address the challenge of MR image segmentation using real clinical data. Toward this goal, we developed a multi-parametric ensemble learning technique to automatically detect and segment lumbar vertebral bodies using MR images of the spine. We use spine imaging data to illustrate our techniques since low back pain is an extremely common condition and a typical spine clinic evaluates patients that have been referred with a wide range of scanning parameters. This method was designed with special emphasis on robustness so that it can perform well despite the inherent variation in scanning protocols. Specifically, we show how a single multi-parameter ensemble model trained with manually labeled T2 scans can autonomously segment vertebral bodies on scans with echo times varying between 24 and 147 ms and relaxation times varying between 1500 and 7810 ms. Furthermore, even though the model was trained using T2-MR imaging data, it can accurately segment vertebral bodies on T1-MR and CT, further demonstrating the robustness and versatility of our methodology. We believe that robust segmentation techniques, such as the one presented here, are necessary for translating computer assisted diagnosis into everyday clinical practice.

Fatal Colloid Cysts: A Systematic Review.

OBJECTIVE: To accurately describe patient characteristics and the clinical presentation of fatal colloid cysts. METHODS: A systematic literature search of 3 popular databases was performed. Inclusion criteria were individuals with sudden-onset death and colloid cysts identified on imaging and/or autopsy. The cause of death must have been ascribed to the colloid cyst to be eligible for data extraction. Deaths precipitated by lumbar puncture were excluded. Clinical data were extracted and descriptive statistics were ascertained. Subgroup analyses were performed to compare adults with pediatric patients. RESULTS: A total of 107 patients were included in the quantitative synthesis. The mean age was 28.5 years (standard deviation 13.3, range 6-79 years). Male and female patients were affected equally. Headache was the most frequent symptom (n = 86, 80%). There were 6 patients (5 adults and 1 child) who reported positional headaches. The mean duration of signs and symptoms was shorter in adults versus pediatric patients (2.1 days vs. 6.5 days, P = 0.02), and more adults presented with signs and symptoms for less than 24 hours than did pediatric patients (38% vs. 6%, P = 0.01). Colloid cyst mean diameter was 2.0 cm (standard deviation 1.1, range 0.5-7.9 cm) and 96% measured 1 cm or larger. CONCLUSIONS: Our data suggests that the prodrome preceding sudden death in the setting of a colloid cyst may be shorter in adults. Also, most fatal colloid cysts measured 1 cm or larger.

A Method of Locating the Dehiscence during Middle Fossa Approach for Superior Semicircular Canal Dehiscence Surgery.

Objectives Superior semicircular canal dehiscence (SSCD) results from a defect in the middle cranial fossa floor. One challenge during SSCD repair is the lack of a consistent landmark. This study proposes a reference point above the external auditory canal at the level of the zygoma as the inferior craniectomy edge during surgery. Design This is a retrospective review of patients with SSCD. Setting/Participants A total of 72 cases of SSCD in 60 patients were repaired via a middle fossa approach at a single institution. Main Outcome Measures The distance from the proposed reference point to the dehiscence was statistically analyzed using Shapiro-Wilk's goodness-of-fit test and Student's t -test. Results Average distance for all patients was 28.84 ± 2.22 mm (range: 22.96-33.43). Average distance for females was 29.08 mm (range: 24.56-33.43) versus 28.26 mm (range: 22.96-32.36) for males. There was no difference in distance by sex ( p = 0.174). The distance measurements followed a normal distribution with 95% of the patients between 24.49 and 33.10 mm. Conclusion This study analyzed a potential reference point during a middle fossa approach for SSCD surgery. The distance from this reference point to the SSCD was found to be consistent and may serve as a readily identifiable landmark in localizing the dehiscence.

Predictors of Outcomes in Fourth Ventricular Epidermoid Cysts: A Case Report and a Review of Literature.

OBJECTIVE: To present an illustrative case of fourth ventricular epidermoid cyst and review the literature to identify predictors of surgical outcomes. METHODS: A case of fourth ventricular epidermoid cyst is presented and a systematic review of 5 popular databases was performed by independent authors. Stepwise logistic regression was performed to identify clinical predictors of outcomes. RESULTS: A 21-year-old woman presented with 3 months of headaches and visual obscurations and was diagnosed with a multilobulated mass in the fourth ventricle. The patient underwent suboccipital craniotomy. Complete removal of the mass was achieved and the final diagnosis was consistent with an epidermoid cyst. The systematic review identified 23 studies that reported 37 patients. Mean age was 42.8 years. Mean length of time between symptom onset and diagnosis was 4.43 years. Age (P = 0.049) and duration of symptoms (P < 0.001) were significantly different between patients who experienced symptom improvement and those who did not. Duration of symptom onset to diagnosis was a significant predictor of poor outcomes (odds ratio, 1.19, 95% confidence interval, 1.003-4.785). CONCLUSIONS: Our review found that in patients with fourth ventricular epidermoid cysts, unfavorable outcomes were predicted by older age and by longer intervals from symptom onset to diagnosis. Clinicians should maintain a high index of suspicion for fourth ventricular epidermoid cysts in patients presenting with cerebellar signs and visual disturbances.

Isolated Transverse Process Fractures and Markers of Associated Injuries: The Experience at University of California, Los Angeles.

OBJECTIVES: To report a single-institution experience with isolated transverse process fractures (ITPFs) and provide increasing support for the development of evidence-based guidelines. The authors also evaluated the presence of concerning symptoms or red flags that may indicate additional, underlying injuries in the setting of ITPFs. METHODS: The Ronald Reagan UCLA Medical Center patient database was queried (years 2005-2016) using International Classification of Diseases, Ninth Revision, code 805: fracture of the vertebral column without mention of spinal cord injury. RESULTS: A total of 129 patients with ITPFs were identified. Mean age was 38.1 years (range 15-92 years). Women were more likely to present with abdominal pain and associated kidney injury (P = 0.018 and P = 0.012, respectively). Motor vehicle accident (MVA) was the most common mechanism of injury (n = 81, 62.8%) and was associated with thoracic (P = 0.032) and lower extremity pain/injury (P = 0.005). Back pain was the most common presenting symptom (n = 71, 64.6%) and was associated with intraabdominal and lower extremity injuries (P = 0.032 and P = 0.016, respectively). Chest and neck pain were associated with vascular injuries (P < 0.001 and P = 0.001, respectively). Spine consult (neurosurgery or orthopedic surgery) was frequent (n = 94, 72.9%) and was more common after MVA versus fall (P = 0.018). CONCLUSIONS: Several factors were identified as significant markers of associated injuries, including female sex, MVA, and presenting symptoms. Neck and chest pain were significantly associated with vascular injuries. Clinicians should maintain high indices of suspicion for associated injuries in patients with ITPFs, especially after high-velocity mechanisms.

Computerized Assessment of Superior Semicircular Canal Dehiscence Size using Advanced Morphological Imaging Operators.

Superior semicircular canal dehiscence (SSCD) describes a pathological aperture at the level of the arcuate eminence. Techniques for quantifying defect size are described with most studies using two-dimensional lengths that underestimate the pathology. The objective of this study is to describe a novel method of measurement that combines manual segmentation of high-resolution computed tomography (HRCT) images of the temporal bone and a morphological skeletonization transform to calculate dehiscence volume. Images were imported into a freely available image segmentation tool: ITK-SNAP (version 3.4.0; available at: http://www.itksnap.org/) software. Coronal and sagittal planes were used to outline the dehiscence in all slices demonstrating the defect using the paintbrush tool. A morphological skeletonization transform derived a single-pixel thick representation of the original delineation. This "sheet" of voxels overlaid the dehiscence. Volume was calculated by counting the number of nonzero image voxels within this "sheet" and multiplying this number by the volume (mm3) of each voxel. A total of 70 cases of SSCD were identified. Overall, mean volume was 0.88 mm3 (standard deviation: 0.57, range: 0.11-2.27). We present a novel technique for measuring SSCD, which we believe provides a more accurate representation of the pathology, and has the potential to standardize measurement of SSCD.

Coil embolization through the Marathon microcatheter: Advantages and pitfalls.

Due to technical limitations, small, distal, and tortuous intracranial pathology is sometimes out of reach of the current armamentarium of microcatheters designed for intracranial coil embolization. The Marathon microcatheter (Medtronic, Minneapolis, Minnesota, USA), designed specifically for the delivery of Onyx, is longer and more flexible than most coil delivery catheters. We report on nine patients (three with arteriovenous fistula, three with arteriovenous malformation, two with intracranial aneurysm, and one with tumor) where Marathon was used to deliver commercially available platinum coils. We also conducted laboratory compatibility testing and conclude that the Marathon can be used as a coil delivery catheter for Barricade coils (Blockade Medical, Irvine, California, USA) with diameter less than 0.012 in.

United States Medical Licensing Examination Step 1 Scores Directly Correlate with American Board of Neurological Surgery Scores: A Single-Institution Experience.

BACKGROUND: Neurosurgery residency is becoming an increasingly competitive match. The process of screening and ranking applicants is a multifactorial process that lacks uniformity across residency programs. A significant factor is the applicant's performance on the United States Medical Licensing Examination (USMLE) Step 1. USMLE Step 1 scores are often used to project future success in residency and performance on specialty boards like the American Board of Neurological Surgery (ABNS) examination. The authors of this study investigate the strength of correlations between USMLE Step 1 and ABNS scores. METHODS: Data were extracted from records of graduating residents from the neurosurgery residency program at the University of California, Los Angeles, between 2003 and 2010. Twenty-one residents were selected. USMLE Step 1 scores were deidentified and paired with ABNS scores. Correlation and regression analyses were performed. RESULTS: Higher USMLE Step 1 scores significantly correlated with higher ABNS scores (P = 0.01; Spearman correlation coefficient, 0.7). CONCLUSIONS: USMLE Step 1 and ABNS scores are directly correlated. USMLE Step 1 scores will continue to be a valuable measure of projected success on ABNS written examinations, but more sophisticated measures are needed.

Normalization of brain morphology after surgery in sagittal craniosynostosis.

OBJECT Nonsyndromic craniosynostosis (NSC) is associated with significant learning disability later in life. Surgical reconstruction is typically performed before 1 year of age to correct the cranial vault morphology and to allow for normalized brain growth with the goal of improving cognitive function. Yet, no studies have assessed to what extent normalized brain growth is actually achieved. Recent advances in MRI have allowed for automated methods of objectively assessing subtle and pronounced brain morphological differences. The authors used one such technique, deformation-based morphometry (DBM) Jacobian mapping, to determine how previously treated adolescents with sagittal NSC (sNSC) significantly differ in brain anatomy compared with healthy matched controls up to 11.5 years after surgery. METHODS Eight adolescent patients with sNSC, previously treated via whole-vault cranioplasty at a mean age of 7 months, and 8 age- and IQ-matched control subjects without craniosynostosis (mean age for both groups = 12.3 years), underwent functional 3-T MRI. Statistically significant group tissue-volume differences were assessed using DBM, a whole-brain technique that estimates morphological differences between 2 groups at each voxel (p < 0.01). Group-wise Jacobian volume maps were generated using a spacing of 1.5 mm and a resolution of 1.05 × 1.05 × 1.05 mm(3). RESULTS There were no significant areas of volume reduction or expansion in any brain areas in adolescents with sNSC compared with controls at a significance level of p < 0.01. At the more liberal threshold of p < 0.05, two areas of brain expansion extending anteroposteriorly in the right temporooccipital and left frontoparietal regions appeared in patients with sNSC compared with controls. CONCLUSIONS Compared with previous reports on untreated infants with sNSC, adolescents with sNSC in this cohort had few areas of brain dysmorphology many years after surgery. This result suggests that comprehensive cranioplasty performed at an early age offers substantial brain normalization by adolescence, but also that some effects of vault constriction may still persist after treatment. Specifically, few areas of expansion in frontoparietal and temporooccipital regions may persist. Overall, data from this small cohort support the primary goal of surgery in allowing for more normalized brain growth. Larger samples, and correlating degree of normalization with cognitive performance in NSC, are warranted.

Altered brain connectivity in sagittal craniosynostosis.

OBJECT: Sagittal nonsyndromic craniosynostosis (sNSC) is the most common form of NSC. The condition is associated with a high prevalence (> 50%) of deficits in executive function. The authors employed diffusion tensor imaging (DTI) and functional MRI to evaluate whether hypothesized structural and functional connectivity differences underlie the observed neurocognitive morbidity of sNSC. METHODS: Using a 3-T Siemens Trio MRI system, the authors collected DTI and resting-state functional connectivity MRI data in 8 adolescent patients (mean age 12.3 years) with sNSC that had been previously corrected via total vault cranioplasty and 8 control children (mean age 12.3 years) without craniosynostosis. Data were analyzed using the FMRIB Software Library and BioImageSuite. RESULTS: Analyses of the DTI data revealed white matter alterations approaching statistical significance in all supratentorial lobes. Statistically significant group differences (sNSC < control group) in mean diffusivity were localized to the right supramarginal gyrus. Analysis of the resting-state seed in relation to whole-brain data revealed significant increases in negative connectivity (anticorrelations) of Brodmann area 8 to the prefrontal cortex (Montreal Neurological Institute [MNI] center of mass coordinates [x, y, z]: -6, 53, 6) and anterior cingulate cortex (MNI coordinates 6, 43, 14) in the sNSC group relative to controls. Furthermore, in the sNSC patients versus controls, the Brodmann area 7, 39, and 40 seed had decreased connectivity to left angular gyrus (MNI coordinates -31, -61, 34), posterior cingulate cortex (MNI coordinates 13, -52, 18), precuneus (MNI coordinates 10, -55, 54), left and right parahippocampus (MNI coordinates -13, -52, 2 and MNI coordinates 11, -50, 2, respectively), lingual (MNI coordinates -11, -86, -10), and fusiform gyri (MNI coordinates -30, -79, -18). Intrinsic connectivity analysis also revealed altered connectivity between central nodes in the default mode network in sNSC relative to controls; the left and right posterior cingulate cortices (MNI coordinates -5, -35, 34 and MNI coordinates 6, -42, 39, respectively) were negatively correlated to right hemisphere precuneus (MNI coordinates 6, -71, 46), while the left ventromedial prefrontal cortex (MNI coordinates 6, 34, -8) was negatively correlated to right middle frontal gyrus (MNI coordinates 40, 4, 33). All group comparisons (sNSC vs controls) were conducted at a whole brain-corrected threshold of p < 0.05. CONCLUSIONS: This study demonstrates altered neocortical structural and functional connectivity in sNSC that may, in part or substantially, underlie the neuropsychological deficits commonly reported in this population. Future studies combining analysis of multimodal MRI and clinical characterization data in larger samples of participants are warranted.

Does an elevated bony ridge along the course of the metopic suture equal metopic synostosis? Implications for management.

Metopic synostosis represents an increasingly prevalent form of nonsyndromic craniosynostosis. Premature fusion of the metopic suture classically results in trigonocephaly, hypotelorism, temporal narrowing, and a pronounced midline forehead ridge. However, as varying degrees of skull deformity exist, there is confusion regarding the appropriate management for an infant with a metopic ridge. We report on a 2-month-old infant with clinical manifestations of metopic synostosis but with a patent metopic suture documented on computed tomography scan. We examine the implications for management related to fusion of the suture, age of the patient, and severity of the head deformity.