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OBJECT Distraction osteogenesis (DO) may allow for maximal volumetric expansion in the posterior vault (PV) by overcoming viscoelastic forces of overlying soft tissues. Little evidence exists regarding surgical planning and anticipated 3D volumetric changes pre- and post-operatively. We aim to study the volumetric changes occurring in PV distraction in lambdoid craniosynostosis. METHODS From 2007 to 2019, a single institution retrospective review revealed 232 craniosynostosis patients. Fourteen demonstrated lambdoid synostosis (6%), and of those, 11 patients were included in the study due to treatment with PVDO or representative sample. Six patients had unilateral synostosis and 5 had bilateral synostosis. Imaging protocol for PVDO patients included preoperative head CT within 1 month of surgery and 8 weeks following distraction cessation with weekly skull plain films. 3D volumetric analyses were performed on pre and postoperative head CT using 3D Slicer software. RESULTS Posterior fossa volume (PFV) increased by 38.7% and foramen magnum area increased by 26.9% postoperatively. Unilateral lambdoid craniosynostosis patients had greater increases in PFV versus bilateral lambdoid craniosynostosis patients (63.5% versus 8.9%, P = 0.007). Osteotomy to the asterion was more effective in increasing PFV versus osteotomy to foramen magnum (P = 0.050). Placement of distractor in the inferior third of the lambdoid suture is more effective in increasing PFV versus placement in the middle or top third of the suture (P = 0.041). CONCLUSIONS Highest volumetric increases are seen in unilateral lambdoid synostosis. Extending osteotomy beyond the asterion is not necessary for maximal PV volumetric gain. Placement of distractor in the inferior third of the suture leads to maximal PV volumetric gains.

Ventriculomegaly in infants with congenital myotonic dystrophy (CDM) is common, and the neurosurgical determination of shunting is complex. The natural history of CDM-associated ventriculomegaly from prenatal to natal to postnatal stages is poorly known. The relationship between macrocephaly and ventriculomegaly, incidence of shunt necessity, and early mortality outcomes lack pooled data analysis. This study aims to review clinical features and pathophysiology of CDM, with emphasis on ventriculomegaly progression, ventriculomegaly association with macrocephaly, and incidence of shunting. This is a literature review with pooled data analysis and case report. One hundred four CDM patients were reviewed in 13 articles that mentioned CDM with ventriculomegaly and/or head circumference. Data was very limited: only 7 patients had data on the presence or absence of prenatal ventriculomegaly, 97 on ventriculomegaly at birth, and 32 on whether or not the ventricles enlarged post-natally. Three patients of 7 (43 %) had pre-natally diagnosed ventriculomegaly, 43 of 97 (44 %) had ventriculomegaly at birth, and only 5 of 32 (16 %) had progressive enlargement of ventricles post-natally. Only 5 of 104 patients had a documented shunt placement: 1 for obstructive, 1 for a post-hemorrhagic communicating, 2 for a communicating hydrocephalus without hemorrhage, and 1 with unknown indication. Of 13 macrocephalic patients with data about ventricular size, 12 had ventriculomegaly. Ventriculomegaly occurs regularly with CDM but most often does not require CSF diversion. Decisions regarding neurosurgical intervention will necessarily be based on limited information, but shunting should only occur once dynamic data confirms hydrocephalus.

Study Objective To describe how pediatric and adolescent patients present to the gynecologist when they have tethered cord syndrome (TCS). Design We conducted a retrospective chart review on all patients suspected by the gynecologist of having TCS. Setting Single pediatric and adolescent gynecology clinic in a mid-sized city in the midwest. Participants Thirty-two patients, first seen between 2005 and 2012, suspected of having TCS and for whom follow-up information was available. Interventions and Main Outcome Measures Patient characteristics, including patient history, gynecologic clinical indicators, clinical outcomes, indications for surgery, and postoperative resolution of symptoms, were reviewed. Results The initial review of systems indicated stress urinary incontinence, back pain, and constipation as common markers in the 32 patients who were suspected of having TCS. All 32 patients underwent lumbar magnetic resonance imaging without contrast and evaluation by neurosurgery. Of the 32 patients with suspected TCS, 18 were later confirmed and 14 were shown to not have TCS. Of the 18 patients with sufficient information to justify a detethering procedure, 14 patients were followed and 93% (13 patients) had complete resolution of symptoms. Final diagnosis in the non-TCS group varied, including vulvovaginitis, enuresis, chronic constipation, and lichen sclerosis. Symptoms improved with the treatment of each primary condition. Conclusions TCS symptoms overlap with gynecologic conditions; therefore, patients with TCS may present initially to the gynecologist. In pediatric/adolescent patients, TCS should be considered when stress urinary incontinence, back pain, and constipation are discovered in the review of systems. Because possible irreversible ischemic and neurologic changes are believed to be involved, early diagnosis and surgery are crucial for resolution. Providers should be aware of TCS in these pediatric and adolescent settings, because quick assessment may result in complete resolution of a chronic progressive disease.

Molding helmet therapy is a widely accepted treatment for positional plagiocephaly that is generally considered to be low risk. Multiple large outcome studies have shown good results, but adverse events are rarely reported. The literature on helmet therapy was reviewed to clarify the clinical experience with associated complications. Although significant complications were extremely rare, there was a large degree of variability in detection of lesser problems such as minor skin irritation. Patients with a primarily brachycephalic morphology may be at higher risk for poorly fitting orthoses. Most reported complications are minor and self-limited. Maintenance of good helmet hygiene appears to be the most effective strategy for reducing or eliminating complications.

Pituitary gland duplication is a rare malformation of unknown cause that is often associated with a nasopharyngeal teratoma, among other secondary malformations. This clinical report describes a case of pituitary gland duplication with a nasopharyngeal teratoma, cleft palate, and hypothalamic hamartoma, as well as the surgical management of this patient. This case also raises the question of whether the nasopharyngeal teratoma is the cause of the pituitary duplication above and the cleft palate below or whether it is a result of the primary duplication of the notochordal process. Various theories are presented in an attempt to answer this question, but the exact cause of these malformations remains equivocal. Future research in this topic may elucidate the answer to this question.

Langerhans cell histiocytosis (LCH) is a clonal proliferation of Langerhans cells of unknown etiology that results in a range of clinical manifestations. LCH has been known to be associated with a variety of malignant diseases. A 7-year-old boy was treated for standard-risk acute lymphoblastic leukemia (ALL) at age 2 years, on a Children's Cancer Group chemotherapy protocol for 3 years and developed LCH 2 years after completion of chemotherapy. The case and a review of literature on the association of LCH and ALL are presented.

Intraoperative and interventional MR have opened a new chapter in neurosurgery bringing both new therapeutic opportunities and creating unique safety challenges for the MR operating room. The presence of a large magnetic field in the otherwise familiar environment of the operating room necessitates site-specific comprehensive policies for safety, staff training, infection control, and MR compatibility. Intraoperative MRI also creates unique MR image interpretation challenges that are of paramount significance for patient safety. These safety concerns are reviewed with particular reference to the nine years experience of the authors.

Neurosurgical procedures demand precision, and efforts to create accurate neurosurgical navigation have been central to the profession through its history. Magnetic resonance image (MRI)-guided navigation offers the possibility of real-time, image-based stereotactic information for the neurosurgeon, which makes possible a number of diagnostic and therapeutic procedures. This article will review both current options for intraoperative MRI operative suite arrangements and the current therapeutic/diagnostic uses of intraoperative MRI.

In this paper, we present an automatic statistical approach for extracting 3D blood vessels from time-of-flight (TOF) magnetic resonance angiography (MRA) data. The voxels of the dataset are classified as either blood vessels or background noise. The observed volume data is modeled by two stochastic processes. The low level process characterizes the intensity distribution of the data, while the high level process characterizes their statistical dependence among neighboring voxels. The low level process of the background signal is modeled by a finite mixture of one Rayleigh and two normal distributions, while the blood vessels are modeled by one normal distribution. The parameters of the low level process are estimated using the expectation maximization (EM) algorithm. Since the convergence of the EM is sensitive to the initial estimate of the model parameters, an automatic method for parameter initialization, based on histogram analysis, is provided. To improve the quality of segmentation achieved by the proposed low level model especially in the regions of significantly vascular signal loss, the high level process is modeled as a Markov random field (MRF). Since MRF is sensitive to edges and the intracranial vessels represent roughly 5% of the intracranial volume, 2D MRF will destroy most of the small and medium sized vessels. Therefore, to reduce this limitation, we employed 3D MRF, whose parameters are estimated using the maximum pseudo likelihood estimator (MPLE), which converges to the true likelihood under large lattice. Our proposed model exhibits a good fit to the clinical data and is extensively tested on different synthetic vessel phantoms and several 2D/3D TOF datasets acquired from two different MRI scanners. Experimental results showed that the proposed model provides good quality of segmentation and is capable of delineating vessels down to 3 voxel diameters.

In this paper, we present a novel algorithm for fuzzy segmentation of magnetic resonance imaging (MRI) data and estimation of intensity inhomogeneities using fuzzy logic. MRI intensity inhomogeneities can be attributed to imperfections in the radio-frequency coils or to problems associated with the acquisition sequences. The result is a slowly varying shading artifact over the image that can produce errors with conventional intensity-based classification. Our algorithm is formulated by modifying the objective function of the standard fuzzy c-means (FCM) algorithm to compensate for such inhomogeneities and to allow the labeling of a pixel (voxel) to be influenced by the labels in its immediate neighborhood. The neighborhood effect acts as a regularizer and biases the solution toward piecewise-homogeneous labelings. Such a regularization is useful in segmenting scans corrupted by salt and pepper noise. Experimental results on both synthetic images and MR data are given to demonstrate the effectiveness and efficiency of the proposed algorithm.

Introduction: Intracavitary treatment of solitary cystic craniopharyngiomas with 32P is an emerging treatment option, especially for pediatric patients. We have treated two patients with solitary cystic craniopharyngiomas using intraoperative MRI (iMRI)-guided catheter placement. Methods: The optical tracking system of the General Electric Signa SP iMRI system was utilized for preoperative planning and intraoperative catheter tracking during insertion. Intraoperative volumetric imaging was then used to confirm final catheter position. Patients were brought back to the iMRI suite approximately 8 weeks later and diluted gadolinium was injected with further MRI to confirm the absence of communication between the cyst lumen and surrounding CSF spaces and for volumetric analysis. Results: Intraoperative imaging illustrated deformation and changes in the cyst wall during catheter placement and cyst aspiration and confirmed final catheter placement. Images acquired 8 weeks following catheter placement prior to the instillation of 32P showed decreases in cyst volume of 40 and 85%. Conclusion: iMRI-guided catheter placement for cystic craniopharyngiomas helps to assure successful catheter placement. Significant decreases in cyst volume occur in the interval between catheter placement and 32P administration and must be accounted for to prevent overdosing of the radioisotope.

Children with spastic diplegia from cerebral palsy (CP) experience measurable improvement in their spasticity and motor function following selective dorsal rhizotomy (SDR). The role of this operation in the treatment of other spasticity causes is less well defined. A literature review was undertaken to survey outcomes from SDRs performed outside the CP population. Multiple sclerosis was the most common diagnosis found, accounting for 74 of 145 patients described. Selective dorsal rhizotomies have also been reported in patients with traumatic brain and spinal cord injuries, ischemic and hemorrhagic stroke, neurodegenerative disease, hypoxic encephalopathy, and other causes of spasticity. Outcomes from surgery are generally described as favorable, although postoperative assessments and follow-up times are not standardized across reports. Long-term outcomes are sparsely reported. Larger numbers of patients and more detailed outcomes data have the potential to form a basis for expanding the inclusion criteria for SDR.

OBJECTIVE To assess the application accuracy of intraoperative magnetic resonance imaging for frameless stereotactic surgery, and to evaluate the performance of intraoperative magnetic resonance imaging for the brain biopsy, a standard stereotactic procedure. METHODS A series of spatial coordinate and phantom experiments were performed to analyze the application accuracy of the system. A prospective analysis of 68 consecutive patients undergoing stereotactic brain biopsy was then performed. RESULTS The spatial coordinate experiments revealed a mean overall error in acquisition of 0.2 mm. The phantom experiments demonstrated a 1:1 correlation between the magnetic resonance image of a stereotactically guided probe and its relationship to a target and the actual relationship of the probe and target. Sixty-eight brain biopsies were successfully performed in all intracranial compartments except the sella. The radiographic abnormality was localized successfully in all patients (100%). Sixty-six (97.1%) of the biopsies yielded diagnostic tissue. Two biopsies (2.9%) were complicated by intraparenchymal hemorrhage. One expanding temporal lobe hemorrhage was evacuated by immediate craniotomy in the magnet with no postoperative sequelae. A deep hemorrhage from a lymphoma was managed conservatively with interval resolution of symptoms. There were no infections. There was no perioperative mortality. CONCLUSION Intraoperative magnetic resonance imaging allows excellent target localization, provides true real-time imaging to account for anatomic changes during surgery, and permits intraoperative confirmation that the biopsy needle has reached the targeted lesion. Immediate postoperative imaging in the operating room allows assessment of adverse events and the potential for immediate management of hemorrhagic complications.