Congenital myotonic dystrophy: ventriculomegaly and shunt considerations for the pediatric neurosurgeon.

PURPOSE: 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. METHODS: This is a literature review with pooled data analysis and case report. RESULTS: 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. CONCLUSIONS: 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.

Intraoperative MRI in pediatric neurosurgery-an update.

Since the advent of intraoperative magnetic resonance imaging (ioMRI) at the Brigham and Women's Hospital in 1994, ioMRI has spread widely and in many different forms. This article traces the developmental history of ioMRI and reviews the relevant literature regarding it's effectiveness in pediatric neurosurgery. While of considerable expense, current trends in healthcare essentially mandate the use of ioMRI in a growing number of cases.

Selective dorsal rhizotomy for spasticity not associated with cerebral palsy: reconsideration of surgical inclusion criteria.

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.

Complications associated with molding helmet therapy for positional plagiocephaly: a review.

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.

The evolution of iMRI utilization for pediatric neurosurgery: a single center experience.

From its inception intraoperative magnetic resonance imaging (ioMRI) was envisioned to have significant applications in neurosurgery in general and pediatrics specifically. Over the last 9 years we have noted a dramatic shift in our ioMRI usage from intracranial tumors to cerebrospinal fluid management and complex cysts. Here we present seven selected cases to illustrate lessons learned from our operative experience within the GE Signa SP/I open-configuration "double-doughnut" MRI. These cases including a ganglioglioma, ependymoma, and pilocytic astrocytoma tumor resection, as well as arachnoid cysts, complex cyst, and microabscess drainage reflect our current use of ioMRI in pediatric neurosurgical cases. Namely that ioMRI is optimal for (1) resection of small tumors with poorly differentiated tumor margins, (2) large tumors with mass effect, and (3) shunt or catheter placement requiring either extreme accuracy or intraoperative confirmation of catheter placement. We also comment on the legitimate limitations of this technology in certain operations. Additionally emphasized are cases in which ioMRI imaging drives operative decision making, highlighting the unique and unequaled abilities of this technology for a subset of pediatric neurosurgical cases.

Decompression of Chiari malformation with and without duraplasty: morbidity versus recurrence.

OBJECT: The optimal surgical management of Chiari malformation (CM) is evolving. Evidence continues to accrue that supports decompression without duraplasty as an effective treatment to achieve symptomatic relief and anatomical decompression. The risks and benefits of this less invasive operation need to be weighed against decompression with duraplasty. METHODS: The authors performed a retrospective review of all CM decompressions from 2003 to 2007. All operations were performed by a single surgeon at a single institution. Data were analyzed for outcome, postoperative morbidity, and recurrence. RESULTS: Of 121 unique patients, 56 underwent posterior fossa decompressions without duraplasty (PFD) and 64 patients underwent posterior fossa decompressions with duraplasty (PFDD). Of the 56 PFD patients, 7 (12.5%) needed a subsequent PFDD for symptomatic recurrence. Of the 64 patients who underwent a PFDD, 2 (3.1%) needed a repeated PFDD for symptomatic recurrence. Patients treated with PFDD had an average operative time of 201 minutes in contrast to 127 minutes for those who underwent PFD (p = 0.0001). Patients treated with PFDD had average hospital stays of 4.0 days, whereas that for patients treated with PFD was 2.7 days (p = 0.0001). While in the hospital, patients treated with PFDD used low-grade narcotics, intravenous narcotics, muscle relaxants, and antiemetic medications at statistically significant differing rates. CONCLUSIONS: While PFD was associated with a higher rate of recurrent symptoms requiring repeated decompression, this may be justified by the significantly lower morbidity rate. Clearer delineation of the trade-off between morbidity and recurrence may be used to help patients and their families make decisions regarding care.

Intraoperative MRI: safety.

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.

Safety protocols for interventional MRI.

RATIONALE AND OBJECTIVES: To review magnetic resonance safety protocols and supplement them for interventional applications. MATERIALS AND METHODS: The American College of Radiology White Papers on MR Safety are summarized. Elements relevant to interventional MR procedures are emphasized. Additional policies and procedures specifically for interventional MR applications covering safety, training, and MR compatibility are proposed. RESULTS: A comprehensive operational policy for an interventional MR department is proposed. The policies and procedures helped our department perform over 400 surgeries and maintain a perfect safety record for 5 years. CONCLUSION: Interventional MR departments can operate safely but require policies and procedures beyond those required for diagnostic MR departments.

Neurosurgical uses for intraprocedural magnetic resonance imaging.

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.

Dynamic weight-bearing cervical magnetic resonance imaging: technical review and preliminary results.

BACKGROUND: Conventional magnetic resonance imaging (MRI) of complex cervical spine disorders may underestimate the magnitude of structural disease because imaging is performed in a nondynamic non-weight-bearing manner. Myelography provides additional information but requires an invasive procedure. METHODS: This was a prospective review of the first 20 upright weight-bearing cervical MRI procedures with patients in the flexed, neutral, and extended positions conducted in an open-configuration MRI unit. RESULTS: This technique clearly illustrated the changes in spinal cord compression, angulation, and spinal column alignment that occur during physiologic movements with corresponding changes in midsagittal spinal canal diameter (P < 0.05). Image quality was excellent or good in 90% of the cases. CONCLUSIONS: Dynamic weight-bearing MRI provides an innovative method for imaging complex cervical spine disorders. This technique is noninvasive and has adequate image quality that may make it a good alternative to cervical myelography.

Interventional MRI-guided frameless stereotaxy in pediatric patients.

INTRODUCTION: We prospectively reviewed our experience with intraoperative MRI (iMRI)-guided stereotactic procedures in pediatric patients. METHODS: All procedures were performed within the magnet bore of the General Electric Signa SP MRI system, which allows for either continuous real-time or periodic imaging. The internal optical tracking system was used to plan and monitor target localization and instrument trajectory. RESULTS: Fifteen patients underwent 16 frameless stereotactic procedures, consisting of 4 tumor biopsies and 12 cyst aspirations and stereotactic catheter placements (average age 6 years, range 6 weeks to 18 years). There were no hemorrhagic, neurologic or infectious complications. CONCLUSION: iMRI is an important component in expanding the horizon of minimally invasive neurosurgery for pediatric patients. Thus far, we have found this technology to be safe, reliable and extremely useful for frameless stereotactic procedures.