Aneurysmal bone cysts (ABCs) are benign, expansile, osteolytic lesions that represent 1%–2% of primary bone tumors. Cranial ABCs are even more rare and represent 3%–6% of these unique lesions. The authors describe the case of a 3-year-old girl who presented with an acute posterior fossa epidural hematoma after minor trauma. Imaging workup revealed a previously undiagnosed suboccipital ABC that appeared to have ruptured as a result of her trauma, leading to a life-threatening hemorrhage. To the authors' knowledge, a ruptured ABC has never before been presented in the pediatric literature. In this case report, the authors review the imaging findings, natural history, clinical course, and treatment of these rare lesions.
Sarah T. Garber and Jay K. Riva-Cambrin
Sarah T. Garber and Douglas L. Brockmeyer
Subaxial cervical instability in very young or small-for-age children is uncommon and typically arises from trauma or skeletal dysplasia. Various operative techniques have been used to achieve stabilization in pediatric patients with evidence of instability, including anterior, posterior, and combined approaches. In this study, the authors report their results with subaxial cervical instability in this patient population treated using a static single-screw anterior cervical plate (ACP) system and allograft fusion.
In a retrospective chart review, the authors identified all patients 6 years of age or younger who underwent an anterior cervical fusion procedure using a static single-screw ACP system either as a stand-alone construct or as part of an anterior-posterior stabilization procedure. Reasons for fusion included trauma, tumor, and congenital anomalies.
Five patients 6 years of age or younger underwent anterior cervical fusion using a static single-screw system during the 19-year study period. Follow-up ranged from 12 to 51 months (mean 26.8 months). Two patients underwent repeat surgery, one 7 days after and the other 21 months after their initial procedure. At last follow-up, a mean vertical growth of 22.8% was seen across the fused segments, with no evidence of kyphotic or lordotic abnormalities.
In very young or small-for-age children, the use of a static single-screw ACP system appears to be a safe and effective option to manage subaxial cervical instability. Bony fusion and continued longitudinal growth occur within the fused segments, with no evidence of long-term cervical malalignment.
Sarah T. Garber, Robert J. Bollo and Jay K. Riva-Cambrin
Pediatric spinal pilomyxoid astrocytoma (PMA) is an extremely rare tumor that merits recognition as a specific, unique entity. The authors present the case of an intramedullary PMA in the thoracic spinal cord of an 11-year-old boy who presented with back pain, scoliosis, and multiple lung nodules. The patient underwent T5–11 laminoplasty and near-total resection of the spinal tumor. The final pathological diagnosis was WHO Grade II PMA. The patient did well for 14 months until the tumor progressed both clinically and radiographically. A literature review focusing on the clinical characteristics, histology, and treatment of PMAs provides a better understanding of these rare lesions. Because of the small number of cases optimal treatment guidelines have not been established, but gross-total resection and adjuvant chemotherapy with alkylating agents appear to confer a better long-term prognosis. Pediatric patients with PMAs can remain recurrence free at least 5 years after surgery, although these tumors may disseminate or dedifferentiate into more malignant gliomas. Recognition of intramedullary PMA as a unique entity in children is vital to the development of specific surgical and adjuvant treatment regimens.
Sarah T. Garber, Walavan Sivakumar and Richard H. Schmidt
Dabigatran etexilate is an oral anticoagulant that acts as a direct, competitive thrombin inhibitor. Large randomized clinical trials have shown higher doses of dabigatran (150 mg taken twice daily) to be superior to warfarin in terms of stroke and systemic embolism rates in patients with nonvalvular atrial fibrillation. As a result, in 2010 the US FDA approved the use of dabigatran for the prevention of stroke and systemic embolism in patients with atrial fibrillation. Dabigatran is especially attractive in the outpatient setting because patients do not require routine monitoring with prothrombin times or international normalized ratios. To date, no effective reversal agent for dabigatran in the event of catastrophic hemorrhage has been identified. The authors report a case of an elderly patient, being treated with dabigatran for atrial fibrillation, who presented with a rapidly expanding intracranial hemorrhage after a ground-level fall. This case highlights an impending neurosurgical quandary of complications secondary to this new anticoagulation agent and suggests potential options for management.
Rebecca Gryka and Douglas C. Anderson Jr.
Sarah T. Garber, Jay Riva-Cambrin, Frank S. Bishop and Douglas L. Brockmeyer
Fourth ventricle hydrocephalus, or a “trapped” fourth ventricle, presents a treatment challenge in pediatric neurosurgery. Fourth ventricle hydrocephalus develops most commonly as a result of congenital anomalies, intraventricular hemorrhage, or infection. Standard management of loculated fourth ventricle hydrocephalus consists of fourth ventricle shunt placement via a suboccipital approach. An alternative approach is stereotactic-guided transtentorial fourth ventricle shunt placement via the nondominant superior parietal lobule. In this report, the authors compare shunt survival after placement via the suboccipital and stereotactic parietal transtentorial (SPT) approaches.
A retrospective chart review was performed to find all patients with a fourth ventricle shunt placed between January 1, 1998, and December 31, 2011. Time to shunt failure was quantified as the number of days from shunt placement to first shunt revision or removal. Other variables studied included patient age and sex, origin of hydrocephalus, comorbidities, number of existing supratentorial catheters at the time of fourth ventricle shunt placement (as a proxy for complexity), operating surgeon, and number of previous shunt revisions. The crossover rate from one technique to the other after shunt failure from the original approach was also investigated.
In the 29 fourth ventricle shunts placed during the study period, 18 were placed via the suboccipital approach (62.1%) and 11 via the SPT approach (37.9%). There was a statistically significant difference in time to shunt failure, with the SPT shunts lasting an average of 901 days and suboccipital shunts lasting 122 days (p = 0.04). In addition, there was a significant difference in the rate of crossover from one technique to another, with 1 SPT shunt changed to a suboccipital shunt (5.6%) and 5 suboccipital shunts changed to SPT shunts (45.5%).
Fourth ventricle shunt placement using an SPT approach resulted in significantly longer shunt survival times and lower rates of revision than the traditional suboccipital approach, despite a higher rate of crossover from previously failed shunting procedures. Stereotactic parietal transtentorial shunt placement may be considered for patients with loculated fourth ventricle hydrocephalus, especially when shunt placement via the standard suboccipital approach fails. It is therefore reasonable to offer this procedure either as a first option for the treatment of fourth ventricle hydrocephalus or when the need for fourth ventricle shunt revision arises.
Ruth S. Kuo, Wililiam D. Freeman and Rabih G. Tawk
Amy R. U. L. Calhoun, Robert J. Bollo, Sarah T. Garber, Jamie McDonald, David A. Stevenson, Irene H. Hung, Douglas L. Brockmeyer and Marion L. Walker
Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant angiodysplasia with high penetrance and variable expression. The manifestations of HHT are often age related, and spinal arteriovenous fistula (AVF) may be the initial presentation of HHT in young children. Because spinal AVFs are rarely reported, however, screening is not incorporated into current clinical recommendations for the treatment of patients with HHT. The authors describe 2 cases of children younger than 2 years of age with acute neurological deterioration in the context of a spinal AVF and in whom HHT was subsequently diagnosed. One patient presented with intraventricular and subarachnoid hemorrhage and the other with acute thrombosis of an intramedullary varix. These cases highlight the potential for significant neurological morbidity from a symptomatic AVF in very young children with HHT. Given the lack of data regarding the true incidence and natural history of these lesions, these cases raise the question of whether spinal cord imaging should be incorporated into screening recommendations for patients with HHT.