Os odontoideum is a common cause of atlantoaxial instability in the pediatric population. The authors present the cases of 2 patients whose initial clinical presentation and MR imaging findings were suggestive of an intramedullary neoplasm, but whose ultimate diagnosis was determined to be cervical spine instability and cord injury due to os odontoideum.
Paul R. Gigante, Neil A. Feldstein, and Richard C. E. Anderson
Abstract (Jea et al.)
The authors describe the novel use of C-1 lateral mass screws in four children 8 years of age or younger, in whom occipitocervical or atlantoaxial fusion was performed for trauma or os odontoideum. The authors retrospectively reviewed the demographics and procedural data of four children, ranging in age from 2 to 8 years, who required and underwent surgical fixation. Although C1–2 screw/rod constructs involving individual C-1 lateral mass screws and C-2 pars interarticularis or pedicle screws have been widely applied in adults, only C1–2 transarticular screw fixation has been reported in children less than 8 years of age. This report demonstrates the successful results of rigid occipitocervical and atlantoaxial fusion in four children in whom C-1 lateral mass screws were placed as part of a screw/rod construct. There was one instance of a vertebral artery injury, and the lessons learned from this complication are discussed.
Hannah E. Goldstein, Neil A. Feldstein, and Richard C. E. Anderson
Report of two cases and review of the literature
Ganesh Rao, Richard C. E. Anderson, Neil A. Feldstein, and Douglas L. Brockmeyer
✓Arachnoid cysts are intracranial, space-occupying lesions that typically remain stable in size on serial imaging. The authors describe two cases of rapidly enlarging arachnoid cysts, including one located in the anterior fossa.
In the first case a 7-month-old boy presented with increasing head circumference and a rapidly enlarging arachnoid cyst in the left middle fossa, which had been documented by serial imaging over the preceding 6 months. In the second case a 4-year-old girl presented with an arachnoid cyst compressing the right frontal lobe. The cyst had not been present on imaging studies performed during the perinatal period. In both cases, a craniotomy for open fenestration of the cyst was performed with successful resolution of the mass effect.
Rare cases of expansion of arachnoid cysts have been reported in the literature. In this article the authors report the dramatic enlargement of two arachnoid cysts, including the first description of enlargement of an arachnoid cyst located in the anterior fossa.
Cervical spine clearance
Joseph H. Piatt Jr.
Richard C. E. Anderson, Peter Kan, Kris W. Hansen, and Douglas L. Brockmeyer
Currently, no diagnostic or procedural standards exist for clearing the cervical spine in children after trauma. The purpose of this study was to determine if reeducation of nonneurosurgical personnel and initiation of a new protocol based on the National Emergency X-Radiography Utilization Study criteria could safely increase the number of pediatric cervical spines cleared of suspected injury without a neurosurgical consultation.
Data regarding cervical spine clearance in children (ages 0–18 years) after trauma protocol activation at Primary Children's Medical Center between 2001 and 2005 were collected and reviewed. Radiographic and clinical methods of clearing the cervical spine as well as the type and management of injuries were determined for two time frames: Period I (January 2001–December 2003) and Period II (January 2004–July 2005).
Between 2001 and 2003, 95% of 936 cervical spines were cleared of suspected injury by the neurosurgical service. Twenty-one ligamentous injuries (2.2%) and 12 fracture–dislocations (1.3%) were detected, with five patients requiring surgical stabilization (0.5%). Between January 2004 and July 2005, 507 (68%) of 746 cervical spines were cleared by nonneurosurgical personnel. Six ligamentous injuries (0.8%) and 10 fracture–dislocations (1.3%) were identified, with three patients (0.4%) requiring surgical stabilization. No late injuries were detected in either period.
The protocol used has been effective in enabling detection of cervical spine injuries in children after trauma, with the new protocol increasing by more than 60% the number of cervical spines cleared by nonneurosurgical personnel. Reeducation with establishment of the new protocols can safely facilitate clearance of the cervical spine by nonneurosurgical personnel after trauma.
Benjamin C. Kennedy, Michael B. Cloney, Richard C. E. Anderson, and Neil A. Feldstein
Choroid plexus papillomas (CPPs) are rare neoplasms, often found in the atrium of the lateral ventricle of infants, and cause overproduction hydrocephalus. The extensive vascularity and medially located blood supply of these tumors, coupled with the young age of the patients, can make prevention of blood loss challenging. Preoperative embolization has been advocated to reduce blood loss and prevent the need for transfusion, but this mandates radiation exposure and the additional risks of vessel injury and stroke. For these reasons, the authors present their experience using the superior parietal lobule approach to CPPs of the atrium without adjunct therapy.
A retrospective review was conducted of all children who presented to Columbia University/Morgan Stanley Children's Hospital of New York with a CPP in the atrium of the lateral ventricle and who underwent surgery using a superior parietal lobule approach without preoperative embolization.
Nine children were included, with a median age of 7 months. There were no perioperative complications or new neurological deficits. All patients had intraoperative blood loss of less than 100 ml, with a mean minimum hematocrit of 26.9% (range 19.6%–36.2%). No patients required a blood transfusion. The median follow-up was 39 months, during which time no patient demonstrated residual or recurrent tumor on MRI, nor did any have an increase in ventricular size or require CSF diversion.
The superior parietal lobule approach is safe and effective for very young children with CPPs in the atrium of the lateral ventricle. The results suggest that preoperative embolization is not essential to avoid transfusion or achieve overall good outcomes in these patients. This management strategy avoids radiation exposure and the additional risks associated with embolization.
Richard C. E. Anderson, Ronald G. Emerson, Kathryn C. Dowling, and Neil A. Feldstein
Object. The optimal treatment for patients with symptoms related to Chiari I malformation remains controversial. Although a suboccipital decompression with duraplasty is most commonly performed, there may be a subset of patients who improve in response to bone decompression alone. In an initial attempt to identify such patients, we performed a continuous study of intraoperative brainstem auditory evoked potentials (BAEPs) in patients undergoing a standard decompression with duraplasty and compared conduction times at three different time points: 1) baseline while the patient is supine (before positioning); 2) immediately after opening of the bone and release of the atlantooccipital membrane (that is, the dural band); and 3) after opening of the dura mater.
Methods. Eleven children and young adults (mean age 9.8 years) with symptoms related to Chiari I malformation underwent suboccipital decompression and duraplasty with intraoperative monitoring of BAEPs and somatosensory evoked potentials (SSEPs). Six patients (55%) had associated syringomyelia.
At baseline, the I to V interpeak latency (IPL) for both sides (total 21 BAEPs) was 4.19 ± 0.22 msec (mean ± standard deviation). After complete bone decompression and before the dura mater was opened, the I to V IPL decreased to 4.03 ± 0.25 msec (p = 0.0005). When the dura was opened, however, no further decrease in the I to V IPL was detected (4.03 ± 0.25 msec; p = 0.6). The SSEPs remained stable throughout the procedure.
Conclusions. In children and young adults undergoing suboccipital decompression with duraplasty for Chiari I malformation, the vast majority of improvement in conduction through the brainstem occurs after bone decompression and division of the atlantooccipital membrane, rather than after opening of the dura. Additional studies are needed to establish whether the improvement seen with BAEP monitoring during bone decompression will predict long-term clinical improvement in these patients.
Todd C. Hankinson, J Mocco, Brent Kimball, Richard C. E. Anderson, and Neil A. Feldstein
✓The authors describe the internal cranial expansion (ICE) procedure, a surgical technique that was used to treat two chronically shunt-treated children who presented with medically and surgically refractory intracranial hypertension despite the presence of functioning cerebrospinal fluid shunt systems. The ICE procedure was used as a means to increase intracranial volume without sacrificing calvarial rigidity. Intracranial volume was increased by 5% in one case and 10% in the other. Both patients have returned to their neurological and functional baselines, and they are free of symptoms related to intracranial hypertension.