Solitary fibrous tumors of the spine are rare lesions. Their description in the literature is limited to case reports and small case series. While generally benign lesions, they can recur and occasionally occur as malignancies. Here the authors present the case of a 10-year-old boy, the youngest patient and first preadolescent reported thus far, with this condition. In addition, they perform a comprehensive review of all previously published cases of spinal solitary fibrous tumors.
Gregory W. Albert and Murat Gokden
Gregory W. Albert and Arnold H. Menezes
The objective of this study was to describe a single surgeon's experience managing craniovertebral junction (CVJ) disease due to ankylosing spondylitis.
The authors undertook a retrospective review of the records of patients with CVJ disease due to ankylosing spondylitis who were evaluated and treated by the senior author. Charts were reviewed for symptoms and signs at presentation, radiography results, treatment, and outcome. In addition, some of the patients had pathology reports available for review.
Eight patients with CVJ disease due to ankylosing spondylitis were identified who were evaluated by the senior author in the years 1990–2008. The most common presenting symptoms were neck pain (37.5%), cranial neuropathy (37.5%), and sensory disturbance (62.5%). On examination, the most common findings were limited cervical range of motion (37.5%), weakness (50%), and myelopathy (75%). Radiographic evaluation revealed atlantoaxial subluxation, retroodontoid pannus formation, basilar invagination, and bone erosion. Surgery was offered to all of the patients, 7 of whom underwent operations. In most cases, the treatment was transoral–transpalatopharyngeal decompression followed by occipitocervical fusion. One patient with a reducible lesion underwent dorsal fusion alone. Neurological outcomes were favorable overall.
The incidence of CVJ disease in patients with ankylosing spondylitis varies among reports. These cases are rare in most neurosurgery clinics. It is important to recognize that patients with ankylosing spondylitis are at risk for CVJ disease, similar to patients with rheumatoid arthritis. Principles common to the management of other CVJ pathologies apply to these patients as well.
Angela W. Palmer and Gregory W. Albert
Various surgical techniques have been described to treat subdural fluid collections in infants, including transfontanelle aspiration, burr holes, subdural drain, subduroperitoneal shunt, and minicraniotomy. The purpose of this study was to describe a modification of the minicraniotomy technique that avoids the implantation of external drainage catheters and potentially carries a higher success rate.
In this retrospective study, the authors describe 11 cases involving pediatric patients who underwent parietal minicraniotomies for the evacuation of subdural fluid collections. In contrast to cases previously described in the literature, no patient received a drain; instead, a subgaleal pocket was created such that the fluid could flow from the subdural to the subgaleal space. Preoperative and postoperative data were reviewed, including neurological examination findings, radiological findings, complications, hospital length of stay, and findings on follow-up examinations and imaging. The primary outcome was failure of the treatment strategy, defined as an increase in subdural fluid collection requiring further intervention.
Eleven patients (8 boys and 3 girls, median age 4.5 months) underwent the described procedure. Eight of the patients had complete resolution of the subdural collection on follow-up imaging, and 2 had improvement. One patient had a new subdural collection due to a second injury. Only 1 patient underwent aspiration and subsequent surgical repair of a pseudomeningocele after the initial surgery. Notably, no patients required subduroperitoneal shunt placement.
The authors describe a new surgical option for subdural fluid collections in infants that allows for more aggressive evacuation of the subdural fluid and eliminates the need for a drain or shunt placement. Further work with more patients and direct comparison to other alternative therapies is necessary to fully evaluate the efficacy and safety of this new technique.
Gregory W. Albert, Arnold H. Menezes, Daniel R. Hansen, Jeremy D. W. Greenlee and Stuart L. Weinstein
The authors conducted a study to evaluate the unique presenting signs and symptoms of Chiari malformation Type I (CM-I) in children younger than 6 years of age and highlight the benefits of early surgical treatment in this patient population.
The authors reviewed the medical records of patients who presented to the neurosurgery department before their 6th birthday and subsequently underwent surgery for CM-I. They identified 39 patients who had been evaluated between 1984 and 2007 and examined the medical records for presentation, surgical intervention, and outcome.
Children aged 0–2 years commonly presented with oropharyngeal dysfunction (77.8%). Children aged 3–5 years more frequently presented with syringomyelia (85.7%), scoliosis (38.1%), and/or headache (57.1%). All patients underwent posterior fossa craniectomy. Additionally, in many patients cervical laminectomy and/or duraplasty was performed. A few patients required transoral decompression and occipitocervical fusion. In most cases, surgery led to resolution or dramatic improvement of initial symptoms.
Early recognition and surgical treatment of CM-I in young children leads to good outcomes in the majority of patients. Additional therapies for oropharyngeal dysfunction, syringomyelia, and scoliosis can frequently be avoided.
Gregory W. Albert, Nader S. Dahdaleh, Chandan Reddy, Daniel R. Hansen, Timothy W. Vogel, Hiroto Kawasaki and Matthew A. Howard III
In this study the authors sought to determine whether any correlations existed between postimplantation head CT findings and the need to perform decompression surgery in patients with grid electrodes.
The authors identified 74 patients who underwent intracranial electrode monitoring for medically refractory epilepsy from January 2000 through June 2008. Only the 46 patients who had head CT scans available for review were included in the study. The authors were able to determine the number and types of electrodes placed as well as complications experienced. They reviewed the CT scans for abnormal findings including extraaxial fluid collections, intracranial hemorrhages, and signs of mass effect.
All patients developed some degree of extraaxial fluid collection following the placement of intracranial electrodes. The maximum width of the extraaxial fluid collection and the degree of midline shift were not predictive of the need for decompressive surgery. The presence, but not degree, of midline shift was associated with the need for decompressive surgery. Likewise, the presence of ventricular asymmetry was correlated with the need for removal of the electrodes and bone flap. Patients without midline shift or ventricular asymmetry on CT did not require decompressive surgery.
After undergoing placement of intracranial electrodes all patients develop extraaxial fluid collections. In addition, many patients develop signs of mass effect including midline shift and ventricular asymmetry. When these findings are absent it is highly unlikely that surgical decompression is required.
Chandan G. Reddy, Nader S. Dahdaleh, Gregory Albert, Fangxiang Chen, Daniel Hansen, Kirill Nourski, Hiroto Kawasaki, Hiroyuki Oya and Matthew A. Howard III
A wide range of devices is used to obtain intracranial electrocorticography recordings in patients with medically refractory epilepsy, including subdural strip and grid electrodes and depth electrodes. Penetrating depth electrodes are required to access some brain regions, and 1 target site that presents a particular technical challenge is the first transverse temporal gyrus, or Heschl gyrus (HG). The HG is located within the supratemporal plane and has an oblique orientation relative to the sagittal and coronal planes. Large and small branches of the middle cerebral artery abut the pial surface of the HG and must be avoided when planning the electrode trajectory.
Auditory cortex is located within the HG, and there are functional connections between this dorsal temporal lobe region and medial sites commonly implicated in the pathophysiology of temporal lobe epilepsy. At some surgical centers, depth electrodes are routinely placed within the supratemporal plane, and the HG, in patients who require intracranial electrocorticography monitoring for presumed temporal lobe epilepsy. Information from these recordings is reported to facilitate the identification of seizure patterns in patients with or without auditory auras.
To date, only one implantation method has been reported to be safe and effective for placing HG electrodes in a large series of patients undergoing epilepsy surgery. This well-established approach involves inserting the electrodes from a lateral trajectory while using stereoscopic stereotactic angiography to avoid vascular injury. In this report, the authors describe an alternative method for implantation. They use frameless stereotaxy and an oblique insertion trajectory that does not require angiography and allows for the simultaneous placement of subdural grid arrays. Results in 19 patients demonstrate the safety and efficacy of the method.
Blake C. Phillips, Michael Gelsomino, Ambre' L. Pownall, Eylem Ocal, Horace J. Spencer, Mark S. O'Brien and Gregory W. Albert
Many patients with myelomeningocele (MMC) develop hydrocephalus, and most will undergo CSF diversion. The goal of this retrospective study was to determine whether there was a change in the shunt rate over the 7 consecutive years of the study. The authors will also identify the criteria used to determine the need for shunt placement.
During a 7-year period, 73 patients underwent MMC closure at Arkansas Children's Hospital. The shunt rate for each year was calculated. Clinical characteristics were evaluated, including apneic and bradycardic spells, CSF leak, level of the MMC, head circumference, and rate of head growth. In addition, radiological images were reviewed, and the frontooccipital horn ratio (FOHR), ventricular index (VI), and thalamooccipital distance (TOD) were calculated. Comparisons were made between those patients who underwent shunt placement and those who did not.
One patient was excluded due to death in the perinatal period. Of the 72 remaining patients, 54 (75%) underwent placement of a ventriculoperitoneal shunt. This rate did not change significantly over time. Between the cohorts with and without a shunt there was no significant difference in age, sex, or race. There was no significant difference in apneic episodes or bradycardic episodes. There was a statistically significant difference in fontanelle characteristics, head circumference at birth, and rate of head growth. Patients who required CSF diversion had a mean head growth of 0.32 cm/day compared with those who did not receive a shunt (0.13 cm/day; p < 0.05). All radiological parameters were found to be statistically significant.
In this study, several classic indicators of hydrocephalus in the neonate were not found to be significantly associated with the need for CSF diversion. Fontanelle characteristics, head circumference at birth, and head growth velocity were associated with the need for shunt placement. Imaging information including the VI, TOD, and FOHR are statistically significant measures to evaluate prior to placement of a ventriculoperitoneal shunt. The optimal patient with MMC for CSF diversion will have full to tense fontanelle, increasing head circumference of more than 3 mm/day, and radiological evidence of an elevated VI, TOD, and/or FOHR.
Gregory W. Albert, George M. Ibrahim, Hiroshi Otsubo, Ayako Ochi, Cristina Y. Go, O. Carter Snead III, James M. Drake and James T. Rutka
Resective surgery is increasingly used in the management of pediatric epilepsy. Frequently, invasive monitoring with subdural electrodes is required to adequately map the epileptogenic focus. The risks of invasive monitoring include the need for 2 operations, infection, and CSF leak. The aim of this study was to evaluate the feasibility and outcomes of resective epilepsy surgery guided by magnetoencephalography (MEG) in children who would have otherwise been candidates for electrode implantation.
The authors reviewed the records of patients undergoing resective epilepsy surgery at the Hospital for Sick Children between 2001 and 2010. They identified cases in which resections were based on MEG data and no intracranial recordings were performed. Each patient's chart was reviewed for presentation, MRI findings, MEG findings, surgical procedure, pathology, and surgical outcome.
Sixteen patients qualified for the study. All patients had localized spike clusters on MEG and most had abnormal findings on MRI. Resection was carried out in each case based on the MEG data linked to neuronavigation and supplemented with intraoperative neuromonitoring. Overall, 62.5% of patients were seizure free following surgery, and 20% of patients experienced an improvement in seizures without attaining seizure freedom. In 2 cases, additional surgery was performed subsequently with intracranial monitoring in attempts to obtain seizure control.
MEG is a viable alternative to invasive monitoring with intracranial electrodes for planning of resective surgery in carefully selected pediatric patients with localization-related epilepsy. Good candidates for this approach include patients who have a well-delineated, localized spike cluster on MEG that is concordant with findings of other preoperative evaluations and patients with prior brain pathologies that make the implantation of subdural and depth electrodes somewhat problematic.
Anderson Chun-On Tsang
Judith M. Wong, John E. Ziewacz, Allen L. Ho, Jaykar R. Panchmatia, Albert H. Kim, Angela M. Bader, B. Gregory Thompson, Rose Du and Atul A. Gawande
As part of a project to devise evidence-based safety interventions for specialty surgery, we sought to review current evidence concerning the frequency of adverse events in open cerebrovascular neurosurgery and the state of knowledge regarding methods for their reduction. This review represents part of a series of papers written to consolidate information about these events and preventive measures as part of an ongoing effort to ascertain the utility of devising system-wide policies and safety tools to improve neurosurgical practice.
The authors performed a PubMed search using search terms “cerebral aneurysm”, “cerebral arteriovenous malformation”, “intracerebral hemorrhage”, “intracranial hemorrhage”, “subarachnoid hemorrhage”, and “complications” or “adverse events.” Only papers that specifically discussed the relevant complication rates were included. Papers were chosen to be included to maximize the range of rates of occurrence for the reported adverse events.
The review revealed hemorrhage-related hyperglycemia (incidence rates ranging from 27% to 71%) and cerebral salt-wasting syndromes (34%–57%) to be the most common perioperative adverse events related to subarachnoid hemorrhage (SAH). Next in terms of frequency was new cerebral infarction associated with SAH, with a rate estimated at 40%. Many techniques are advocated for use during surgery to minimize risk of this development, including intraoperative neurophysiological monitoring, but are not universally used due to surgeon preference and variable availability of appropriate staffing and equipment. The comparative effectiveness of using or omitting monitoring technologies has not been evaluated.
The incidence of perioperative seizure related to vascular neurosurgery is unknown, but reported seizure rates from observational studies range from 4% to 42%. There are no standard guidelines for the use of seizure prophylaxis in these patients, and there remains a need for prospective studies to support such guidelines.
Intraoperative rupture occurs at a rate of 7% to 35% and depends on aneurysm location and morphology, history of rupture, surgical technique, and surgeon experience. Preventive strategies include temporary vascular clipping.
Technical adverse events directly involving application of the aneurysm clip include incomplete aneurysm obliteration and parent vessel occlusion. The rates of these events range from 5% to 18% for incomplete obliteration and 3% to 12% for major vessel occlusion. Intraoperative angiography is widely used to confirm clip placement; adjuncts include indocyanine green video angiography and microvascular Doppler ultrasonography. Use of these technologies varies by institution.
A significant proportion of these complications may be avoidable through development and testing of standardized protocols to incorporate monitoring technologies and specific technical practices, teamwork and communication, and concentrated volume and specialization. Collaborative monitoring and evaluation of such protocols are likely necessary for the advancement of open cerebrovascular neurosurgical quality.