Ossification of the posterior longitudinal ligament (OPLL) is a disease of progressive ectopic calcification of the PLL of the spine. It occurs most frequently in the cervical spine, followed by the thoracic spine. The disease was first described in the Japanese population, and the prevalence of OPLL is highest in Japan at a rate of 1.9%–4.3%. Note, however, that OPLL is also seen and is a known cause of cervical myelopathy in other Asian countries and in the white population. Research into the underlying cause of OPLL over the past few decades has shown that it is a multifactorial disease with significant genetic involvement. Genetic studies of OPLL have revealed several gene loci that may be involved in the pathogenesis of this disease. Genes encoding for proteins that process extracellular inorganic phosphate, collagen fibrils, and transcription factors involved in osteoblast and chondrocyte development and differentiation have all been implicated in the pathophysiology of OPLL. In this paper, the authors review current understanding of the genetics and pathophysiology of OPLL.
Christopher J. Stapleton, Martin H. Pham, Frank J. Attenello and Patrick C. Hsieh
Matthew J. McGirt, Frank J. Attenello, Daniel M. Sciubba, Ziya L. Gokaslan and Jean-Paul Wolinsky
✓ Pediatric basilar invagination and cranial settling have traditionally been approached through a transoral–transpharyngeal route with or without extended maxillotomy or mandibulotomy for resection of the anterior portion of C-1 and the odontoid. The authors hypothesize that application of a recently described endoscopic transcervical odontoidectomy (ETO) technique would allow an alternative approach for the treatment of ventral pathological entities at the craniocervical junction in pediatric patients.
The authors performed ETO in a consecutive series of pediatric patients presenting with myelopathy or bulbar dysfunction resulting from basilar invagination or cranial settling. All clinical, radiographic, surgical, and follow-up data were prospectively collected. The initial experience with ETO in the pediatric population is analyzed and outcomes are reported. Three patients required ETO for basilar invagination and 1 required ETO with anterior C-1 arch and distal clivus resection for cranial settling. All patients presented with myelopathy. One patient was wheelchair bound with severe quadriparesis. The mean age was 14 ± 3 years (mean ± standard deviation [SD]) in the 2 male and 2 female patients. The ETO and posterior fusion were performed as a 2-stage procedure in 2 (50%) and as a single-stage procedure in 2 (50%) cases. Prolonged intubation or postoperative placement of a gastrostomy tube was not needed in any case. The postoperative hospitalization lasted 9 ± 4 days (mean ± SD). At last follow-up (mean 5 months), head and neck pain had resolved and motor strength had improved or stabilized in all cases. All 4 children were independently functioning and ambulatory at the last follow-up.
In the authors' initial experience, ETO has allowed ventral brainstem decompression without the need for prolonged intubation, worsening dysphagia requiring enteral tube feeding, or prolonged hospitalization, and has resulted in cosmetically appealing results. The ETO technique allows an alternative approach for the treatment of ventral pathological entities at the craniocervical junction in pediatric patients.
Eric Laurent, Irvin Sam Schonfeld and Renzo Bianchi
Eisha A. Christian, Diana L. Jin, Frank Attenello, Timothy Wen, Steven Cen, William J. Mack, Mark D. Krieger and J. Gordon McComb
Even with improved prenatal and neonatal care, intraventricular hemorrhage (IVH) occurs in approximately 25%–30% of preterm infants, with a subset of these patients developing hydrocephalus. This study was undertaken to describe current trends in hospitalization of preterm infants with posthemorrhagic hydrocephalus (PHH) using the Nationwide Inpatient Sample (NIS) and the Kids’ Inpatient Database (KID).
The KID and NIS were combined to generate data for the years 2000–2010. All neonatal discharges with ICD-9-CM codes for preterm birth with IVH alone or with IVH and hydrocephalus were included.
There were 147,823 preterm neonates with IVH, and 9% of this group developed hydrocephalus during the same admission. Of patients with Grade 3 and 4 IVH, 25% and 28%, respectively, developed hydrocephalus in comparison with 1% and 4% of patients with Grade 1 and 2 IVH, respectively. Thirty-eight percent of patients with PHH had permanent ventricular shunts inserted. Mortality rates were 4%, 10%, 18%, and 40%, respectively, for Grade 1, 2, 3, and 4 IVH during initial hospitalization. Length of stay has been trending upward for both groups of IVH (49 days in 2000, 56 days in 2010) and PHH (59 days in 2000, 70 days in 2010). The average hospital cost per patient (adjusted for inflation) has also increased, from $201,578 to $353,554 (for IVH) and $260,077 to $495,697 (for PHH) over 11 years.
The number of neonates admitted with IVH has increased despite a decrease in the number of preterm births. Rates of hydrocephalus and mortality correlated closely with IVH grade. The incidence of hydrocephalus in preterm infants with IVH remained stable between 8% and 10%. Over an 11-year period, there was a progressive increase in hospital cost and length of stay for preterm neonates with IVH and PHH that may be explained by a concurrent increase in the proportion of patients with congenital cardiac anomalies.
Martin H. Pham, Frank J. Attenello, Joshua Lucas, Shuhan He, Christopher J. Stapleton and Patrick C. Hsieh
Ossification of the posterior longitudinal ligament (OPLL) can result in significant myelopathy. Surgical treatment for OPLL has been extensively documented in the literature, but less data exist on conservative management of this condition.
The authors conducted a systematic review to identify all reported cases of OPLL that were conservatively managed without surgery.
The review yielded 11 published studies reporting on a total of 480 patients (range per study 1–359 patients) over a mean follow-up period of 14.6 years (range 0.4–26 years). Of these 480 patients, 348 (72.5%) were without myelopathy on initial presentation, whereas 76 patients (15.8%) had signs of myelopathy; in 56 cases (15.8%), the presence of myelopathy was not specified. The mean aggregate Japanese Orthopaedic Association score on presentation for 111 patients was 15.3. Data available for 330 patients who initially presented without myelopathy showed progression to myelopathy in 55 (16.7%), whereas the other 275 (83.3%) remained progression free. In the 76 patients presenting with myelopathy, 37 (48.7%) showed clinical progression, whereas 39 (51.5%) remained clinically unchanged or improved.
Patients who present without myelopathy have a high chance of remaining progression free. Those who already have signs of myelopathy at presentation may benefit from surgery due to a higher rate of progression over continued follow-up.
Matthew J. McGirt, Frank J. Attenello, Ghazala Datoo, Muraya Gathinji, April Atiba, Jon D. Weingart, Benjamin Carson and George I. Jallo
Indications for duraplasty in treatment of Chiari malformation Type I (CM-I) remain unclear. In the present study, the authors evaluate their surgical experience to determine whether intraoperative ultrasonography is effective in the selection of patients with CM-I who can be adequately treated with craniectomy alone without duraplasty.
The authors reviewed the records of 256 children who underwent first-time hindbrain decompression for CM-I. Craniectomy alone (without duraplasty) was performed when intraoperative ultrasonography suggested adequate decompression of the subarachnoid spaces ventral and dorsal to the tonsils after suboccipital craniectomy alone. Duraplasty was performed if intraoperative ultrasonography demonstrated persistent dural compression of the tonsils following craniectomy. Symptom recurrence as a function of time was compared between cases of duraplasty versus suboccipital decompression alone stratified by extent of tonsillar herniation.
Duraplasty was performed in 140 patients (55%), and suboccipital decompression alone was performed in 116 patients (45%). Patients underwent follow-up for 29 ± 15 months. Symptoms included headache in 192 patients (75%) and lower cranial nerve and brainstem dysfunction in 68 (27%). In 38 patients (15%) there was tonsillar herniation rostral to the C-1 lamina, in 195 (76%) it extended between the C-1 and C-2 lamina, and in 23 patients (9%) there was herniation caudal to the lower border of the C-2 lamina. In children with tonsillar herniation caudal to C-1, ultrasonography-guided suboccipital decompression alone was associated with a 2-fold increase in the risk of symptom recurrence compared with those who also underwent duraplasty (p = 0.01). In children with tonsillar herniation rostral to C-1, outcome was equivalent between suboccipital decompression alone and duraplasty (p = 0.41).
In the setting of moderate-to-severe tonsillar CM-I, intraoperative ultrasonography demonstrating decompression of the subarachnoid spaces ventral and dorsal to the tonsils may not effectively select patients in whom bone decompression alone is sufficient. Duraplasty may be warranted in cases of tonsillar herniation that extends below the C-1 lamina regardless of intraoperative ultrasonography findings. More objective cerebrospinal fluid flow or volumetric measures may be needed intraoperatively to guide duraplasty in patients with more pronounced tonsillar herniation.
Frank J. Attenello, Matthew J. McGirt, April Atiba, Muraya Gathinji, Ghazala Datoo, Jon Weingart, Benjamin Carson and George I. Jallo
Chiari malformation Type I (CM-I) is often associated with scoliosis. It remains unclear which subgroups of patients are most likely to experience progression of spinal deformity after cervicomedullary decompression. The authors' goal was to determine the time frame of curvature progression and assess which patient subgroups are at greatest risk for progression of spinal deformity after surgery.
The authors retrospectively reviewed the records of all pediatric patients with significant scoliosis in whom suboccipital decompression was performed to treat for CM-I during a 10-year period at a single academic institution. Clinical, radiological, and operative variables were assessed as independent factors for failure (worsening of scoliosis) by using a univariate regression analysis.
Twenty-one children (mean age 9 ± 3 years; 4 male) underwent hindbrain decompression for CM-I–associated scoliosis and were followed for a mean of 39 months. All patients harbored a syrinx. Eight patients (38%) experienced improvement in scoliosis curvature, whereas 10 (48%) suffered a progression. Thoracolumbar junction scoliosis (p = 0.04) and failure of the syrinx to improve (p = 0.05) were associated with 5- and 4-fold respective increases in the likelihood of deformity progression. Each increasing degree of preoperative Cobb angle was associated with an 11% increase in the likelihood of scoliotic curve progression (p < 0.05).
Over one third of patients with CM-I–associated scoliosis will improve after cervicomedullary decompression alone. Cervicomedullary decompression is a good first-line option, particularly in children with concordant posterior fossa symptoms. Patients presenting with more severe scoliosis (increasing Cobb angle) or scoliosis that crosses the thoracolumbar junction may benefit from earlier orthopedic involvement and should be monitored regularly for curvature progression after cervicomedullary decompression. In cases in which there is a failure of the syrinx to show improvement after suboccipital decompression, the patients are also more likely to develop curvature progression.
Matthew J. McGirt, Kaisorn L. Chaichana, April Atiba, Frank Attenello, Kevin C. Yao and George I. Jallo
With modern surgical advances, radical resection of pediatric intramedullary spinal cord tumors (IMSCTs) can be expected to preserve long-term neurological function. Nevertheless, postoperative neurological decline is not uncommon after surgery, and many patients continue to experience long-term dysesthetic symptoms. Preoperative predictors of postoperative neurological decline and sensory syndromes have not been investigated and may serve as a guide for surgical risk stratification.
Neurological function (as determined using the modified McCormick Scale [mMS]) preoperatively, postoperatively, and 3 months after surgery was retrospectively recorded from patient charts in 164 consecutive patients undergoing resection of IMSCTs. A median 4 years (interquartile range [IQR] 1–8 years) after surgery, long-term motor and sensory symptoms were assessed by telephone interviews and corroborated by subsequent medical visits in 120 available patients. This long-term assessment was retrospectively reviewed for the purposes of this study. The authors reviewed this series to assess long-term motor, sensory, and urinary outcomes and to determine independent risk factors of postoperative neurological decline and long-term sensory dysfunction.
Patients were 8.6 ± 5.7 years old and presented with a median mMS of 2 (IQR 2–4). Three months after surgery, 38 patients (23%) continued to experience decreased neurological function (1 mMS point) incurred perioperatively. Increasing age (p = 0.028), unilateral symptoms (p = 0.046), and urinary dysfunction at presentation (p = 0.004) independently predicted persistent 3-month perioperative decline. At long-term follow-up (median 4 years), 39 (33%) exhibited improvements in their mMS scores, 13 (30%) had improvement in their urinary dysfunction, and 27 (30%) had resolution of their dysesthesias. Seventy-eight patients (65%) experienced long-term dysesthetic symptoms. Increasing age (p = 0.024), preoperative symptom duration > 12 months (p = 0.027), and worsened postoperative mMS score at hospital discharge (p = 0.013) independently increased the risk of long-term dysesthesias.
In the authors' experience, nearly one third of patients may experience improvement in motor, sensory, and urinary dysfunction years after IMSCT resection, whereas the majority will continue to experience long-term dysesthetic symptoms. Improvement in motor deficits preceded improvement in sensory syndromes, and urinary dysfunction typically resolved much longer after surgery. The risk of persistent perioperative motor decline was increased with older age, unilateral symptoms, preoperative urinary symptoms, and less severe preoperative neurological deficit. The risk of long-term dysesthesias was increased with older age, increased duration of symptoms prior to resection, and greater postoperative neurological deficit.
Daniel A. Donoho, Timothy Wen, Jonathan Liu, Hosniya Zarabi, Eisha Christian, Steven Cen, Gabriel Zada, J. Gordon McComb, Mark D. Krieger, William J. Mack and Frank J. Attenello
Although current pediatric neurosurgery guidelines encourage the treatment of pediatric malignant brain tumors at specialized centers such as pediatric hospitals, there are limited data in support of this recommendation. Previous studies suggest that children treated by higher-volume surgeons and higher-volume hospitals may have better outcomes, but the effect of treatment at dedicated children’s hospitals has not been investigated.
The authors analyzed the Healthcare Cost and Utilization Project Kids’ Inpatient Database (KID) from 2000–2009 and included all patients undergoing a craniotomy for malignant pediatric brain tumors based on ICD-9-CM codes. They investigated the effects of patient demographics, tumor location, admission type, and hospital factors on rates of routine discharge and mortality.
From 2000 through 2009, 83.6% of patients had routine discharges, and the in-hospital mortality rate was 1.3%. In multivariate analysis, compared with children treated at an institution designated as a pediatric hospital by NACHRI (National Association of Children’s Hospitals and Related Institutions), children receiving treatment at a pediatric unit within an adult hospital (OR 0.5, p < 0.01) or a general hospital without a designated pediatric unit (OR 0.4, p < 0.01) were less likely to have routine discharges. Treatment at a large hospital (> 400 beds; OR 1.8, p = 0.02) and treatment at a teaching hospital (OR 1.7, p = 0.02) were independently associated with greater likelihood of routine discharge. However, patients transferred between facilities had a significantly decreased likelihood of routine discharge (OR 0.5, p < 0.01) and an increased likelihood of mortality (OR 5.0, p < 0.01). Procedural volume was not associated with rate of routine discharge or mortality.
These findings may have implications for planning systems of care for pediatric patients with malignant brain tumors. The authors hope to motivate future research into the specific factors that may lead to improved outcomes at designated pediatric hospitals.
Frank J. Attenello, Eisha Christian, Timothy Wen, Steven Cen, Gabriel Zada, Erin N. Kiehna, Mark D. Krieger, J. Gordon McComb and William J. Mack
Recently published data have suggested an increase in adverse outcomes in pediatric patients after insertion or revision of a ventricular CSF diversion shunt after a same-day weekend procedure. The authors undertook an evaluation of the impact of weekend admission and time to shunting on surgery-related quality outcomes in pediatric patients who underwent ventricular shunt insertion or revision.
Pediatric patients with hydrocephalus who underwent ventriculoperitoneal, ventriculoatrial, or ventriculopleural shunt placement were selected from the 2000–2010 Nationwide Inpatient Sample and Kids’ Inpatient Database. Multivariate regression analyses (adjusted for patient, hospital, case severity, and time to shunting) were used to determine the differences in inpatient mortality and routine discharge rates among patients admitted on a weekday versus those among patients admitted on a weekend.
There were 99,472 pediatric patients with shunted hydrocephalus, 16% of whom were admitted on a weekend. After adjustment for disease severity, time to procedure, and admission acuity, weekend admission was not associated with an increase in the inpatient mortality rate (p = 0.46) or a change in the percentage of routine discharges (p = 0.98) after ventricular shunt procedures. In addition, associations were unchanged after an evaluation of patients who underwent shunt revision surgery. High-volume centers were incidentally noted in multivariate analysis to have increased rates of routine discharge (OR 1.04 [95% CI 1.01–1.07]; p = 0.02).
Contrary to those of previous studies, the authors’ data suggest that weekend admission is not associated with poorer outcomes for ventricular shunt insertion or revision. Increased rates of routine discharge were noted at high-volume centers.