Tofey J. Leon, Elizabeth N. Kuhn, Anastasia A. Arynchyna, Burkely P. Smith, R. Shane Tubbs, James M. Johnston, Jeffrey P. Blount, Curtis J. Rozzelle, W. Jerry Oakes and Brandon G. Rocque
There are sparse published data on the natural history of “benign” Chiari I malformation (CM-I)—i.e., Chiari with minimal or no symptoms at presentation and no imaging evidence of syrinx, hydrocephalus, or spinal cord signal abnormality. The purpose of this study was to review a large cohort of children with benign CM-I and to determine whether these children become symptomatic and require surgical treatment.
Patients were identified from institutional outpatient records using International Classification of Diseases, 9th Revision, diagnosis codes for CM-I from 1996 to 2016. After review of the medical records, patients were excluded if they 1) did not have a diagnosis of CM-I, 2) were not evaluated by a neurosurgeon, 3) had previously undergone posterior fossa decompression, or 4) had imaging evidence of syringomyelia at their first appointment. To include only patients with benign Chiari (without syrinx or classic Chiari symptoms that could prompt immediate intervention), any patient who underwent decompression within 9 months of initial evaluation was excluded. After a detailed chart review, patients were excluded if they had classical Chiari malformation symptoms at presentation. The authors then determined what changes in the clinical picture prompted surgical treatment. Patients were excluded from the multivariate logistic regression analysis if they had missing data such as race and insurance; however, these patients were included in the overall survival analysis.
A total of 427 patients were included for analysis with a median follow-up duration of 25.5 months (range 0.17–179.1 months) after initial evaluation. Fifteen patients had surgery at a median time of 21.0 months (range 11.3–139.3 months) after initial evaluation. The most common indications for surgery were tussive headache in 5 (33.3%), syringomyelia in 5 (33.3%), and nontussive headache in 5 (33.3%). Using the Kaplan-Meier method, rate of freedom from posterior fossa decompression was 95.8%, 94.1%, and 93.1% at 3, 5, and 10 years, respectively.
Among a large cohort of patients with benign CM-I, progression of imaging abnormalities or symptoms that warrant surgical treatment is infrequent. Therefore, these patients should be managed conservatively. However, clinical follow-up of such individuals is justified, as there is a low, but nonzero, rate of new symptom or syringomyelia development. Future analyses will determine whether imaging or clinical features present at initial evaluation are associated with progression and future need for treatment.
Ross L. Dawkins, Joseph H. Miller, Omar I. Ramadan, Michael C. Lysek, Elizabeth N. Kuhn, Brandon G. Rocque, Michael J. Conklin, R. Shane Tubbs, Beverly C. Walters, Bonita S. Agee and Curtis J. Rozzelle
There are many classification systems for injuries of the thoracolumbar spine. The recent Thoracolumbar Injury Classification and Severity Score (TLICS) has been shown to be a reliable tool for adult patients. The aim of this study was to assess the reliability of the TLICS system in pediatric patients. The validity of the TLICS system is assessed in a companion paper.
The medical records of pediatric patients with acute, traumatic thoracolumbar fractures at a single Level 1 trauma center were retrospectively reviewed. A TLICS was calculated for each patient using CT and MRI, along with the neurological examination recorded in the patient’s medical record. TLICSs were compared with the type of treatment received. Five raters scored all patients separately to assess interrater reliability.
TLICS calculations were completed for 81 patients. The mean patient age was 10.9 years. Girls represented 51.8% of the study population, and 80% of the study patients were white. The most common mechanisms of injury were motor vehicle accidents (60.5%), falls (17.3%), and all-terrain vehicle accidents (8.6%). The mean TLICS was 3.7 ± 2.8. Surgery was the treatment of choice for 33.3% of patients. The agreement between the TLICS-suggested treatment and the actual treatment received was statistically significant (p < 0.0001). The interrater reliability of the TLICS system ranged from moderate to very good, with a Fleiss’ generalized kappa (κ) value of 0.69 for the TLICS treatment suggestion among all patients; however, interrater reliability decreased when MRI was used to contribute to the TLICS. The κ value decreased from 0.73 to 0.57 for patients with CT only vs patients with CT/MRI or MRI only, respectively (p < 0.0001). Furthermore, the agreement between suggested treatment and actual treatment was worse when MRI was used as part of injury assessment.
The TLICS system demonstrates good interrater reliability among physicians assessing thoracolumbar fracture treatment in pediatric patients. Physicians should be cautious when using MRI to aid in the surgical decision-making process.
Joyce Koueik, Carolina Sandoval-Garcia, John R. W. Kestle, Brandon G. Rocque, David M. Frim, Gerald A. Grant, Robert F. Keating, Carrie R. Muh, W. Jerry Oakes, Ian F. Pollack, Nathan R. Selden, R. Shane Tubbs, Gerald F. Tuite, Benjamin Warf, Victoria Rajamanickam, Aimee Teo Broman, Victor Haughton, Susan Rebsamen, Timothy M. George and Bermans J. Iskandar
Despite significant advances in diagnostic and surgical techniques, the surgical management of Chiari malformation type I (CM-I) with associated syringomyelia remains controversial, and the type of surgery performed is surgeon dependent. This study’s goal was to determine the feasibility of a prospective, multicenter, cohort study for CM-I/syringomyelia patients and to provide pilot data that compare posterior fossa decompression and duraplasty (PFDD) with and without tonsillar reduction.
Participating centers prospectively enrolled children suffering from both CM-I and syringomyelia who were scheduled to undergo surgical decompression. Clinical data were entered into a database preoperatively and at 1–2 weeks, 3–6 months, and 1 year postoperatively. MR images were evaluated by 3 independent, blinded teams of neurosurgeons and neuroradiologists. The primary endpoint was improvement or resolution of the syrinx.
Eight clinical sites were chosen based on the results of a published questionnaire intended to remove geographic and surgeon bias. Data from 68 patients were analyzed after exclusions, and complete clinical and imaging records were obtained for 55 and 58 individuals, respectively. There was strong agreement among the 3 radiology teams, and there was no difference in patient demographics among sites, surgeons, or surgery types. Tonsillar reduction was not associated with > 50% syrinx improvement (RR = 1.22, p = 0.39) or any syrinx improvement (RR = 1.00, p = 0.99). There were no surgical complications.
This study demonstrated the feasibility of a prospective, multicenter surgical trial in CM-I/syringomyelia and provides pilot data indicating no discernible difference in 1-year outcomes between PFDD with and without tonsillar reduction, with power calculations for larger future studies. In addition, the study revealed important technical factors to consider when setting up future trials. The long-term sequelae of tonsillar reduction have not been addressed and would be an important consideration in future investigations.
Phoenix, Arizona • March 6–9, 2013