As with many pathologies, the course of our understanding of the Chiari I malformation (CIM) has developed extensively over time. The early descriptions of the Chiari malformations by Hans Chiari in 1891 opened the door for future classification and research on this topic. However, even over a long timeframe, our understanding of the pathophysiology and, more importantly, treatment, remained in its infancy. As recently as the 1970s, CIM was not discussed in popular neurology textbooks. Syringomyelia is listed as a degenerative disorder with no satisfactory treatment. Radiation therapy was considered an option in treatment, and surgery was thought to play no role. During the last 40 years, equivalent to the duration of a neurosurgical career, our understanding of the pathophysiology and natural history of CIM, coupled with modern MRI, has improved the treatment paradigm for this patient population. More importantly, it has given us evidence confirming that CIM is a disorder responsive to surgical intervention, giving patients once thought to be destined for lifelong disability a comparatively normal life after treatment. The purpose of this article is to offer a review of CIM and its important associated entities. The authors will discuss the evolution in understanding of the Chiari malformation and, importantly, distinguish between symptomatic CIM and asymptomatic tonsillar ectopia, based on imaging and presenting symptomatology. They will discuss techniques for surgical intervention, expected outcomes, and complications after surgery. Proper patient selection for surgery based on appropriate symptomatology is tantamount to achieving good surgical outcomes in this population, separating those who can be helped by surgery from those who are unlikely to improve. While our knowledge of the Chiari malformations continues to improve through the efforts of clinical and basic science researchers, surgeons, and patients, our current understanding of these entities represents a monumental improvement in patient care over a relatively short time period.
JNSPG 75th Anniversary Invited Review Article
Samuel G. McClugage III and W. Jerry Oakes
Paul Foreman, Samuel McClugage III, Robert Naftel, Christoph J. Griessenauer, Benjamin J. Ditty, Bonita S. Agee, Jay Riva-Cambrin, and John Wellons III
Postresection hydrocephalus is observed in approximately 30% of pediatric patients with posterior fossa tumors. However, which patients will develop postresection hydrocephalus is not known. The Canadian Preoperative Prediction Rule for Hydrocephalus (CPPRH) was developed in an attempt to identify this subset of patients, allowing for the optimization of their care. The authors sought to validate and critically appraise the CPPRH.
The authors conducted a retrospective chart review of 99 consecutive pediatric patients who presented between 2002 and 2010 with posterior fossa tumors and who subsequently underwent resection. The data were then analyzed using bivariate and multivariate analyses, and a modified CPPRH (mCPPRH) was applied.
Seventy-six patients were evaluated. Four variables were found to be significant in predicting postresection hydrocephalus: age younger than 2 years, moderate/severe hydrocephalus, preoperative tumor diagnosis, and transependymal edema. The mCPPRH produced observed likelihood ratios of 0.737 (95% CI 0.526–1.032) and 4.688 (95% CI 1.421–15.463) for low- and high-risk groups, respectively.
The mCPPRH utilizes readily obtainable and reliable preoperative variables that together stratify children with posterior fossa tumors into high- and low-risk categories for the development of postresection hydrocephalus. This new predictive model will aid patient counseling and tailor the intensity of postoperative clinical and radiographic monitoring for hydrocephalus, as well as provide evidence-based guidance for the use of prophylactic CSF diversion.
Samuel G. McClugage III, Nicholas M. B. Laskay, Brian N. Donahue, Anastasia Arynchyna, Kathrin Zimmerman, Inmaculada B. Aban, Elizabeth N. Alford, Myriam Peralta-Carcelen, Jeffrey P. Blount, Curtis J. Rozzelle, James M. Johnston, and Brandon G. Rocque
Posthemorrhagic hydrocephalus of prematurity remains a significant problem in preterm infants. In the literature, there is a scarcity of data on the early disease process, when neurosurgeons are typically consulted for recommendations on treatment. Here, the authors sought to evaluate functional outcomes in premature infants at 2 years of age following treatment for posthemorrhagic hydrocephalus. Their goal was to determine the relationship between factors identifiable at the time of the initial neurosurgical consult and outcomes of patients when they are 2 years of age.
The authors performed a retrospective chart review of premature infants treated for intraventricular hemorrhage (IVH) of prematurity (grade III and IV) between 2003 and 2014. Information from three time points (birth, first neurosurgical consult, and 2 years of age) was collected on each patient. Logistic regression analysis was performed to determine the association between variables known at the time of the first neurosurgical consult and each of the outcome variables.
One hundred thirty patients were selected for analysis. At 2 years of age, 16% of the patients had died, 88% had cerebral palsy/developmental delay (CP), 48% were nonverbal, 55% were nonambulatory, 33% had epilepsy, and 41% had visual impairment. In the logistic regression analysis, IVH grade was an independent predictor of CP (p = 0.004), which had an estimated probability of occurrence of 74% in grade III and 96% in grade IV. Sepsis at or before the time of consult was an independent predictor of visual impairment (p = 0.024), which had an estimated probability of 58%. IVH grade was an independent predictor of epilepsy (p = 0.026), which had an estimated probability of 18% in grade III and 43% in grade IV. The IVH grade was also an independent predictor of verbal function (p = 0.007), which had an estimated probability of 68% in grade III versus 41% in grade IV. A higher weeks gestational age (WGA) at birth was an independent predictor of the ability to ambulate (p = 0.0014), which had an estimated probability of 15% at 22 WGA and up to 98% at 36 WGA. The need for oscillating ventilation at consult was an independent predictor of death before 2 years of age (p = 0.001), which had an estimated probability of 42% in patients needing oscillating ventilation versus 13% in those who did not.
IVH grade was consistently an independent predictor of functional outcomes at 2 years. Gestational age at birth, sepsis, and the need for oscillating ventilation may also predict worse functional outcomes.
Galal Elsayed, Matthew S. Erwood, Matthew C. Davis, Esther C. Dupépé, Samuel G. McClugage III, Paul Szerlip, Beverly C. Walters, and Mark N. Hadley
This study defines the association of preoperative physical activity level with functional outcomes at 3 and 12 months following surgical decompression for lumbar spinal stenosis.
Data were collected as a prospective observational registry at a single institution from 2012 through 2015, and then analyzed with a retrospective cohort design. Patients who were able to participate in activities outside the home preoperatively were compared to patients who did not participate in such activities, with respect to 3-month and 12-month functional outcomes postintervention, adjusted for relevant confounders.
Ninety-nine patients were included. At baseline, sedentary/inactive patients (n = 55) reported greater back pain, lower quality of life, and higher disability than similarly treated patients who were active preoperatively. Both cohorts experienced significant improvement from baseline in back pain, leg pain, disability, and quality of life at both 3 and 12 months after lumbar decompression surgery. At 3 months postintervention, sedentary/inactive patients reported more leg pain and worse disability than patients who performed activities outside the home preoperatively. However, at 12 months postintervention, there were no statistically significant differences between the two cohorts in back pain, leg pain, quality of life, or disability. Multivariate analysis revealed that sedentary/inactive patients had improved disability and higher quality of life after surgery compared to baseline. Active patients experienced greater overall improvement in disability compared to inactive patients.
Sedentary/inactive patients have a more protracted recovery after lumbar decompression surgery for spinal stenosis, but at 12 months postintervention can expect to reach similar long-term outcomes as patients who are active/perform activities outside the home preoperatively.
Galal A. Elsayed, Esther B. Dupépé, Matthew S. Erwood, Matthew C. Davis, Samuel G. McClugage III, Paul Szerlip, Beverly C. Walters, and Mark N. Hadley
The goal of this study was to analyze the effect of patient education level on functional outcomes following decompression surgery for symptomatic lumbar spinal stenosis.
Patients with surgically decompressed symptomatic lumbar stenosis were collected in a prospective observational registry at a single institution between 2012 and 2014. Patient education level was compared to surgical outcomes to elucidate any relationships. Outcomes were defined using the Oswestry Disability Index score, back and leg pain visual analog scale (VAS) score, and the EuroQol–5 Dimensions questionnaire score.
Of 101 patients with symptomatic lumbar spinal stenosis, 27 had no college education and 74 had a college education (i.e., 2-year, 4-year, or postgraduate degree). Preoperatively, patients with no college education had statistically significantly greater back and leg pain VAS scores when compared to patients with a college education. However, there was no statistically significant difference in quality of life or disability between those with no college education and those with a college education. Postoperatively, patients in both cohorts improved in all 4 patient-reported outcomes at 3 and 12 months after treatment for symptomatic lumbar spinal stenosis.
Despite their education level, both cohorts showed improvement in their functional outcomes at 3 and 12 months after decompression surgery for symptomatic lumbar spinal stenosis.
Nisha Gadgil, Ganesh Rao, Raymond Sawaya, Daniel Yoshor, Lucia Ruggieri, Natalie Cormier, Daniel J. Curry, William E. Whitehead, Guillermo Aldave, David F. Bauer, Samuel McClugage III, and Howard L. Weiner
Texas Children’s Hospital opened its doors in 1954, and since that time the institution has remained dedicated to a three-part mission: patient care, education, and research. Dr. William R. Cheek developed an early interest in pediatric neurosurgery, which led to his efforts in building and developing a service at Texas Children’s Hospital at a time when the field was just emerging. His work with other early pioneers in the field led to the establishment of organized societies, educational texts, and governing bodies that have led to significant advances in the field over the past 50 years.
Galal Elsayed, Samuel G. McClugage III, Matthew S. Erwood, Matthew C. Davis, Esther B. Dupépé, Paul Szerlip, Beverly C. Walters, and Mark N. Hadley
Insurance disparities can have relevant effects on outcomes after elective lumbar spinal surgery. The aim of this study was to evaluate the association between private/public payer status and patient-reported outcomes in adult patients who underwent decompression surgery for lumbar spinal stenosis.
A sample of 100 patients who underwent surgery for lumbar spinal stenosis from 2012 to 2014 was evaluated as part of the prospectively collected Quality Outcomes Database at a single institution. Outcome measures were evaluated at 3 months and 12 months, analyzed in regard to payer status (private insurance vs Medicare/Veterans Affairs insurance), and adjusted for potential confounders.
At baseline, patients had similar visual analog scale back and leg pain, Oswestry Disability Index, and EQ-5D scores. At 3 months postintervention, patients with government-funded insurance reported significantly worse quality of life (mean difference 0.11, p < 0.001) and more leg pain (mean difference 1.26, p = 0.05). At 12 months, patients with government-funded insurance reported significantly worse quality of life (mean difference 0.14, p < 0.001). There were no significant differences at 3 months or 12 months between groups for back pain (p = 0.14 and 0.43) or disability (p = 0.19 and 0.15). Across time points, patients in both groups showed improvement at 3 months and 12 months in all 4 functional outcomes compared with baseline (p < 0.001).
Both private and public insurance patients had significant improvement after elective lumbar spinal surgery. Patients with public insurance had slightly less improvement in quality of life after surgery than those with private insurance but still benefited greatly from surgical intervention, particularly with respect to functional status.
Brandon G. Rocque, Matthew C. Davis, Samuel G. McClugage III, Dang Anh Tuan, Donald T. King III, Nguyen Thi Huong, Nguyen Thi Bich Van, Pongkiat Kankirawatana, Cao Vu Hung, Le Nam Thang, James M. Johnston, and Nguyen Duc Lien
The purpose of this report was to describe an international collaboration model to facilitate the surgical treatment of children with epilepsy in Vietnam.
This model uses three complementary methods to achieve a meaningful expansion in epilepsy surgery capacity: US-based providers visiting Hanoi, Vietnam; Vietnamese providers visiting the US; and ongoing telecollaboration, including case review and real-time mentorship using internet-based communication platforms.
Introductions took place during a US neurosurgeon’s visit to Vietnam in 2014. Given the Vietnamese surgeon’s expertise in intraventricular tumor surgery, the focus of the initial visit was corpus callosotomy. After two operations performed jointly, the Vietnamese surgeon went on to perform 10 more callosotomy procedures in the ensuing 6 months with excellent results. The collaborative work grew and matured in 2016–2017, with 40 pediatric epilepsy surgeries performed from 2015 through 2017. Because pediatric epilepsy care requires far more than neurosurgery, teams traveling to Vietnam included a pediatric neurologist and an electroencephalography (EEG) technologist. Also, in 2016–2017, a neurosurgeon, two neurologists, and an EEG nurse from Vietnam completed 2- to 3-month fellowships at Children’s of Alabama (COA) in the US. These experiences improved EEG capabilities and facilitated the development of intraoperative electrocorticography (ECoG), making nonlesional epilepsy treatment more feasible. The final component has been ongoing, i.e., regular communication. The Vietnamese team regularly sends case summaries for discussion to the COA epilepsy conference. Three patients in Vietnam have undergone resection guided by ECoG without the US team present, although there was communication via internet-based telecollaboration tools between Vietnamese and US EEG technologists. To date, two of these three patients remain seizure free. The Vietnamese team has presented the results of their epilepsy experience at two international functional and epilepsy surgery scientific meetings.
Ongoing international collaboration has improved the surgical care of epilepsy in Vietnam. Experience suggests that the combination of in-country and US-based training, augmented by long-distance telecollaboration, is an effective paradigm for increasing the capacity for highly subspecialized, multidisciplinary neurosurgical care.