✓ Two cases of spinal arteriovenous malformation (AVM) are reported because of a previously unobserved clinical feature: recurrent transient postprandial paresis of the legs. The authors believe the paresis was caused by chronic shunting of blood away from the cord and into the low-resistance AVM. Symptomatic cord ischemia might then be precipitated by vasodilatation in other areas of the body such as the splanchnic, brachial, or uterine vessels. We believe that in some instances this mechanism should be considered as an explanation for episodic neurological deficits seen in association with spinal AVM's.
Anthony D. Oliver, Charles B. Wilson and Edwin B. Boldrey
Andrew D. Firlik, Anthony M. Kaufmann, Charles A. Jungreis and Howard Yonas
✓ In this study the authors have examined the effects of transluminal angioplasty on cerebral blood flow (CBF) in the management of intractable vasospasm following aneurysmal subarachnoid hemorrhage (SAH). Fourteen consecutively enrolled patients underwent attempted angioplasty with or without intraarterial infusion of papaverine. Twelve patients underwent pre- and postangioplasty xenon-enhanced computerized tomography (Xe-CT) scanning to measure regional CBF in 55 to 65 regions of interest (ROIs) per patient. Angioplasty was possible in 13 (93%) of 14 patients, with angiographically demonstrated improvement in all 13. Twelve (92%) of the 13 patients were neurologically improved following angioplasty; seven (58%) of the 12 patients who improved had a complete reversal of all delayed ischemic deficits. Angioplasty significantly decreased the mean number of ROIs at risk (11.4 ROIs pre- and 0.9 ROIs postangioplasty) (p < 0.00005, t-test). All patients had a reduction in the number of ROIs at risk after angioplasty; six (50%) of 12 no longer had any ROIs remaining at risk after angioplasty. Angioplasty significantly increased the mean CBF within at-risk ROIs (13 ml/100 g/minute pre- and 44 ml/100 g/minute postangioplasty) (p < 0.00005, t-test). All patients experienced an improvement in mean CBF in at-risk ROIs after angioplasty, with the mean CBF improving to above 20 ml/100 g/minute in all cases. No differences in the degree of improvement were found in patients who received intraarterial papaverine compared with those who did not. In the majority of patients with refractory vasospasm following SAH, angioplasty effectively dilated spastic arteries, reversed delayed neurological deficits, and significantly improved CBF in areas of brain at risk of infarction.
Carolyn Quinsey, Jessica Eaton, Weston Northam, Matt Gilleskie, Anthony Charles and Eldad Hadar
Global health research can transform clinical and surgical practice worldwide. Partnerships between US academic centers and hospitals in low- and middle-income counties can improve clinical care at the host institution hospital and give the visiting institution access to a large volume of valuable research data. Recognizing the value of these partnerships, the University of North Carolina (UNC) formed a partnership with Kamuzu Central Hospital (KCH) in Lilongwe, Malawi.
The Department of Neurosurgery joined the partnership with KCH and designed a Head Trauma Surveillance Registry. The success of this registry depended on the development of methods to accurately collect head injury data at KCH. Since medical record documentation is often unreliable in this setting, data collection teams were implemented to capture data from head trauma patients on a 24-hours-a-day, 7-days-a-week basis. As data collection improved, pilot groups tested methods to collect new variables and the registry expanded. UNC provided onsite and remote oversight to strengthen the accuracy of the data.
Data accuracy still remains a hurdle in global research. Data collection teams, oversight from UNC, pilot group testing, and meaningful collaboration with local physicians improved the accuracy of the head trauma registry. Overall, these methods helped create a more accurate epidemiological and outcomes-centered analysis of brain injury patients at KCH to date.
Ashley D. Meagher, Christopher A. Beadles, Jennifer Doorey and Anthony G. Charles
Disparities in access to inpatient rehabilitation services after traumatic brain injury (TBI) have been identified, but less well described is the likelihood of discharge to a higher level of rehabilitation for Hispanic or black patients compared with non-Hispanic white patients. The authors investigate racial disparities in discharge destination (inpatient rehabilitation vs skilled nursing facility vs home health vs home) following TBI by using a nationwide database and methods to address racial differences in prehospital characteristics.
Analysis of discharge destination for adults with moderate to severe TBI was performed using National Trauma Data Bank data for the years 2007–2010. The authors performed propensity score weighting followed by ordered logistic regression in their analytical sample and in a subgroup analysis of older adults with Medicare. Likelihood of discharge to a higher level of rehabilitation based on race/ethnicity accounting for prehospital and in-hospital variables was determined.
The authors identified 299,205 TBI incidents: 232,392 non-Hispanic white, 29,611 Hispanic, and 37,202 black. Propensity weighting resulted in covariate balance among racial groups. Hispanic (adjusted OR 0.71, 95% CI 0.68–0.75) and black (adjusted OR 0.94, 95% CI 0.91–0.97) populations were less likely to be discharged to a higher level of rehabilitation than were non-Hispanic whites. The subgroup analysis indicated that Hispanic (adjusted OR 0.79, 95% CI 0.71–0.86) and black (OR 0.87, 95% CI 0.81–0.94) populations were still less likely to receive a higher level of rehabilitation, despite uniform insurance coverage (Medicare).
Adult Hispanic and black patients with TBI are significantly less likely to receive intensive rehabilitation than their non-Hispanic white counterparts; notably, this difference persists in the Medicare population (age ≥ 65 years), indicating that uniform insurance coverage alone does not account for the disparity. Given that insurance coverage and a wide range of prehospital characteristics do not eliminate racial disparities in discharge destination, it is crucial that additional unmeasured patient, physician, and institutional factors be explored to eliminate them.
Charles Milchteim, Warren D. Yu, Anthony Ho and Joseph R. O'Brien
Cervical transfacet screw placement has been described in the literature. Although the technique shows promise for percutaneous application, parameters for screw placement have not been well delineated. This study used reconstructed CT scans with imaging software to assess the feasibility of percutaneous transfacet screw placement, analyzing potential entry angles, transfacet lengths, and sex differences at each subaxial level.
Fifty consecutive cervical CT scans (obtained in 26 males and 24 females [mean age 41.5 years]) were reformatted using OsiriX software, and transfacet lengths, entry angles, and potential occipital clearance were analyzed at all subaxial levels. Statistical analyses were used to determine the differences, if any, between transfacet lengths, entry angle, and occipital clearance across individual cervical levels. Repeatability was quantified by calculating the intraclass correlation coefficient and Cohen kappa value.
A total of 200 transfacet lengths and 200 entry angles in 50 patients were analyzed. The mean transfacet lengths were 17.9 ± 2.6, 17.6 ± 3.2, 16.3 ± 3.6, and 13.1 ± 2.2 mm at C3–4, C4–5, C5–6, and C6–7, respectively, with mean entry angles at 52.7° ± 7.8°, 56.5° ± 8.0°, 55.0° ± 8.8°, and 53.0° ± 8.7°, respectively. Analysis of variance revealed a significant difference between the mean transfacet lengths, while post hoc analysis revealed significantly larger transfacet lengths in the upper 2 cervical levels (C3–4 and C4–5) than in the lower 2 cervical levels (C5–6 and C6–7). Analysis of variance demonstrated no significant difference between the entry angles. Males had significantly larger transfacet lengths at C5–6 (17.4 vs 15.1 mm) and C6–7 (13.7 vs 12.4 mm) than females. The occiput would have blocked percutaneous screw placement in 86%, 78%, 54%, and 20% of the cases at C3–4, C4–5, C5–6, and C6–7, respectively. Transfacet lengths may accommodate longer screws in the upper cervical spine, but potential screw sizes decrease in the lower subaxial levels. A transfacet entry angle of approximately 50° or greater was associated with a higher incidence of occipital clearance. Additionally, the occiput may pose a significant obstruction to percutaneous transfacet fixation in upper subaxial levels. Interrater reliability was poor for screw angle and length measurements, but was satisfactory in intrarater analysis in 6 of 8 measurements. There was moderate to good agreement of occipital clearance in all but one measurement.
Cervical transfacet screw placement is possible from C-3 to C-7. Because occipital clearance can be difficult at C3–4 and C6–7, the use of curved or flexible instruments may be necessary to obtain the appropriate screw trajectory. Screw lengths varied with spinal level and the sex of the patient.
Charles H. Crawford III, Steven D. Glassman, Praveen V. Mummaneni, John J. Knightly and Anthony L. Asher
The relief of leg symptoms by surgical decompression for lumbar stenosis is well supported by the literature. Less is known about the effect on back pain. Some surgeons believe that the relief of back pain should not be an expected outcome of decompression and that substantial back pain may be a contraindication to decompression only; therefore, stabilization may be recommended for patients with substantial preoperative back pain even in the absence of well-accepted indications for stabilization such as spondylolisthesis, scoliosis, or sagittal malalignment. The purpose of this study is to determine if patients with lumbar stenosis and substantial back pain—in the absence of spondylolisthesis, scoliosis, or sagittal malalignment—can obtain significant improvement after decompression without fusion or stabilization.
Analysis of the National Neurosurgery Quality and Outcomes Database (N2QOD) identified 726 patients with lumbar stenosis (without spondylolisthesis or scoliosis) and a baseline back pain score ≥ 5 of 10 who underwent surgical decompression only. No patient was reported to have significant spondylolisthesis, scoliosis, or sagittal malalignment. Standard demographic and surgical variables were collected, as well as patient outcomes including back and leg pain scores, Oswestry Disability Index (ODI), and EuroQoL 5D (EQ-5D) at baseline and 3 and 12 months postoperatively.
The mean age of the cohort was 65.6 years, and 407 (56%) patients were male. The mean body mass index was 30.2 kg/m2, and 40% of patients had 2-level decompression, 29% had 3-level decompression, 24% had 1-level decompression, and 6% had 4-level decompression. The mean estimated blood loss was 130 ml. The mean operative time was 100.85 minutes. The vast majority of discharges (88%) were routine home discharges. At 3 and 12 months postoperatively, there were significant improvements from baseline for back pain (7.62 to 3.19 to 3.66), leg pain (7.23 to 2.85 to 3.07), EQ-5D (0.55 to 0.76 to 0.75), and ODI (49.11 to 27.20 to 26.38).
Through the 1st postoperative year, patients with lumbar stenosis—without spondylolisthesis, scoliosis, or sagittal malalignment—and clinically significant back pain improved after decompression-only surgery.
Charles H. Crawford III, Leah Y. Carreon, Mohamad Bydon, Anthony L. Asher and Steven D. Glassman
Patient satisfaction is a commonly used metric in the current health care environment. While factors that affect patient satisfaction following spine surgery are complex, the authors of this study hypothesized that specific diagnostic groups of patients are more likely to be satisfied after spine surgery and that this is reflected in patient-reported outcome measures. The purpose of this study was to determine if the preoperative diagnosis—disc herniation, stenosis, spondylolisthesis, adjacent segment degeneration, or mechanical disc collapse—would impact patient satisfaction following surgery.
Patients enrolled in the Quality Outcomes Database, formerly known as the National Neurosurgery Quality and Outcomes Database (N2QOD), completed patient-reported outcome measures, including the Oswestry Disability Index (ODI) and Numeric Rating Scale (NRS) for back pain (NRS-BP) and leg pain (NRS-LP) preoperatively and 1-year postoperatively. Patients were stratified by diagnosis and by their response to the satisfaction question: 1) surgery met my expectations; 2) I did not improve as much as I hoped, but I would undergo the same operation for the same results; 3) surgery helped, but I would not undergo the same operation for the same results; or 4) I am the same or worse as compared with before surgery.
A greater proportion of patients with primary disc herniation or spondylolisthesis reported that surgery met expectations (66% and 67%, respectively), followed by recurrent disc herniation and stenosis (59% and 60%, respectively). A smaller proportion of patients who underwent surgery for adjacent segment degeneration or mechanical disc collapse had their expectations met (48% and 41%, respectively). The percentage of patients that would undergo the same surgery again, by diagnostic group, was as follows: disc herniation 88%, recurrent disc herniation 79%, spondylolisthesis 86%, stenosis 82%, adjacent segment disease 75%, and mechanical collapse 73%. Regardless of diagnosis, mean improvement and ultimate 1-year postoperative ODI, NRS-BP, and NRS-LP reflected patient satisfaction.
Preoperative diagnosis was predictive of patient satisfaction following spine surgery. The mean change in and 1-year ODI, NRS-BP, and NRS-LP reflected patient satisfaction regardless of preoperative diagnosis.
Trista Reid, Joanna Grudziak, Nidia Rodriguez-Ormaza, Rebecca G. Maine, Nelson Msiska, Carolyn Quinsey and Anthony Charles
Hydrocephalus is the most common pediatric neurosurgical condition, with a high prevalence in low- and middle-income countries. Untreated, hydrocephalus leads to neurological disability or death. The epidemiology and outcomes of hydrocephalus treated by ventriculoperitoneal (VP) shunts in Sub-Saharan Africa are not well defined and vary by region. The aim of the present study was to examine the mortality and morbidity rates and predictors of mortality in children treated by VP shunt placement for hydrocephalus at Kamuzu Central Hospital in Lilongwe, Malawi.
This is a prospective study of 100 consecutive children presenting with hydrocephalus who were treated with VP shunt placement from January 2015 to August 2017. Demographics, nutritional status, maternal characteristics, developmental delay, shunt complications, readmissions, and in-hospital and 3-month mortality data were collected. Multivariate logistic regression was used to identify predictors of death within 3 months of surgery.
Overall, 46% of participants were female, with an average age of 5.4 ± 3.7 months at the time of surgery. The majority of patients were term deliveries (87.8%) and were not malnourished (72.9%). Only 10.8% of children were diagnosed with meningitis before admission. In-hospital and 3-month mortality rates were 5.5% and 32.1%, respectively. The only significant association with mortality was maternal age, with older maternal age demonstrating decreased odds of 3-month mortality (OR 0.9, 95% CI 0.8–1.0, p = 0.045).
Surgical management of hydrocephalus with VP shunts portends a high mortality rate in Malawi. The association of younger maternal age with mortality is likely a proxy for social determinants, which appear to contribute as much to mortality as patient factors. VP shunting is inadequate as a sole surgical management of hydrocephalus in resource-limited settings.
Charles H. Tator, Alex S. Rivlin, Anthony J. Lewis and Beatrice Schmoll
✓ Studies were performed on the effect of triiodo-L-thyronine (T3) on clinical recovery and axonal counts in the pyramidal tract of 56 rats subjected to an acute spinal cord compression injury at T-7. The T3 was given at a daily dose of 5 µg/kg for 4 weeks to 28 rats in the treatment group. The treatment and control animals were tested weekly for clinical recovery, and cord function as determined by the inclined-plane technique. Groups of animals were killed at 4 weeks and 12 weeks, and the axons in the pyramidal tract cephalad and caudad to the injury site were counted in sections prepared with Holmes' silver stain.
There was no difference in clinical recovery between the treatment and control groups. This negative result contrasts with other studies which showed improved recovery of cord-injured animals treated with thyroid hormones. The possible explanations for this discrepancy are discussed. Similarly, there was no difference in the axon counts between the treated and control groups. Thus, T3 did not improve recovery or axonal regeneration in the pyramidal tract of rats after acute spinal cord compression injury. Between 4 and 12 weeks, there was a marked reduction in the cephalad axon counts in the pyramidal tract in both groups, indicating that approximately 50% of the axons in the pyramidal tract had undergone retrograde degeneration or dying back by 12 weeks after this degree of injury. The T3 did not affect the degree of retrograde degeneration.
Charles H. Tator, Alex S. Rivlin, Anthony J. Lewis and Beatrice Schmoll
✓ The concentration of axons in the pyramidal tract of normal and spinal cord-injured rats was determined by counting axons in sections of spinal cord stained by the Holmes technique. In the normal rat the axon concentration was uniform in the cervical, thoracic, and lumbar regions, although the size of the tract diminished progressively with its descent in the cord. After acute cord transection or compression injury, the axon concentration distal to the injury site diminished markedly. However, an appreciable number of distal axons persisted after injury, due to either delayed degeneration or to the presence of an admixture of afferent fibers. The axonal counting technique developed in this study should be helpful in experiments on spinal cord injury and regeneration.