Brainstem cavernous malformations (CMs) are complex lesions associated with hemorrhage and neurological deficit. In this review, the authors describe the anatomical nuances relating to the operative techniques for these challenging lesions. The resection of brainstem CMs in properly selected patients has been demonstrated to reduce the risk of rehemorrhage and can be achieved relatively safely in experienced hands.
Wael F. Asaad, Brian P. Walcott, Brian V. Nahed and Christopher S. Ogilvy
Jonathan J. Lee, David J. Segar, John F. Morrison, William M. Mangham, Shane Lee and Wael F. Asaad
Early radiographic findings in patients with traumatic brain injury (TBI) have been studied in hopes of better predicting injury severity and outcome. However, prior attempts have generally not considered the various types of intracranial hemorrhage in isolation and have typically not excluded patients with potentially confounding extracranial injuries. Therefore, the authors examined the associations of various radiographic findings with short-term outcome to assess the potential utility of these findings in future prognostic models.
The authors retrospectively identified 1716 patients who had experienced TBI without major extracranial injuries, and categorized them into the following TBI subtypes: subdural hematoma (SDH), traumatic subarachnoid hemorrhage, intraparenchymal hemorrhage (which included intraventricular hemorrhage), and epidural hematoma. They specifically considered isolated forms of hemorrhage, in which only 1 subtype was present.
In general, the presence of an isolated SDH was more likely to result in worse outcomes than the presence of other isolated forms of traumatic intracranial hemorrhage. Discharge to home was less likely and perihospital mortality rates were generally higher in patients with SDH. These findings were not simply related to age and were not fully captured by the admission Glasgow Coma Scale (GCS) score. The presence of SDH had a much higher sensitivity for poor outcome than the presence of other TBI subtypes, and was more sensitive for these poor outcomes than having a low GCS score (3–8).
In these ways, SDH was the most important finding associated with poor outcome, and the authors show that consideration of SDH, specifically, can augment age and GCS score in classification and prognostic models for TBI.
Andrew Y. Powers, Mauricio B. Pinto, Oliver Y. Tang, Jia-Shu Chen, Cody Doberstein and Wael F. Asaad
Traumatic intracranial hemorrhage (tICH) is a significant source of morbidity and mortality in trauma patients. While prognostic models for tICH outcomes may assist in alerting clinicians to high-risk patients, previously developed models face limitations, including low accuracy, poor generalizability, and the use of more prognostic variables than is practical. This study aimed to construct a simpler and more accurate method of risk stratification for all tICH patients.
The authors retrospectively identified a consecutive series of 4110 patients admitted to their institution’s level 1 trauma center between 2003 and 2013. For each admission, they collected the patient’s sex, age, systolic blood pressure, blood alcohol concentration, antiplatelet/anticoagulant use, Glasgow Coma Scale (GCS) score, Injury Severity Score, presence of epidural hemorrhage, presence of subdural hemorrhage, presence of subarachnoid hemorrhage, and presence of intraparenchymal hemorrhage. The final study population comprised 3564 patients following exclusion of records with missing data. The dependent variable under study was patient death. A k-fold cross-validation was carried out with the best models selected via the Akaike Information Criterion. These models risk stratified the study partitions into grade I (< 1% predicted mortality), grade II (1%–10% predicted mortality), grade III (10%–40% predicted mortality), or grade IV (> 40% predicted mortality) tICH. Predicted mortalities were compared with actual mortalities within grades to assess calibration. Concordance was also evaluated. A final model was constructed using the entire data set. Subgroup analysis was conducted for each hemorrhage type.
Cross-validation demonstrated good calibration (p < 0.001 for all grades) with a mean concordance of 0.881 (95% CI 0.865−0.898). In the authors’ final model, older age, lower blood alcohol concentration, antiplatelet/anticoagulant use, lower GCS score, and higher Injury Severity Score were all associated with greater mortality. Subgroup analysis showed successful stratification for subarachnoid, intraparenchymal, grade II–IV subdural, and grade I epidural hemorrhages.
The authors developed a risk stratification model for tICH of any GCS score with concordance comparable to prior models and excellent calibration. These findings are applicable to multiple hemorrhage subtypes and can assist in identifying low-risk patients for more efficient resource allocation, facilitate family conversations regarding goals of care, and stratify patients for research purposes. Future work will include testing of more variables, validation of this model across institutions, as well as creation of a simplified model whose outputs can be calculated mentally.
Joseph A. Carnevale, David J. Segar, Andrew Y. Powers, Meghal Shah, Cody Doberstein, Benjamin Drapcho, John F. Morrison, John R. Williams, Scott Collins, Kristina Monteiro and Wael F. Asaad
Traumatic brain injury (TBI) remains a significant cause of neurological morbidity and mortality. Each year, more than 1.7 million patients present to the emergency department with TBI. The goal of this study was to evaluate the prognosis of traumatic cerebral intraparenchymal hemorrhage (tIPH), to develop subclassifications of these injuries that relate to prognosis, and to provide a more comprehensive assessment of hemorrhagic progression contusion (HPC) by analyzing the rate at which tIPH “blossom” (i.e., expansion), depending on a variety of intrinsic and modifiable factors.
In this retrospective study, 726 patients (age range 0–100 years) were admitted to a level 1 trauma center with tIPH during an 8-year period (2005–2013). Of these patients, 491 underwent both admission and follow-up head CT (HCT) within 72 hours. The change in tIPH volume over time, the expansion rate, was recorded for all 491 patients. Effects of prehospital and in-hospital variables were examined using ordinal response logistic regression analyses. These variables were further examined using multivariate linear regression analysis to accurately predict the extent to which a hemorrhage will progress.
Of the 491 (67.6%) patients who underwent both admission and follow-up HCT, 368 (74.9%) patients experienced HPC. These hemorrhages expanded on average by 61.6% (4.76 ml) with an average expansion rate of 0.71 ml per hour. On univariate analysis, certain patient characteristics were significantly (p < 0.05) related to HPC, including age (> 60 years), admission Glasgow Coma Scale score, blood alcohol level, international normalized ratio, absolute platelet count, transfusion of platelets, concomitant anticoagulation and antiplatelet medication, the initial tIPH volume on admission HCT, and ventriculostomy. Increased expansion rate was significantly associated with patient disposition to hospice or death (p < 0.001). To determine which factors most accurately predict overall patient disposition, an ordinal-response logistic regression identified systolic blood pressure, Injury Severity Score, admission Glasgow Coma Scale score, follow-up scan volume, transfusion of platelets, and ventriculostomy as predictors of patient discharge disposition following tIPH. A multivariate logistic regression identified several prehospital and in-hospital variables (age, Injury Severity Score, blood alcohol level, initial scan volume, concomitant epidural hematoma, presence of subarachnoid hemorrhage, transfusion of platelets, and ventriculostomy) that predicted the volumetric expansion of tIPH. Among these variables, the admission tIPH volume by HCT proved to be the factor most predictive of HPC.
Several factors contribute to the rate at which traumatic cerebral contusions blossom in the acute posttraumatic period. Identifying the intrinsic and modifiable aspects of cerebral contusions can help predict the rate of expansion and highlight potential therapeutic interventions to improve TBI-associated morbidity and mortality.
Brian P. Walcott, Churl-Su Kwon, Sameer A. Sheth, Corey R. Fehnel, Robert M. Koffie, Wael F. Asaad, Brian V. Nahed and Jean-Valery Coumans
Decompressive craniectomy mandates subsequent cranioplasty. Complications of cranioplasty may be independent of the initial craniectomy, or they may be contingent upon the craniectomy. Authors of this study aimed to identify surgery- and patient-specific risk factors related to the development of surgical site infection and other complications following cranioplasty.
A consecutive cohort of patients of all ages and both sexes who had undergone cranioplasty following craniectomy for stroke or trauma at a single institution in the period from May 2004 to May 2012 was retrospectively established. Patients who had undergone craniectomy for infectious lesions or neoplasia were excluded. A logistic regression analysis was performed to model and predict determinants related to infection following cranioplasty.
Two hundred thirty-nine patients met the study criteria. The overall rate of complication following cranioplasty was 23.85% (57 patients). Complications included, predominantly, surgical site infection, hydrocephalus, and new-onset seizures. Logistic regression analysis identified previous reoperation (OR 3.25, 95% CI 1.30–8.11, p = 0.01) and therapeutic indication for stroke (OR 2.45, 95% CI 1.11–5.39, p = 0.03) as significantly associated with the development of cranioplasty infection. Patient age, location of cranioplasty, presence of an intracranial device, bone flap preservation method, cranioplasty material, booking method, and time interval > 90 days between initial craniectomy and cranioplasty were not predictive of the development of cranioplasty infection.
Cranioplasty complications are common. Cranioplasty infection rates are predicted by reoperation following craniectomy and therapeutic indication (stroke). These variables may be associated with patient-centered risk factors that increase cranioplasty infection risk.
Francisco A. Ponce, Wael F. Asaad, Kelly D. Foote, William S. Anderson, G. Rees Cosgrove, Gordon H. Baltuch, Kara Beasley, Donald E. Reymers, Esther S. Oh, Steven D. Targum, Gwenn S. Smith, Constantine G. Lyketsos and Andres M. Lozano
This report describes the stereotactic technique, hospitalization, and 90-day perioperative safety of bilateral deep brain stimulation (DBS) of the fornix in patients who underwent DBS for the treatment of mild, probable Alzheimer's disease (AD).
The ADvance Trial is a multicenter, 12-month, double-blind, randomized, controlled feasibility study being conducted to evaluate the safety, efficacy, and tolerability of DBS of the fornix in patients with mild, probable AD. Intraoperative and perioperative data were collected prospectively. All patients underwent postoperative MRI. Stereotactic analyses were performed in a blinded fashion by a single surgeon. Adverse events (AEs) were reported to an independent clinical events committee and adjudicated to determine the relationship between the AE and the study procedure.
Between June 6, 2012, and April 28, 2014, a total of 42 patients with mild, probable AD were treated with bilateral fornix DBS (mean age 68.2 ± 7.8 years; range 48.0–79.7 years; 23 men and 19 women). The mean planned target coordinates were x = 5.2 ± 1.0 mm (range 3.0–7.9 mm), y = 9.6 ± 0.9 mm (range 8.0–11.6 mm), z = −7.5 ± 1.2 mm (range −5.4 to −10.0 mm), and the mean postoperative stereotactic radial error on MRI was 1.5 ± 1.0 mm (range 0.2–4.0 mm). The mean length of hospitalization was 1.4 ± 0.8 days. Twenty-six (61.9%) patients experienced 64 AEs related to the study procedure, of which 7 were serious AEs experienced by 5 patients (11.9%). Four (9.5%) patients required return to surgery: 2 patients for explantation due to infection, 1 patient for lead repositioning, and 1 patient for chronic subdural hematoma. No patients experienced neurological deficits as a result of the study, and no deaths were reported.
Accurate targeting of DBS to the fornix without direct injury to it is feasible across surgeons and treatment centers. At 90 days after surgery, bilateral fornix DBS was well tolerated by patients with mild, probable AD.
Clinical trial registration no.: NCT01608061 (clinicaltrials.gov)