Per K. Eide, Benjamin I. Rapoport, William B. Gormley and Joseph R. Madsen
In the search for optimal monitoring and predictive tools in neurocritical care, the relationship of the pulsatile component of intracranial pressure (ICP) and the pressure itself has long been of great interest. Higher pressure often correlates with a higher pulsatile response to the heartbeat, interpreted as a type of compliance curve. Various mathematical approaches have been used, but regardless of the formula used, it is implicitly assumed that a reproducible curve exists. The authors investigated the stability of the correlation between static and pulsatile ICPs in patients with subarachnoid hemorrhage (SAH) who were observed for several hours by using data sets large enough to allow such calculations to be made.
The ICP recordings were obtained in 39 patients with SAH and were parsed into 6-second time windows (1,998,944 windows in 197 recordings). The ICP parameters were computed for each window as follows: static ICP was defined as the mean ICP, and pulsatile ICP was characterized by mean ICP wave amplitude, rise time, and rise time coefficient.
The mean ICP and ICP wave amplitudes were simultaneously high or low (the expected correlation) in only ~ 60% of observations. Furthermore, static and pulsatile ICP correlated well only over short intervals; the degree of correlation weakened over periods of hours and was inconsistent across patients and within individual patients over time. Decorrelation originated with abrupt shifting and gradual drifting of mean ICP and ICP wave amplitude over several hours.
The relationship between the static and pulsatile components of ICPs changes over time. It evolves, even in individual patients, over a number of hours. This can be one reason the observation of high pulsatile ICP (indicative of reduced intracranial compliance) despite normal mean ICP that is seen in some patients with SAH. The meaning and potential clinical usefulness of such changes in the curves is uncertain, but it implies that clinical events result not only from moving further out on a compliance curve; in practice, the curve, and the biological system that underlies the curve, may itself change.
Ryan Brewster, Wenya Linda Bi, Timothy R. Smith, William B. Gormley, Ian F. Dunn and Edward R. Laws Jr.
Baseball maintains one of the highest impact injury rates in all athletics. A principal causative factor is the “beanball,” referring to a pitch thrown directly at a batter’s head. Frequent morbidities elicited demand for the development of protective gear development in the 20th century. In this setting, Dr. Walter Dandy was commissioned to design a “protective cap” in 1941. His invention became widely adopted by professional baseball and inspired subsequent generations of batting helmets. As a baseball aficionado since his youth, Walter Dandy identified a natural partnership between baseball and medical practice for the reduction of beaning-related brain injuries. This history further supports the unique position of neurosurgeons to leverage clinical insights, inform innovation, and expand service to society.
Panagiotis G. Simos, Andrew C. Papanicolaou, Joshua I. Breier, James W. Wheless, Jules E. C. Constantinou, William B. Gormley and William W. Maggio
Object. In this paper the authors demonstrate the concordance between magnetic source (MS) imaging and direct cortical stimulation for mapping receptive language cortex.
Methods. In 13 consecutive surgical patients, cortex specialized for receptive language functions was identified noninvasively by obtaining activation maps aided by MS imaging in the context of visual and auditory word-recognition tasks. Surgery was then performed for treatment of medically intractable seizure disorder (eight patients), and for resection of tumor (four), or angioma (one). Mapping of language areas with cortical stimulation was performed intraoperatively in 10 patients and extraoperatively in three. Cortical stimulation mapping verified the accuracy of the MS imaging—based localization in all cases.
Conclusions. Information provided by MS imaging can be especially helpful in cases of atypical language representation, including bihemispheric representation, and location of language in areas other than those expected within the dominant hemisphere, such as the anterior portion of the superior temporal gyrus, the posteroinferior portion of the middle temporal gyrus, the basal temporal cortex, and the lateral temporooccipital cortex.
Matthew L. Vestal, Emily B. Wong, Dan A. Milner Jr., William B. Gormley and Ian F. Dunn
This report is the first published case of cerebral melioidosis in the western hemisphere. In this paper the authors review the literature on neurological melioidosis and its presentation and treatment in endemic areas, describe the clinical course of this unique case of a presentation of the disease with cranial abscess in the US, review the pathological and radiological findings associated with this seminal case, and put forth recommendations for recognizing and treating possible future instances of the disease within the western hemisphere.
Hormuzdiyar H. Dasenbrock, Robert F. Rudy, Pui Man Rosalind Lai, Timothy R. Smith, Kai U. Frerichs, William B. Gormley, M. Ali Aziz-Sultan and Rose Du
Although cigarette smoking is one of the strongest risk factors for cerebral aneurysm development and rupture, there are limited data evaluating the impact of smoking on outcomes after aneurysmal subarachnoid hemorrhage (SAH). Additionally, two recent studies suggested that nicotine replacement therapy was associated with improved neurological outcomes among smokers who had sustained an SAH compared with smokers who did not receive nicotine.
Patients who underwent endovascular or microsurgical repair of a ruptured cerebral aneurysm were extracted from the Nationwide Inpatient Sample (NIS, 2009–2011) and stratified by cigarette smoking. Multivariable logistic regression analyzed in-hospital mortality, complications, tracheostomy or gastrostomy placement, and discharge to institutional care (a nursing or an extended care facility). Additionally, the composite NIS-SAH outcome measure (based on mortality, tracheostomy or gastrostomy, and discharge disposition) was evaluated, which has been shown to have excellent agreement with a modified Rankin Scale score greater than 3. Covariates included in regression constructs were patient age, sex, race/ethnicity, insurance status, socioeconomic status, comorbidities (including hypertension, drug and alcohol abuse), the NIS-SAH severity scale (previously validated against the Hunt and Hess grade), treatment modality used for aneurysm repair, and hospital characteristics. A sensitivity analysis was performed matching smokers to nonsmokers on age, sex, number of comorbidities, and NIS-SAH severity scale score.
Among the 5784 admissions evaluated, 37.1% (n = 2148) had a diagnosis of tobacco use, of which 31.1% (n = 1800) were current and 6.0% (n = 348) prior tobacco users. Smokers were significantly younger (mean age 51.4 vs 56.2 years) and had more comorbidities compared with nonsmokers (p < 0.001). There were no significant differences in mortality, total complications, or neurological complications by smoking status. However, compared with nonsmokers, smokers had significantly decreased adjusted odds of tracheostomy or gastrostomy placement (11.9% vs 22.7%, odds ratio [OR] 0.63, 95% confidence interval [CI] 0.51–0.78, p < 0.001), discharge to institutional care (OR 0.71, 95% CI 0.57–0.89, p = 0.002), and a poor outcome (OR 0.65, 95% CI 0.55–0.77, p < 0.001). Similar statistical associations were noted in the matched-pairs sensitivity analysis and in a subgroup of poor-grade patients (the upper quartile of the NIS-SAH severity scale).
In this nationwide study, smokers experienced SAH at a younger age and had a greater number of comorbidities compared with nonsmokers, highlighting the negative ramifications of cigarette smoking among patients with cerebral aneurysms. However, smoking was also associated with paradoxical superior outcomes on some measures, and future research to confirm and further understand the basis of this relationship is needed.
Hormuzdiyar Dasenbrock, William B. Gormley, Yoojin Lee, Vincent Mor, Susan L. Mitchell and Corey R. Fehnel
Data evaluating the long-term outcomes, particularly with regard to treatment modality, of aneurysmal subarachnoid hemorrhage (SAH) in octogenarians are limited. The primary objectives were to evaluate the disposition (living at home vs institutional settings) and analyze the predictors of long-term survival and return to home for octogenarians after SAH.
Data pertaining to patients age 80 and older who underwent microsurgical clipping or endovascular coiling for SAH were extracted from 100% nationwide Medicare inpatient claims and linked with the Minimum Data Set (2008–2011). Patient disposition was tracked for 2 years after index SAH admission. Multivariable logistic regression stratified by aneurysm treatment modality, and adjusted for patient factors including SAH severity, evaluated predictors of return to home at 60 and 365 days after SAH. Survival 365 days after SAH was analyzed with a multivariable Cox proportional hazards model.
A total of 1298 cases were included in the analysis. One year following SAH, 56% of the patients had died or were in hospice care, 8% were in an institutional post–acute care setting, and 36% had returned home. Open microsurgical clipping (adjusted hazard ratio [aHR] 0.67, 95% confidence interval [CI] 0.54–0.81), male sex (aHR 0.70, 95% CI 0.57–0.87), tracheostomy (aHR 0.63, 95% CI 0.47–0.85), gastrostomy (aHR 0.60, 95% CI 0.48–0.76), and worse SAH severity (aHR 0.94, 95% CI 0.92–0.97) were associated with reduced likelihood of patients ever returning home. Older age (aHR 1.09, 95% CI 1.05–1.13), tracheostomy (aHR 2.06, 95% CI 1.46–2.91), gastrostomy (aHR 1.55, 95% CI 1.14–2.10), male sex (aHR 1.66, 95% CI 1.20–2.23), and worse SAH severity 1.51 (95% CI 1.04–2.18) were associated with reduced survival.
In this national analysis, 56% of octogenarians with SAH died, and 36% returned home within 1 year of SAH. Coil embolization predicted returning to home, which may suggest a benefit to endovascular treatment in this patient population.
Hormuzdiyar H. Dasenbrock, Robert F. Rudy, Timothy R. Smith, William B. Gormley, Nirav J. Patel, Kai U. Frerichs, M. Ali Aziz-Sultan and Rose Du
The complex decision analysis of unruptured intracranial aneurysms entails weighing the benefits of aneurysm repair against operative risk. The goal of the present analysis was to build and validate a predictive scale that identifies patients with the greatest odds of a postsurgical adverse event.
Data on patients who underwent surgical clipping of an unruptured aneurysm were extracted from the prospective National Surgical Quality Improvement Program registry (NSQIP; 2007–2014); NSQIP does not systematically collect data on patients undergoing intracranial endovascular intervention. Multivariable logistic regression evaluated predictors of any 30-day adverse event; variables screened included patient demographics, comorbidities, functional status, preoperative laboratory values, aneurysm location/complexity, and operative time. A predictive scale was constructed based on statistically significant independent predictors, which was validated using both NSQIP (2015–2016) and the Nationwide Inpatient Sample (NIS; 2002–2011).
The NSQIP unruptured aneurysm scale was proposed: 1 point was assigned for a bleeding disorder; 2 points for age 51–60 years, cardiac disease, diabetes mellitus, morbid obesity, anemia (hematocrit < 36%), operative time 240–330 minutes; 3 points for leukocytosis (white blood cell count > 12,000/μL) and operative time > 330 minutes; and 4 points for age > 60 years. An increased score was predictive of postoperative stroke or coma (NSQIP: p = 0.002, C-statistic = 0.70; NIS: p < 0.001, C-statistic = 0.61), a medical complication (NSQIP: p = 0.01, C-statistic = 0.71; NIS: p < 0.001, C-statistic = 0.64), and a nonroutine discharge (NSQIP: p < 0.001, C-statistic = 0.75; NIS: p < 0.001, C-statistic = 0.66) in both validation populations. Greater score was also predictive of increased odds of any adverse event, a major complication, and an extended hospitalization in both validation populations (p ≤ 0.03).
The NSQIP unruptured aneurysm scale may augment the risk stratification of patients undergoing microsurgical clipping of unruptured cerebral aneurysms.
Hormuzdiyar H. Dasenbrock, Timothy R. Smith, Robert F. Rudy, William B. Gormley, M. Ali Aziz-Sultan and Rose Du
Although reoperation and readmission have been used as quality metrics, there are limited data evaluating the rate of, reasons for, and predictors of reoperation and readmission after microsurgical clipping of unruptured aneurysms.
Adult patients who underwent craniotomy for clipping of an unruptured aneurysm electively were extracted from the prospective National Surgical Quality Improvement Program registry (2011–2014). Multivariable logistic regression and recursive partitioning analysis evaluated the independent predictors of nonroutine hospital discharge, unplanned 30-day reoperation, and readmission. Predictors screened included patient age, sex, comorbidities, American Society of Anesthesiologists (ASA) classification, functional status, aneurysm location, preoperative laboratory values, operative time, and postoperative complications.
Among the 460 patients evaluated, 4.2% underwent any reoperation at a median of 7 days (interquartile range [IQR] 2–17 days) postoperatively, and 1.1% required a cranial reoperation. The most common reoperation was ventricular shunt placement (23.5%); other reoperations were tracheostomy, craniotomy for hematoma evacuation, and decompressive hemicraniectomy. Independent predictors of any unplanned reoperation were age greater than 51 years and longer operative time (p ≤ 0.04). Readmission occurred in 6.3% of patients at a median of 6 days (IQR 5–13 days) after discharge from the surgical hospitalization; 59.1% of patients were readmitted within 1 week and 86.4% within 2 weeks of discharge. The most common reason for readmission was seizure (26.7%); other causes of readmission included hydrocephalus, cerebrovascular accidents, and headache. Unplanned readmission was independently associated with age greater than 65 years, Class II or III obesity (body mass index > 35 kg/m2), preoperative hyponatremia, and preoperative anemia (p ≤ 0.04). Readmission was not associated with operative time, complications during the surgical hospitalization, length of stay, or discharge disposition. Recursive partitioning analysis identified the same 4 variables, as well as ASA classification, as associated with unplanned readmission. The most potent predictors of nonroutine hospital discharge (16.7%) were postoperative neurological and cardiopulmonary complications; other predictors were age greater than 51 years, preoperative hyponatremia, African American and Asian race, and a complex vertebrobasilar circulation aneurysm.
In this national analysis, patient age greater than 65 years, Class II or III obesity, preoperative hyponatremia, and anemia were associated with adverse events, highlighting patients who may be at risk for complications after clipping of unruptured cerebral aneurysms. The preponderance of early readmissions highlights the importance of early surveillance and follow-up after discharge; the frequency of readmission for seizure emphasizes the need for additional data evaluating the utility and duration of postcraniotomy seizure prophylaxis. Moreover, readmission was primarily associated with preoperative characteristics rather than metrics of perioperative care, suggesting that readmission may be a suboptimal indicator of the quality of care received during the surgical hospitalization in this patient population.