Publications

2021

Goudarzi, Sogand, Shooka Esmaeeli, Juan D Valencia, Maegan E Lu, Riley R Hales, Corey R Fehnel, Christopher M Conley, Sadeq A Quraishi, and Ala Nozari. (2021) 2021. “Treatment Options for COVID-19-Related Guillain-Barré Syndrome: A Systematic Review of Literature.”. The Neurologist 26 (5): 196-224. https://doi.org/10.1097/NRL.0000000000000342.

BACKGROUND: Central nervous system complications are reported in an increasing number of patients with Coronavirus Disease 2019 (COVID-19). COVID-19-related Guillain-Barré syndrome (GBS) is of particular importance given its association with higher mortality rates and prolonged respiratory failure.

REVIEW SUMMARY: We conducted a systematic review of published cases for COVID-19-related GBS, and provide a summary of clinical management strategies for these cases. Sixty-three studies, including 86 patients, were included. Seventy-six cases with reported outcome data were eligible for the outcome analysis. Ninety-nine percent of patients were diagnosed with COVID-19 before diagnosis of GBS (median: 14 d prior, interquartile range: 7 to 20). Intravenous immunotherapy (intravenous immunoglobulin: 0.4 g/kg/d for 5 d) was the most frequently used treatment approach. The review indicated that the outcome was not favorable in 26% of cases (persistent neurological deficits). A mortality rate of 3.5% was observed in patients with COVID-19-related GBS.

CONCLUSIONS: Although evidence to support specific treatments is lacking, clinicians should consider the benefits of immunotherapy and plasma exchange in addition to the standard antimicrobial and supportive therapies for patients who meet the diagnostic criteria for acute sensory and motor polyradiculoneuritis. Intravenous immunoglobulin treatment alone is not shown to result in improved outcomes or mortality. More extensive studies aimed at exploring the neurological manifestations and complications of COVID-19 and distinctive treatment options for COVID-19-related GBS are warranted.

Esmaeeli, Shooka, Juan Valencia, Lauren K Buhl, Andres Brenes Bastos, Sogand Goudarzi, Matthias Eikermann, Corey Fehnel, et al. (2021) 2021. “Anesthetic Management of Unruptured Intracranial Aneurysms: A Qualitative Systematic Review.”. Neurosurgical Review 44 (5): 2477-92. https://doi.org/10.1007/s10143-020-01441-w.

Intracranial aneurysms (IA) occur in 3-5% of the general population and may require surgical or endovascular obliteration if the patient is symptomatic or has an increased risk of rupture. These procedures carry an inherent risk of neurological complications, and the outcome can be influenced by the physiological and pharmacological effects of the administered anesthetics. Despite the critical role of anesthetic agents, however, there are no current studies to systematically assess the intraoperative anesthetic risks, benefits, and outcome effects in this population. In this systematic review of the literature, we carefully examine the existing evidence on the risks and benefits of common anesthetic agents during IA obliteration, their physiological and clinical characteristics, and effects on neurological outcome. The initial search strategy captured a total of 287 published studies. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, 28 studies were included in the final report. Our data showed that both volatile and intravenous anesthetics are commonly employed, without evidence that either is superior. Although no specific anesthetic regimens are promoted, their unique neurological, cardiovascular, and physiological properties may be critical to the outcome in vulnerable patients. In particular, patients at risk for perioperative ischemia may benefit from timely administration of anesthetic agents with neuroprotective properties and optimization of their physiological parameters. Further studies are warranted to examine if these anesthetic regimens can reduce the risk of neurological injury and improve the overall outcome in these patients.

2020

Fehnel, Corey R, Miguel Armengol de la Hoz, Leo A Celi, Margaret L Campbell, Khalid Hanafy, Ala Nozari, Douglas B White, and Susan L Mitchell. (2020) 2020. “Incidence and Risk Model Development for Severe Tachypnea Following Terminal Extubation.”. Chest 158 (4): 1456-63. https://doi.org/10.1016/j.chest.2020.04.027.

BACKGROUND: Palliative ventilator withdrawal (PVW) in the ICU is a common occurrence.

RESEARCH QUESTION: The goal of this study was to measure the rate of severe tachypnea as a proxy for dyspnea and to identify characteristics associated with episodes of tachypnea.

STUDY DESIGN AND METHODS: This study assessed a retrospective cohort of ICU patients from 2008 to 2012 mechanically ventilated at a single academic medical center who underwent PVW. The primary outcome of at least one episode of severe tachypnea (respiratory rate > 30 breaths/min) within 6 h after PVW was measured by using detailed physiologic and medical record data. Multivariable logistic regression was used to examine the association between patient and treatment characteristics with the occurrence of a severe episode of tachypnea post extubation.

RESULTS: Among 822 patients undergoing PVW, 19% and 30% had an episode of severe tachypnea during the 1-h and 6-h postextubation period, respectively. Within 1 h postextubation, patients with the following characteristics were more likely to experience tachypnea: no pre-extubation opiates (adjusted OR [aOR], 2.08; 95% CI, 1.03-4.19), lung injury (aOR, 3.33; 95% CI, 2.19-5.04), Glasgow Coma Scale score > 8 (aOR, 2.21; 95% CI, 1.30-3.77), and no postextubation opiates (aOR, 1.90; 95% CI, 1.19-3.00).

INTERPRETATION: Up to one-third of ICU patients undergoing PVW experience severe tachypnea. Administration of pre-extubation opiates (anticipatory dosing) represents a key modifiable factor that may reduce poor symptom control.

Caplan, Rachel A, Jonah P Zuflacht, Jed A Barash, and Corey R Fehnel. (2020) 2020. “Neurotoxicology Syndromes Associated With Drugs of Abuse.”. Neurologic Clinics 38 (4): 983-96. https://doi.org/10.1016/j.ncl.2020.08.005.

Substance use disorders-and their associated neurologic complications-are frequently encountered by neurologists as well as emergency room physicians, internists, psychiatrists, and medical intensivists. Prominent neurologic sequelae of drug abuse, such as seizure and stroke, are common and often result in patients receiving medical attention. However, less overt neurologic manifestations, such as dysautonomia and perceptual disturbances, may be initially misattributed to primary medical or psychiatric illness, respectively. This article focuses on the epidemiology, pharmacology, and complications associated with commonly used recreational drugs, including opioids, alcohol, marijuana, cocaine, and hallucinogens.

2019

2018

Fehnel, Corey R, Kimberly M Glerum, Linda C Wendell, Stevenson Potter, Brian Silver, Muhib Khan, Ali Saad, et al. (2018) 2018. “Safety and Costs of Stroke Unit Admission for Select Acute Intracerebral Hemorrhage Patients.”. The Neurohospitalist 8 (1): 12-17. https://doi.org/10.1177/1941874417712158.

BACKGROUND AND PURPOSE: There are limited data to guide intensive care unit (ICU) versus dedicated stroke unit (SU) admission for intracerebral hemorrhage (ICH) patients. We hypothesized select patients can be safely cared for in SU versus ICU at lower costs.

METHODS: We conducted a retrospective cohort study of consecutive patients with predefined minor ICH (≤20 cm3, supratentorial, no coagulopathy) receiving care in either an ICU or an SU. Multiple linear regression and inverse probability weighting were used to adjust for differences in patient characteristics and nonrandom ICU versus SU assignment. The primary outcome was poor functional status at discharge (modified Rankin score [mRS] ≥3). Secondary outcomes included complications, discharge disposition, hospital length of stay, and direct inpatient costs.

RESULTS: The study population included 104 patients (41 admitted to the ICU and 63 admitted to the SU). After controlling for differences in baseline characteristics, there were no differences in poor functional outcome at discharge (93% vs 85%, P = .26) or in mean mRS (2.9 vs 3.0, P = .73). Similarly, there were no differences in the rates of complications (6% vs 10%, P = .44), discharged dead or to a skilled nursing facility (8% vs 13%, P = .59), or direct patient costs (US$7100 vs US$6200, P = .33). Median length of stay was significantly longer in the ICU group (5 vs 4 days, P = .01).

CONCLUSIONS: This study revealed a shorter length of stay but no large differences in functional outcome, safety, or cost among patients with minor ICH admitted to a dedicated SU compared to an ICU.

Dasenbrock, Hormuzdiyar, William B Gormley, Yoojin Lee, Vincent Mor, Susan L Mitchell, and Corey R Fehnel. (2018) 2018. “Long-Term Outcomes Among Octogenarians With Aneurysmal Subarachnoid Hemorrhage.”. Journal of Neurosurgery 131 (2): 426-34. https://doi.org/10.3171/2018.3.JNS173057.

OBJECTIVE: 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.

METHODS: 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.

RESULTS: 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.

CONCLUSIONS: 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.

Fehnel, Corey R, Alissa Trepman, Dale Steele, Muhib A Khan, Brian Silver, and Susan L Mitchell. (2018) 2018. “Survival After In-Hospital Cardiac Arrest Among Cerebrovascular Disease Patients.”. Journal of Clinical Neuroscience : Official Journal of the Neurosurgical Society of Australasia 54: 1-6. https://doi.org/10.1016/j.jocn.2018.04.033.

Stroke is a leading cause of death and disability, and while preferences for cardiopulmonary resuscitation (CPR) are frequently discussed, there is limited evidence detailing outcomes after CPR among acute cerebrovascular neurology (inclusive of stroke, subarachnoid hemorrhage (SAH)) patients. Systematic review and meta-analysis of PubMed and Cochrane libraries from January 1990 to December 2016 was conducted among stroke patients undergoing in-hospital CPR. Primary data from studies meeting inclusion criteria at two levels were extracted: 1) studies reporting survival to hospital discharge after CPR with cerebrovascular primary admitting diagnosis, and 2) studies reporting survival to hospital discharge after CPR with cerebrovascular comorbidity. Meta-analysis generated weighted, pooled survival estimates for each population. Of 818 articles screened, there were 176 articles (22%) that underwent full review. Three articles met primary inclusion criteria, with an estimated 8% (95% Confidence Interval (CI) 0.01, 0.14) rate of survival to hospital discharge from a pooled sample of 561 cerebrovascular patients after in-hospital CPR. Twenty articles met secondary inclusion criteria, listing a cerebrovascular comorbidity, with an estimated rate of survival to hospital discharge of 16% (95% CI 0.14, 0.19). All studies demonstrated wide variability in adherence to Utstein guidelines, and neurological outcomes were detailed in only 6 (26%) studies. Among the few studies reporting survival to hospital discharge after CPR among acute cerebrovascular patients, survival is lower than general inpatient populations. These findings synthesize the limited empirical basis for discussions about resuscitation among stroke patients, and highlight the need for more disease stratified reporting of outcomes after inpatient CPR.

2017

Khan, Muhib, Grayson L Baird, Roderick Elias, Joshua Rodriguez-Srednicki, Shadi Yaghi, Sandra Yan, Scott Collins, et al. (2017) 2017. “Comparison of Intracerebral Hemorrhage Volume Calculation Methods and Their Impact on Scoring Tools.”. Journal of Neuroimaging : Official Journal of the American Society of Neuroimaging 27 (1): 144-48. https://doi.org/10.1111/jon.12370.

BACKGROUND: Intracerebral hemorrhage (ICH) volumes are frequently used for prognostication and inclusion of patients in clinical trials. We sought to compare the original ABC/2 method and sABC/2, a simplified version with the planimetric method.

METHODS: We retrospectively reviewed admission head CT scans of consecutive ICH patients admitted to a single academic center from July 2012 to April 2013. We assessed ICH volume on the admission. In ABC/2 method, A = greatest hemorrhage diameter by CT, B = diameter perpendicular to A, C = the approximate number of CT slices with hemorrhage multiplied by the slice thickness. C is weighted by area as < 25%, 25-50%, or > 75%. However, in the sABC/2 method, C is the total number of cuts with ICH without any weighting. Bland-Altman plots were generated for both the ABC/2 and sABC/2 methods in comparison to the planimetric method.

RESULTS: One hundred thirty-five patients with spontaneous ICH were included in the final analysis. Bland-Altman analysis illustrated that both ABC/2 and sABC/2 were concordant with the planimetric method. ABC/2 had more bias than sABC/2 (47% vs. 5%, respectively) with no evidence of a linear trend. For differentiating a volume threshold of 30 mL, ABC/2 was less sensitive but more specific than sABC/2 (P < .0001). Concordance between planimetry, ABC/2, and sABC/2 was high, evidenced by most coefficients exceeding .90.

CONCLUSION: Simplified ABC/2 (sABC/2) method performs better than ABC/2 in calculating ICH volumes. Moreover, it is better in differentiating a volume threshold of 30 mL. These findings may have implications for outcomes prediction and clinical trials inclusion.