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.

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.



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.

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.

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.

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.


Sacchetti, Daniel C, Sandra C Yan, Bradford B Thompson, and Corey R Fehnel. (2017) 2017. “Insular Infarction in Subdural Hematoma: A Case Series and Pathophysiologic Review”. Journal of Clinical Neuroscience : Official Journal of the Neurosurgical Society of Australasia 39: 4-8.

Subdural hematoma (SDH) is among the most common conditions managed by neurologists and neurosurgeons. As SDH incidence rates increase, a wider spectrum of SDH related complications have become evident. We prospectively identified a series of three patients with similar patterns of ipsilateral insular diffusion weighted imaging (DWI) hyperintensity associated with subdural hematoma. Detailed chart review was performed, and cases are described in relation to anatomy and proposed pathophysiology of venous hypertension and arterial vasospasm. The DWI changes were evident in all cases where clinical deficits following SDH evacuation were out of proportion to computed tomography findings. Therefore SDH-associated insular infarction may be a marker of greater disease severity, and further study of management and outcomes is needed.

Miller-Patterson, Cameron, and Corey R Fehnel. (2017) 2017. “Pazopanib-Associated Posterior Reversible Encephalopathy Syndrome With Intracerebral Haemorrhage”. BMJ Case Reports 2017.

Pazopanib is a tyrosine kinase receptor antagonist used for renal cell carcinoma and soft tissue sarcoma that inhibits tumour growth and angiogenesis. A common side effect of pazopanib is hypertension. We report a case of a 69-year-old woman with clear cell renal cell carcinoma who developed a large right occipital intracerebral haemorrhage 3 weeks after initiating pazopanib. Although this was initially suspected to be a haemorrhagic metastasis, MRI revealed bi-occipital oedema, supporting a diagnosis of posterior reversible encephalopathy syndrome (PRES). A craniectomy was required. Immunohistochemical stains for renal cell carcinoma antigen, CA IX and PAX8 were negative. This case suggests that PRES and intracerebral haemorrhage may result from pazopanib use and are important complications to consider prior to initiating this agent.

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.

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.

Fehnel, Corey R, Yoojin Lee, Linda C Wendell, Bradford B Thompson, Stevenson Potter, and Vincent Mor. (2017) 2017. “Utilization of Long-Term Care After Decompressive Hemicraniectomy for Severe Stroke Among Older Patients”. Aging Clinical and Experimental Research 29 (4): 631-38.

BACKGROUND: While clinical trial data support decompressive hemicraniectomy (DHC) as improving survival among patients with severe ischemic stroke, quality of life outcomes among older persons remain controversial.

AIMS: To aid decision-making and understand practice variation, we measured long-term outcomes and patterns of regional variation for a nationwide cohort of ischemic stroke patients after DHC.

METHODS: Medicare fee-for-service ischemic stroke cases over age 65 during the year 2008 were used to create a cohort followed for 2 years (2009-2010) after stroke and DHC procedure. Rates of mortality, acute hospital readmission, and long-term care (LTC) utilization were calculated. Multiple logistic regression was used to identify individual predictors of institutional LTC. Regional variation in DHC was calculated through aggregation and merging with the state-level data.

RESULTS: Among 397,503 acute ischemic stroke patients, 130 (0.03 %) underwent DHC. Mean age was 72 years, and 75 % were between the ages of 65 and 74. Mortality was highest (38 %) within the first 30 days. At 2 years, 59 % of the original cohort had died. The 30-day rate of acute hospital readmission was 25 %. Among survivors, 75 % returned home 1 year after index stroke admission. States with higher per capita health expenditures were associated with wider variation in utilization of DHC.

CONCLUSIONS: There is a high rate of mortality among older stroke patients undergoing DHC. Although most survivors of DHC are not permanently institutionalized, there is wide variation in utilization of DHC across the USA.

Halvorson, Karin, Sameer Shah, Corey Fehnel, Bradford Thompson, Stevenson Potter, Mitchell Levy, and Linda Wendell. (2017) 2017. “Procalcitonin Is a Poor Predictor of Non-Infectious Fever in the Neurocritical Care Unit”. Neurocritical Care 27 (2): 237-41.

BACKGROUND: Fever is a common occurrence in the Neurocritical Care Unit (NCCU). It is reported that up to 50 % of these fevers are associated with a non-infectious source. As this is a diagnosis of exclusion, a complete fever evaluation must be done to rule out infection. Procalcitonin (PCT) has been identified as a possible biomarker to distinguish infectious from non-infectious etiologies of fever. We hypothesized that PCT could be used as a predictor of infectious fever in febrile patients with intracranial hemorrhage admitted to the NCCU.

METHODS: A prospective observational cohort of patients admitted to a 12-bed NCCU in a tertiary-care university hospital from January 1, 2014, to October 1, 2014, was studied. Patients with intracranial hemorrhage (aneurismal subarachnoid hemorrhage, traumatic brain injury, intracerebral hemorrhage, or non-traumatic subdural hemorrhage) and fever defined as ≥101.4 °F were included. All patients had a urinalysis, chest X-ray, two sets of blood cultures, and PCT as part of their fever evaluation. Patients also had urine, sputum, CSF cultures, and Clostridium difficile toxin PCR as clinically indicated. Patients with incomplete fever evaluations were excluded.

RESULTS: Seventy-three patients met inclusion criteria: 36 had infections identified and 37 did not. Type of intracranial hemorrhage was similar between groups. For those with identified infection, median PCT was 0.15 ng/mL (IQR 0.06-0.5 ng/mL). For those without identified infection, median PCT was 0.09 ng/mL (IQR 0.05-0.45 ng/mL), p = 0.30. Analyzing subgroups of intracranial hemorrhage patients revealed no group with a significant difference in PCT values. Patients with identified infection did have higher white blood cell counts (median 14.1 × 109/L (11.6-17.4 × 109/L) compared to those without identified infection 12 × 109/L (9.9-14.1 × 109/L), p = 0.02.

CONCLUSION: Among patients with intracranial hemorrhage, PCT did not differentiate infectious fever from non-infectious fever.