159 Stroke-Alert Activation in Patients With a Diagnosis Other Than Stroke

Research Forum Abstracts relative positive and negative predictive values for subarachnoid hemorrhage were calculated for the different ranges of red blood cells in tube 3. A second assessment was made based on red blood cell clearance from tube 1 to 3. Xanthochromia and the mean percentage of red blood cell clearance were also calculated for both groups and relative negative and positive predictive values were calculated for the different ranges of clearance. Continuous variables were analyzed using Student’s t-test and p values were calculated. Results: A total of 2315 patients were screened; 506 had cerebrospinal fluid red blood cell counts and were included in the study. Of these, 474 (94%) had no evidence of aneurysm after angiography and determined to be traumatic taps; subarachnoid hemorrhage was confirmed in 32 (6%). Traumatic taps had a mean of 4,968 red blood cell counts in tube 1 and 499 in tube 3. Mean cerebrospinal fluid red blood cell counts for the subarachnoid hemorrhage group were 62,978 in tube 1 and 78,072 in tube 3. The overall sensitivity of sequential red blood cell count in detecting subarachnoid hemorrhage was 50%; the specificity was 71%. The range of values in tube 3 for the subarachnoid hemorrhage group was 120 to 521,500 red blood cell count, suggesting that there is not a cerebrospinal fluid red blood cell count cutoff value at which one can safely exclude a subarachnoid hemorrhage. The sensitivity and specificity of xanthochromia for detecting subarachnoid hemorrhage was 59% and 99% respectively. Conclusion: The results of this study indicate that there is not a cerebrospinal fluid red blood cell count cutoff value at which one can safely exclude subarachnoid hemorrhage. In addition, the presence of xanthrochromia had a significantly higher specificity than the sequential red blood cell count count in detecting subarachnoid hemorrhage.

157

Clinical Feature of Patients With False Negative Diffusion-weighted MR Finding in Acute Ischemic Stroke: A Pilot Study

Cho H, Moon S, Lee S, Choi S, Hong Y, Han K/Korea University Ansan Hospital, Ansan, Korea, Republic of; Korea University College of Medicine, Seoul, Korea, Republic of; Korea University College of Medicine, Seoul, Korea, Democratic People’s Republic of

Study Objectives: Diffusion-weighted MRI (DWI) has advantages for the assessment of acute stroke. However, DWI finding in acute ischemic stroke may have been false negative on initial study. The purpose of this study was to estimate the rate of initial false-negative DWI studies in acute ischemic stroke and to identify the characteristics of patients being false-negative DWI. Methods: We conducted a retrospective chart review study in urban tertiary teaching hospital. Acute ischemic stroke patients within 6 hours after stroke onset from January 2010 to June 2011 were enrolled in this study. Ninety-five patients were finally diagnosed with acute stroke. Cases of negative initial DWI finding with an ischemic lesion visible on follow-up MR studies were analyzed in times between onset of symptoms and initial DWI, NIHSS, location of ischemic stroke lesion. Results: Among 95 stroke patients, 70 patients were acute ischemic stroke and 25 were hemorrhagic stroke. Among 70 patients, 56 patients were performed with DWI and 14 were investigated with computed tomography. Finally, 56 patients were enrolled in this study. We found 7 cases (12.5%) of false negative initial DWI studies. The initial false negative DWI group had shorter time from onset of symptom to initial DWI compare to initial positive DWI group with significance (99.1 min:197.8 min, p⫽0.011). Brain stem lesions were more in false negative group (57.1%:16.3%, p⫽0.032). The National Institutes of Health Stroke Scale (NIHSS) were lower in false negative group but not statistically significant (2.86:7.98, p⫽0.091). Conclusion: A false-negative DWI study is not uncommon acute ischemic stroke. Stoke suspected patients should not be ruled out on the basis of negative DWI, especially suspected low NIHSS, earlier onset of symptoms.

158

Utility Cranial Nerve Testing Obtained in the Emergency Department as Early Predictors of Neurologic Outcome Post Cardiac Arrest

Kessler J, Medado P, Cloyd J, Wilburn J, Engle T, O’Neil B/Wayne State University, Detroit, MI

Study Objective: Severe neurologic deficit is a major morbidity in patients who survive cardiac arrest. Early prognostication of neurologic function after survival from cardiac arrest in the emergency department (ED) would aid in resource allocation and potentially reduce emotional stress. Lack of cranial nerve findings post-resuscitation is often thought to portend a poor neurologic outcome.

Volume , .  : October 

Methods: We obtained cranial nerve testing in the ED on adult patients post cardiac arrest with ROSC being admitted to the hospital. Our convenience sample yielded 39 patients and informed consent was obtained from their legal authorized representative. Cranial nerve testing was conducted after initial ROSC in the ED. We collected dichotomous present/absent data on 9 neurological categories: pupillary reflex, corneal reflex, doll’s eye, response to pain, myoclonus, seizure activity, spontaneous respirations, cold caloric response and response to verbal stimuli. Neurological outcome was determined using Glasgow-Pittsburgh Outcome Categorization of Brain Injury Cerebral Performance Categories (CPC) at hospital discharge. CPC of 1-2 was dichotomized as a “good” outcome and 3-5 as “bad. Data was analyzed by Chi square analysis. Results: Out of 39 patients with ROSC after cardiac arrest 30 patients had primary outcome of 3-5 on CPC at discharge with 9 having CPC of 1-2. Of all the neurologic parameters only the presence of the corneal reflex, pupillary response and response to pain predicted good outcome. Corneal reflex was present in 66.7% of patients with a CPC 1-2, and was absent 86.2% CPC 3-5 (p ⫽ 0.007). The pain response was present in 77.8% of patients with CPC 1-2, and was absent in 89.7% CPC 3-5, (p⬍0.001). Pupillary reflex was also present in 66.7% in good outcome absent in 80%, (p ⫽ 0.025). Conclusion: In our small study the most prognostic tests were the presence of response to pain, corneal reflex and papillary response. However, the absence of these reflexes still occurred in up to 22 to 33% of patients with a good outcome.

159

Stroke-Alert Activation in Patients With a Diagnosis Other Than Stroke

Paolo WF, Schreffler S, Lavoie T, Wojcik S, Grant W/SUNY Upstate, Syracuse, NY

Study Objectives: The advent of the time-sensitive treatment of cerebral vascular accident (CVA) with tissue plasminogen activator accompanied by the regionalization of stroke care has altered the way emergency physicians approach this devastating disease. Patients presenting to an emergency department (ED) with a possible CVA undergo a rapid evaluation by an ED physician during which time the physician may choose to initiate a CVA-alert that immediately activates the CVA team within the hospital. We intend to determine the outcomes of patients in which a CVA alert was activated who were subsequently found to have a diagnosis other than CVA. Primary data analysis was performed to determine the hospitalization and patient course as measured by dispositional results (ie nursing home referral, death) when compared to patients with a diagnosis of CVA. In addition, the nature and frequency of CVAmimics, NIH Stroke Scale (NIHSS) as a surrogate marker for presentation severity, and patient demographics were analyzed in an effort to elucidate their potential effects on erroneous CVA alert activation. Methods: This is an institutional review board-exempt, retrospective database study, at a tertiary referral New York State designated stroke center. As per protocol, all stroke alerts are determined by the treating ED physician and entered into an internal database where patient demographics, time, neuroimaging, patient outcomes, and dispositions are kept. All CVA alerts over the 5-year time period from 2005-2010 were analyzed using a standard Microsoft Excel spreadsheet. Patients were excluded only if the initial presentation of their CVA did not occur primarily at our institution and were transferred to the emergency department. All data were analyzed using IBM-SPSS Statistics 19™. Results: Over the course of 5 years there were a total of 232 CVA alerts out of which 83 (35.7%) were ultimately given an alternative diagnosis. Baseline demographics demonstrated an equal frequency of men and woman in each group (␹2⫽3.32, p⫽0.075); however, the CVA group was significantly older 70.7⫾14 versus 62.1⫾18 (t⫽3.65, p⬍0.001). Table 1 demonstrates the frequencies and diagnosis other than CVA designated upon discharge. Calculated NIHSS for the non CVA group was 4.62⫾5.96 and 6.03⫾5.72 for the CVA group (t⫽1.25, p⫽0.214). Those ultimately diagnosed as having a CVA were more likely to be sent to a rehab facility (20 versus 0), expire (13 versus 2), or a sent to a nursing home (12 versus 7) than the group with a diagnosis other than CVA (␹2⫽17.8, p⬍0.001). Conclusions: Patients without a subsequent diagnosis of CVA were less likely to have a deleterious outcome than those with a confirmed diagnosis of CVA demonstrating the relative safety of inaccurate CVA activation. Patients without CVA tended to be younger and most commonly were diagnosed with seizure, migraine, or cardiac disease.

Annals of Emergency Medicine S57

Research Forum Abstracts Conclusion: Analysis revealed that a qEEG discriminant score for prediction of positive head CT was weakly correlated with post-concussion syndrome at 7 and 45 days.

161

Emergency Department Patient Perception of Stroke

Benaron D, Castillo E, Vilke G, Guluma K/University of California, San Diego, La Jolla, CA; University of California, San Diego, La Jolla, CA

160

Utility of Hand-held EEG Device in Predicting Postconcussion Syndrome in Patients With Closed Head Injury

Mika V, Ayaz SI, Robinson D, Medado P, Pearson C, Millis S, O’Neil B/Wayne State University, Detroit, MI

Background: In the year 2000, loss of productivity and direct medical costs from traumatic brain injury (TBI) totaled $60 billion in the United States. From 2002 to 2006, an increase of 14.4% in TBI-related emergency department visits resulted in an increase of the direct and indirect cost of TBI. According to the CDC, 80% of TBI patients are treated and discharged from the ED. The number of patients that continue to have symptoms after ED discharge is difficult to estimate. Patients who have persistent symptoms after suffering from a mild traumatic brain injury (mTBI) or concussion are said to suffer from post-concussion syndrome. The patients who are destined for post-concussion syndrome are difficult to identify in the ED as there are no good predictive instruments. Study Objective: The objective of this study is to determine the ability of a handheld EEG acquisition device to predict post-concussion syndrome after a closed head injury. Methods: A total of 74 patients presenting to the ED after closed head trauma between the ages of 18 and 80, and a GCS score of 9-15, with a negative head CT were enrolled in this prospective cohort study at 2 academic emergency departments. An 8 Lead EEG was obtained and a quantitative electroencephalography (qEEG) discriminant score previously validated for acute CT pathology was tested for prediction of post-concussion syndrome. Post-concussion syndrome was defined as a score of greater than 12 on the Concussion Symptom Inventory at 7 and/or 45 day follow up. Logistic regression was used to classify and predict post-concussion syndrome against the qEEG discriminant score of the device. Results: Of the 74 negative head CT patients included in the study, 44% of patients with post-concussion syndrome (CSI ⬎12) were identified correctly at 1 week and 32% of patients with post-concussion syndrome were identified correctly at 45 days by this qEEG discriminant score. Discussion: The previously defined abnormality index cut off of 65 based on a ROC curve analysis of earlier data was a poor discriminator of post-concussion syndrome. Additionally, multiple clinical evaluations and neuropsych testing have been performed on these patients with post-concussion syndrome and all have poor predictive value. Since post-concussive syndrome involves neuronal dysfunction without CT findings of intracranial injury, a hand-held qEEG device with a real time algorithm has theoretic potential as a clinically useful predictor. A larger study would allow identification of a more precise cut off for this syndrome.

S58 Annals of Emergency Medicine

Background: Stroke is one of the top ten leading causes of disability in the United States. Much of the disability associated with stroke can be prevented by adequate treatment with t-PA within 3 hours of initial stroke symptoms but only a small percentage of patients are eligible to receive therapy, largely due to a delayed presentation for care. Study Objectives: The goal of this project is to gain a better understanding of the factors potentially influencing a patient’s decision to pursue timely care for acute stroke symptoms. Methods: We conducted a prospective, multi-center cross sectional survey of English-speaking patients presenting to 2 EDs with a combined census of 62,000. One hospital is an urban, academic teaching hospital (Level 1 trauma center) with an annual census of approximately 38,000 visits. The other hospital is a suburban community hospital with an annual census of approximately 24,000 visits. Participants were presented with second-person vignettes of a patient experiencing stroke. The vignettes alter timing (time of day, day of week) of the stroke, the nature of stroke symptoms and geographical location (home, public, work) of the stroke. The study subjects are then asked to rank choices, A) calling 911 wait a couple of hours and get a ride to the ED if the symptoms do not improve, B) having someone drive them to an ED immediately, C) going to a community clinic, D) calling 911, E) going to a primary care doctor the next day, or F) calling a health care hotline for advice. Additional questions include: 1) demographic data (age, sex, income, race/ ethnicity and education level), 2) past and current medical conditions, and 3) knowledge of stroke symptoms. Informed consent and data collection was, and continues to be, collected by trained research associates. Means and frequencies were used to describe participants. Results: Thus far 241 surveys have been completed. When provided a list of typical stroke symptoms, the percentages of participants identifying dizziness, severe headache, problems with vision, slurred speech, weakness and numbness as a stroke symptom were 82%, 79%, 80%, 93%, 97% and 94% respectively. Preliminary data is showing that, depending on the vignette, an overwhelming majority (73%-90%) of patients chose to dial 911 as either their most likely, or second most likely responses when faced with stroke. The same trend was found when patient were grouped by sex and race. Conclusion: Regardless of time, place or stroke symptoms, patients overwhelmingly decide to dial 911 immediately when faced with stroke. This highlights the fact that a majority of patients do recognize common stroke symptoms, and are likely to appropriately access emergent treatment when these symptoms arise.

162

Can Quantitative Brain Electrical Activity Aid in the Triage of Mild Traumatic Brain Injured Patients?

Ayaz SI, Parsons D, Robinson D, Medado P, O’Neil B/Wayne State University, Detroit, MI

Background: The incidence of US emergency department (ED) visits for traumatic brain injury (TBI) exceeds 1,000,000 cases per year, with the vast majority classified as mild (mTBI). Current decision rules, such as the New Orleans Criteria (NOC) is utilized as a decision tool before these patients get a head computed tomography (CT) scan. Approximately 70% of these patients have a negative CT scan. Study Objective: To evaluate the use of quantified brain electrical activity in the initial triage of ED mTBI patients as compared to the NOC. Methods: 88 patients between the ages of 18 to 80, who reported to the ED with head trauma and received head CT, were included in the study. Utilizing a hand-held device for EEG acquisition and analysis, data was collected from frontal leads. Algorithmic analysis of brain electrical activity was stored and processed off-line to generate a discriminant score. Only a discriminant score of 17 or above was included in the study because it was considered to have high probability in predicting head CT positive in this population. This discriminant was derived from a selected subset of qEEG features which are extracted from the artifact-free EEG and entered into the algorithm. The threshold was computed from the ROC curve for the performance of

Volume , .  : October 