Background Therapeutic hypothermia is commonly used in comatose survivors’ post-cardiopulmonary resuscitation (CPR). It is unknown whether outcome predictors perform accurately after hypothermia treatment. Methods Post-CPR comatose survivors were prospectively enrolled. Six outcome predictors [pupillary and corneal reflexes, motor response to pain, and somatosensory-evoked potentials (SSEP) >72 h; status myoclonus, and serum neuron-specific enolase (NSE) levels <72 h] were systematically recorded. Poor outcome was defined as death or vegetative state at 3 months. Patients were considered “sedated” if they received any sedative drugs ≤12 h prior the 72 h neurological assessment. Results Of 85 prospectively enrolled patients, 53 (62%) underwent hypothermia. Furthermore, 53 of the 85 patients (62%) had a poor outcome. Baseline characteristics did not differ between the hypothermia and normothermia groups. Sedative drugs at 72 h were used in 62 (73%) patients overall, and more frequently in hypothermia than in normothermia patients: 83 versus 60% (P = 0.02). Status myoclonus <72 h, absent cortical responses by SSEPs >72 h, and absent pupillary reflexes >72 h predicted poor outcome with a 100% specificity both in hypothermia and normothermia patients. In contrast, absent corneal reflexes >72 h, motor response extensor or absent >72 h, and peak NSE >33 ng/ml <72 h predicted poor outcome with 100% specificity only in non-sedated patients, irrespective of prior treatment with hypothermia. Conclusions Sedative medications are commonly used in proximity of the 72-h neurological examination in comatose CPR survivors and are an important prognostication confounder. Patients treated with hypothermia are more likely to receive sedation than those who are not treated with hypothermia.

Objective-Outcome prediction is challenging in comatose post-cardiac arrest survivors. We assessed the feasibility and prognostic utility of brain diffusion-weighted MRI (DWI) during the first week.Corresponding Author Christine AC Wijman, MD, PhD, Stanford Stroke Center, 701 Welch Road, B325, Palo Alto, CA 94304, Fax: (650) Tel: (650) NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author ManuscriptMethods-Consecutive comatose post-cardiac arrest patients were prospectively enrolled. MRI data of patients who met predefined specific prognostic criteria were used to determine distinguishing ADC thresholds. Group 1: death at 6 months and absent motor response or absent pupillary reflexes or bilateral absent cortical responses at 72 hours, or vegetative at 1 month. Group 2A: Glasgow outcome scale (GOS) score of 4 or 5 at 6 months. Group 2B: GOS of 3 at 6 months. The percentage of voxels below different apparent diffusion coefficient (ADC) thresholds was calculated at 50 × 10 −6 mm 2 /sec intervals.Results-Overall, 86% of patients underwent MR imaging. Fifty-one patients with 62 brain MRIs were included in the analyses. Forty patients met the specific prognostic criteria. The percentage of brain volume with an ADC value below 650-700 × 10 −6 mm 2 /sec best differentiated between group 1 and groups 2A and 2B combined (p<0.001), while the 400-450 × 10 −6 mm 2 /sec threshold best differentiated between groups 2A and 2B (p=0.003). The ideal time window for prognostication using DWI was between 49 to 108 hours after the arrest. When comparing MRI in this time window with the 72 hour neurological examination MRI improved the sensitivity for predicting poor outcome by 38% while maintaining 100% specificity (p=0.021).Interpretation-Quantitative DWI in comatose post-cardiac arrest survivors holds great promise as a prognostic adjunct.Approximately 350,000 cardiac arrests occur annually in the United States1. Up to half of these patients are successfully resuscitated. In the past, only 10% to 30% of comatose postcardiac arrest patients had good functional recovery. These numbers will likely improve with the increasing use of therapeutic hypothermia2 , 3.Post-cardiac arrest brain injury is a common cause of morbidity and mortality. Many comatose post-cardiac arrest patients die or survive with severe disability after a prolonged intensive care unit stay associated with a tremendous cost burden4 , 5. Conversely, the potential for premature withdrawal of life support from patients who may have a chance of functional recovery represents an additional ethical dilemma. Thus, early accurate identification of patients who have no likelihood of meaningful recovery is a very important health care issue.Although several prognostic variables have been studied in comatose post-cardiac arrest patients, the currently accepted variables (neurological examination, neurophysiologic tests, and serum markers) have substantive limitations. First, they identify only a subset of poor outcome patients with high specificity. Se...

Background and Purpose-Agreement between physicians to define the likelihood of a transient ischemic attack (TIA) remains poor. Several studies have compared neurologists with nonneurologists, and neurologists among themselves, but not between fellowship-trained stroke neurologists. We investigated the diagnostic agreement in 55 patients with suspected TIA. Methods-The history and physical examination findings of 55 patients referred to the Stanford TIA clinic from the Stanford emergency room were blindly reviewed by 3 fellowship-trained stroke neurologists who had no knowledge of any test results or patient outcomes. Each patient's presentation was rated as to the likelihood that the presentation was consistent with TIA. We used 3 different scales (2-, 3-, and 4-point scales) to define TIA likelihood. We assessed global agreement between the raters and evaluated the biases related to individual raters and scale type. Results-The agreement between fellowship-trained stroke neurologists remained poor regardless of the rating system used and the statistical test used to measure it. Difference in rating bias among all raters was significant for each scale: Pϭ0.001, 0.012, and Ͻ0.001. In addition, for each reviewer, the rate of labeling an event an "unlikely TIA" progressively decreased with the number of points that composed the scale. Conclusions-TIA remains a highly subjective diagnosis, even among stroke subspecialists. The use of confirmatory testing beyond clinical judgment is needed to help solidify the diagnosis. Caution should be used when diagnosing an event as a possible TIA. (Stroke. 2010;41:1367-1370.)