Transcranial Doppler during the first week after cardiac arrest and association with 6-month outcomes.

Background: Early prediction of outcomes in comatose patients after out-of-hospital cardiac arrest is challenging. Prognostication tools include clinical examination, biomarkers, and neuroradiological and neurophysiological tests. We studied the association between transcranial Doppler (TCD) and the outcome. Methods: This was a pre-defined sub-study of the prospective observational Norwegian Cardiorespiratory Arrest Study. Patients underwent standardized post-resuscitation care, including target temperature management (TTM) to 33°C for 24 h. TCD was performed at days 1, 3, and 5-7. The primary endpoint was cerebral performance category (CPC) at 6 months, dichotomized into good (CPC 1-2) and poor (CPC 3-5) outcomes. We used linear mixed modeling time-series analysis. Results: Of 139 TCD-examined patients, 81 (58%) had good outcomes. Peak systolic velocity in the middle cerebral artery (PSV) was low during TTM (Day 1) and elevated after rewarming (Day 3). Thereafter, it continued to rise in patients with poor, but normalized in patients with good, outcomes. At days 5-7, PSV was 1.0 m/s (95% CI 0.9; 1.0) in patients with good outcomes and 1.3 m/s (95% CI 1.1; 1.4) in patients with poor outcomes (p < 0.001). Conclusion: Elevated PSV at days 5-7 indicated poor outcomes. Our findings suggest that serial TCD examinations during the first week after cardiorespiratory arrest may improve our understanding of serious brain injury.

Late awakening, prognostic factors and long-term outcome in out-of-hospital cardiac arrest - results of the prospective Norwegian Cardio-Respiratory Arrest Study (NORCAST).

BACKGROUND: Outcome prediction after out-of-hospital cardiac arrest (OHCA) may lead to withdrawal of life-sustaining therapy if the prognosis is perceived negative. Single use of uncertain prognostic tools may lead to self-fulfilling prophecies and death. We evaluated prognostic tests, blinded to clinicians and without calls for hasty outcome prediction, in a prospective study. METHODS: Comatose, sedated TTM 33-treated OHCA patients of all causes were included. Clinical-neurological/-neurophysiological/-biochemical predictors were registered. Patients were dichotomized into good/poor outcome using cerebral performance category (CPC) six months and > four years post-arrest. Prognostic tools were evaluated using false positive rates (FPR). RESULTS: We included 259 patients; 49 % and 42 % had good outcome (CPC 1-2) after median six months and 5.1 years. Unwitnessed arrest, non-shockable rhythms, and no-bystander-CPR predicted poor outcome with FPR (CI) 0.05 (0.02-0.10), 0.13 (0.08-0.21), and 0.13 (0.07-0.20), respectively. Time to awakening was median 6 (0-25) days in good outcome patients. Among patients alive with sedation withdrawal >72 h, 49 % were unconscious, of whom 32 % still obtained good outcome. Only absence of pupillary light reflexes (PLR) -and N20-responses in somato-sensory evoked potentials (SSEP), as well as increased neuron-specific enolase (NSE) later than 24 h to >80 µg/L, had FPR 0. Malignant EEG (burst suppression/epileptic activity/flat) differentiated poor/good outcome with FPR 0.05 (0.01-0.15). CONCLUSION: Time to awakening was over six days in good outcome patients. Most clinical parameters had too high FPRs for prognostication, except for absent PLR and SSEP-responses >72 h after sedation withdrawal, and increased NSE later than 24 h to >80 µg/L.

Middle Cerebral Artery Pulsatility Index is Associated with Cognitive Impairment in Lacunar Stroke.

BACKGROUND AND PURPOSE: Pulsatility index (PI) of the middle cerebral artery is postulated to reflect the vascular resistance in the artery distal of the probe, and has been reported to increase in small vessel disease, diabetes mellitus, ageing, and dementia. Lacunar infarcts are considered to be related to cognitive impairment. We therefore conducted a study to assess the association between cognitive impairment and PI in patients with a lacunar infarct. METHODS: Consecutive patients presenting with an acute lacunar syndrome who were admitted to the stroke unit were enrolled. The patients were examined with Doppler ultrasonography of the intracranial arteries, and the PI of the middle cerebral artery was recorded. Cognitive function was evaluated by mini-mental state examination (MMSE), clock drawing test, and trail making test (TMT) A and B. RESULTS: Among the 113 patients included, 85 patients had an acute lacunar infarct and 28 had one or more nonlacunar infarcts. The mean PI was 1.46 (SD = .33). PI was significantly (P < .05) associated with MMSE, TMT A and TMT B in patients with lacunar infarct, even after adjustment for multiple patient characteristics (age, sex, prestroke hypertension, smoking, previous stroke, and diabetes). CONCLUSIONS: PI was associated with the cognitive performance in patients with lacunar infarcts and a lacunar syndrome. An elevated PI may be related to impairment in several cognitive domains. These findings suggest that transcranial Doppler ultrasonography could be an adjunct tool for early diagnosis of cognitive impairment after stroke.

Blood pressure differences between patients with lacunar and nonlacunar infarcts.

BACKGROUND: Elevated blood pressure is frequently seen in acute stroke, and patients with lacunar and nonlacunar infarcts may have different underlying mechanisms for increase in blood pressure. The impact of hypertension as a risk factor may also vary. The aims of the present study were to investigate blood pressure in patients presenting with lacunar syndromes but with different anatomical subtypes of stroke, to explore the impact of subtype on blood pressure, and to identify stroke-related factors associated with hypertension. METHODS: Consecutive patients presenting with an acute lacunar syndrome were enrolled. Patients were classified into a lacunar or nonlacunar group based on radiological verified infarcts. Blood pressure was measured. Between-group differences were analyzed by χ2-test, t-test, and Mann-Whitney U test, as appropriate. We performed linear regression to analyze the association between blood pressure and lacunar infarct, and multiple linear regression to adjust for other covariates. RESULTS: One hundred thirteen patients were included. Seventy five percent had lacunar and 25% nonlacunar infarcts. There was no significant difference in clinical severity between the two groups. In the linear regression model, we found a significant association between blood pressure and lacunar infarct. No other factor was significantly associated with blood pressure in the two groups. CONCLUSIONS: Lacunar infarcts may be independently associated with higher blood pressure compared to nonlacunar infarcts with the same clinical severity. Blood pressure differences between different subtypes of stroke may not be related to clinical severity but to the underlying cause of stroke.

Diagnostic accuracy and risk factors of the different lacunar syndromes.

BACKGROUND: The lacunar syndrome is characterized by pure motor, pure sensory, or sensorimotor hemisymptoms without cortical deficits. It may be less predictable for a lacunar infarct (LI) than previously believed. The aims of the present study were to evaluate the diagnostic accuracy of the different lacunar syndromes and investigate factors associated with acute LI on diffusion-weighted imaging (DWI). METHODS: Consecutive patients presenting with an acute lacunar syndrome who were admitted to the stroke unit were enrolled. The patients were examined clinically and underwent magnetic resonance imaging. The sensitivity and specificity of the different lacunar syndromes were assessed using DWI as reference test, and we estimated positive and negative predictive values. Patients were divided into a LI group and a group without LI. Between-group differences were analyzed by χ(2) test, t test, and Mann-Whitney U test, as appropriate. Logistic regression was performed to analyze predictors of LI. Candidate variables were pure motor syndrome, age, gender, hypertension, precerebral or intracerebral stenosis, atrial fibrillation, diabetes, coronary heart disease, and smoking. RESULTS: Eighty-six patients with lacunar syndrome underwent DWI. The positive predictive value of the lacunar syndrome was 65.1% and 75% for the pure motor syndrome. Of the candidate variables, only pure motor syndrome and male gender had significant associations with LI on imaging. CONCLUSIONS: The clinical diagnosis of patients with lacunar syndromes is inaccurate, especially among patients with sensorimotor syndrome. DWI is mandatory for obtaining an accurate diagnosis of the infarct.