Utility of perfusion-weighted CT imaging in acute middle cerebral artery stroke treated with intra-arterial thrombolysis: prediction of final infarct volume and clinical outcome.

BACKGROUND AND PURPOSE: The goal of this study was to evaluate the utility of perfusion-weighted CT (PWCT) in predicting final infarct volume and clinical outcome in patients with acute middle cerebral artery (MCA) stroke. METHODS: Twenty-two consecutive patients with MCA stem occlusion who underwent intra-arterial thrombolysis within 6 hours of stroke onset had noncontrast CT and CT angiography with whole-brain PWCT imaging before treatment. Infarct volumes were computed from the initial PWCT and follow-up scans; clinical outcome was measured with the modified Rankin scale. RESULTS: Initial PWCT lesion volumes correlated significantly with final infarct volume (P=0.0002) and clinical outcome (P=0.01). For the 10 patients with complete recanalization, the relationship between initial and final lesion volume was especially strong (R(2)=0.94, P<0.0001, slope of regression line=0.92). For those without complete recanalization, there was progression of lesion volume on follow-up imaging (R(2)=0.50, P=0.01, slope of regression line=1.61). All patients with either initial PWCT lesion volumes >100 mL or no recanalization had poor outcomes (Rankin scores, 4 to 6). Mean admission NIH Stroke Scale scores and mean lesion volumes in the poor outcome group were significantly different compared with the good or fair outcome (Rankin scores, 0 to 3) group (21+/-4 versus 17+/-5, P=0.05, and 106+/-79 versus 29+/-37 mL, P=0.01). Patients with initial volumes <100 mL and partial or complete recanalization all had good (Rankin scores, 0 to 2) or fair (Rankin score, 3) outcomes. CONCLUSIONS: Lesion volumes on admission PWCT images approximate final infarct volume for patients with early complete recanalization of MCA stem occlusion. For those without complete recanalization, there is subsequent enlargement of lesion volume on follow-up. Initial PWCT lesion volumes also have predictive value; volumes >100 mL are associated with a poor clinical outcome. In these highly selected patients, initial PWCT lesion volume was a stronger predictor of clinical outcome than was initial NIH Stroke Scale score.

Clinical characteristics of pathologically proved cholesterol emboli to the brain.

Cholesterol emboli (CE) to the brain are an important but often unrecognized cause of stroke. The authors reviewed 29 cases of brain CE identified on autopsy. Most patients were elderly (mean age, 74 years) and presented with encephalopathy and acute renal failure. Ten patients developed symptoms spontaneously, 19 after a procedure involving manipulation of the aorta. Brain imaging revealed multiple, small ischemic lesions and border zone infarcts in 11 of 17 patients. Pathology in most patients demonstrated multiple CE mixed with emboli of other types.

A pilot study of drug-induced hypertension for treatment of acute stroke.

The aim of this pilot study was to determine whether the use of induced hypertension in acute stroke is feasible and associated with neurologic improvement. Phenylephrine was used to raise the systolic blood pressure in patients with acute stroke by 20%, not to exceed 200 mmHG: Of 13 patients treated, 7 improved by 2 points on the NIH Stroke SCALE: No systemic or neurologic complications were seen. The authors conclude that induced hypertension in acute stroke is feasible and likely safe and can improve the neurologic examination in some patients.

Fever in subarachnoid hemorrhage: relationship to vasospasm and outcome.

OBJECTIVE: To investigate the causes of fever in subarachnoid hemorrhage (SAH) and examine its relationship to outcome. BACKGROUND: Fever adversely affects outcome in stroke. Patients with SAH are at risk for cerebral ischemia due to vasospasm (VSP). In these patients, fever may be both caused by, and potentiate, VSP-mediated brain injury. METHODS: The authors prospectively studied patients admitted to a neurologic intensive care unit with nontraumatic SAH, documenting Hunt-Hess grade, Fisher group, Glasgow Coma Score, bacterial culture data, daily transcranial Doppler mean velocities, and maximum daily temperatures. Patients were classified as febrile (temperature above 38.3 degrees C for at least 2 consecutive days) or afebrile (no fever or isolated episodes of temperature above 38.3 degrees C). VSP was verified by either transcranial Doppler or angiographic criteria. Rankin scale scores on discharge were dichotomized into good (0 to 2) or poor (3 to 6) outcomes. RESULTS: Ninety-two consecutive patients were studied. Thirty-eight patients were classified as febrile. No source for infection was found in 10 of 38 (26%) patients. In a multivariate analysis, three variables independently predicted fever occurrence: ventriculostomy (OR, 8.5 [CI, 2.4 to 29.7]), symptomatic VSP (OR, 5.0 [CI, 1.03 to 24.5]), and older age (OR, 1.75 per 10 years [CI, 1.02 to 3.0]). Poor outcome was related to fever (OR, 1.4 per each day febrile [CI, 1.1 to 1.88]), older age (OR, 1.64 per 10 years [CI, 1.04 to 2.58]), and intubation (OR, 21.8 [CI, 5.6 to 84.5]). CONCLUSION: Fever in SAH is associated with vasospasm and poor outcome independently of hemorrhage severity or presence of infection.

Is IV tissue plasminogen activator beneficial in patients with hyperdense artery sign?

OBJECTIVE: To evaluate the effect of IV recombinant tissue plasminogen activator (rt-PA) in patients with hyperdense artery sign (HAS) on initial CT scan. METHODS: The authors determined the differential effect of IV rt-PA (0.9 mg/kg) in patients with HAS by testing the interaction of rt-PA and HAS in a logistic regression model after adjusting for age, sex, initial NIH Stroke Scale score (NIHSSS), time to randomization, systolic blood pressure, serum glucose, body temperature, and rt-PA in 616 patients treated within 3 hours of symptom onset. Outcomes evaluated included intracranial hemorrhage, modified Rankin scale (mRS) 0-1, Barthel Index (BI) of > or = 95, Glasgow Outcome Scale (GOS) of 0-1, NIHSSS 0-1, and death at 90 days. RESULTS: HAS was detected on the initial CT scan in 91 (15%) of the 616 patients by an independent neuroradiologist. Significantly lower rates of mRS 0-1, BI > or = 95, GOS of 0-1, or NIHSSS 0-1 at 90 days were observed among patients with HAS. IV rt-PA significantly increased the rates of mRS 0-1, BI > or = 95, GOS of 0-1, or NIHSSS 0-1 at 90 days after adjusting for potential confounders without any significant modifying effect (interaction) of HAS. Among the 91 patients with HAS, rt-PA use demonstrated a trend or significance for increased adjusted rates of favorable outcomes by mRS (p = 0.04), BI (p = 0.1), GOS (p = 0.03), and NIHSSS (p = 0.01). CONCLUSION: Although hyperdense artery sign is associated with poor outcome, IV recombinant tissue plasminogen activator may be beneficial in this subgroup of patients with ischemic stroke.