Computed tomography perfusion prognostic maps do not predict reversible and irreversible neurological dysfunction following reperfusion therapies.

BACKGROUND: We aimed to evaluate the ability of commercially available computed tomography perfusion (CTP) prognostic maps software to identify reversibly and irreversibly damaged brain functions in the best case scenario: patients who achieved early and complete tissue reperfusion. METHODS: Consecutive ischemic stroke patients who received reperfusion therapies, those with early (less than two-hours from treatment initiation) and complete Thrombolysis in Myocardial Infarction grade III or equivalent reperfusion were included in the analysis. Computed tomography perfusion prognostic maps were assigned as 'red,' or irreversible if cerebral blood volume declined below 2 ml/100 g and 'green,' or recoverable if the affected/unaffected mean transit time ratio was >1.45. Only patients with middle cerebral artery territory affected were included and subcomponents of the National Institutes of Health Stroke Scale scale pre- and posttreatment were analyzed based on anatomical correlation of the affected CTP areas and corresponding neurological functions. RESULTS: Among 109 consecutive patients who had intra-arterial reperfusion procedures, 16 (age 60 ± 17 years, 56% men, median National Institutes of Health Stroke Scale 13 . 5, interquartile range 7-18) had pretreatment CTP and had early complete reperfusion. We identified 44 affected areas on CTP (red 12 (27%), green 32 (73%)) with corresponding measurable neurological deficits including aphasia, arm, face weakness, and inattention. Red areas correctly identified 5/12 (42%) of functions that did not recover despite early reperfusion. Green areas correctly identified 18/32 (56%) of functions that recover after early reperfusion (OR 0.92, 95% CI 0.25-3.39, P = 1.0). CONCLUSIONS: In-patients achieving early and complete reperfusion, pretreatment CTP prognostic maps were not predictive for irreversibly or reversibly lost neurologic functions.

Safety and tolerability of early noninvasive ventilatory correction using bilevel positive airway pressure in acute ischemic stroke.

BACKGROUND AND PURPOSE: Hypercapnia can induce intracranial blood-flow steal from ischemic brain tissues, and early initiation of noninvasive ventilator correction (NIVC) may improve cerebral hemodynamics in acute ischemic stroke. We sought to determine safety and tolerability of NIVC initiated on hospital admission without polysomnography study. SUBJECTS AND METHODS: Consecutive acute ischemic stroke patients were evaluated for the presence of a proximal arterial occlusion, daytime sleepiness, or history of obstructive sleep apnea, and acceptable pulse oximetry readings while awake (96%-100% on 2 to 4 L supplemental oxygen delivered by nasal cannula). NIVC was started on hospital admission as standard of care when considered necessary by treating physicians. NIVC was initiated using bilevel positive airway pressure at 10 cmH(2)O inspiratory positive airway pressure and 5 cmH(2)O expiratory positive airway pressure in combination with 40% fraction of inspired oxygen. All potential adverse events were prospectively documented. RESULTS: Among 356 acute ischemic stroke patients (median NIHSS score, 5; interquartile range, 2-13), 64 cases (18%) received NIVC (median NIHSS score, 12; interquartile range, 6-17). Baseline stroke severity was higher and proximal arterial occlusions were more frequent in NIVC patients compared to the rest (P<0.001). NIVC was not tolerated by 4 patients (7%). Adverse events in NIVC included vomiting (n=1), aspiration pneumonia (n=1), respiratory failure/intubation (n=1), hypotension requiring pressors (n=1), and facial skin breakdown (n=3). The in-hospital mortality rate was 13% in NIVC patients and 8% in the rest (P=0.195). Neurological improvement during hospitalization tended to be greater in the NIVC group (median NIHSS score decrease, 2 points; interquartile range, 0-4) compared to the rest (median NIHSS score decrease, 1; interquartile range, 0-2; P=0.078). CONCLUSIONS: In acute ischemic stroke patients with proximal arterial occlusion and excessive sleepiness or obstructive sleep apnea, NIVC can be initiated early with good tolerability and a relatively small risk of serious complications.

Diagnostic criteria and yield of real-time transcranial Doppler monitoring of intra-arterial reperfusion procedures.

BACKGROUND AND PURPOSE: Intra-arterial (IA) rescue procedures are increasingly used to treat acute ischemic stroke. We implemented continuous transcranial Doppler (TCD) monitoring during these procedures to detect any potentially harmful flow changes. Here, we report diagnostic criteria and yield of TCD monitoring. METHODS: We studied consecutive acute stroke patients who underwent IA reperfusion procedures. TCD flow signatures during these procedures were analyzed and any abnormal findings were documented. RESULTS: Patients were included only if there was successful insonation through the skull; of 56 eligible patients, 51 were included. IA procedures included IA tissue plasminogen activator, use of the Merci retriever, the Penumbra system, balloon angioplasty, and stenting. On TCD monitoring, contrast injections produced high-intensity signals and increased the mean flow velocity (MFV). Deployment of the Merci device appeared as high-intensity, short-duration signals with a transient MFV decrease of 11.5%. The Penumbra system produced lower-intensity signals with a greater transient decrease in MFV during aspiration. IA tissue plasminogen activator significantly increased MFV by 7.5% over Merci and Penumbra flow velocity changes. Power motion Doppler-TCD detected reocclusion in 13 patients, artery-to-artery embolization in 2 patients, air embolism in 2 patients, and hyperperfusion in 6 patients. Overall, the yield of TCD monitoring was positive in 23 (49%) patients who received IA reperfusion procedures. CONCLUSIONS: Our velocity, intensity, and flow signatures criteria for TCD monitoring of IA reperfusion procedures detect reocclusion, hyperperfusion, or thromboembolism and air embolism in nearly half of all procedures. This hemodynamic information can be particularly helpful when neurological assessment is limited or delayed.