Decrease in shunt volume in patients with cryptogenic stroke and patent foramen ovale.

BACKGROUND: In patients with patent foramen ovale (PFO) there is evidence supporting the hypothesis of a change in right-to-left shunt (RLS) over time. Proven, this could have implications for the care of patients with PFO and a history of stroke. The following study addressed this hypothesis in a cohort of patients with stroke and PFO. METHODS: The RLS volume assessed during hospitalisation for stroke (index event/T0) was compared with the RLS volume on follow-up (T1) (median time between T0 and T1 was 10 months). In 102 patients with a history of stroke and PFO the RLS volume was re-assessed on follow-up using contrast-enhanced transcranial Doppler/duplex (ce-TCD) ultrasound. A change in RLS volume was defined as a difference of ≥20 microembolic signals (MES) or no evidence of RLS during ce-TCD ultrasound on follow-up. RESULTS: There was evidence of a marked reduction in RLS volume in 31/102 patients; in 14/31 patients a PFO was no longer detectable. An index event classified as cryptogenic stroke (P < 0.001; OD = 39.2, 95% confidence interval 6.0 to 258.2) and the time interval to the follow-up visit (P = 0.03) were independently associated with a change in RLS volume over time. CONCLUSIONS: RLS volume across a PFO decreases over time, especially in patients with cryptogenic stroke. These may determine the development of new strategies for the management in the secondary stroke prevention.

Can early neurosonology predict outcome in acute stroke?: a metaanalysis of prognostic clinical effect sizes related to the vascular status.

BACKGROUND AND PURPOSE: Prediction of short- and long-term prognosis is an important issue in acute stroke care. This metaanalysis explores the prognostic value of initial bed-side transcranial ultrasound in acute stroke. METHODS: All studies prospectively applying TCCS or TCD within 24 hours of symptom onset in acute stroke, with a minimal cohort size of 20 patients, and reporting clinical outcome variables in relation to the vascular findings were included into this metaanalysis. Study quality was assessed by 2 independent reviewers. RESULTS: Twenty-five studies with 1813 included patients identified by electronic and manual search fulfilled the inclusion criteria. Middle cerebral artery (MCA) occlusion was associated with a significantly increased risk for a fatal course of stroke (OR 2.46, 95% CI 1.33 to 4.52). Patients with patent MCA were more likely to clinically improve within 4 days than patients with MCA occlusion (OR 11.11, 95% CI 5.44 to 22.69). Full recanalization within 6 hours after symptom onset was highly significantly associated with clinical improvement within 48 hours (OR 5.64, 95% CI 3.82 to 8.31) and functional independence after 3 months (OR 6.07, 95% CI 3.94 to 9.35). CONCLUSIONS: Transcranial ultrasound provides important information on prognosis in patients with acute stroke.

Safety and efficacy of the sonographic acceleration of the middle cerebral artery recanalization: results of the pilot thrombotripsy study.

The aim was to demonstrate the safety and efficacy of continuous ultrasound monitoring of the artery occlusion area (sonothrombotripsy) in patients with acute middle cerebral artery (MCA) occlusion. A total of 52 consecutive patients with acute MCA occlusion were included in the thrombotripsy group. Doppler monitoring of the region of occlusion was performed for up to 45 min. The control group was created from the NAIS study database. Patients were matched for their vascular status, age, sex, artery occlusion, NIHSS at admission, rt-PA treatment and time to the first ultrasound examination. The number of recanalized arteries at 6 and 24 h after the onset of symptoms, the number of independent patients (mRS 0-2 versus 3-6) after 90 d, and the number of serious adverse events were statistically evaluated. In the thrombotripsy group, 19 patients (36.5%) had complete recanalization and 27 (51.9%) patients had partial recanalization at 1 h after the start of the TCCS monitoring. Higher recanalization rates at 6 and 24 h after stoke onset were also seen compared with controls (69.2% versus 7.7% and 92.3% versus 61.5% complete recanalizations, respectively, p < 0.05). Independence (mRS 0-2) at day 90 was achieved by 61.5% of the thrombotripsy patients and 32.7% controls, p < 0.05, odds ratio 1.88 (95% confidence interval = 1.23 - 2.90). In both groups, two symptomatic intracerebral hemorrhages and one symptomatic brain edema occurred. Sonothrombotripsy with diagnostic transcranial duplex technology is safe and may offer benefit in addition to standard of care stroke treatment.

Prognostic value of transcranial sonography in acute stroke patients.

Accurate assessment of stroke is critical for patient prognosis and selection of appropriate treatment regimens in order to optimize patient outcomes. Advanced neurosonologic techniques are straightforward, portable, and cost-effective, representing significant advantages over other noninvasive imaging modalities for monitoring of the hemodynamic status of acute ischemic stroke. Ultrasound findings acquired both early (<3 h from onset of stroke) and later (6-24 h after stroke) have demonstrated feasibility and validity for the detection of stenosis/occlusion of key intracranial structures, such as the middle cerebral artery, and for immediate and unambiguous indication of flow velocities, particularly when contrast enhancement is used. In addition, the target of thrombolysis can be identified and localized, and the success of therapy monitored, by transcranial ultrasound. Finally, transcranial ultrasound can be used to gauge the appropriateness of more complex and costly imaging studies, thereby optimizing utilization of health care resources.

Prognostic relevance of ultra-early doppler sonography in acute ischaemic stroke: a prospective multicentre study.

BACKGROUND: Ischaemic stroke can result from a temporary or permanent occlusion of intracranial arteries. In the hyperacute stage of the disease cerebrovascular ultrasound can be used to determine the vascular pathology, but the significance of very early findings on ultrasound is unclear. The present study aimed to assess the prognostic value of doppler ultrasonography within the first hours after stroke for functional outcome. METHODS: In a prospective multicentre design, patients with clinical signs of ischaemic anterior-circulation stroke were examined by doppler ultrasonography of the intracranial and extracranial arteries. Patients were separated into three groups according to the findings: normal middle-cerebral artery (MCA); branch occlusions; or a main-stem occlusion. The primary endpoint was functional outcome at 3 months. Logistic regression was used to test the association between the ultrasound diagnosis and functional outcome. RESULTS: 361 patients were identified with moderate to severe clinical deficits (National Institutes of Health Stroke Scale score 5-25). Of these, 121 (34%) had a normal MCA, 176 (48%) had branch occlusions, 7 (2%) had severe MCA stenosis, and 57 (16%) had a main-stem occlusion. 50 of the 57 (88%) patients with main-stem occlusion were dead or dependent 3 months after stroke. An occlusion of the main stem of the MCA within 6 h after stroke was an independent predictor for poor outcome (p=0.0006). 50% of patients with ultrasonographic diagnosis of branch occlusions and 63% with normal MCA had a good outcome. Combination of CT scan without early signs of infarction and a normal MCA resulted in a predictive value of 71% for a good functional outcome. INTERPRETATION: Cerebrovascular ultrasonography provides additional functional prognostic information in the hyperacute stage of ischaemic stroke. The technique is practical in a well-resourced unit, can be used to identify patients with high risk for poor functional outcome, and thus would be an appropriate investigation for future trials.

Design of a multicentre study on neurosonology in acute ischaemic stroke. A project of the neurosonology research group of the World Federation of Neurology.

This report summarises the design and organisation of a multicentre study on neurosonology in acute ischaemic stroke. The Neurosonology in Acute Ischaemic Stroke Study will determine whether extracranial and transcranial Doppler and duplex sonography performed within 6 h after onset of stroke improves prediction of functional outcome if applied in addition to routine diagnostic admission investigations, i.e. medical history, standardised neurological examination, brain imaging by computed or magnetic resonance tomography, electrocardiography, and baseline laboratory examination. The primary hypothesis is that there is a consistent and persuasive difference between patients with an occluded middle cerebral artery and those with an open artery in terms of the functional deficit after 3 months. Power calculations are based on the assumption of alpha=0.05 (two-sided test) and a probability of a maximally mild functional deficit of 0.4. Detection of a 20% difference with a power of 0.8 resulted in a calculated sample of 400 patients to be observed. Calculation took into consideration that only 50% of admitted patients would have a moderate to severe neurological deficit of whom only 30% will have an occlusion of the corresponding middle cerebral artery. Furthermore, the study is designed to evaluate a difference of the functional outcome in relation to occurrence and time of recanalisation in-patients presenting with an initially occluded middle cerebral artery.