Clinical Importance of Temporal Bone Features for the Efficacy of Contrast-Enhanced Sonothrombolysis: a Retrospective Analysis of the NOR-SASS Trial
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Contrast-enhanced sonothrombolysis (CEST) seems to be a safe and promising treatment in acute ischemic stroke. It remains unknown if temporal bone features may influence the efficacy of CEST. We investigated the association between different temporal bone features on admission computed tomography (CT) scan and the outcome in acute ischemic stroke patients included in the randomized Norwegian Sonothrombolysis in Acute Stroke Study (NOR-SASS). Patients diagnosed as stroke mimics and those with infratentorial stroke or with incorrect insonation were excluded. We retrospectively assessed temporal bone heterogeneity (presence of diploë), diploë ratio, thickness, and density on admission CT scans. National institute of Health Stroke Scale (NIHSS) at 24 h and modified Rankin Scale (mRS) at 3 months were correlated with CT findings both in CEST and sham CEST patients. A total of 99 patients were included of which 52 were assigned to CEST and 47 to sham CEST. Approximately 20% patients had a heterogeneous temporal bone in both the CEST and sham CEST group. All temporal bone CT features studied were associated with female sex. In the CEST group, temporal bone heterogeneity (p = 0.006) and higher temporal bone diploë ratio (p = 0.002) were associated with higher NIHSS at 24 h. There was no association between temporal bone features and mRS at 3 months. Approximately 20% of acute ischemic stroke patients have heterogeneous temporal bone and may be resistant to standard 2-MHz transcranial Doppler ultrasound treatment. Sonothrombolysis resistance may easily be predicted by admission CT for better selection.
KeywordsSonothrombolysis Cerebral infarction Ultrasound CT scan Temporal bone Thrombolysis
We gratefully acknowledge study nurses Leila Marie Frid, Linn Elin Rødal, and Maren Inselseth for study administration.
Sources of Funding
This study was supported by the University of Bergen and Bergen Stroke Research Group.
Compliance with Ethical Standards
Conflict of Interest
The authors declare that they have no conflict of interest.
All procedures performed in studies involving human participants were in accordance with the ethical standards of the regional local ethics committee (REK Vest) and with the 1964 Helsinki declaration and its later amendments.
Informed consent was obtained from all individual participants included in the study.
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