Collateral Activation of the Early Temporal Branch - A Neurosonological Sign of Distal M1 Middle Cerebral Artery Occlusion.

In most cases large vessel occlusion (LVO) in the anterior circulation causes a severe stroke syndrome with a high National Institutes of Health Stroke Scale score (NIHSS). However, there is also a smaller group of patients (up to 10 % of all LVO) presenting with a minor stroke syndrome, transient or even absent neurological symptoms, who may develop early clinical deterioration. They may be candidates for thrombolysis and mechanical thrombectomy (MT). Due to low clinical suspicion, many of these patients are not included in the diagnostic fast track of a comprehensive stroke center with immediate vessel imaging by means of CTor MR-angiography. In this scenario neurosonography can be the first vessel imaging performed. We present such a clinical case and its neurosonographic findings of a distal M1 middle cerebral artery occlusion (MCA) with an emphasis on the early temporal branch (ETB) as an important M1-M2 collateral pathway (aside from established neurosonological signs).