Extending the Time Window for Tenecteplase by Recanalization of Basilar Artery Occlusion in Posterior Circulation Stroke

Inclusion Criteria: * Patients presenting with posterior circulation ischemic stroke symptoms due to partial or complete basilar artery occlusion within 24 hours from symptom onset (or clinical deterioration/coma) or the time the patient was last known to be well. * Patient's age is ≥18 years * Presence of basilar artery occlusion, proven by CT Angiography or MR Angiography. Basilar artery occlusion is defined as 'potentially retrievable' occlusion at the basilar artery. This can be a partial or complete occlusion. * Premorbid mRS ≤3 (independent function or requiring only minor domestic assistance and able to manage alone for at least 1 week). * Local legal requirements for consent have been satisfied. Exclusion Criteria: * Intracerebral hemorrhage (ICH) or other diagnosis (e.g. tumour) identified by baseline imaging. * Posterior circulation Acute Stroke Prognosis Early CT score (pc-ASPECTS) \<7 on non-contrast CT, CT Angiography source images or DWI MRI. * Significant cerebellar mass effect or acute hydrocephalus. * Established frank hypodensity on non-contrast CT indicating subacute infarction. * Bilateral extensive brainstem ischemia. * Strong suspicion of underlying intracranial atherosclerotic disease (e.g diffuse arterial calcifications, basilar stenosis) or dissection which may require immediate neuro-interventional procedure with intracranial stenting and not benefit from intravenous thrombolysis at investigator's discretion. * Pre-stroke mRS of ≥4 (indicating moderate to severe previous disability). * Other standard contraindications to intravenous thrombolysis. * Contraindication to imaging with contrast agents. * Clinically evident pregnant women. * Current participation in another research drug treatment protocol. * Known terminal illness such that the patients would not be expected to survive a year. * Planned withdrawal of care or comfort care measures. * Any condition that, in the judgment of the investigator could impose hazards to the patient if study therapy is initiated or affect the participation of the patient in the study.