If the infarct is small, it can be cured with aggressive and correct treatment. If the infarct is large, the signs and symptoms are generally more severe, and the death and disability rates are higher. The brainstem is the life center of the body, including the pons, medulla and midbrain, and even small infarcts may present with clinically severe signs and symptoms. Patients may suddenly experience dizziness, nausea, vomiting, and balance disturbances, as well as difficulty swallowing and choking on water. Some patients may present with nystagmus and diplopia, or in severe cases, bulbar palsy and tetraplegia. They may also present with urinary and fecal disturbances, including urinary and fecal retention and incontinence, and may even present with disturbances in consciousness, including drowsiness, lethargy, and coma, or they may present with a decortical state. Patients can develop unstable vital signs, including unstable respiration, blood pressure and heart rate, and may also develop decreased oxygen saturation. If the correct treatment is given promptly after the onset, try to give intravenous treatment when thrombolysis is suitable in the ultra-early stage. Thrombolysis can rapidly restore cerebral blood flow and improve brain tissue metabolism, which can save only the ischemic semidark zone tissue with functional changes and maximize the improvement of neurological deficit symptoms and signs, thus may reduce the lethality and disability of patients.