1. What are the symptoms of breast cancer brain metastasis? The most common symptom of breast cancer brain metastasis is cranial hypertension, which mainly manifests as headache, nausea and vomiting, and in serious cases, drowsiness. Breast cancer brain metastasis may also show symptoms related to neuronal agitation, such as epilepsy; it may also show symptoms of localized neurological damage, such as limb weakness or hemiparesis, aphasia, sensory abnormalities, visual field defects and ataxia. 2. How to confirm the diagnosis of breast cancer brain metastasis? What examinations are needed? Brain metastasis of breast cancer should be diagnosed through cranial CT or cranial MRI. Cranial CT can be used as initial screening or emergency examination, which can detect metastatic tumor and its surrounding edema, metastatic tumor stroke (intratumor hemorrhage), brain hernia and obstructive hydrocephalus. Cranial MRI, especially enhanced MRI, is more sensitive and should be the first choice of diagnosis of brain metastasis of breast cancer, which can clearly identify parenchymal metastasis, dural metastasis, molluscum contagiosum metastasis or ventricular metastasis (carcinomatosis meningocele) and spinal cord metastasis, and also differentiate them from other types of lesions. 3. When do breast cancer brain metastases usually occur? Brain metastasis of breast cancer can occur at any time after diagnosis. Generally speaking, the median time from diagnosis of breast cancer to the occurrence of brain metastasis is 2~3 years. 4. What is the prognosis of breast cancer brain metastasis? How long can I live with brain metastasis of breast cancer? Generally speaking, the prognosis of breast cancer brain metastasis is related to molecular subtype, KPS score, number and size of brain metastases, extracranial metastasis, etc. Among them, whether to receive timely surgical treatment and resect intracranial metastatic foci is the most critical factor determining the length of survival of patients. The median survival of patients with symptomatic parenchymal brain metastases is only about 1 month, and about 95-100% of patients with brain metastases from breast cancer die from progressive increase in intracranial pressure due to the tumor and its peripheral edema, therefore, the diagnosis should be confirmed in time and receive surgical treatment in neurosurgery.