Dizziness, weakness and numbness in the extremities may be due to brainstem hemorrhage or brainstem infarction, but also to brainstem inflammation or brainstem tumors. Brainstem infarction usually starts in the quiet state and the main causes include atherosclerosis, hyperlipidemia, hypertension, diabetes mellitus and hyperhomocysteinemia. Patients with brainstem hemorrhage usually have an active onset, mostly due to aneurysms or hypertension, and have high-density lesions on cranial CT, while patients with brainstem infarction usually have low-density lesions on cranial CT. If the patient has brainstem inflammation, fever may occur and other symptoms may also be present. Blood tests should be performed and cranial MRI should be performed if necessary. If the patient is a cranial tumor, it usually has a subacute onset and may be accompanied by headache, nausea, and vomiting.