If the patient has the symptom of left deviation of tongue extension, it is considered to be caused by acute cerebrovascular disease, if the patient has left deviation of tongue extension, the patient’s speech will also be clumsy. It may be caused by mild cerebral infarction or transient ischemic attack. It is necessary to consult the hospital in time for examination and treatment, and to do head CT to clarify whether there is any bleeding problem, if there is no bleeding, it is considered to be ischemic cerebrovascular disease, and it is necessary to carry out treatment in time. Extension of the tongue to the left, the localization on the cerebral hemisphere, consider the right cerebral hemisphere problem, the right cerebral hemisphere has an infarction or ischemic attack, the patient will be tilted to the left when extending the tongue. Because the innervating tongue muscle is the extensor muscle, when the right cerebral hemisphere lesion occurs, the left side of the tongue muscle is no strength, when the tongue is stretched out, the tongue will be skewed to the left.