Crossed paresis is the characteristic sign as well as the specific type of paresis that refers to the simultaneous presence of symptoms of cranial nerve damage on the ipsilateral side of the lesion and symptoms of central hemiparesis in the limb contralateral to the lesion. This condition occurs in lesions on one side of the brainstem, such as brainstem infarction, brainstem hemorrhage, brainstem tumor, or brainstem encephalitis. The damage occurs in the crossed cortical brainstem tract fibers and nuclei of the cranial nerves. Most commonly, in cerebral bridge infarction, ipsilateral peripheral facial palsy and contralateral limb palsy occur, and the patient presents with shallow frontal lines on the ipsilateral side of the lesion, a shallow or absent nasolabial fold, a deviation of the corner of the mouth to the contralateral side when showing the teeth, and incomplete eyelid closure on the ipsilateral side of the lesion. However, there is limb paralysis and decreased muscle strength on the contralateral side of the lesion. In the acute phase, the muscle tone is reduced and the pathological signs can be negative, and after the disease progresses, there can be increased muscle tone and positive pathological signs.