Brain stem infarction is divided into medullary, pontine and midbrain infarction according to the site of infarction.
1. Medullary infarction
(1) Dorsolateral region of the upper part of the medulla oblongata: at the onset of the disease, there are dizziness, nausea, vomiting, nystagmus, difficulty in swallowing, and dysfunction of contralateral hemiplegia and nociceptive sensation.
(2) Damage to the middle ventral side of the medulla oblongata: at the onset of the disease, patients will show paralysis of the lingual muscles on the side of the lesion, muscle atrophy, motor dysfunction of the contralateral side of the limbs, and deep sensory impairment of the lower limbs on the lateral side of the limbs.
2. Infarction of cerebral bridge
(1) Damage to the ventral-lateral part of the cerebral bridge: facial nerve paralysis, contralateral central hemiparesis, and hemiparetic sensory deficits may occur at the onset of this disease.
(2) Damage to the medial ventral portion of the pons: Peripheral facial paralysis, gaze of the eyes to the opposite side of the lesion, and contralateral hemiplegia.
(3) Damage to the dorsolateral part of the pons: dizziness, nausea, vomiting, facial nerve paralysis, and contralateral hemiplegia.
(4) Bilateral lesions at the base of the cerebral bridges: clear consciousness at the onset of the disease, no obvious obstacles to language comprehension, bilateral central paralysis, only up and down movement of the eyeballs to indicate, and inability to speak.
3. Midbrain infarction
(1) Damage to the peduncle of one side of the midbrain: At the onset of the disease, the patient will have dilated pupils, paralysis of the opposite side of the limbs, facial nerve paralysis, and tongue paralysis.
(2) Damage to the medial ventral part of the midbrain: patients mainly manifest eye muscle paralysis, pupil dilatation, contralateral limb tremor or tremor of the hands and feet, and deep sensory impairment of the contralateral limb.
When cerebral infarction occurs, seek medical treatment promptly.