What causes drooling after a cerebral infarction?

Generally, drooling after a cerebral infarction may be caused by physiological factors, facial paralysis, or swallowing dysfunction, and can be treated with medications or other methods.

1. Physiological factors: Drooling may occur as a conditioned reflex when seeing appetizing food. For example, delicious foods such as braised pork or plums can stimulate taste and vision, activating sensory receptors. Signals are transmitted via afferent nerves to the brain and ultimately trigger the salivary glands through effectors, resulting in saliva secretion and drooling. This is considered a normal physiological response.

2. Facial paralysis: Patients may develop central facial paralysis due to cerebral infarction, leading to loss of control over facial muscles. Symptoms may include mouth corner deviation, shallower nasolabial folds, and incomplete lip closure, causing saliva to leak from the mouth. If accompanied by slurred speech or impaired limb mobility, prompt medical evaluation is necessary to prevent progression to cerebral infarction.

3. Swallowing dysfunction: In stroke patients with comorbid conditions such as Guillain-Barré syndrome or myasthenia gravis, damage to the posterior cranial nerves may occur, disrupting nerve signal transmission and impairing muscular control, thereby causing swallowing difficulties and drooling. Treatment may include oral administration of medications such as mecobalamin tablets or piracetam tablets, as directed by a physician.