Soft palate paralysis is a relatively common type of pharyngeal paralysis and can occur either in isolation or in conjunction with other nerve paralyses. Its causes can be central or peripheral.
Etiology
Central Causes
These are commonly associated with various conditions, such as tumors, hemorrhage, thrombosis, inflammatory lesions, syringomyelia, or syphilis. Central causes are often accompanied by ipsilateral paralysis of the lips, tongue, and laryngeal muscles.
Peripheral Causes
Peripheral causes frequently involve conditions such as polyneuritis, with Guillain-Barré syndrome being a typical example. In addition to motor dysfunction, sensory impairments are often present. Conditions affecting the area near the jugular foramen (e.g., jugular foramen syndrome) or lesions at the skull base or foramen magnum, such as primary tumors, hematomas, or metastatic lymph nodes causing compression, may result in soft palate paralysis, often associated with paralysis of the glossopharyngeal (IX), vagus (X), and accessory (XI) cranial nerves.
Clinical Manifestations
Unilateral soft palate paralysis may produce no clinical symptoms, whereas bilateral paralysis is more symptomatic. Symptoms often include choking while drinking, voice changes, and other abnormalities. In cases where the soft palate cannot elevate, the nasopharynx remains open, leading to a hypernasal voice when speaking. During swallowing, food can easily regurgitate into the nasal cavity and, occasionally, into the middle ear via the Eustachian tube. Patients are unable to perform actions such as sucking, whistling, or puffing out their cheeks.
Examinations
In unilateral soft palate paralysis, the uvula deviates toward the healthy side. When the patient attempts to phonate (e.g., produces the "ah" sound), the uvula and soft palate move toward the unaffected side, and the paralyzed side of the soft palate fails to elevate. In bilateral paralysis, the soft palate appears flaccid and droops, showing no ability to elevate. Dysfunction of the Eustachian tube may produce symptoms and signs involving the middle ear. Paralysis of the pharyngeal constrictor muscles may lead to the retention of saliva or food in the pyriform sinus.
Diagnosis
The diagnosis of soft palate paralysis is generally straightforward, but it is important to identify its underlying cause. Consultation with relevant departments is recommended to assist in diagnosing the etiology.
Treatment
Treatment is directed at addressing the underlying cause. For cases of peripheral paralysis, intravenous immunoglobulin (IVIG) is an option. Steroid pulse therapy can be utilized for immune-mediated neuropathies, along with neurotrophic agents such as vitamin B1 and B12. Ischemic cerebrovascular disease may be treated with medications like aspirin and atorvastatin, while hemorrhagic cerebrovascular disease may require agents such as mannitol to reduce intracranial pressure. Space-occupying lesions may necessitate surgical intervention, chemotherapy, or radiotherapy as appropriate.