The pharyngeal muscles are primarily innervated by motor nerve fibers from the pharyngeal plexus, with soft palate paralysis being the most common manifestation. The causes can be categorized into central and peripheral paralysis. Central paralysis is seen in various conditions affecting the medulla oblongata, such as bulbar paralysis, pseudobulbar paralysis, cerebellar infarction with thrombosis, encephalitis, acoustic neuroma invading the medulla, and syringobulbia. Peripheral paralysis is more frequently observed in polyneuritis, as well as other conditions like infections, jugular foramen syndrome, botulism, myasthenia gravis, dermatomyositis, and compression of cranial nerves IX, X, and XI due to skull base lesions (trauma or tumors).

bubble_chart Clinical Manifestations

Depending on the extent of the lesion, pharyngeal muscle paralysis can be classified as complete or incomplete, unilateral or bilateral. Unilateral paralysis is often asymptomatic, while bilateral paralysis is more severe. Due to palatal paralysis, the nasopharynx fails to close, resulting in open nasal speech and easy reflux of liquid food into the nasal cavity, though solid food intake is less affected. When the pharyngeal constrictor muscles are paralyzed, swallowing function is impaired. Initially, there may be difficulty with liquids, while solid food passes without obstruction. However, progression may lead to the risk of aspiration into the larynx.

On physical examination, when the patient opens their mouth and says "ah," the unaffected side moves while the affected side fails to elevate. In cases of bilateral paralysis, the soft palate becomes flaccid and cannot lift. If the pharyngeal constrictor muscles are paralyzed, saliva or food retention may be observed in the pyriform sinuses.

Treat the underlying cause of the disease. For central cases, collaborate with internal medicine and neurology for diagnosis and treatment. For peripheral paralysis, anticholinesterase drugs, neurostimulants, or vitamin-based medications can be used, along with acupuncture therapy. For pharyngeal constrictor paralysis causing inability to eat or aspiration, insert a nasogastric tube.