Bulbar Syndrome

Bulbar syndrome (from the Latin bulbus — bulb) is a severe neurological symptom complex caused by focal damage to the lower part of the brainstem.

Pathology develops due to damage to the nuclei or roots of three cranial nerves: glossopharyngeal, vagus, and hypoglossal.

Etiology and pathophysiology

The medulla oblongata is a vital center connecting the brain to the spinal cord. In severe traumatic brain injury, its damage is rarely primary. Most often, the brainstem structures suffer secondarily — they are grossly compressed and pinched in the great occipital foramen of the skull due to increasing hemisphere swelling (a process of herniation).

Compression or ischemia of the motor nuclei of the 9th, 10th, and 12th cranial nerve pairs leads to the development of flaccid (peripheral) paralysis of the muscles of the pharynx, larynx, soft palate, and tongue. The pathological process completely disrupts the complex reflex act of swallowing and phonation.

Clinical significance

The syndrome manifests as a classic and extremely dangerous triad of symptoms. Dysphagia (complete inability to swallow food or saliva), dysarthria (inarticulate, slurred speech), and dysphonia (hoarseness or loss of voice) occur. Examination reveals the absence of a gag reflex and drooping of the soft palate.

This condition poses a direct threat to the patient’s life. Due to paralysis of the pharyngeal muscles and epiglottis, saliva and food flow freely into the airways (aspiration), inevitably leading to choking or severe aspiration pneumonia. Additionally, the respiratory and vasomotor centers located nearby, when compressed, can cause cardiac and respiratory arrest. Patients with such a syndrome require immediate transfer to mechanical ventilation and tube feeding.