Bulbar palsy refers to a range of different signs and symptoms linked to impairment of function of the glossopharyngeal nerve (CN IX), the vagus nerve (CN X), the accessory nerve (CN XI), and the hypoglossal nerve (CN XII). It is caused by a lower motor neuron lesion in the medulla oblongata, or from lesions to these nerves outside the brainstem, and also botulism. This may be caused by any of a number of genetic, vascular, degenerative, inflammatory, and other underlying conditions. It can be differentiated from pseudobulbar palsy. When there is airway obstruction, intubation is used.

Signs and symptoms

Symptoms

Signs

In addition, there may be lower motor neuron lesions of the limbs. The ocular muscles are spared and this differentiates it from myasthenia gravis.

Causes

Mechanism

Bulbar palsy involves problems with function of the glossopharyngeal nerve (CN IX), the vagus nerve (CN X), the accessory nerve (CN XI), and the hypoglossal nerve (CN XII). These all emerge from pathways in the medulla oblongata. A lower motor neuron lesion can impair their function.

Diagnosis

Differential diagnosis

In contrast, pseudobulbar palsy is a clinical syndrome similar to bulbar palsy but in which the damage is located in upper motor neurons of the corticobulbar tracts in the mid-pons (i.e., in the cranial nerves IX-XII), that is the nerve cells coming down from the cerebral cortex innervating the motor nuclei in the medulla. This is usually caused by stroke.

Treatment

In patients with airway obstruction due to bulbar palsy, intubation may be used. This can be tracheal intubation or supraglottal intubation.