Facial expressions: absent (expressionless face).

Dysphagia, drooling, nasal regurgitation.

Upper motor neuron palsy of the respective muscles.

Bilateral damage or injury of corticobulbar tracts to nerve nuclei of cranial nerves V, VII, IX, X, XI, and XII.

Lower motor neuron palsy of the respective muscles.

Bilateral damage or injury of the nerve nuclei of cranial nerves IX, X, XI, and XII.Injury or malignancy of the high brainstem.Neurodegenerative disease: amyotrophic lateral sclerosis, progressive supranuclear palsy, multiple sclerosis.Infectious neuropathies: poliomyelitis, diphtheria, neurosyphilis.Autoimmune neuropathies: Guillain-Barré syndrome, myasthenia gravis.Neurodegenerative diseases: amyotrophic lateral sclerosi s, s yringobulbia.CSF analysis and MRI of the brain help identify the etiology. Lower motor neuron signs ( atrophy and fasciculations of the tongue, absent gag reflex) differentiate bulbar palsy from pseudobulbar palsy, which presents with upper motor neuron signs ( spastic tongue, exaggerated gag, and jaw jerk reflexes). In addition, patients with pseudobulbar palsy present with a lack of facial expression, difficulty chewing, and emotional lability.

Both bulbar and pseudobulbar palsy are seen mainly in men over 75 years old and present with dysarthria and dysphagia. Any condition which disrupts or damages the cranial nerve nuclei or corticobulbar tracts can cause bulbar or pseudobulbar palsy (e.g., stroke, multiple sclerosis, infections, brain stem tumors). Pseudobulbar palsy is an upper motor neuron palsy that affects the corticobulbar tracts of the V th, VII th, IX th, X th, XI th, and XII th cranial nerves. Bulbar palsy is a lower motor neuron palsy that affects the nuclei of the IX th, X th, XI th, and XII th cranial nerves.

No gag reflex bj