Differentiation of pseudobulbar and bulbar palsies

1. Big picture

Both bulbar palsy and pseudobulbar palsy cause problems with:

• Swallowing → dysphagia

• Speech articulation → dysarthria

• Voice/phonation → nasal or weak voice

• Chewing and tongue movements

The exam question is usually not asking for a full dysphagia topic. It wants you to localize the lesion:

• Bulbar palsy = lower motor neuron lesion of brainstem cranial nerve nuclei or their peripheral nerves.

• Pseudobulbar palsy = bilateral upper motor neuron lesion of corticobulbar fibers.

The key practical difference is:

Bulbar palsy is flaccid LMN weakness with atrophy, fasciculations, and reduced reflexes. Pseudobulbar palsy is spastic UMN weakness with preserved or increased reflexes and emotional lability.