A bulbar palsy is a lower motor neuron lesion of cranial nerves IX, X and XII.

A pseudobulbar palsy is an upper motor neuron lesion of cranial nerves IX, X and XII.

The clinical features include:

• Gag reflex -- absent
• Tongue -- wasted, fasciculations
  “wasted, wrinkled, thrown into folds and increasingly motionless”.
• Palatal movement -- absent.
• Jaw jerk -- absent or normal
• Speech -- nasal
  “indistinct (flaccid dysarthria), lacks modulation and has a nasal twang”
• Emotions -- normal
• Other -- signs of the underlying cause, e.g. limb fasciculations.

The clinical features include:

• Gag reflex -- increased or normal
• Tongue -- spastic
  “it cannot be protruded, lies on the floor of the mouth and is small and tight”.
• Palatal movement -- absent.
• Jaw jerk -- increased
• Speech -- spastic: “a monotonous, slurred, high-pitched, ‘Donald Duck’ dysarthria”  that “sounds as if the patient is trying to squeeze out words from tight lips”.
• Emotions -- labile
• Other -- bilateral upper motor neuron (long tract) limb signs.

Causes include:

• Motor neurone disease
• Syringobulbia
• Guillain-Barre syndrome
• Poliomyelitis
• Subacute menignitis (carcinoma, lymphoma)
• Neurosyphilis
• Brainstem CVA

The commonest cause is bilateral CVAs affecting the internal capsule.

Other causes include:

• Multiple sclerosis
• Motor neurone disease
• High brainstem tumours
• Head injury