Bulbar and pseudobulbar palsy

Overview

• 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.

Causes

Bulbar palsy

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

Pseudobulbar palsy

The commonest cause is bilateral CVAs affecting the internal capsule.

Other causes include:

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

Features

Bulbar palsy

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.

Pseudobulbar palsy

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.

References and Links

LITFL

• Neurological Mind Boggler 005 — Pseudobulbar and Bulbar Palsies