Bulbar Palsy

Relevant physical signs

• Bulbar palsy (LMN)
  • Nasal speech which lacks modulation
  • Speaks in short phrases
  • Slurred words, especially of the consonants
  • Palatal weakness
  • Wasted, flaccid, fasciculating tongue
  • Absent jaw jerk
  • Reduced gag reflex
• Pseudobulbar palsy (UMN)
  • High-pitched, slow speech
  • Imprecise articulation, sounds forced
  • Palatal weakness
  • Small, spastic, poorly mobile tongue
  • Brisk jaw jerk
  • Exaggerated gag reflex
  • Pseudobulbar affect – emotional lability
• Other signs
  • Nasogastric tube (dysphagia)
  • Radiation marks – radiotherapy for previous base of skull tumour
  • Ptosis – myasthenia gravis
  • Pronator drift – medial medullary stroke
  • Dissociated sensory loss in limbs – syringobulbia
  • Generalized fasciculations – motor neurone disease

Differential diagnosis

• Bulbar palsy
  • Motor neurone disease
  • Myotonic dystrophy
  • Myasthenia gravis
  • Multiple system atrophy
  • Syringobulbia
  • Poliomyelitis
  • Leptomeningeal disease
  • Radiation damage
  • Nasopharyngeal carcinoma
  • Medullary stroke
• Pseudobulbar palsy
  • Bilateral strokes of the internal capsule
  • High brainstem tumour
  • Multiple sclerosis
  • Motor neurone disease
  • Trauma
• Pseudobulbar palsy is only seen with bilateral lesions as most cranial nerve nuclei receive dual innervation from the cortices. The only exceptions are VII and XII, which receive contralateral innervation only.