[23] Bulbar Palsy Flashcards
What is bulbar palsy?
A range of different signs and symptoms linked to impairment of function of CN 9-12 due to LMN lesion in the medulla oblongata or lesions of the lower cranial nerves outside the brainstem
What parts of the oral cavity are required for speech?
- Larynx
- Pharynx
- Palate
- Tongue
- Lips
As well as components of the oral cavity, what else is required for speech?
Controlled expiration to release air at appropriate speeds and volumes
Via what do the motor cortices send signals to initiate speech?
Corticobulbar tracts
What nerves are involved in speech production?
- Vagal nerve (CN 10)
- Facial nerve (CN 7)
- Hypoglossal nerve (12)
- Phrenic nerve
How are the motor aspects of speech co-ordinated?
By the extra-pyramidal system via the basal ganglia and the cerebellum
What are the two aspects of speech production (motor aspects)?
- Phonation
- Articulation
What is phonation?
The production of sound as a result of the vocal cords in the larynx
What is articulation?
Contractions of the muscles of the various other structures involved in speech
Why is articulation important?
Muscle contractions change the sounds from the larynx to result in noises recognised as words
What are the types of causes of Bulbar palsy?
- Genetic
- Vascular causes
- Degenerative diseases
- Inflammatory/infective
- Malignancy
- Toxic
- Autoimmune
What are the genetic causes of Bulbar palsy?
- Kennedy’s disease
- Acute intermittent porphyria
Give 1 vascular cause of Bulbar palsy?
Medullary infarction
What are 2 degenerative disease that can cause Bulbar palsy?
- Amyotrophic lateral sclerosis
- Syringobulbia
Give 3 infective/inflammatory causes of Bulbar palsy?
- Guillain-Barre syndrome
- Poliomyelitis
- Lyme disease
Give 2 malignant causes of Bulbar palsy?
- Brainstem glioma
- Malignant meningitis
Give 2 toxic causes of Bulbar palsy?
- Botulism
- Some scorpion and snake venom
Give 1 autoimmune cause of Bulbar palsy?
Myasthenia gravis
What are the potential presenting symptoms of Bulbar palsy?
- Dysphagia
- Difficulty in chewing
- Nasal regurgitation
- Slurring of speech
- Difficulty in handling secretions
- Choking on liquids
- Dysphonia
- Dyarthria
What is dysphonia?
Defective use of the voice due to the inability to produce sounds due to laryngeal weakness
What are the potential signs of Bulbar palsy?
- Nasal speech lacing
- Difficulty with consonants
- Atrophic tongue with fasciculations
- Dribbling
- Weakness of soft palate
- Normal or absent jaw jerk
- Absent gag reflex
How can strength of soft palate be assessed?
Ask patient to say ahhh
How can true bulbar palsy be differentiated from myasthenia gravis?
There is sparing of the ocular muscles
What investigations can be used to assess speech dysfunction?
- Electromagnetic articulography
- Electropalatography
What other tests can be used to assess underlying causes of Bulbar palsy?
- Blood tests
- Imaging of brain and brainstem (CT or MRI)
- Electromyography
What is the main differential for Bulbar palsy?
Pseudobulbar palsy
What is pseudobulbar palsy?
A syndrome similar to Bulbar palsy but where the damage is in the UMN of the corticobulbar tracts in the mid-pons
What usually causes pseudobulbar palsy?
Stroke
What are some other disorders of articulation?
- Cerebellar-ataxic
- Hypokinetic
- Hyperkinetic
How is Bulbar palsy treated?
By treating the underlying cause and involving neurologists, SALT and dieticians
What supportive measures can be used to treat Bulbar palsy?
- Baclofen for spasticity
- Anticholinergics for drooling
- Treatment for aspiration pneumonia if needed
- Attention to nutrition
What are the potential complications of Bulbar palsy?
- Poor dentition
- Poor nutrition
- Psychological dysfunction
