Pseudobulbar and bulbar palsies
aka Neurological Mind-boggler 005
You have an emotionally labile patient in the department who sounds like ‘Donald duck’. Before rounding up some students to ‘pimp‘ you decide to test yourself on bulbar and pseudobulbar palsies so that you don’t get caught out…
Questions
Q1. What neurological lesions are involved in bulbar and pseudobulbar palsies?
Answer and interpretation
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.
Q2. What are the clinical features of a bulbar palsy?
Answer and interpretation
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.
Q3. What are the clinical features of a pseudobulbar palsy?
Answer and interpretation
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.
Q4. What are the causes of a bulbar palsy?
Answer and interpretation
Causes include:
- Motor neurone disease
- Syringobulbia
- Guillain-Barre syndrome
- Poliomyelitis
- Subacute menignitis (carcinoma, lymphoma)
- Neurosyphilis
- Brainstem CVA
Q5. What are the causes of a pseudobulbar palsy?
Answer and interpretation
The commonest cause is bilateral CVAs affecting the internal capsule.
Other causes include:
- Multiple sclerosis
- Motor neurone disease
- High brainstem tumours
- Head injury
References
- Brainstem Rules of 4 (original rules)
- Helpful Brainstem Figures (original figures)
- The rule of 4 of the brainstem (Rules re-imagined)
- Using the Brainstem 1
- Using the Brainstem 2
- The Magic of the Neuro Exam
CLINICAL CASES
Neurological Mind-boggler
Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also a Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.
After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.
He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE. He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.
His one great achievement is being the father of three amazing children.
On Twitter, he is @precordialthump.
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