A disorder of upper motor neurons or their descending tracts to motor neurons in the brainstem can result in pseudobulbar palsy.
Synonym: supranuclear palsy
Muscles affected:
(1) jaw
(2) tongue
(3) soft palate
(4) pharynx
(5) larynx
(6) face
Clinical findings in affected muscles:
(1) spasticity
(2) mild weakness
(3) mild slowing of movements
(4) hyperreflexia (brisk jaw jerk)
Functions affected:
(1) speaking and articulating
(2) chewing (mastication)
(3) swallowing (deglution)
An important diagnostic finding is emotional lability (emotional incontinence) with an emotional stimulus triggering abnormal laughing or crying.
Differential diagnosis:
(1) bulbar palsy (associated with injury to the lower motor neurons)
