INTRACTABLE SINGULTUS - A DIAGNOSTIC AND THERAPEUTIC CHALLENGE

Hiccup or singultus is a repeated involuntary, spasmodic contraction o f the diaphragm accompanied by a sudden closure of the glottis mediate d by sensory branches of the phrenic and vagus nerves as well as dorsa l sympathetic afferents. The principle efferent limb and diaphragmatic spasms are mediated by motor fibers of the phrenic nerve. Hiccup has been classified as a respiratory reflex and the central connection pro bably consists of an interaction among the brainstem respiratory cente rs, phrenic nerve nuclei, medullary reticular formation and the hypoth alamus. Chronic intractable hiccup may be due to brainstem seizures, a nd baclofen may be the long-awaited remedy for intractable hiccup as d emonstrated in three illustrative cases.