Bulbar Reflexes

Bulbar reflexes, reflexes whose arcs are completed in the nuclei of the medulla oblongata. Of practical importance are especially the reflexes of Oppenheim and Hennenberg, which appear with bilateral lesions of supranuclear conductors, i.e., in pseudobulbar paralysis. The Oppenheim feeding reflex is caused by stroking stimulation of the lips and consists of a series of sucking, swallowing, and chewing movements. The Hennenberg reflex is caused by stroking stimulation of the hard palate and is expressed by contraction of the musculus orbicularis oris. The presence of these reflexes indicates a deep disconnection of the bulbar centers from the centers of the cerebrum. Accordingly, in adults, bulbar reflexes are observed in comatose states, in apoplectic stroke, in progressive paralysis, in certain stages of amyotrophic lateral sclerosis, etc. In early childhood (up to 8 months), the feeding reflex is also observed in normal conditions (Oppenheim). The Hennenberg reflex is rarely encountered even in early childhood in normal conditions.