A patient develops tearing while eating several months after recovering from Bell's palsy. The mechanism involves regeneration of salivary secretomotor fibres that have grown into which wrong pathway?

• A Chorda tympani fibres regenerating along the greater superficial petrosal nerve to the lacrimal gland ✓
• B Greater superficial petrosal fibres regenerating along the chorda tympani to the submandibular gland
• C Nerve to stapedius fibres regenerating into the lesser petrosal nerve
• D Facial motor fibres regenerating into the trigeminal sensory root

Explanation

Crocodile tears (gustatory lacrimation, Bogorad syndrome) result from aberrant regeneration: preganglionic salivary fibres destined for the chorda tympani and submandibular and sublingual glands sprout into the greater superficial petrosal pathway and reach the pterygopalatine ganglion, whose postganglionic fibres supply the lacrimal gland. Eating therefore triggers tearing. The reverse misdirection in option B would cause gustatory sweating patterns, and options C and D involve fibre types unrelated to lacrimation.

Reference: Cummings Otolaryngology: Head and Neck Surgery, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.