Surgical reneurotization of the tongue after unilateral paralysis of the hypoglossal nerve.

Hemiglossal paralysis due to lesions of the peripheral hypoglossal nerve leads to marked muscle atrophy with disturbed functioning in a minority of cases. Reinnervation from the unparalyzed, contralateral side may then be desired. In animal experiments on cats, a Z-plasty of the midportion of the tongue was carried out by transposing a portion of the normal tongue musculature into the opposite side following denervation 1 month previously by resection of the hypoglossal nerve. Electromyography was performed 13 months later. The tongue was then examined histochemically in serial sections in search of the motor endplates together with the nerves fibers. However, there was no evidence for reinnervation in the specimens examined. Signs of successful "reanimation" of the tongue by Z-plasty may be caused by mechanical synkinesia due to scar formation rather than by actual reneurotization.