[Taste disturbance after tonsillectomy]

There are some patients, though few in number, who complain of taste disturbance after tonsillectomy. Actual measurement of the distance between the lingual branch of the glossopharyngeal nerve, which controls taste in the posterior portion of the tongue, and the lower pole of the palatine tonsil, using a cadaver, showed the distance to be only 2-4 mm, thereby suggesting the danger of direct or indirect disturbance of this nerve by tonsillectomy. Among the 3,583 outpatients complaining of taste disturbance whom we have treated at our taste disorder clinic in the last 15 years, 11 (0.31%) were found to be suffering from taste disorder triggered by tonsillectomy. Among these 11 causes, the causes of taste disturbance have been identified in 8 cases. In three cases, the taste disturbance was caused by direct or indirect damage to the lingual branch of the glossopharyngeal nerve, whereas in another two cases, the disturbance was attributable to medication following tonsillectomy. In the remaining three cases, the diagnosis was a taste disturbance initiated by tonsillectomy but actually caused by a lack of dietary zinc. It is therefore important that patients be informed of the risk of post-operative taste disorder following tonsillectomy, at the time informed consent for tonsillectomy is obtained. It is equally important to measure the taste threshold values for each taste nerve and the serum zinc value as part of the pre-operational examination, and to ask the patients what drugs, if any, they take habitually.