Quality-specific taste changes in multiple sclerosis.

Taste sensitivity in 79 patients with multiple sclerosis (MS) and 65 age- and sex-matched control subjects was measured with a sip-and-spit, suprathreshold scaling, magnitude estimation procedure using six concentrations each of sodium chloride, sucrose, citric acid, and quinine hydrochloride. Results were analyzed with a taste scoring system and by plotting psychophysical functions (log concentration versus log magnitude estimate) normalized to 1.0 M sucrose. Gender did not affect taste scores, but age was inversely related, so the results were analyzed by an analysis of covariance with age as the covariant. There was a significant alteration in taste sensitivity in the subjects with MS for sodium chloride and quinine hydrochloride stimuli but not for sucrose and citric acid; these results were confirmed by a separate analysis of the psychophysical functions. Some of the MS taste scores correlated with MS functional and physical disability scores. Taste sensitivity was not correlated with clinical history or presence of facial symptoms.