"Tip-of-the-tongue" phenomenon in Parkinson disease.

Articulatory disturbances are frequently described in Parkinson disease, but language disorders are not. We have occasionally encountered parkinsonian patients with word-finding difficulty unrelated to memory loss, intellectual impairment, or dysarthria. To examine this, 22 medically stable parkinsonian patients were given the vocabulary subtest of the WAIS, the Boston Naming Test, measures of verbal fluency, and sentence repetition. Signs and symptoms of parkinsonism were rated. WAIS vocabulary subtest scores were above the mean for normal aged subjects, but confrontation naming was one standard deviation below norms for age and education. Naming was facilitated by cues in most patients. Only sentence repetition correlated with dysarthria. Category naming was impaired and correlated significantly with the severity of parkinsonism, especially bradykinesia. This suggests that a type of anomia may occur in Parkinson disease. it shares the clinical characteristics of the "tip-of-the-tongue" phenomenon and "word production anomia" seen in some aphasics.