Word Finding Difficulty as a Post-Polio Sequelae

OBJECTIVE: Seventy-nine percent of respondents to the 1990 National Post-Polio Survey reported difficulty "thinking of words I want to say," with 37% reporting frequent, moderate-to-severe word finding difficulty. This study was undertaken to objectively document polio survivors' word finding difficulty and to identify its relationship to fatigue, neuropsychologic processes requiring cortical activation, and a peripheral marker for brain dopamine secretion. DESIGN: In this study, 33 polio survivors were administered the Post-Polio Fatigue Questionnaire, Animal Naming and FAS Tests, and tests of attention and information processing speed. Plasma prolactin was also measured as a marker for brain dopamine secretion. RESULTS: Subjects reporting high fatigue severity and word finding difficulty had clinically abnormal or significantly lower Animal Naming Test scores compared with subjects with low symptom severity. Impaired performance on the most difficult tests of attention and information processing speed were also associated with lower scores on the word finding tests. A significant negative correlation between Animal Naming Test scores and plasma prolactin suggests that a decrement in brain dopamine secretion is related to reduced animal naming ability. CONCLUSIONS: These data support the hypothesis that decreased dopamine secretion, possibly secondary to poliovirus damage to the basal ganglia, may underlie not only fatigue and impaired attention but also word finding difficulty in polio survivors.