Comparison of performance on the oral versus written trail making test in patients with movement disorders

The Oral Trail Making Test (O-TMT) was designed as a clinical analog of the written version (W-TMT). There is debate, however, about whether the measurement of processing speed and set shifting is equivalent between versions. Given the administration advantages of the O-TMT - especially for patients with motor impairments - we examined convergent validity with the W-TMT in patients with movement disorders. Fifty patients (n = 43 idiopathic Parkinson's disease [PD]) were evaluated in a movement disorders clinic. Patients averaged 71 years old (SD = 8.07 years), 16 years of education (SD = 2.30 years), and the majority were non-Hispanic White (n = 46) and male (n = 35). In addition to other neuropsychological measures, patients completed the O-TMT and the W-TMT, counterbalanced and separated by thirty-minutes. Part A scores on O-TMT and W-TMT were not significantly correlated. In contrast, Part B scores were strongly correlated, such that slower performances on O-TMT Part B corresponded with slower performances on W-TMT Part B. Discrepancy scores (Part B minus Part A completion times) were also strongly correlated, such that more time on O-TMT, indicative of slower set shifting speed, corresponded with more time on W-TMT. Better performances on both O-TMT B and W-TMT B were associated with better scores on measures of overall cognitive status, verbal learning, and both phonemic and semantic fluency. Part B of the O-TMT shows promise as an analog for Part B of the W-TMT when evaluating set shifting abilities in patients with movement disorders. Future research with diverse patient populations is recommended to establish generalizability.