Figure 2. Cognition-related responses to levodopa treatment: Network effects.
(A) Changes in verbal learning performance with levodopa treatment differed (p < 0.001; 2 × 2 repeated-measures analysis of variance [RMANOVA], see Results) in cognitive responders (LDR; n = 8) and nonresponders (LDNR; n = 9). (B) Levodopa-mediated changes in Parkinson disease–related cognitive pattern (PDCP) expression differed for cognitive responders and nonresponders (p = 0.03; 2 × 2 RMANOVA, interaction effect), with treatment-mediated declines in the former (p = 0.008; post hoc Bonferroni test) but not the latter (p = 0.78). (C) Levodopa-mediated changes in Parkinson disease–related motor pattern (PDRP) expression also differed for the 2 subgroups (p = 0.001; 2 × 2 RMANOVA, interaction effect). For this motor-related metabolic network, levodopa-mediated reductions were present in both cognitive responders (p < 0.001; post hoc Bonferroni test) and nonresponders (p = 0.03). *p < 0.05, **p < 0.01, ***p < 0.001, Student t tests for comparisons of network activity in each subgroup with corresponding healthy control values; see Methods.