Table 1.
Regions of Dissociated Vasomotor and Metabolic Levodopa Responses.
| Voxel Search | Coordinates | Cluster Size (Voxels) | Zmax | p-valuea | CBF | CMR | Interaction Effect (VOI Analysis) | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| x | y | z | OFF/PRE | ON | OFF/PRE | ON | F-valuec | p-value | ||||
| CBF/CMR × OFF/ON | 3.2 | −1.4 | −7.2 | 49 | 3.78 | p < 0.001 | 1.04(0.20)b | 1.34(0.18) | 1.13(0.07)b | 1.16(0.07) | 10.85 | 0.011 |
| CBF/CMR × PRE/ON | 3.4 | −1.4 | −7.4 | 107 | 4.12 | p < 0.001 | 1.05(0.10) | 1.29(0.20) | 1.21(0.05) | 1.17(0.08) | 16.42 | 0.005 |
aCorrected for cluster extent at p ≤ 0.05.
bMean(SD) for local cerebral blood flow (CBF) and cerebral metabolic rate for glucose (CMR) in each of the significant clusters.
cF-tests for tracer × condition interaction effects in each volume-of-interest (VOI); repeated measured analysis of variance (RMANOVA).
PRE = drug-naïve baseline condition; OFF = saline injection; ON = levodopa injection following three weeks of daily drug administration (see text).