Table 2.
Significant differences in striatal RAC BP at rest and its changes during task production
| Striatum divisions | RAC BPND (spasmodic dysphonia/healthy controls) | Group difference in RAC BP-ND (spasmodic dysphonia < HV) (%) | ΔRAC BP (spasmodic dysphonia/healthy controls) (%) | Group difference in ΔRAC BP (spasmodic dysphonia < HV) (%) | Group difference in ΔRAC BP (spasmodic dysphonia > HV) (%) |
|---|---|---|---|---|---|
| Baseline | |||||
| L putamen | 1.8 ± 0.5/2.4 ± 0.5 | 25.8 | |||
| R putamen | 1.7 ± 0.5/2.3 ± 0.4 | 25.7 | |||
| L caudate | 1.0 ± 0.5/1.5 ± 0.4 | 31.8 | |||
| R caudate | 0.9 ± 0.5/1.3 ± 0.3 | 33.6 | |||
| Symptomatic sentence production | |||||
| L putamen | 1.2 ± 0.2/1.3 ± 0.2 | −5.7/−12.4 | 6.7 | ||
| L caudate | 0.9 ± 0.4/1.0 ± 0.2 | −3.5/−17.2 | 13.7 | ||
| Asymptomatic finger tapping | |||||
| L putamen | 1.6 ± 0.5/2.3 ± 0.4 | −11.0/−1.5 | 9.6 | ||
| R putamen | 1.7 ± 0.7/2.4 ± 0.4 | −11.0/−5.3 | 5.7 | ||
| L caudate | 0.6 ± 0.3/1.0 ± 0.4 | −17.9/−2.9 | 15.0 | ||
| R caudate | 0.8 ± 0.4/1.4 ± 0.4 | −10.8/−0.9 | 10.0 |
For RAC BPND at resting baseline, compared to controls, patients with spasmodic dysphonia showed significantly decreased RAC binding to striatal dopamine D2/3 receptors. RAC BPND values are derived from the resting PET scan preceding speech production and provide group means and SDs for each striatal regions at the resting state and the percentage group difference at a corrected value of p ≤ 0.017. There were no statistical differences in the RAC BPND measures in either controls or patients between the two resting scans obtained prior to speech and tapping respectively. For RAC BPND and ΔRAC BP during symptomatic sentence production, RAC BPND values are derived from the PET scan during speaking and provide group means and SDs, mean percentage change in RAC BP (ΔRAC BP), and the percentage group difference in ΔRAC BP at a corrected value of p ≤ 0.025. Compared to controls, patients showed decreased RAC displacement in the left putamen and caudate nucleus. There were no differences between the two groups in the right striatum. For RAC BPND and ΔRAC BP during asymptomatic finger tapping, RAC BPND values are derived from the PET scan during finger tapping and provide group means and SDs, mean percentage change in RAC BP (ΔRAC BP), and the percentage group difference in ΔRAC BP at a corrected value of p ≤ 0.025. Compared to controls, patients with spasmodic dysphonia showed increased RAC displacement during sequential tapping in the bilateral striatum. L, Left; R, right; HV, healthy volunteers.