Table 1.

Parameters for the Time Course of Tic Severity Function

ParametersMean (SD)
Age at onset (τ1)4.8 (0.50)
Age when tics were at their worst (τ2)9.9 (0.85)
Onset slope (α)0.15 (0.05)
Intercept for quadratic function (β0)−11.9 (8.6)
Ascending slope (β1)3.5 (2.4)
Ascending quadratic coefficient (β2)−0.19 (0.16)
Intercept for linear decline (γ0)6.5 (1.1)
Slope for linear decline (γ1)0.29 (0.07)