PRL and Parkinson disease: Results of the Kruskal-Wallis test revealed a statistically significant difference in PD, CAL, and serum prolactin level among the 3 study groups (P ≤ 0.001, P = 0.001, and P ≤ 0.001 respectively), while BOP was slightly significant (P = 0.058), whereas mobility was not significantly different among the 3 groups (P = 0.214), as shown in Table 2.