Figure 4.

Responses to cold application in patients with painful posttraumatic trigeminal neuropathy (PTTN) and healthy controls. Results show evaluations in the subjects' affected (injured) and contralateral trigeminal sites. Data are presented as mean ± SD. Nonparametric analysis was used to compare the difference between study groups. The exact Wilcoxon rank sum test was used to compare the medians of 2 groups (PTTN and control), and the exact Kruskal–Wallis test was used to compare the medians across multiple groups (PTTN > 1 year, PTTN < 1 year, and controls). (A) The duration of pain after cold application in patients with PTTN was significantly (*) longer at both the affected (injured) and contralateral sites relative to controls. (B) Patients with PTTN who suffered from the condition for more than a year had significantly (*) increased duration of cold pain sensation in the affected and contralateral sides relative to controls.