Pain experience and expression in Rett syndrome: Subjective and objective measurement approaches.

Rett syndrome (RTT) is associated with myriad debilitating health issues and significant motor and communicative impairments. Because of the former there is concern about the possibility of recurrent and chronic pain but because of the latter it remains difficult to determine what pain 'looks like' in RTT. This study investigated pain experience and expression using multiple complementary subjective and objective approaches among a clinical RTT sample. Following informed consent, 18 participants (all female) with RTT (mean age= 12.8 years, SD= 6.32) were characterized in terms of pain experience and interference, typical pain expression, and elicited pain behavior during a passive range of motion-like examination procedure. Parents completed the Dalhousie Pain Interview (DPI; pain type, frequency, duration, intensity), the Brief Pain Inventory (BPI; pain interference), and the Non-Communicating Children's Pain Checklist - Revised (NCCPC-R; typical pain expression). A Pain Examination Procedure (PEP) was conducted and scored using the Pain and Discomfort Scale (PADS). The majority of the sample (89%) were reported to experience pain in the previous week which presented as gastrointestinal (n=8), musculoskeletal (n=5), and seizure related pain (n=5) that was intense (scored 0-10; M = 5.67, SD = 3.09) and long in duration ( M = 25.22 hours, SD = 53.52). Numerous pain-expressive behaviors were inventoried (e.g., vocal, facial, mood/interaction changes) when parents reported their child's typical pain behaviors and based on independent direct observation during a reliably coded pain exam. This study provides subjective and objective evidence that individuals with RTT experience recurring and chronic pain for which pain expression appears intact.