Evaluation of Central Sensitization, Fear-Avoidance, and Pain-Pressure Threshold With Chronic Pain After Hysterectomy

Performed on bilateral trapezius muscles. Pressure will be applied at 90 degrees downward with an algometer, with the speed of pressure increase approximately 1kgf/s. Upon the sensation of pain, the patient will vocalize or raise her hand to terminate the test, and the highest reading will be recorded (up to maximum 6kgf). If two values are recorded within 0.2kgf of each other, the mean value will be recorded. If two values are greater than 0.2kgf of each other, a third test will be performed and the mean obtained.

"Pinprick hyperalgesia will be evoked using a Von Frey filament, applied to the volar aspect of the dominant forearm. Participants will report using the numerical rating scale the intensity of pain from the first stimulus. Subsequently, ten repetitive stimuli one second apart will be applied with the same filament within an area of 1cm diameter of the same forearm. Subjects will report the rate the pain intensity of the tenth stimulus. The magnitude of MTS is calculated as the difference between the last to the first pain scores. The investigators will classify the participants according to evoked MTS if the last stimulus is rated higher than the first, or no MTS if the last stimulus is rated equal or lower than the first. The research team administering the test will follow a set script."

Standardized questionnaire to determine the level of anxiety and depression.

Standardized questionnaire to determine the level of pain catastrophizing.

Standardized questionnaire to determine the level of central sensitization.

Standardized questionnaire to determine the level of fear and avoidance.

Standardized questionnaire to assess generic health-related quality of life.

Heart rate variability will be determined from the R-to-R intervals obtained from a 5-minute ECG recording.

Preoperative anxiety (0 to 100), anticipated pain (0 to 100), and anticipated analgesia requirement (0 to 5).

Standardized questionnaire to assess anxiety.

Standardized questionnaire to assess depressive symptoms.