Quantitative sensory testing
NRS, Pain, pain
Bi-weekly (during their visit to the coordinating center), we will apply two experimental tests to determine the pain system of the patient. Pain test 1 is a pressure pain threshold test. Pain test 2 tests pain summation to repetitive pinprick stimuli (wind-up). For pain pressure, we will use the FDN 100 N Algometer (FDN 100, Wagner Instruments Inc., Greenwich, CT, USA). The algometer is used to deliver pressure pain on a skin area of 1 cmPain summation is obtained by applying a pin prick stimulator (MRC Systems, Germany) to the dorsal part of the hand. The patient will be requested to score the pin pricks on a 10-point numerical rating scale (NRS) ranging from 0 (no pain) to 10 (most severe pain imaginable). We will collect the NRS of the first and the last poke. An increase in NRS over the course of poking is a sign of central sensitization.