Two-point discrimination To determine the patients' tactile spatial resolution, the static two-point discrimination threshold (2PD) was investigated 17. The smallest distance between two simultaneously presented punctiform stimuli was evaluated using a medical calliper (Schieblehre Zürcher Modell, 125mm, Hammacher Instrumente, Germany). The separation between the two tips ranged from 0 to 15 mm; the cut-off was set to 15 mm. A staircase method was used with descending distances. The participant was asked to indicate whether he/ she sensed one or two points and the corresponding distances were noted. The mean between those two distances was considered as individual minimum 2PD.