Quantitative Sensory Testing

Quantitative Sensory Testing (QST) is a non-invasive and no-painful technique and a valuable method for diagnosing peripheral nervous system disorders, pain and pain related to various diseases. QST determines the sensation and pain thresholds for cold or warm temperatures, vibration and pressure sensation threshold by stimulating the skin and comparing the results with baseline measurements. The nociceptive threshold is considered to be the magnitude of stimulus at which the patient responds, evaluated by a behavioural reflex (skin twitch, limb withdrawal, tail flick) or by a more organized and co-ordinated response (look at the stimulated area, attempt to remove the stimulating source or attempt to escape from it) (Le Bars et al. 2001). Organized attempts to avoid the stimulus reflect an aversive cortical perception of the stimulus and a spinal reflex actions reflect a stimulation of nociceptive pathways without a mandatory aversive conscious experience of the stimulus (35).

1996). PA provides an objective assessment of nociception and also enable pain localization to the affected structures (Keating et al. 2001). (33) Mechanical hyperalgesia resulting from peripheral and/or central sensitization is detected by the reduction in tolerance of the force applied on the area around the wound with the comparison to a baseline, measured before surgical intervention. The differentiation between peripheral and central sensitization has been described by applying a stimulus at a site distant to the surgical site (Lascelles et al 1997)