Quantitative Sensory Testing (QST) - Does assessing ... - TI Pharma

4. QST and neuropathic pain mechanisms
Fig. 4-2: Mechanical Pain Sensitivity (MPS) stimulus-response functions for neuropathic pain
patients (n=24). Patients with MPS z-score values outside of the 95% CI showed an absence
of stimulus-response function to pinpricks. Stimulus-response functions were assessed by
seven pinpricks exerting forces of 8mN, 16mN, 32mN, 64mN, 128mN, 256mN and 512mN.
Each data point represents mean value for numerical rating scale (NRS (0-100)) for the painfulness
of five stimulations for each pinprick force.
3.4. Clinical diagnoses of patients with MPS abnormalities and different
stimulus-response functions for pinpricks
All patients with MPS abnormalities have been diagnosed with neuropathic pain.
Patients with stimulus-response function for MPS included peripheral nerve injury
(n=13), complex regional pain syndrome (CRPS)-II (n=1) and central pain (n=2). Similar
clinical entities are reflected in the group of patients with a lack of a stimulus-response
function for MPS. In this group, patients were diagnosed with peripheral nerve injury
(n=14), polyneuropathy (n=6), central pain (n=3) and postherpatic neuralgia (n=1).
Disease duration for each of these two groups ranged between 1 year and 15 years.
Similar clinical entities of neuropathic pain patients were for both groups of MPS
abnormalities indicating that the phenomenon of different responder to pinprick pain is
not restricted to the clinical entity.