Quantification of the human painful sensory experience is an essential step in the
translation of knowledge from animal nociception to human pain. Translational models
for assessment of pain are very important, as such models can be used in: 1) basic
mechanistic studies in healthy volunteers; 2) clinical studies for diagnostic and
monitoring purposes; 3) pharmacological studies to evaluate analgesic efficacy of
new and existing compounds. Quantitative pain assessment, or quantitative sensory
testing (QST), provides psychophysical methods that systematically document alterations
and reorganization in nervous system function and, in particular, the nociceptive
system. QST is defined as the determination of thresholds or stimulus response curves
for sensory processing under normal and pathophysiological conditions. The modern
concept of advanced QST for experimental pain assessment is a multimodality, multitissue
approach where different pain modalities (thermal, mechanical, electrical, and chemical)
are applied to different tissues (skin, muscles, and viscera) and the responses are
assessed by psychophysical methods (thresholds and stimulus-response functions). Many
new and advanced technologies have been developed to help relieve evoked, standardized,
and painful reactions. Assessing pain has become a question of solving a multi-input,
multi-output problem, with the solution providing the possibility of teasing out which
pain pathways and mechanisms are involved, impaired, or affected.
Many methodologies have been developed for quantitative assessment of pain perception
and involved mechanisms. This paper describes the background for the different methods,
the use in basic pain experiments on healthy volunteers, how they can be applied in
drug profiling, and the applications in clinical practice.