Pain in tones - Is it possible to hear the pain quality? A pilot trial.
The adequate treatment of chronic pain also calls for measuring its quality not only its intensity. For this reason, this pilot study investigated the non-verbal description of pain quality based on tones, distinguishing between nociceptive and neuropathic pain. A nociceptive and a neuropathic pain stimulus were applied to 80 chronic pain patients and 80 healthy subjects. Using a tone generator, all participants matched both pain stimuli to an appropriate tone (in Hz). The stimulus intensity was measured using the NRS-scale, and the PainDETECT questionnaire was completed. Both groups matched a significantly higher tone to the neuropathic than to the nociceptive pain stimulus. Compared to healthy participants, chronic pain patients allocated higher tones to both pain stimuli. Higher values were also shown for the neuropathic pain stimulus, and chronic pain patients indicated an overall higher intensity of pain as healthy participants. It is possible to differentiate pain stimuli non-verbally through tones, however, whether quality or intensity, was the key factor remains unknown. Future studies could investigate the influence of additional factors. A practical tool using tones should be developed to detect pain quality in patients - without verbal descriptions - quickly and more precisely.