Quantitative sensory testing (QST) is a panel of diagnostic tests used to assess
somatosensory function, in the context of research and as a supplemental tool in the diagnosis of somatosensory disorders, including pain insensitivity, painless and painful
neuropathy
Peripheral neuropathy, often shortened to neuropathy, is a general term describing disease affecting the peripheral nerves, meaning nerves beyond the brain and spinal cord. Damage to peripheral nerves may impair sensation, movement, gland, or or ...
. The panel of tests examine a broad range of different sensations, including hot, cold, touch, vibration. It has both positive and negative tests (can test for increased or reduced sensitivity). QST reflects a formalisation of existing neurological tests into a standardised battery designed to detect subtle changes in sensory function.
Large datasets representing normal responses to sensory tests have been established to quantitate deviation from the mean and allow comparison with normal patients. It is thought that a detailed evaluation of somatosensory function may be useful in identifying subtypes of pain and as a potential tool to identify
asymptomatic
In medicine, any disease is classified asymptomatic if a patient tests as carrier for a disease or infection but experiences no symptoms. Whenever a medical condition fails to show noticeable symptoms after a diagnosis it might be considered as ...
neuropathy, which may represent up to 50% of total people with neuropathy (or loss of the nerve fibres). In clinical use, it is often combined with other tests such as
clinical electrophysiology
Clinical electrophysiology is the application of electrophysiology principles to medicine. The two main branches of this discipline are electrotherapy and electrophysiologic testing (EEG, electromyography, etc.) Clinical electrophysiology can be ...
.
In research settings it is increasingly applied in combination with advanced imaging such as
fMRI, epidermis "nerve" biopsies and
microneurography to classify subtypes of painful disorders.
Clinical recommendations
The Neuropathic Pain Special Interest Group (NeuPSIG) of the
International Association for the Study of Pain (IASP) have recommended the clinical use of QST in the diagnosis and evaluation of patients with small and large fibre neuropathy as well as screening for deficits of the somatosensory system (which may include deficits in the brain for instance). The group