Quantitative Sensory Testing (QST): Difference between revisions
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== Introduction == | == Introduction == | ||
Quantitative sensory testing (QST) is a systematic psychophysical test method used to measure sensory thresholds for pain, touch, vibration, and temperature sensations.<ref name=":0">Horowitz SH. Neuropathic pain: is the emperor wearing clothes. Current Therapy in Pain, WB Saunders. 2009:9-14.</ref>It quantifies individual sensory perceptions using direct patient feedback. Sophisticated computerised equipment is often used in clinical trials, but hand-held tools are also available for clinical use<ref name=":0" />. | |||
== | == Clinical Application == | ||
QST can be used to evaluate any condition that affects sensory function - it may help with diagnosis and disease monitoring. QST can be very useful to identify underlying pain mechanisms and pathophysiology, which can assist with targeted intervention strategies<ref name=":1">Mucke M, Cuhls H, Radbruch L, Baron R, Maier C, Tolle T, Treede RD, Rolke R. Quantitative sensory testing (QST). English version. Schmerz. 2016;35:153-60.</ref>. It is best to compare results with normative values, and it is best conducted early after onset of a condition. Conditions for which QST can be useful include<ref name=":1" />: | |||
== | * Neuropathic pain | ||
* Polyneuropathy (diabetic, HIV-related, chemotherapy-related) | |||
* Postherpetic neuralgia | |||
* Complex regional pain syndrome (CRPS) | |||
* Chronic lower back pain | |||
=== Procedure and Components === | |||
To perform QST, a patient is stimulated with quantified sensory stimuli and based on patient feedback, perception thresholds are identified for the following sensory functions: light touch, pressure, vibration, thermal sensations, heat and cold pain. This way A-delta fibres (small diameter myelinated) and C-fibres (unmyelinated) are assessed. | |||
* '''Vibration''' | |||
* '''Cold''' | |||
* Heat | |||
* | |||
=== Interpretation === | |||
{| class="wikitable" | |||
|+Meaning of QST results<ref name=":0" /> | |||
!'''Underlying mechanism''' | |||
!'''QST finding''' | |||
|- | |||
|Hypoesthesia (sensory loss) | |||
|Elevated sensory thresholds | |||
|- | |||
|Allodynia and hyperalgesia | |||
|Lowered sensory thresholds | |||
|- | |||
|Peripheral sensitisation | |||
|Heat hyperalgesia | |||
|- | |||
|Central sensitisation | |||
|Static mechanical hyperalgesia or dynamic mechanical allodynia | |||
|- | |||
|Polyneuropathy | |||
|All thresholds elevated | |||
|- | |||
|Small fibre neuropathy | |||
|Vibration thresholds are normal, but others elevated | |||
|} | |||
=== Limitations === | |||
* QST abnormalities are present in non neuropathic pain, making it difficult to use QST as a definitive tool for identifying neuropathic pain<ref name=":0" /> | |||
* Abnormal findings are not specific for peripheral nerve dysfunction, as central nervous system disorders will also alter sensory thresholds<ref name=":0" /> | |||
* It is a subjective psychophysical test, entirely dependent on patient alertness, motivation and willingness to supply accurate feedback. There is large intra- and interindividual variation<ref name=":0" /> | |||
=== Complementary Tests === | |||
'''2-point discrimination''' | |||
== Evidence == | |||
== Resources == | == Resources == | ||
* | *'''[https://www.researchgate.net/publication/292339047_Quantitative_sensory_testing_QST_English_version#fullTextFileContent Quantitative Sensory Testing] -''' standardised full procedure | ||
* | * | ||
or | or | ||
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<references /> | <references /> | ||
[[Category:Assessment]] | |||
[[Category:Neurology]] | |||
[[Category:Pain]] | |||
Revision as of 16:45, 22 August 2023
This article or area is currently under construction and may only be partially complete. Please come back soon to see the finished work! (22/08/2023)
Original Editor - Melissa Coetsee
Top Contributors - Melissa Coetsee and Carina Therese Magtibay
Introduction[edit | edit source]
Quantitative sensory testing (QST) is a systematic psychophysical test method used to measure sensory thresholds for pain, touch, vibration, and temperature sensations.[1]It quantifies individual sensory perceptions using direct patient feedback. Sophisticated computerised equipment is often used in clinical trials, but hand-held tools are also available for clinical use[1].
Clinical Application[edit | edit source]
QST can be used to evaluate any condition that affects sensory function - it may help with diagnosis and disease monitoring. QST can be very useful to identify underlying pain mechanisms and pathophysiology, which can assist with targeted intervention strategies[2]. It is best to compare results with normative values, and it is best conducted early after onset of a condition. Conditions for which QST can be useful include[2]:
- Neuropathic pain
- Polyneuropathy (diabetic, HIV-related, chemotherapy-related)
- Postherpetic neuralgia
- Complex regional pain syndrome (CRPS)
- Chronic lower back pain
Procedure and Components[edit | edit source]
To perform QST, a patient is stimulated with quantified sensory stimuli and based on patient feedback, perception thresholds are identified for the following sensory functions: light touch, pressure, vibration, thermal sensations, heat and cold pain. This way A-delta fibres (small diameter myelinated) and C-fibres (unmyelinated) are assessed.
- Vibration
- Cold
- Heat
Interpretation[edit | edit source]
| Underlying mechanism | QST finding |
|---|---|
| Hypoesthesia (sensory loss) | Elevated sensory thresholds |
| Allodynia and hyperalgesia | Lowered sensory thresholds |
| Peripheral sensitisation | Heat hyperalgesia |
| Central sensitisation | Static mechanical hyperalgesia or dynamic mechanical allodynia |
| Polyneuropathy | All thresholds elevated |
| Small fibre neuropathy | Vibration thresholds are normal, but others elevated |
Limitations[edit | edit source]
- QST abnormalities are present in non neuropathic pain, making it difficult to use QST as a definitive tool for identifying neuropathic pain[1]
- Abnormal findings are not specific for peripheral nerve dysfunction, as central nervous system disorders will also alter sensory thresholds[1]
- It is a subjective psychophysical test, entirely dependent on patient alertness, motivation and willingness to supply accurate feedback. There is large intra- and interindividual variation[1]
Complementary Tests[edit | edit source]
2-point discrimination
Evidence[edit | edit source]
Resources[edit | edit source]
- Quantitative Sensory Testing - standardised full procedure
or
- numbered list
- x
References[edit | edit source]
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Horowitz SH. Neuropathic pain: is the emperor wearing clothes. Current Therapy in Pain, WB Saunders. 2009:9-14.
- ↑ 2.0 2.1 Mucke M, Cuhls H, Radbruch L, Baron R, Maier C, Tolle T, Treede RD, Rolke R. Quantitative sensory testing (QST). English version. Schmerz. 2016;35:153-60.
