Name of the Procedure:

Quantitative Sensory Testing (QST), Heat-Pain Stimuli

Summary

Quantitative Sensory Testing (QST) using heat-pain stimuli is a diagnostic procedure to evaluate the sensation and sensitivity of small nerve fibers in the extremities. It helps doctors understand how your nerves respond to heat and identify any abnormal pain sensations.

Purpose

This procedure aims to assess the function of small nerve fibers, which are crucial for detecting pain and temperature changes. It allows doctors to determine if there is any nerve damage or hyperalgesia (increased sensitivity to pain) in the extremities.

Indications

• Chronic pain in the extremities.
• Suspected small fiber neuropathy.
• Diabetic neuropathy.
• Unexplained burning or tingling sensations.
• Monitoring progression of nerve damage.

Preparation

• No fasting required.
• Continue taking regular medications unless otherwise directed by your doctor.
• Inform your doctor about any medications or conditions that might affect your pain sensitivity.

Procedure Description

1. The patient sits comfortably in a chair.
2. A heat probe is placed on the skin of the extremity being tested.
3. The probe gradually increases in temperature until the patient starts to feel pain.
4. The patient indicates when pain is first felt, and the temperature is recorded.
5. Several measurements are taken to ensure accuracy and consistency.
6. The same process is repeated for each extremity being tested.

Duration

The procedure typically takes 30-60 minutes, depending on the number of extremities tested.

Setting

QST is usually conducted in a hospital or outpatient clinic.

Personnel

• Neurologist or pain specialist.
• Trained technician or nurse.

Risks and Complications

• Mild discomfort or pain during the test.
• Rarely, minor skin irritation or burns.
• No significant long-term complications.

Benefits

• Accurate assessment of nerve function.
• Helps in diagnosing neuropathy and other nerve conditions.
• Guides treatment decisions for pain management.

Recovery

• No specific recovery process is needed.
• Patients can return to their normal activities immediately.
• Follow-up appointments may be scheduled to discuss test results.

Alternatives

• Electromyography (EMG) and Nerve Conduction Studies (NCS) for larger nerve fiber function.
• Skin biopsy to directly examine nerve fibers.
• Clinical examination and patient history review.

Patient Experience

During the procedure, you might feel mild discomfort or a burning sensation when the heat exceeds your pain threshold. The discomfort is temporary and stops once the probe is removed. Pain management measures and breaks can be provided to ensure comfort throughout the test.