Alternative Names isolated cold stress testing, ICST
Definition This test looks for reduced blood flow in the fingers after they are exposed to cold temperatures.
Who is a candidate for the test? Rarely, a cold stimulation test may be advised when a doctor suspects Raynaud's phenomenon. This condition causes the small arteries of the fingers, toes, ears, or nose to go into spasm. The spasm causes changes in skin colour. Feelings of numbness and pain also often occur. Cold temperatures or emotional stress can bring on symptoms of Raynaud's phenomenon. When this condition lasts for 2 years or more and an underlying cause cannot be found, it is called Raynaud's disease. The cold stimulation test is used to see if a person's symptoms are from Raynaud's phenomenon or other causes of low blood flow, such as arteriosclerosis.
How is the test performed? A heat sensor is attached to the person's fingers to measure their normal temperature. Then, each finger is chilled with cold water or some other device. The fingers are removed from the cold after a short period of time. The skin temperature of the fingers is measured every 5 minutes until it returns to normal.
What is involved in preparation for the test? No special preparation is needed for this test.
What do the test results mean? Normally, cold causes little decrease in blood flow to the fingers. Skin temperature generally returns to normal within 15 minutes. Raynaud's phenomenon is often present if it takes more than 20 minutes for the fingers to return to normal temperature.
Author: Reviewer: eknowhow Medical Review Panel Editor: Dr John Hearne Last Updated: 25/04/2005 Contributors Potential conflict of interest information for reviewers available on request
