.

Vanderbilt Autonomic Dysfunction Center

Transcranial Doppler

What is the purpose of transcranial doppler?

The purpose of performing transcranial doppler is to determine cerebral blood flow velocity.

How is the test performed?

This test is usually performed with the patient upright either standing or during head up tilt. A doppler probe will be placed on the head near the temple. The probe will emit high frequency sound waves (too high of a frequency to be heard) and detect them after they bounce off structures in the head. When a specific frequency is used, the moving blood inside the head causes changes to the sound waves that are related to how fast the blood is moving. This allows the determination of the speed of the blood in the cerebral vessels.

What are the expected results for a patient with POTS?

Patients with POTS often have decreased cerebral blood flow velocity when upright.

This page was last updated July 11, 2012 and is maintained by