Expect to sit or lie still while a small probe with gel is held against your temple, behind your ear and sometimes at your closed eyelid. You will hear a pulsing sound representing blood flow. It is painless and takes no preparation beyond avoiding caffeine if asked.
Expect to sit or lie still while a small probe with gel is held against your temple, behind your ear and sometimes at your closed eyelid. You will hear a pulsing sound representing blood flow. It is painless and takes no preparation beyond avoiding caffeine if asked.
Ultrasound cannot pass through thick bone, so the study uses thin areas of the skull called acoustic windows: at the temple, just behind and below the ear, and through the closed eyelid. The technologist applies gel and moves the probe around to locate each window, which can take a little searching. Some people have poor windows, particularly with increasing age, and that is a technical limitation of anatomy rather than a finding about your circulation.
You feel steady pressure from the probe and the coolness of the gel, and nothing else. You will hear a rhythmic pulsing or whooshing, which is the Doppler signal representing blood movement and changes pitch with flow speed. That sound is entirely expected. You may be asked to hold still, to turn your head slightly, or occasionally to breathe in a particular way for part of the study. Nothing is injected in a standard examination.
Sustained pressure at the temple can become tiresome, and the eyelid approach feels odd though it is done gently and briefly at a lower power setting. Say if either is uncomfortable, since there is usually more than one route to the same vessel. If a bubble study or another specialised version involving an injected agent is planned, that is explained and consented separately beforehand. Transcranial Doppler is performed at both CNS offices and interpreted by the ordering neurologist.
Clinical Neurology Specialists has been physician-owned since 1998, when Leo Germin, M.D., FAANEM founded it. Five board-certified neurologists and four advanced practice providers see patients at the Las Vegas and Henderson offices, each with its own AANEM-accredited electrodiagnostic laboratory.
Clinical Neurology Specialists is an adult outpatient neurology practice for patients 18 and older. The practice performs no surgery and operates no imaging suite, infusion suite or interventional pain programme, and provides no emergency or inpatient care.
Physician-reviewed. Reviewed by the physicians of Clinical Neurology Specialists — board-certified neurologists, AANEM-accredited electrodiagnostic laboratories, physician-owned since 1998. Reviewed 1 August 2026. This article is general education for adults 18 and older and is not a substitute for a consultation.
Sources and further reading: National Institute of Neurological Disorders and Stroke; MedlinePlus: carotid artery disease; MedlinePlus, National Library of Medicine.
Adults 18 and older, at the Las Vegas and Henderson offices. Call 702-804-1212 or request an appointment online.