Pulsatile tinnitus is a distinct type of tinnitus characterized by a rhythmic sound, often noticed or worsened when lying down. This internal sound typically synchronizes with one’s heartbeat, manifesting as a whooshing, thumping, or pulsing sensation. This article explores the specific nature of pulsatile tinnitus and its connection to body position, especially when a person is lying flat.
What is Pulsatile Tinnitus?
Pulsatile tinnitus contrasts with more common forms of tinnitus, which often involve ringing, buzzing, or hissing sounds not synchronized with the pulse. Unlike subjective tinnitus, which only the affected individual perceives, pulsatile tinnitus can sometimes be objective, meaning a healthcare professional might also hear it during an examination.
This condition stems from its direct link to the body’s circulatory system. The sounds are essentially amplified perceptions of blood flowing through nearby vessels. Pulsatile tinnitus is a symptom, not a disease in itself, and its presence often indicates an underlying physiological change or medical condition that warrants further investigation.
Why Position Matters
Pulsatile tinnitus often becomes more noticeable when lying down due to physiological adjustments in blood flow dynamics and pressure within the head and neck. When a person lies flat, gravity no longer assists blood drainage from the head and upper body, which can lead to increased venous return to the heart and head. This shift in blood volume and flow can make existing turbulent blood flow in vessels near the ear more perceptible.
Lying down can also influence intracranial pressure (ICP), the pressure within the skull. An increase in ICP can affect the flow of blood through veins, potentially causing or exacerbating the pulsatile sound. The quieter environment when lying down, especially at night, also plays a significant role. With reduced external noise to mask internal sounds, the body’s own circulatory sounds become more apparent.
Common Underlying Causes
Pulsatile tinnitus can stem from various medical conditions that alter blood flow near the ear. Vascular issues are frequently implicated, involving both arterial and venous systems. Arterial causes include atherosclerosis, where plaque buildup narrows arteries and creates turbulent blood flow, and aneurysms, which are weakened, bulging arterial walls. Conditions like carotid artery dissection, a tear in the major neck artery, or fibromuscular dysplasia, an abnormal development of arterial walls, can also lead to turbulent flow.
Venous causes often involve issues with large veins, such as the jugular veins. Venous hums, characterized by turbulent blood flow in these large veins, are a common benign cause. Benign intracranial hypertension, where there is elevated pressure of cerebrospinal fluid around the brain, can also cause pulsatile tinnitus by affecting venous outflow. Dural arteriovenous fistulas, abnormal connections between arteries and veins in the brain’s covering, can reroute blood flow and cause the sound.
Ear-related conditions can also contribute to pulsatile tinnitus. Glomus tumors, typically benign but highly vascular growths near the middle ear or jugular bulb, can create a sound as blood flows through them. Ear infections leading to fluid buildup in the middle ear, or a dehiscent jugular bulb, where part of the jugular vein wall is missing, can amplify internal body sounds. Systemic conditions affecting circulation, such as anemia, which increases blood flow velocity, or hyperthyroidism, which elevates metabolic rate and heart activity, may also lead to pulsatile tinnitus.
Seeking Medical Evaluation and Management
Any pulsatile tinnitus warrants medical evaluation by a healthcare professional, as it often signals an underlying condition that can range from benign to serious. The diagnostic process begins with a detailed medical history and a physical examination, where the doctor may listen for the sound.
Further diagnostic steps often involve imaging tests to pinpoint the source. These may include Magnetic Resonance Imaging (MRI) or Magnetic Resonance Angiography (MRA) to visualize blood vessels and brain structures, Computed Tomography (CT) or Computed Tomography Angiography (CTA), and sometimes venography or ultrasound. Blood tests may also be conducted to check for systemic causes like anemia or thyroid dysfunction.
Treatment focuses on addressing the underlying cause. This may involve medication for blood pressure or thyroid issues, surgical intervention for vascular malformations or tumors, or lifestyle modifications for conditions like benign intracranial hypertension. For benign causes like venous hums, watchful waiting may be recommended.