Pulsatile tinnitus is a rhythmic whooshing or throbbing sound that aligns with one’s heartbeat. This sensation can become more pronounced or appear when an individual bends over. Understanding why body position influences this unique auditory experience can provide insight into its potential origins.
Understanding Pulsatile Tinnitus
Pulsatile tinnitus is a rhythmic sound, often described as a whooshing, throbbing, or humming, that synchronizes with the heartbeat. This differs from other forms of tinnitus, which typically involve constant ringing, buzzing, or hissing noises. Its key characteristic is a direct connection to the body’s circulatory system.
Unlike non-pulsatile tinnitus, which is generally subjective and heard only by the affected individual, pulsatile tinnitus can sometimes be objective. This means a medical professional may hear the sound using a stethoscope placed near the ear or neck. A doctor’s ability to detect the sound often indicates a physical source within the body, usually related to blood flow.
Why Bending Over Affects It
Bending over can significantly affect pulsatile tinnitus due to temporary physiological changes in the head and neck. When the head is lowered, blood flow to the brain and head increases, and venous return from the head can slow down. This positional change leads to a transient rise in both blood volume and pressure within the blood vessels of the head and neck.
The increased pressure and volume can cause greater turbulence in blood flow through arteries and veins located near the ear. Any existing irregularities or narrowing in these vessels, which might otherwise be silent, can become audible as blood rushes through them with greater force. This amplified turbulent flow is then perceived as the pulsatile sound.
Bending over also temporarily increases intracranial pressure, the pressure within the skull. This elevated pressure can affect the large veins that drain blood from the brain, such as the transverse and sigmoid sinuses. If these veins have narrowing or unusual anatomy, the increased pressure can exacerbate turbulent flow, making the pulsatile sound more noticeable.
The change in position creates a temporary “stress test” on the vascular system around the ear and head. It can reveal subtle blood flow disturbances not apparent in an upright position, thereby making an underlying vascular anomaly or condition more evident. For some individuals, this positional change is the primary trigger for experiencing pulsatile tinnitus.
Common Underlying Causes
Pulsatile tinnitus often stems from an identifiable medical condition affecting blood flow or structures near the ear. Vascular issues are frequently implicated, including conditions where blood vessels are malformed, narrowed, or experience turbulent flow.
Vascular Causes
Arteriovenous malformations (AVMs) and dural arteriovenous fistulas (DAVFs) are abnormal connections between arteries and veins that create turbulent blood flow.
Atherosclerosis, or hardening of the arteries, can cause pulsatile tinnitus when plaques build up and create uneven, noisy blood flow through narrowed vessels, particularly in the carotid arteries.
High blood pressure, by increasing the force of blood flow, can similarly contribute to the perception of these sounds.
Venous hums, which are benign sounds from turbulent blood flow in the jugular veins, often heard more clearly in certain positions.
Structural anomalies like a high-riding jugular bulb, where the jugular vein is unusually close to the middle ear, or a sigmoid sinus diverticulum, an outpouching of a vein, can also lead to pulsatile tinnitus.
Tumors located near blood vessels in the head or neck, such as glomus tumors, may produce this symptom by altering blood flow.
Non-Vascular Causes
Idiopathic intracranial hypertension (IIH), a condition characterized by increased pressure of the fluid surrounding the brain, is a frequent cause, often linked to narrowing of the brain’s venous sinuses.
Anemia and hyperthyroidism can lead to increased blood flow velocity throughout the body, which may become audible.
Diagnosis and Treatment Approaches
Seeking a medical evaluation is a sensible first step for anyone experiencing pulsatile tinnitus. A primary care physician can provide an initial assessment and may refer to specialists like an otolaryngologist (ENT), neurologist, or neurointerventional radiologist. The diagnostic process begins with a thorough medical history and physical examination, which may include listening with a stethoscope over the neck and skull to determine if the sound is objective.
Imaging studies are essential to pinpoint the underlying cause. Common tests include Magnetic Resonance Imaging (MRI) and Magnetic Resonance Angiography (MRA) of the head and neck, which provide detailed images of soft tissues and blood vessels. Computed Tomography (CT) scans, particularly CT Angiography (CTA) or CT Venography (CTV), can also visualize blood vessels and bone structures. A specialized ultrasound of the carotid arteries may be performed to assess for narrowing.
Treatment for pulsatile tinnitus is directed at addressing the specific underlying condition. If high blood pressure is the cause, medication and lifestyle adjustments like diet and exercise may be recommended. For IIH, weight loss and certain medications are often the primary treatments.
Vascular anomalies like AVMs or DAVFs might require interventional procedures or surgery to correct the blood flow abnormality. If a tumor is identified, its removal may resolve the tinnitus. Sometimes, even after addressing the underlying cause, sound therapy or masking devices can help manage any residual perception of the sound.