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Keen’s Syndrome (Pulsatile Tinnitus)

What is Keen's syndrome (pulsatile tinnitus)?

Keen’s syndrome is another name for pulsatile tinnitus, a type of ringing, buzzing, or whooshing in the ears that is in sync with the patient’s heartbeat. Unlike the more common “subjective” tinnitus, which only the person hears, pulsatile tinnitus can sometimes be heard by a clinician using a stethoscope placed behind the ear or on the neck. The rhythmical nature of the sound points to a vascular origin—blood flowing through a vessel near the ear or abnormal blood flow patterns.

The condition is named after Dr. Bernard Keen, who first described the association between vascular abnormalities and rhythmic ear sounds in the 1960s. While often benign, pulsatile tinnitus can be a sign of serious underlying disease, so a systematic evaluation is essential.

Common Causes

More than a dozen conditions can produce pulsatile tinnitus. The most frequent causes are vascular, but structural and metabolic factors also play a role.

• Aberrant or tortuous carotid artery – an unusually routed internal carotid artery that lies close to the cochlea.
• Sigmoid sinus wall dehiscence or diverticulum – thinning or outpouching of the bone covering the venous sinus.
• Arteriovenous malformations (AVMs) or fistulas – abnormal direct connections between arteries and veins in the brain.
• Idiopathic intracranial hypertension (IIH) – increased pressure in the skull that transmits pulsations to the auditory system.
• Carotid artery stenosis or atherosclerotic plaque – turbulent flow through a narrowed segment.
• Venous sinus thrombosis – clot formation within the dural sinuses alters normal venous flow.
• Glomus tumors (paragangliomas) – highly vascular tumors of the middle ear or the jugular bulb.
• Eustachian tube dysfunction – especially when coupled with high‑frequency blood flow near the middle ear.
• Hyperthyroidism or anemia – increased cardiac output can amplify the audible pulse.
• Prenatal or developmental vascular anomalies – such as a persistent stapedial artery.

Associated Symptoms

Patients with pulsatile tinnitus often report additional signs that help narrow the cause.

• Unilateral or bilateral “whooshing” sound, typically louder when lying down or after exercise.
• Hearing loss (sensorineural or conductive), especially if a middle‑ear tumor is present.
• Fullness or pressure in the ear.
• Vertigo or imbalance.
• Headaches, particularly those that worsen with Valsalva maneuvers.
• Visual disturbances (blurred vision, transient scotomas) – a clue toward IIH.
• Neck bruit or palpable pulsation over the carotid artery.
• Swelling or tenderness over the mastoid region (possible sigmoid sinus pathology).

When to See a Doctor

Because pulsatile tinnitus can signal life‑threatening disease, prompt evaluation is recommended when any of the following are present:

• The sound is new, persistent, or has changed in character.
• It is louder when you turn your head, strain, or perform a Valsalva maneuver.
• You notice hearing loss, dizziness, or balance problems.
• There is associated facial pain, visual changes, or neurological deficits.
• There is a family history of vascular malformations or known high blood pressure.
• You have risk factors for clotting disorders (e.g., recent pregnancy, oral contraceptive use, clotting disease).

Diagnosis

Evaluation typically proceeds in steps, beginning with a thorough history and physical exam, followed by targeted imaging.

1. Clinical Evaluation

• History – onset, laterality, relation to heartbeat, aggravating/relieving factors, prior head/neck surgery, medication list.
• Physical exam – otoscopic inspection, auscultation over the mastoid and neck with a stethoscope, assessment of cranial nerves, measurement of blood pressure.
• Bedside maneuvers – Valsalva, bending over, or rotating the head can accentuate the bruit and help localize the source.

2. Audiologic Testing

• Pure‑tone audiometry to quantify hearing loss.
• Speech‑in‑noise testing if central auditory processing is a concern.

3. Imaging Studies

• CT angiography (CTA) or MR angiography (MRA) – visualizes arterial and venous anatomy, identifies stenosis, diverticula, or tumors.
• Contrast‑enhanced MRI of the brain – best for detecting dural AVFs, glomus tumors, and venous sinus thrombosis.
• Digital subtraction angiography (DSA) – gold‑standard for confirming AVFs/AVMs; usually reserved for cases where endovascular treatment is considered.
• Ultrasound of the carotid arteries – non‑invasive screening for atherosclerotic disease.

4. Laboratory Tests (selective)

• Complete blood count (anemia or polycythemia).
• Thyroid function tests (hyperthyroidism).
• Coagulation profile if venous thrombosis is suspected.
• Lumbar puncture opening pressure if IIH is a possibility.

Treatment Options

Therapy is tailored to the underlying cause. In many cases, removing the trigger eliminates the tinnitus.

Medical Management

• Blood pressure control – ACE inhibitors, ARBs, or calcium‑channel blockers for carotid stenosis or arteriovenous fistulas.
• Weight loss and diuretics – first‑line for idiopathic intracranial hypertension (e.g., acetazolamide).
• Thyroid medication – levothyroxine for hypothyroidism or antithyroid drugs for hyperthyroidism.
• Iron supplementation – if anemia is contributing to increased cardiac output.
• Anticoagulation – for venous sinus thrombosis, directed by hematology.

Surgical / Endovascular Interventions

• Endovascular embolization of dural AVFs or high‑flow AVMs.
• Stent placement or angioplasty of a narrowed carotid artery.
• Surgical repair of sigmoid sinus wall dehiscence or diverticulum (often via a mastoidectomy approach).
• Resection of glomus tumors – either microsurgical removal or stereotactic radiosurgery.
• Transverse sinus or jugular bulb surgery in rare refractory cases.

Conservative / Home Remedies

• Sound therapy (white‑noise generators) to mask the pulse.
• Stress‑reduction techniques – meditation, yoga, or biofeedback can lessen perception.
• Avoidance of caffeine, nicotine, and alcohol, which may heighten vascular pulsations.
• Use of a supportive pillow or sleeping with the head slightly elevated.
• Regular aerobic exercise (moderate) to improve overall cardiovascular health, unless it worsens the symptom.

Prevention Tips

While not all causes are preventable, several strategies lower the risk of developing pulsatile tinnitus:

• Maintain a healthy blood pressure and cholesterol level through diet, exercise, and medication compliance.
• Achieve and sustain a healthy body weight; obesity is a major risk factor for IIH.
• Quit smoking and limit alcohol and caffeine intake.
• Wear protective headgear during activities that could cause temporal bone trauma.
• Promptly treat chronic ear infections or eustachian tube dysfunction to avoid secondary vascular changes.
• Monitor and manage thyroid disease or anemia with regular medical follow‑up.

Emergency Warning Signs

Seek immediate medical attention (call 911 or go to the nearest emergency department) if you experience any of the following with pulsatile tinnitus:

• Sudden, severe headache or “thunderclap” headache.
• Rapid loss of vision or double vision.
• Weakness, numbness, or paralysis on one side of the body.
• Sudden, profound hearing loss.
• Vomiting, seizures, or a change in mental status.
• Neck stiffness or signs of a stroke (facial droop, slurred speech, inability to move a limb).

These symptoms may indicate a cerebrovascular event, severe intracranial pressure rise, or bleeding, all of which require urgent care.

Key Take‑aways

• Keen’s syndrome is pulsatile tinnitus, a rhythmic ear sound that matches the heartbeat.
• Most often it stems from vascular abnormalities, but tumors, pressure changes, and systemic conditions can be culprits.
• A thorough history, focused physical exam, audiology testing, and targeted imaging are essential for diagnosis.
• Treatment ranges from lifestyle changes and medication to minimally invasive endovascular procedures or surgery.
• Because pulsatile tinnitus can herald serious disease, any new or worsening symptoms—especially neurological signs—warrant prompt medical evaluation.

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References:

1. Mayo Clinic. “Pulsatile tinnitus.” Updated 2023. https://www.mayoclinic.org
2. Cleveland Clinic. “Pulsatile Tinnitus: Causes and Treatment.” 2022. https://my.clevelandclinic.org
3. National Institute of Neurological Disorders and Stroke (NINDS). “Idiopathic Intracranial Hypertension Fact Sheet.” 2021.
4. American Academy of Otolaryngology–Head and Neck Surgery. Clinical Practice Guideline: Tinnitus (2020).
5. Kim, J. et al. “Sigmoid sinus wall abnormalities in pulsatile tinnitus: imaging and surgical outcomes.” *Laryngoscope*, 2020.
6. World Health Organization. “Noise-Induced Hearing Loss and Tinnitus.” WHO Fact Sheet, 2022.

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