A 34-year-old man comes to the office due to intermittent dizziness over the past 3 months. The patient has had episodes of a sudden spinning sensation, accompanied by nausea, that resolve spontaneously after approximately a minute. Symptoms occur when he is lifting heavy weights, riding on an elevator, or after sneezing. He has had no headache or ear pain but has trouble hearing out of the right ear. The patient had a concussion after a bicycle collision 4 months ago but has no other medical conditions and has had no recent upper respiratory illness. Vital signs are within normal limits. Physical examination shows normal ears, including tympanic membranes. There is no extremity weakness or sensory loss. No nystagmus is present at rest but performing a Valsalva maneuver provokes nystagmus and the other reported symptoms. Which of the following is the most likely diagnosis?

Question

A 34-year-old man comes to the office due to intermittent dizziness over the past 3 months.  The patient has had episodes of a sudden spinning sensation, accompanied by nausea, that resolve spontaneously after approximately a minute.  Symptoms occur when he is lifting heavy weights, riding on an elevator, or after sneezing.  He has had no headache or ear pain but has trouble hearing out of the right ear.  The patient had a concussion after a bicycle collision 4 months ago but has no other medical conditions and has had no recent upper respiratory illness.  Vital signs are within normal limits.  Physical examination shows normal ears, including tympanic membranes.  There is no extremity weakness or sensory loss.  No nystagmus is present at rest but performing a Valsalva maneuver provokes nystagmus and the other reported symptoms.  Which of the following is the most likely diagnosis?

Quizplus · Accepted Answer

Explanation: The inner ear contains the endolymphatic fluid-filled semicircular canals (which convey movement and position of the head) and the cochlea (which is the sensory organ of hearing). Conditions that cause disruption of endolymph flow can present with vertigo (semicircular canals) and/or sensorineural hearing loss (cochlea). Perilymphatic fistulas are a rare, but debilitating, complication of head injury or barotrauma. They cause leakage of endolymph from the semicircular canals and cochlea into surrounding tissues, resulting in characteristic clinical features: Progressive sensorineural hearing loss caused by damage to cochlear hair cells from loss of endolymph. Episodic vertigo with nystagmus triggered by pressure changes in the inner ear (eg, Valsalva maneuver, elevation changes [eg, riding in elevator]) due to acutely increased endolymph leakage. This can be demonstrated clinically by performing a loud clap (ie, pressure change due to sound conduction through the ossicles) near the patient's ear and observing for nystagmus (Tullio phenomenon). Patients are advised to limit activities that increase inner ear pressure; they also require ENT referral for further management. (Choice A) Benign paroxysmal positional vertigo is caused by debris (otoliths) that temporarily alters endolymph flow through the semicircular canals. Therefore, patients typically have sudden, brief (<1-min) episodes of vertigo triggered by head movement. (Choice B) Eustachian tube dysfunction can result in fluid in the middle ear space (not the inner ear vestibular system) and can cause ear popping, cracking, and hearing loss in response to changes in pressure. However, it also causes a sense of ear fullness or pain, not episodic vertigo with nystagmus. (Choice C) Ménière disease is caused by increased endolymphatic fluid volume or pressure in the vestibular system. It also causes episodic vertigo with hearing loss, but episodes are accompanied by aural fullness or tinnitus, last 20 minutes to 24 hours, and often lack specific, identifiable triggers. (Choice D) Orthostatic hypotension causes lightheadedness, presyncope, or syncope when the patient assumes a standing position due to cerebral hypoperfusion. It does not involve the vestibular system and therefore does not cause true vertigo or nystagmus. (Choice F) This patient's traumatic brain injury puts him at risk for postconcussive syndrome, which is characterized by headache, confusion, difficulty concentrating, mood alterations, and sleep disturbances. It does not cause spinning vertigo with nystagmus triggered by Valsalva maneuvers. Educational objective: A perilymphatic fistula can occur after head trauma and result in episodic vertigo triggered by sudden pressure changes (eg, Valsalva maneuvers) or loud noises (Tullio phenomenon). References: Diagnosis and treatment of perilymphatic fistula. (http://www.ncbi.nlm.nih.gov/pubmed/29794455)

A 34-Year-Old Man Comes to the Office Due to Intermittent