The Ochsner Journal 9:20–26, 2009 f Academic Division of Ochsner Clinic Foundation Vertigo: A Review of Common Peripheral and Central Vestibular Disorders Timothy L. Thompson, MD, Ronald Amedee, MD Department of Otolaryngology – Head and Neck Surgery, Ochsner Clinic Foundation, New Orleans, LA INTRODUCTION with a peripheral disorder demonstrate nystagmus to Dizziness, a common symptom that affects more the contralateral side which suppresses with visual than 90 million Americans, has been reported to be fixation. Nystagmus improves with gaze towards the the most common complaint in patients 75 years of lesion and worsens with gaze opposite the lesion. age or older.1 Dizziness, however, is a common term Patients may also report a falling sensation. Vegeta- used to describe multiple sensations (vertigo, pre- tive symptoms are not uncommon, and one can syncope, disequilibrium), each having numerous expect nausea, vomiting, and possibly sweating and etiologies. It is often difficult for a physician to bradycardia. The rate of recovery typically decreases elucidate the quality of dizziness a patient is experi- with age and severity, and with the use of vestibulo- encing and decide how to proceed with medical suppressive medications. management. The focus of this article is the peripheral and central vestibular system. We review the more MENIERE’S SYNDROME common disorders specific to this system, describe The term Meniere’s syndrome is often used synonymously with the terms Meniere’s disease how patients with these disorders present, and (MD) and endolymphatic hydrops, although they are discuss management protocols. different. Endolymphatic hydrops describes an in- THE VESTIBULAR SYSTEM crease in endolymphatic pressure resulting in inap- propriate nerve excitation which gives rise to the The vestibular system is broadly categorized into symptom complex of vertigo, fluctuating hearing loss, both peripheral and central components. The peripheral and tinnitus. The exact mechanism by which this system is bilaterally composed of three semicircular increase in pressure produces the symptoms of MD is canals (posterior, superior, lateral) and the otolithic greatly debated and beyond the scope of this paper. organs (saccule and utricle). The semicircular canals Numerous disease processes can result in endolym- detect rotational head movement while the utricle and phatic hydrops; if there is a known etiology then it is saccule respond to linear acceleration and gravity, termed Meniere’s syndrome. MD is a term used for respectively. These vestibular organs are in a state of endolymphatic hydrops of unknown etiology. symmetrically tonic activity, that when excited stimulate The true incidence of MD is unclear due to the central vestibular system. This information, along difficulty in diagnosis. Caucasians are more often with proprioceptive and ocular input, is processed by affected, and it is more prevalent in females than the central vestibular pathways (e.g. vestibular nuclei) males. Typically, these patients complain of sponta- and maintains our sense of balance and position. neous episodic attacks of tinnitus, aural fullness, fluctuating hearing loss, and vertigo superimposed on PERIPHERAL VESTIBULAR DISORDERS a gradual decline in hearing. Symptoms are variable, Peripheral vestibular disorders are limited to however, and patients may have a predominance of cranial nerve VIII and all distal structures. Patients either cochlear (tinnitus, hearing loss) or vestibular (vertigo) complaints. Attacks typically last minutes to hours; however, most commonly subside after 2 to Address correspondence to: 3 hours. Ronald Amedee, MD Diagnosis is established with a thorough history Department of Otolaryngology – Head and Neck Surgery detailing the aforementioned complaints, possibly Ochsner Clinic Foundation accompanied by nausea, vomiting, and diaphoresis. 1514 Jefferson Hwy. Audiologic and vestibular testing is unreliable, but New Orleans, LA 70121 may show caloric weakness on electronystagmogra- Tel: (504) 842-3640 phy (ENG) and sensorineural hearing loss on audio- Fax: (504) 842-3979 graphy. Email: [email protected] There is no cure for MD and the goal of treatment is symptomatic relief. Medical treatment is initiated Key Words: vertigo, vestibular system prior to more invasive surgical intervention and 20 The Ochsner Journal Thompson, TL consists of salt restriction, diuretics, vasodilators, maneuvers are reported to be 91% effective.4 anti-emetics, and anti-nausea medications. Those Patients with symptoms refractory to repositioning who fail medical treatment may consider surgical maneuvers may be candidates for singular neurecto- therapy. Surgical treatments can be classified as my or posterior semicircular canal occlusion. either hearing-conservative or non–hearing-conserva- tive procedures and are appropriately chosen based VESTIBULAR NEURONITIS on the patient’s audiometric results. For patients with Vestibular neuronitis is the second most common serviceable hearing, endolymphatic sac decompres- peripheral cause of vestibular vertigo. Infection of the sion, vestibular neurectomy, and intratympanic ami- vestibular nerve results in nerve degeneration and noglycoside infusion are options. Labyrinthectomy is may present bilaterally. Infection is most often thought reserved for patients with no serviceable hearing. to be of viral origin, usually from the herpes virus family. It may also result from bacterial invasion (e.g. BENIGN PAROXYSMAL POSITIONAL Borrelia). It is believed that the superior vestibular VERTIGO nerve is more commonly involved secondary to its Benign paroxysmal positional vertigo (BPPV) is course throughout a long and narrower bony canal, considered the most common peripheral vestibular making it more susceptible to compressive edema. disorder, affecting 64 of every 100,000 Americans.2 The reported incidence of an upper respiratory Women are more often affected and symptoms infection prior to the development of vestibular typically appear in the fourth and fifth decades of life. symptoms varies from 23% to 100%.5 In 1980, Epley proposed that free-floating densities Patients present with complaints of sudden vertigo, (canaliths) located in the semicircular canals deflect lasting up to several days, often with vegetative the cupula creating the sensation of vertigo.3 This is symptoms. As this process affects only the vestibular well documented in his Canalithiasis Theory. Although portion of the vestibulocochlear apparatus, there is an these canaliths are most commonly located in the absence of cochlear symptoms. Vertiginous com- posterior semicircular canal, the lateral and superior plaints gradually improve over days to weeks; howev- canal may also be involved. er, imbalance may persist for months after resolution of Patients with BPPV complain of vertigo with acute disease. Recurrence is not uncommon and may change in head position, rolling over, or getting out occur several times per year. Physical examination is of bed, and the vertigo is often side specific. Vertigo limited and should consist of audiometric evaluation occurs suddenly and lasts for less than 1 minute. and ENG. Patients may demonstrate nystagmus and Attacks are separated by remissions; however, caloric weakness on the affected side. patients may complain of constant light-headedness Treatment is primarily supportive with the use of between episodes. Classic BPPV involving the pos- anti-emetics and anti-nausea medications. Vestibular terior semicircular canal is characterized by the suppressants should be used judiciously in the first following: geotropic nystagmus with the problem ear few days of an acute attack. Prolonged use of these down, predominantly rotary nystagmus toward the medications can delay recovery by inhibiting central undermost ear, latency of a few seconds, duration compensation. Furthermore, early ambulation is par- limited to less than 20 seconds, reversal of nystag- amount in the central nervous system’s ability to mus when the patient returns to an upright position, compensate and is therefore recommended as soon and a decline in response with repetitive provocation. as tolerable. High-dose methylprednisone has been Diagnosis is made primarily through history and shown to hasten recovery; however, prospective, also by eliciting typical physical findings during the randomized, double-blinded studies have failed to Dix-Hallpike maneuver. The Dix-Hallpike maneuver demonstrate added benefit from the use of antivirals entails guiding a patient through a series of move- (i.e. valacyclovir).6 ments known to elicit nystagmus in a patient with BPPV. Electro-oculography and 2D videonystag- LABYRINTHITIS mography are of limited use secondary to the inability Labyrinthitis is an inflammatory disorder of the of these tests to record torsional eye movement. membranous labyrinth, affecting both the vestibular Treatment is often supportive as a large percent- and cochlear end organs. It may present unilaterally or age of patients will have spontaneous resolution of bilaterally, and similar to vestibular neuronitis, it is their symptoms. For those with persistent symptoms, often preceded by an upper respiratory infection. This the first line of treatment is canalith repositioning disorder occurs when infectious microorganisms or maneuvers. These maneuvers attempt to reposition inflammatory mediators invade the membranous the free-floating canalith particles from the semicir- labyrinth, damaging the vestibular and auditory end cular canals to the