Wednesday, May 7, 2014

What is vertigo?


Causes and Symptoms


Vertigo is a sensation of spinning or movement. Dizziness and disequilibrium are broader terms that include vertigo in some cases.



Vertigo results from disorders of the inner ear
or central nervous system. Inner-ear causes include vestibular injury, labyrinthitis, vestibular neuritis, acute or recurrent vestibulopathy, benign positional vertigo, Ménière’s disease, perilymphatic fistula, and vestibular toxicity from drugs. Labyrinthitis or vestibular nerve dysfunction can result from trauma, cancer (acoustic neuroma), benign tumor, infection, connective tissue disorders, autoimmune disorder, otosclerosis, or middle-ear infection. Central nervous system causes of vertigo include brain stem stroke, cervical vertigo, tumors adjacent to the brain stem, migraines, multiple sclerosis, cranial nerve injury or degeneration, seizure disorders, hereditary familial ataxia, and inflammatory paraneoplastic syndromes. Problems with peripheral nerves and vision can contribute to vertigo.


Three systems work together to provide balance. The first is the inner-ear labyrinth system of tiny canals filled with a fluid called endolymph and tiny bones called otoliths. These canals contain tiny hair
cells that sense endolymph movement. Information from the inner ear is conveyed to the brain through the eighth cranial nerve (auditory nerve) as well as branches of the seventh cranial nerve (facial nerve). The second system, vision, provides information to the brain via the optic nerve. The third system is proprioception, the ability to orient the body in space using input from the musculoskeletal system and from peripheral nerves. Specialized areas of the brain process information from these three systems to
provide balance and maintain the vestibular ocular reflex and the vestibular spinal reflex. Adaptation to variations in input from these systems allows for activities such as figure skaters being able to tolerate high-speed spins. Balance is also possible with just two of three balance systems, allowing normal individuals to stand with eyes closed and not lose balance.


Disruption of one or more balance systems causes vertigo. Additional symptoms may include tinnitus, disequilibrium, hearing loss, sensitivity to sound, nausea, blurred vision, oscillopsia, nystagmus, ataxia, clumsiness, or headaches. Symptoms of underlying disease may be present.


Onset and additional symptoms; examination of the ear, nose, and throat; and a general neurological examination will help in diagnosis. Specialized techniques include the Hallpike maneuver (tilting the head over the edge of the examination table) and the fistula test, done by plugging one ear. Testing may include complete eye examination, computed tomography (CT) scan, magnetic resonance imaging (MRI), electronystagmography, hearing test, and rotational chair testing. Diagnosis of the underlying disorder is necessary for treatment.




Treatment and Therapy

Treatment of vertigo depends on the cause. Ménière’s disease and other inner-ear conditions such as vestibular neuronitis may be treated with a salt-restricted diet, diuretics, motion sickness medication, antinausea medication, steroid injections, lifestyle modification including stress reduction, or inner-ear surgery. Otolith repositioning involves specialized physical therapy maneuvers that may be helpful for benign positional vertigo. Perilymphatic fistula may respond to bed rest. Middle-ear infections are treated with antibiotics.


Vertigo requires treatment aimed at correcting the underlying disorder. For example, acoustic neuromas may be treated with surgery and radiation. Symptoms from multiple sclerosis may respond to oral or intravenous steroids.


Diagnosis and treatment of vertigo will require a team of specialists, including a family physician, otorhinolaryngologist, neurologist, audiologist, internist, physical therapist, and occupational therapist.


Vestibular rehabilitation treats vertigo and other balance and dizziness problems through adaptation. Because vision is an important part of the balance system, significant vision impairment might limit rehabilitation effectiveness. Exercises prescribed by a physical or occupational therapist target activities that are problematic and may be done at home, in a rehabilitation center, or both. Exercises include targeted movements such as bending over, walking with one foot in front of the other, or walking with the head turned. Rehabilitation can take several weeks to several months.




Perspective and Prospects

Vertigo and dizziness are common symptoms. Because of the variety of causes, some otolaryngologists and neurologists focus solely on the diagnosis and treatment of vertigo and dizziness.


Ménière’s disease is the best-known cause of vertigo, first presented by Prospère Ménière to the French Academy of Medicine in 1861. Other inner-ear problems cause similar symptoms, but Ménière’s disease specifically affects the endolymph fluid, causing vertigo and tinnitus. With modern diagnosis, Ménière’s disease is now known to be less common than once thought.


Several famous people may have suffered from Ménière’s disease or other forms of vertigo. Julius Caesar was said to have “falling disease” attributed to Ménière’s disease or epilepsy. Other famous sufferers include artist Vincent Van Gogh, poet Emily Dickinson, and film star Marilyn Monroe.


Fortunately, vertigo does not usually indicate serious or life-threatening disease; however, it can take time and numerous tests to pinpoint the cause. With patience and persistence, most people can find a treatment or combination of treatments to reduce or eliminate their symptoms.




Bibliography


Alan, Rick, and Kari Kassir. "Meniere's Disease." Health Library, Sept. 10, 2012.



"Causes of Dizziness." Vestibular Disorders Association, 2012.



"Dizziness and Vertigo." MedlinePlus, May 17, 2013.



Fauci, Anthony, et al. Harrison’s Principles of Internal Medicine. 18th ed. New York: McGraw-Hill. 2012.



Jasmin, Luc, et al. "Vertigo-Associated Disorders." MedlinePlus, Nov. 2, 2012.



Poe, Dennis. The Consumer Handbook on Dizziness and Vertigo. Sedona, Ariz.: Auricle Ink, 2005.



Schroeder, Karen, and Rimas Lukas. "Vertigo." Health Library, Apr. 25, 2013.



West, John. Best and Taylor’s Physiological Basis of Medical Practice. 12th ed. Baltimore: Williams & Wilkins, 1991.

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