Tests for vertigo often attempt to elicit nystagmus and to differentiate vertigo from other causes of dizziness such as presyncope, hyperventilation syndrome, disequilibrium, or psychiatric causes of lightheadedness. Tests of vestibular system (balance) function include electronystagmography (ENG), Dix-Hallpike maneuver, rotation tests, head-thrust test, caloric reflex test, and computerized dynamic posturography (CDP). The HINTS test, which is a combination of three physical examination tests that may be performed by physicians at the bedside, has been deemed helpful in differentiating between central and peripheral causes of vertigo. The HINTS test involves the horizontal head impulse test, observation of nystagmus on primary gaze, and the test of skew. CT scans or MRIs are sometimes used by physicians when diagnosing vertigo. Tests of auditory system (hearing) function include pure tone audiometry, speech audiometry, acoustic reflex, electrocochleography (ECoG), otoacoustic emissions (OAE), and the auditory brainstem response test. A number of specific conditions can cause vertigo. In the elderly, however, the condition is often multifactorial. A recent history of underwater diving can indicate a possibility of barotrauma or decompression sickness involvement, but does not exclude all other possibilities. The dive profile (which is frequently recorded by dive computer) can be useful to assess a probability for decompression sickness, which can be confirmed by therapeutic recompression.<unk><unk><unk>  vertigo<unk><unk><unk>  vertigo (BPPV) is the most common vestibular disorder and occurs when loose calcium carbonate debris has broken off of the otoconial membrane and enters a semicircular canal thereby creating the sensation of motion. People with BPPV may experience brief periods of vertigo, usually under a minute, which occur with change in the position. This is the most common cause of vertigo. It occurs in 0.6% of the population yearly with 10% having an attack during their lifetime. It is believed to be due to a mechanical malfunction of the inner ear. BPPV may be diagnosed with the Dix-Hallpike test and can be effectively treated with repositioning movements such as the Epley maneuver. Ménière's disease Ménière's disease is an inner ear disorder of unknown origin, but is thought to be caused by an increase in the amount of endolymphatic fluid present in the inner ear (endolymphatic hydrops). However, this idea has not been directly confirmed with histopathologic studies, but electrophysiologic studies have been suggestive of this mechanism. Ménière's disease frequently presents with recurrent, spontaneous attacks of severe vertigo in combination with ringing in the ears (tinnitus), a feeling of pressure or fullness in the ear (aural fullness), severe nausea or vomiting, imbalance, and hearing loss. As the disease worsens, hearing loss will progress. Labyrinthitis Labyrinthitis presents with severe vertigo with associated nausea, vomiting, and generalized imbalance and is believed to be caused by a viral infection of the inner ear, although several theories have been put forward and the cause remains uncertain. Individuals with vestibular neuritis do not typically have auditory symptoms, but may experience a sensation of aural fullness or tinnitus. Persisting balance problems may remain in 30% of people affected. Vestibular migraine Vestibular migraine is the association of vertigo and migraines and is one of the most common causes of recurrent, spontaneous episodes of vertigo. The cause of vestibular migraines is currently unclear; however, one hypothesized cause is that the stimulation of the trigeminal nerve leads to nystagmus in individuals suffering from migraines. Approximately 40% of all migraine patients will have an accompanying vestibular syndrome, such as vertigo, dizziness, or disruption of the balance system. Other suggested causes of vestibular migraines include the following: unilateral neuronal instability of the vestibular nerve, idiopathic asymmetric activation of the vestibular nuclei in the brainstem, and vasospasm of the blood vessels supplying the labyrinth or central vestibular pathways resulting in ischemia to these structures. Vestibular migraines are estimated to affect 1–3% of the general population and may affect 10% of people with migraine . Additionally, vestibular migraines tend to occur more often in women and rarely affect individuals after the sixth decade of life. Motion sickness Motion sickness is common and is related to vestibular migraine. It is nausea and vomiting in response to motion and is typically worse if the journey is on a winding road or involves many stops and starts, or if the person is reading in a moving car. It is caused by a mismatch between visual input and vestibular sensation. For example, the person is reading a book that is stationary in relation to the body, but the vestibular system senses that the car, and thus the body, is moving. Alternobaric vertigo Alternobaric vertigo is caused by a pressure difference between the middle ear cavities, usually due to blockage or partial blockage of one eustachian tube, usually when flying or diving underwater. It is most pronounced when the diver is in the vertical position; the spinning is toward the ear with the higher pressure and tends to develop when the pressures differ by 60 cm of water or more. Decompression sickness Vertigo is recorded as a symptom of decompression sickness in 5.3% of cases by the U.S. Navy as reported by Powell, 2008 It including isobaric decompression sickness. Decompression sickness can also be caused at a constant ambient pressure when switching between gas mixtures containing different proportions of inert gas. This is known as isobaric counterdiffusion, and presents a problem for very deep dives. For example, after using a very helium-rich trimix at the deepest part of the dive, a diver will switch to mixtures containing progressively less helium and more oxygen and nitrogen during the ascent. Nitrogen diffuses into tissues 2.65 times slower than helium, but is about 4.5 times more soluble. Switching between gas mixtures that have very different fractions of nitrogen and helium can result in "fast" tissues (those tissues that have a good blood supply) increasing their total inert gas loading. This is often found to provoke inner ear decompression sickness, as the ear seems particularly sensitive to this effect. Stroke A stroke (either ischemic or hemorrhagic) involving the posterior fossa is a cause of central vertigo. Risk factors for a stroke as a cause of vertigo include increasing age and known vascular risk factors. Presentation may more often involve headache or neck pain, additionally, those who have had multiple episodes of dizziness in the months leading up to presentation are suggestive of stroke with prodromal TIAs. The HINTS exam as well as imaging studies of the brain (CT, CT angiogram, MRI) are helpful in diagnosis of posterior fossa stroke. Vertebrobasilar insufficiency Vertebrobasilar insufficiency, notably Bow Hunter's syndrome, is a rare cause of<unk>  vertigo, especially when vertigo is triggered by rotation of the head.
symptom of Benign paroxysmal positional vertigo
medical cause of Tinnitus
symptom of Bulbar palsy
symptom of Vertigo
symptom of Glaucoma
symptom of Oculopharyngeal muscular dystrophy
symptoms of Sympathetic ophthalmia
symptom of Giant cell arteritis