Vertigo is a false sense of motion, and its timing hints at the cause
Vertigo is the conviction that you or the room is spinning or swaying when nothing is moving at all. It is the commonest kind of dizziness, and how long an attack lasts, under a minute, over twenty minutes or several days, points towards very different problems in the balance system.
Somewhere between 7.5 and 10 percent of people experience vertigo at some point, and about 5 percent in any given year. It grows more common with age, strikes women two to three times as often as men, and makes up about 2 to 3 percent of emergency department visits in developed countries. Nausea, vomiting, sweating and trouble walking often come with it, and head movement usually makes things worse.
Most cases trace back to the vestibular system, the inner-ear apparatus of semicircular canals, utricle, saccule and vestibular nerve. Benign paroxysmal positional vertigo, or BPPV, accounts for about 32 percent of these peripheral cases: brief bouts, generally shorter than a minute, triggered by movement, with the person normal in between. A bedside manoeuvre called the Dix-Hallpike test typically sets off rapid jerking eye movements, known as nystagmus. Ménière's disease, about 12 percent of peripheral cases, brings ringing in the ears, hearing loss and attacks lasting more than twenty minutes. Vestibular neuritis starts suddenly and can last for days, with nystagmus even at rest. Because the brain compensates quickly, peripheral vertigo tends to settle within days to weeks.
Central vertigo comes from damage in the brainstem or cerebellum, from strokes, bleeds, tumours, multiple sclerosis or migraine among other causes. Oddly, the spinning illusion and nausea are often milder, but the imbalance can be so severe that people cannot stand. Slurred speech, double vision or purely vertical or twisting nystagmus are warning signs, and recovery may be slow or absent.
There are gentler triggers too. Spinning with the eyes closed or spending a long time on a ship can produce physiologic vertigo, and toxins such as carbon monoxide, alcohol or aspirin can bring it on. Textbooks also separate objective vertigo, where still objects seem to move, from subjective vertigo, where the body seems to move, though it is unclear whether that split helps with understanding or treating it.
Source: Vertigo
