WHEN YOUR WORLD SPINS

Vertigo, or dizziness, is a symptom, not a disease. The term vertigo refers to the sensation of spinning or whirling that occurs when balance (equilibrium) is disturbed. It also may be used to describe feelings of dizziness, light-headedness, faintne ss, and unsteadiness. The sensation of movement is called subjective vertigo and the perception of movement in surrounding objects is called objective vertigo.

Severe vertigo can be disabling and may result in complications such as irritability, loss of self-esteem, depression, and injuries from falls. Falls are the leading cause of serious injury in people over the age of 65.
Causes

Benign paroxysmal positional vertigo occurs when debris made up of calcium carbonate and protein (called otoliths or ear crystals) builds up in and damages the inner ear. Inner ear degeneration (usually occurs in elderly patients), head trauma, and inner ear infection (e.g., otitis media, labyrinthitis) can cause BPPV.

Some medications and environmental chemicals (lead, mercury, tin) can cause ototoxicity (ear poisoning), which may result in damage to the inner ear or the eighth cranial nerve (acoustic nerve) and cause vertigo. The damage can be permanent or temporary. Long-term use or high doses of certain antibiotics and antineoplastics can cause permanent ototoxicity.

Central vestibular disorders that may cause vertigo include the following: Cardiovascular disorders (bradycardia or slowed heart rate, tachycardia or rapid heart rate); Central nervous system (CNS) disorders like stroke or brain haemorrhage); Head trauma; Migraine; Multiple sclerosis (MS may occur when demyelination affects the brainstem or cerebellum).

It is important to diagnose the cause of vertigo, or dizziness quickly to rule out serious conditions such as cardiovascular disease, stroke, haemorrhage, or tumour. Diagnosis includes clinical history, physical and neurological examination, blood tests, and imaging tests (e.g., CT scan, MRI scan). The physician also needs to consider what triggers the vertigo; other symptoms; duration of dizziness and what improves or worsens symptoms.
Diagnosis

There are five cardinal steps in the approach to a patient with vertigo. The first is to identify whether it is true or false vertigo. True vertigo is the spinning sensation or sense of rotation that persists even when the patient lies down. On the contrary false vertigo remits on lying posture. The next step is to find out whether the reason for vertigo lies in the eye, ears, or neck. The third is to identify whether the vertigo is central or peripheral. The next step is to find the aetiology of vertigo. The last is to investigate the patient for causes. The main things to look for are raised blood sugar, raised blood pressure, elevated triglycerides and cholesterol and hypothyroidism. One should also look for upper and lower respiratory infections, gastrointestinal infections, diet, and drugs.

Treatment depends on identifying and eliminating the underlying cause. If a particular medication is responsible for the condition, lowering the dosage or discontinuing the drug may eliminate vertigo.

Vestibular Rehabilitation Therapy (VRT) aims to minimise dizziness, improve balance, and prevent falls by restoring the normal function of the vestibular system. The patient performs exercises designed to allow the brain to adapt to and compensate for whatever is causing the vertigo. The success depends on several factors including patient’s age and overall health; cognitive function; coordination and motor skills; physical strength. As the patient progresses, difficulty of the exercises increases until the highest level of balance is attained.

Ear infections caused by bacteria may be treated using antibiotics. Myringotomy is a surgical procedure that may be used to treat chronic ear infections. In this procedure, which is performed under anesthesia, an incision is made in the eardrum and a small tube is placed in the opening to prevent fluid and bacteria from building up inside the ear.

Benign paroxysmal positional vertigo may be treated with meclizine, an oral anti-emetic that can be taken up to thrice a day, or as needed. But it may cause drowsiness, dry mouth, and blurred vision. If this is ineffective, benzodiazepines or antihistamines may be prescribed. But these have side effects like drowsiness, lack of coordination, fatigue, and tremors.

Ménière’s disease may be treated by reducing salt intake and with diuretics. A short, tapered course of corticosteroids may be prescribed in the early stages to reduce inflammation and stabilise hearing. Antibiotics may be administered into the middle ear to treat severe vertigo caused by this disease.

Vertigo caused by migraine can often be treated with medication. Strokes, tumours, and multiple sclerosis may require treatment with medication, radiation, or surgery.
Prognosis

Prognosis depends on the cause and how well the underlying condition responds to treatment. Severe vertigo can be permanently disabling, especially in elderly patients. Peripheral vestibular disorders may cause progressive hearing loss. It is intellectually a lazy approach to do MRI or CT in every case as it is not justified in all cases. In clinical neurology, a good history and a thorough neurological examination are the two most important diagnostic tools.



Some patients describe a feeling of being pulled down or toward one side. Moving the head, changing position, and turning while lying down often worsen vertigo.The sudden onset of vertigo usually indicates a peripheral vestibular disorder (e.g., BPPV, Ménière disease, vestibular neuritis).

Peripheral vestibular disorders may also cause blurred vision; fatigue and reduced stamina; headache; palpitations; imbalance; inability to concentrate; increased risk for motion sickness; muscle ache (especially of the neck and back); nausea and vomiting; reduced cognitive function; sensitivity to bright lights and noise; sweating.

Vertigo caused by a central vestibular disorder usually develops gradually. In addition to vertigo, central vestibular disorders may cause symptoms like double vision (diplopia), headache (may be severe), impaired consciousness, inability to speak due to muscle impairment (dysarthria), lack of coordination, nausea and vomiting and weakness.



Vertigo is usually the result of a disorder in the vestibular system (structures of the inner ear, the vestibular nerve, brainstem, and cerebellum).

The vestibular system is responsible for integrating sensory stimuli and movement and for keeping objects in visual focus as the body moves. When the head moves, signals are transmitted to the labyrinth, an apparatus in the inner ear made up of three semicircular canals surrounded by fluid.

The labyrinth transmits movement information to the vestibular nerve, which carries the information to the brainstem and cerebellum (that control balance, posture, and motor coordination).