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Sunday, February 15, 2009

What is Vertigo ?

[Extracted from eMedicine Health]

Vertigo is the feeling that you or your environment is moving or spinning. It differs from dizziness in that vertigo describes an illusion of movement. When you feel as if you yourself are moving, it's called subjective vertigo, and the perception that your surroundings are moving is called objective vertigo.

Unlike nonspecific lightheadedness or dizziness, vertigo has relatively few causes.

Vertigo can be caused by problems in the brain or the inner ear.

a) Benign paroxysmal positional vertigo (BPPV) is the most common form of vertigo and is characterized by the sensation of motion initiated by sudden head movements or moving the head in a certain direction. This type of vertigo is rarely serious and can be treated.

b) Vertigo may also be caused by inflammation within the inner ear (labyrinthitis), which is characterized by the sudden onset of vertigo and may be associated with hearing loss. The most common cause of labyrinthitis is a viral or bacterial infection.

c) Meniere's disease is composed of a triad of symptoms: episodes of vertigo, ringing in the ears, and hearing loss. People have the abrupt onset of severe vertigo, fluctuating hearing loss, as well as periods in which they are symptom-free.

d) Acoustic neuroma is a type of tumor that can cause vertigo. Symptoms include vertigo with one-sided ringing in the ear and hearing loss.

e) Vertigo can be caused by decreased blood flow to the base of the brain. Bleeding into the back of the brain (cerebellar hemorrhage) is characterized by vertigo, headache, difficulty walking, and inability to look toward the side of the bleed. The result is that the person's eyes gaze away from the side with the problem. Walking is also extremely impaired.

f) Vertigo is often the presenting symptom in multiple sclerosis. The onset is usually abrupt, and examination of the eyes may reveal the inability of the eyes to move past the midline toward the nose.

g) Head trauma and neck injury may also result in vertigo, which usually goes away on its own.

h) Migraine, a severe form of headache, may also cause vertigo. The vertigo is usually followed by a headache. There is often a prior history of similar episodes but no lasting problems.

Vertigo implies that there is a sensation of motion either of the person or the environment. This should not be confused with symptoms of lightheadedness or fainting.

1) If true vertigo exists, there is a sensation of disorientation or motion. In addition, the patient may also have any or all of these symptoms :

** Nausea or vomiting
** Sweating
** Abnormal eye movements

2) The duration of symptoms can be from minutes to hours, and symptoms can be constant or episodic. The onset may be due to a movement or change in position. It is important to tell the doctor about any recent head trauma or whiplash injury as well as any new medications the patient is taking.

3) The patient may have hearing loss and a ringing sensation in the ears.

4) The patient might have visual disturbances, weakness, difficulty speaking, decreased level of consciousness, and difficulty walking.

Certain signs and symptoms of vertigo may require evaluation in a hospital's emergency department :

i) Double vision

ii) Headache

iii) Weakness

iv) Difficulty speaking

v) Abnormal eye movements

vi) Altered level of consciousness, not acting appropriately, or difficulty arousing

(vii) Difficulty walking or controlling the arms and legs

Exams and Tests
The evaluation of vertigo consists primarily of a medical history and physical exam.

The history is comprised of four basic areas :

1) The doctor may want to know if the patient feels any sensation of motion, which may indicate that true vertigo exists. Report any nausea, vomiting, sweating, and abnormal eye movements.

2) The doctor may ask how long the patient has symptoms and whether they are constant or come and go. Do the symptoms occur when moving or changing positions? Is the patient currently taking any new medications? Has there been any recent head trauma or whiplash injury?

3) Are there any other hearing symptoms? Specifically, report any ringing in the ears or hearing loss.

4) Does the patient have weakness, visual disturbances, altered level of consciousness, difficulty walking, abnormal eye movements, or difficulty speaking ?

The doctor may perform tests such as a CT scan if a brain injury is suspected to be the cause of vertigo.

Blood tests to check blood sugar levels and the use of an electrocardiogram (ECG) to look at heart rhythm may also be helpful.

Medical Treatment
The choice of treatment will depend on the diagnosis.

a) Vertigo can be treated with medicine taken by mouth, through medicine placed on the skin (a patch), or drugs given through an IV.

b) Specific types of vertigo may require additional treatment and referral :

i) Bacterial infection of the middle ear requires antibiotics.

ii) For Meniere's disease, in addition to symptomatic treatment, people might be placed on a low salt diet and may require medication used to increase urine output.

iii) A hole in the inner ear causing recurrent infection may require referral to an ear, nose, and throat (ENT) specialist for surgery.

c) In addition to the drugs used for benign paroxysmal positional vertigo, several physical maneuvers can be used to treat the condition.

** Vestibular rehabilitation exercises consist of having the patient sit on the edge of a table and lie down to one side until the vertigo resolves followed by sitting up and lying down on the other side, again until the vertigo ceases. This is repeated until the vertigo no longer occurs.

** Particle repositioning maneuver is a treatment based on the idea that the condition is caused by displacement of small stones in the balance center (vestibular system) of the inner ear. The head is repositioned to move the stones to their normal position. This maneuver is repeated until the abnormal eye movements are no longer visible.

Commonly prescribed medications for vertigo include the following :

1) meclizine hydrochloride (Antivert)
2) diphenhydramine (Benadryl)
3) scopolamine transdermal patch (Transderm-Scop)
4) promethazine hydrochloride (Phenergan)
5) diazepam (Valium)

These medications should be taken only as directed and under the supervision of a doctor.

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