Thursday 25 October 2012

POSITIONAL VERTIGO (BENIGN PAROXYSMAL POSITIONAL VERTIGO)

Benign paroxysmal positional vertigo is a sensation of spinning related to head movement and position. The spinning sensation or vertigo only lasts for brief periods and is not associated with ear fullness or tinnitus. The vertigo experienced can be quite intense and patient may have nausea.
It may occur repeatedly with certain head positions such as tilting the head backwards and forwards, looking to the sides and turning to right or left on the bed. In between episodes, patients are generally well.
BPPV is one of the most common cause of vertigo and it commonly affects those above 50 years of age. Occasionally it can be related to head trauma especially in young adults.

Understanding the disease process of BPPV
BPPV is a condition affecting the inner ear. Each inner ear consists of organs responsible for hearing (cochlea) and balance (utricle, saccule & 3 semicircular canals). The balance organs especially the semicircular canals are responsible to detect angular head movements.
When the head moves, the fluid within the semicircular canal would move in the opposite direction initially due to inertia. This fluid movement is detected by the cupula which contains hair like sensors. These sensors would then produce electrical signals to the brain.
In BPPV there is dislodgement of crystals from the utricle or saccule which then collects within the semicircular canals. Therefore during head movements, these crystals would cause the semicircular canals to send false signals to the brain. And this brain signal misinterpretation would cause the patient to feel the spinning sensation of vertigo.

Diagnosis of BPPV
The diagnosis of BPPV is a clinical diagnosis which the doctor makes from the patient's history and examination. A complete ENT examination should be performed to assess for other causes of vertigo. In BPPV, the ear examination is generally normal.
Sometimes a hearing assessment is also required. If the symptoms are non specific, imaging studies such as MRI (magnetic resonance imaging) may be performed to assess for any intracranial cause.
The doctor would also perform a Dix Hallpike manouvre to stimulate a vertigo episode. This test would be positive in cases of BPPV.

Treatment of BPPV
A canalith repositioning manouvre for BPPV can be performed by the doctor in the clinic. The side of the ear affected will be determined during the Dix Hallpike manouvre. And then the canalith repositioning manouvre will be performed according to the affected ear; right or left.
The canalith repositioning manouvre, also called the Epley's manouvre, involves a series of head movements aimed at bringing the crystals out from the semicircular canals and back into the utricle. This test may need to be repeated several times. It is usually performed twice and may be repeated during the next clinic review if still symptomatic.
In very rare situations that the canalith repositioning manouvre would fail and surgery is recommended. The surgical procedure performed involves plugging the semicircular canal that causes the vertigo.

Home advice after repositioning manouvre
There is no substantial clinical evidence that has shown that the following restrictions are very useful after the clinic canalith repositioning procedure. However doctors often advise patients to avoid lying flat or on the affected ear for 2-3 days after the procedure. Patients are also advised to lay their head on 2-3 pillows on the first night following the procedure.


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