Dizziness (or giddiness) is a very common complaint among patients. It generally refers to a sense of imbalance, lightheadedness, unsteadiness or motion sickness. When patients complain of a spinning sensation, this is referred to as vertigo. There are many causes of dizziness and they can be broadly divided into two main groups;
- Peripheral (Inner Ear) Causes
- Central Causes, which include brainstem disease, heart disease, drug-induced, stress-induced, associated with migraine etc.
During an assessment of a dizzy patient, history is key to making an accurate assessment. The following characteristics in the history will help distinguish between ear causes from other causes of dizziness;
|Peripheral cause||Central cause|
|Vertiginous (spinning sensation)||Non-vertiginous (eg. floating, unsteadiness, swaying, lightheadedness etc)|
|Episodic (ie. normal in between spells)||Persistent, chronic (always dizzy)|
|Need to lie down||Able to continue with routine|
|Feels better with eyes closed||No difference with eyes closed or opened|
|Improves over time||Worsens or same over time|
|Associated with nausea & vomiting||Not usually associated with nausea|
Some Common Inner Ear Conditions causing Dizziness
1. Benign Paroxysmal Positional Vertigo (BPPV)
This is the commonest cause of peripheral dizziness, accounting for 70 – 80% of all referrals to a Dizzy clinic. The symptoms are caused by loosened otoconia from the utricle stimulating the posterior semicircular canal in head hanging position. Head injury, infections of the inner ear can predispose patients to this condition. In the majority of cases, no known cause is found.
Patients complain of spinning spells when lying down and turning their head to one side. Typical spells last few seconds, although more severe attacks can last minutes. Sometimes, patients also complain of spinning when looking up or down. The Dix-Hallpike maneuver confirms diagnosis.
This condition is usually self-limiting and medications are generally of little use. In resistant cases, the Particle repositioning maneuver improves condition in about 80% of patients with one treatment and up to 95% with repeated treatments.
2. Meniere’s Disease
The pathophysiology of Meniere’s Disease is endolymphatic hydrops (excessive build up of fluid in the inner ear). The cause unknown but allergy and immunologic factors are suspected.
To make the diagnosis, patients must have the triad of vertiginous spells lasting 1 to 24 hours, tinnitus and fluctuating hearing loss (permanent in later stages of disease). Audiograms will reveal low frequency sensorineural hearing loss.
All patients should initially be treated conservatively with medications (eg. vasodilators, diuretics, anxiolytics). The majority of patients will respond to this form of treatment. Certain lifestyle modifications such as low salt diet, caffeine avoidance, therapeutic exercises may help.
For those who suffer persistent symptoms despite medication, intratympanic gentamicin is generally recommended as the next line of treatment. This treatment involves instilling gentamicin via a T-tube into the middle ear. The medication will diffuse into the inner ear compartment where it selectively destroys the vestibular hair cells (organ of balance), while sparing the hearing hair cells. This treatment has a success rate of up to 95%. The main risk is hearing loss. Recently, the Meniett Device (figure 1 & 2) has shown evidence of its effect in reducing frequency and intensity of spells. (http://www.meniett.com/)
Surgery for Meniere’s Disease such as endolymphatic sac or shunt surgery is controversial.
3. Recurrent Episodic Vestibulopathy
This condition has symptoms similar to Meneire’s disease except there is no concomitant hearing loss. It is associated with food hypersensitivy and migraine. About 10% of patients will develop hearing loss and hence Meniere’s disease. Fortunately, this is a self-limiting condition. Treatment includes vasodilators, antihistamines.
4. Vestibular Neuronontis/ Labyrinthitis
Vestibular neuronitis (or neuritis) is a viral infection of the vestibular nerve or its apparatus. Thirty percent of patients will give a history of a preceding upper respiratory tract infection.
In the acute phase, patients experience a sudden onset of spinning spells lasting a few hours to days, associated with nausea and vomiting. Many will have to lie down and close their eyes. Head movements aggravate the symptoms. 30% of patients have history of upper respiratory tract infection. Spells improve dramatically over days. Most patients are well by one week. Recovery is faster in younger patients.
In the convalescent phase, it is common for patients to have a sensation of unsteadiness after spinning spells abate. This recovery period can last up to 4 to 6 weeks. Hearing is generally not affected unless a bacterial infection affects the inner ear (bacterial labyrinthitis).
In the acute phase, bed rest with vestibular suppressives such as prochlorperazine will relieve the intensity of the symptoms. However, once the spinning spells abate, ambulation and light exercises should be encouraged to promote recovery, especially in the elderly and the visually impaired. Vestibular exercises are helpful and can be prescribed by your ENT doctor.
5. Perilymph Fistula
Perilymph fistula (PLF) is the leakage of inner ear fluid (perilymph) into the middle ear. Spontaneous PLFs are extremely rare. Generally, there is an inciting factor. These factors can be divided into implosive and explosive forces. Implosive forces can result from inadequate equalization of the middle ear or with blast injuries. Explosive forces result from severe head injury or abdomen. Patients who have undergone surgery involving the inner ear or ossicular chain are also predisposed to PLF.
The typical presentation is a sudden onset of mild vertigo (spinning) or disequilibrium or hearing loss associated with a traumatic event. The onset is sudden in 95% of proven PLF and in 90% of cases, trauma is related to the onset of symptoms. Seventy five percent will have tinnitus and 50% some degree of deafness that is not fluctuant. Examination may reveal a positive fistula test, positional nystagmus, eyes-closed-turning test and a hearing loss.
Patient selection is important. Surgical exploration of the middle ear should only be performed in patients with a clear history of trauma and symptoms consistent for PLF. The aims of surgery is to resolve dizziness and prevent further hearing loss. Determining which ear to operate on can be difficult when there is no hearing loss. Only a trained otologist will be able to confidently determine which ear has suffered the trauma.