MANAGEMENT OF VERTIGO DUE TOPERIPHERAL VESTIBULAR DISORDERS

MANAGEMENT OF VERTIGO DUE TOPERIPHERAL VESTIBULAR DISORDERS

V G Kasbekar
Hon. ENT Surgeon, Bombay Hospital, MRC Mumbai 20.

Vertigo is defined as hallucination of movement. A large number of people see a doctor for disequilibrium. About 30-35% of the population experience episodes of vertigo by the age of 65 years. It is a common complaint in clinical practice, seen in about 10-15% of patients seen by an Otorhinolaryngologist. A dizzy patient may go to see a cardiologist, neurologist, family physician or an ENT surgeon. Each speciality develops a strategy of evaluating symptoms of vertigo in their own particular area of expertise. This may result in overlooking many causes of dizziness arising in other systems or putting the patient through expensive and inappropriate investigations such as an MRI, scanning or angiography. This approach is unsatisfactory for the patient or for any health care system. A systematic, efficient and formal assessment strategy is required in order to provide appropriate management and rehabilitation.
Good management depends upon an accurate diagnosis. It may be possible to identify a single pathology which can involve more than one system. In an elderly patient vertigo may be due to multiple pathologies like vestibular impairment due to vascular disease, visual impairment due to cataract and proprioceptive impairment due to arthritis.

Vestibular disorders can be extrinsic, peripheral or central. Extrinsic factors are disturbances not arising in the peripheral vestibular system itself like taking ototoxic drugs, anaemia, hypoglycaemia, hypotension, middle ear diseases, head injury causing fracture of the skull with injury to the labyrinth. Peripheral causes are intrinsic to the peripheral vestibular system like Meniere’s disease, Sudden vestibular failure (viral injury to the labyrinth in skull fractures or epidemic labyrinthitis), vestibular neuronitis and benign paroxysmal positional vertigo.

A proper history and a detailed clinical examination is followed by appropriate investigations to come to a correct diagnosis. In patients with neuro-otological symptoms investigations done are audiometry with special tests, Brain stem evoked response audiometry, Vestibular function tests and if necessary CT scan or an MRI.

In patients with vertigo, chronic middle ear disease (cholesteatoma) with labyrinthine erosion must be excluded by clinical examination and audiometry. The presence of positional nystagmus is a valuable clinical sign and is looked for by doing the Hall pike Dix test. The positional nystagmus can be of the benign paroxysmal type or central type. Positional nystagmus of peripheral labyrinthine origin has a latent period of upto 30 seconds, is unidirectional, horizontal and disappears on repeated testing. Benign paroxysmal positional vertigo is a common cause of chronic vertigo after head injury in association with vascular disease and many otological conditions like viral labyrinthitis. The theory of canalithiasis explains all the characteristic features of benign positional nystagmus.

Benign paroxysmal positional vertigo (BPPV)

The treatment of benign paroxysmal positional vertigo includes :

• Single treatment approach

• Habituation exercises approach

• Surgical approach

Single treatment approach

The aim is to remove the debris from the semicircular canals into the vestibule where it does not cause symptoms. This is done by Epley’s method or Semont’s manoeuvre.

Epley’s method for BPPV

The patient is seated in front of the doctor. The head is placed over the end of the table and turned 45° to the affected side. While the head is kept tilted downward it is now rotated 45° to the opposite side. Then the head and body are rotated until they face downward 135° from the supine position. While the head is kept turned to the opposite side the patient is brought to a sitting position. The head is now turned forward and the chin is tilted down 20° (Fig. 1). At every change in position one must pause till the vertigo and nystagmus disappear.

Semont’s Manoeuvre

The patient is made to sit on the side of the treatment table with the head turned 45° away from the affected ear. The patient is rapidly moved in to a side-lying position on the affected side. After a few minutes the patient is rapidly moved en bloc through the initial sitting position to the opposite side-lying position. As the patient is moved the original alignment of the head on the body is maintained by the doctor. After a few minutes the patient is moved from the side-lying position to the sitting position (Fig. 2).

Habituation Exercises Approach

Brandt and Daroff’s exercises for BPPV are a sequence of lateral head and trunk tilts repeated many times a day for 2-3 weeks. Some patients find it difficult to do these exercises because of the vertigo they experience during the repeated position changes.

Fig.1

Surgical Approach

In cases of refractory benign paroxysmal positional vertigo posterior canal plugging procedures can be considered.

Meniere’s Disease

The principle of treatment in Meniere’s disease is to give the patient relief from episodic attacks ofvertigo and preserve the hearing. The drugs used in the treatment of Meniere’s disease are vestibular sedatives and vasodilator drugs. The patient is asked to go on a fluid and salt restricted diet. In severe cases a diuretic such as hydrochlorothiazide can also be given. If the medical treatment fails to control the vertigo, surgery has to be considered.

Fig. 2

Conservative surgical procedures (hearing preserved) include endolymphatic sac decompression, grommet insertion, vestibular nerve section or intratympanic injection of ototoxic drugs.

Administration of aminoglycosides such as gentamycin or streptomycin through the round window have given encouraging results. It selectively ablates the vestibular cells, sparing the hearing function. Transtympanic or intratympanic steroid therapy is also used in properly selected patients as it controls the vertigo effectively and improves the hearing function.

In radical surgical procedures there is total loss of cochlear and vestibular function. This is done by a transmastoid or transtympanic labyrinthectomy.

Vestibular Neuritis

Vestibular neuritis is the third most common cause of peripheral vestibular vertigo. It is commonly associated with a history of upper respiratory infections and occurs in epidemics. In the acute phase the patient is given labyrinthine sedatives and antiemetics if required. Some studies have reported that patients have benefited by the use of corticosteroids. Most patients have complete symptomatic recovery. In some patients where vertigo persists, vestibular rehabilitation exercises are beneficial.

Sudden vestibular failure is a clinical syndrome where vestibular function is suddenly lost on one side. The treatment of such an episode includes bed rest and vestibular sedation.

In conclusion balance disorders are common and encountered by a variety of specialists. Although rarely life threatening they may be associated with significant morbidity. A rational systematic diagnostic strategy enables a quick diagnosis in majority of cases, so that appropriate management can be started, preventing anxiety and depression, leading to limitations of social and occupational activities.

REFERENCES

Ariyasu L, Byl FM, Sprague MS, et al. The beneficial effect of methylprednisolone in acute vestibular vertigo. Arch Otolyryngol Head Neck Surg 1990; 116 : 700-703.

Epley JM. The canalith repositioning procedure for treatment of benign paroxysmal positional vertigo. Otolaryngol Head Neck Surg 1992; 107 : 399-404.

Hall SF, Ruby RPF, McClure JA. The mchanics of benign paroxysmal vertigo. J Otolaryngol 1979; 8 : 151-158.

Nadol JB. Vestibular neuritis. Otolaryngol Head Neck Surg 1995; 112 : 162-172.

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