Vertigo

Disorders of vestibular system cause vertigo and are
divided into:
A. Peripheral, which involve vestibu lar end organs
and the ir first order neurons (i.e. the vesti bu lar nerve).
The cause lies in the internal ear or the Vlllth nerve.
They are responsib le for 85% of all cases of vertigo.
B. Central, which involve central nervous system
after the entrance of vestibular nerve in the brainstem
and involve vestibulo-ocular, vestibulo-spinal and other
central nervous system pathways.
Table 7.1 lists the common causes of vertigo of peripheral
and central origin.
A. PERIPHERAL VESTIBULAR DISORDERS
1. Meniere's disease (endolymphatic hydrops). It is
characterised by vertigo, f1uctuating hearing loss, tinnitus
and sense of pressure in the involved ear. Vertigo is of
sudden onset, las ts for a few minutes to 24 hours or so.
(The disease has been discussed on page 99).
2. Benign paroxysmal positional vertigo (BPPV). It
is characterised by vertigo when the head is placed in a
certain critical posi tion . There is no hearing loss or oth er
neurologic symptoms. Positional testing establishes the
diagnosis and helps to differentiate it from positional vertigo
of central origin (Table 7.1). Disease is caused by a disorder
of posterior semicircular canal though many patients
have history of head trauma and ear infection.
I t has been demonstrated that otoconial debris, consisting
of crystals of calcium carbonate, is released from the
degenerating macula of the utricle and f10ats freely in the
endolymph. When it se ttles on the cupula of posterior
Table 7.1 Vestibular disorders
Peripheral
(Lesions of end organs
vestibular nerve)
• Meniere's disease
• Benign paroxysmal
positiona l veliigo
• Vestibular neuron itis
• Labyrinthit is
• Vestibu lotoxic drugs
• Head trauma
• Perilymph fistula
• Syphilis
• Acoustic neuroma
Central
(Lesions of brainstem
and central connections)
• Veriebrobas ilar insuffi ciency
• Posterior inferior
cerebellar ariery syndrome
• Basilar mig raine
• Cerebellar disease
• Multiple sclerosis
• Tumours of brainstem and
fou rih ventricle
• Epilepsy
• Cervical veriigo
semicirc ular canal in a cr itical head position, it causes
displacement of the cupu la and vertigo. The vertigo is
fat iguable on assurning the same position repeatedly due
to dispersal of the otoconia but can be induced again
after a period of rest. Thus, typica l history and Hallpike
manoeuvre es tablishes the diagnosis.
The condition can be treated by performing Epley's
manoeuvre. The principle of this manoeuvre is to reposition
the otoconial debris from the posterior se micircular canal
back into the utricle. The doctor stands behind the patient
and the assistant on the side. The patient is made to sit on
the table so that when he is made to lie down, his head
is beyond the edge of the table as is done in Dix-Hallpike
manoeuvre. His face is turned 45° to the affected side.
The manoeuvre consis ts of five positions.
Position 1. With the head turned 45°, the patient is made
to lie down in head-hanging posi tion (DixHallpike
manoeuvre). It will cause vertigo and
nystagmus. Wait till vertigo and nys tagmus
subside.
Position 2. Head is now turned so that affec ted ear is up.
Position 3. The who'le body and head are now rorated
away from the affected ear to a la teral recumbent
posi tion in a face-down position.
Position 4. Patient is now brought to a Sitting pO,,'ition
with head st ill turned to the unaffected side::
hy 45°
Position 5. The head is now turned forward and chin
brought down 20°.
There should be a pause at each position till there is
no nystagmus or there is slowing of nystagmus, before
changing to the next posi tion. After manoeuvre is complete,
patient should maintain an upright posture for 48
hours. Eighty percent of the patients will he cured by
a single manoeuvre. If the patient remains symptomati c,
the manoeuvre can be repeated. A bone vibrator placed
on the mastoid bone helps to loosen the debris.
3. Vestibular neuronitis. It is charac terised by
severe vertigo of sudden onset with no cochlear symptoms.
Attacks may last from a few days to 2 or 3 weeks. It is
thought to occur due to a virus that attacks ves tibular
ganglion. Management of acute attack is similar to th at
in Meniere's disease. The disease is usually self-limiting.
4. Labvr inthitis. It has been discussed in detail on
page 79.
Circumscribed labyrinthitis is seen in cases of unsafe
type of CSOM, and fistu la test is positive.
Serous labyrinthitis is caused by trauma or infection
(viral or hacterial) adjacent to inner ear but without
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DISEASES OF EAR
actual in vasion. There is severe vertigo and sensorineural
h earing loss. A partial or full recovery of inner ear functions
is possible if trcated early.
PLLndent labpinthitis is a complication of CSUM. There
is actual bacte rial in vr\sion of inner ear with total loss of
cochlear and vesl ibuLlr func tions. Vertigo in this condition
is due to acu te vestibular fa ilure. There is severe nausea
and vomiting. Ny~ ragnlll ~ is seen to the opposite side due
to destruction of the affected labyrinth .
5. Vestibulotoxic drugs. Several drugs cause otOtox icity
by dclll1:1ging the hair cells of the inner ear. Some primarily
affect the cochlear while others affect the vestibular
labyrinth. A minoglycoside antib iotic" p,m icularly strep tomycin,
gentamicin, kanamycin have he n shown to affect
hair cells of the crista <1mpullaris and to some extent those
of the maculae. Certain oth er drugs which cause dizziness
or unsteadiness are antihy pertens ives, labyrinthine sedatives,
oestrogen preparations, diuretics, antimicrobia ls
(nalidixic ac id, metronidazo le) and antima lar ia ls.
HoweVt'f, their mode of action may be diffe rent.
6. Head trauma. Head injury may cause concus:;ion
of labyrimh, complet' ly disrupt the bony labyrinth or
VIllth nerve, or cause a perilymph fistula. Severe
acoustic trauma, slich a:i th'lt caused by an explosion can
also disturh the vestibular end organ (oro liths) and result
in vertigo.
7. Perilymph fistula. In this condition, perilymph
leaks into the middle ear through the oval or round window.
It can follow as a complication of stapedectomy, or ear
surgery when siapes is accidenta lly dislocated. It can also
result from sudden prc:- ure changes in the middle ear (t- .cz
barotrau ma, diving, forceful Valsalva) or raised intracranial
prellsure (weightlifting or vigorous coughing). A perilymph
fistula causes intermittent verLigo 8nd fluctuating
sensorineural hearing loss, sometimes wi th tinnit us and
sense of fulln ess in the ear (compare Meniere's disease ).
8. Sypbilis. Syphilis of inner ear, both acquired and
congenital, causes dizzines in addition tn .ensorineural
hearing loss. Late congenital syphilis uSllally manifesting
between 8 and 20 years, mimics Meniere's disease with
episodes of acute vertigo, sensorineural hearing loss and
tinnitus. Hennebe rt 's ign, i.e. a positive fistula test in the
presence of an intact tympanic memhrane, is present in
congenital syphilis. Neurosyphilis (tertiary acquired) can
cause central type of vestibular dysfunctiun.
9. Acoustic neuroma. It has been cia-sified in peripheral
vestibu lar disorders as it arises from CN VIII within
internal acoll stic meatus. It causes only unstead iness or
vague sensation of motion. Severe episod ic vertigo, as s n
in the end organ disease, is usually miss in g. (For details
refer Chapter 18) .
Other tumours of temporal bone (e. g. glomus tumour,
carcinoma of external or midd le ear and secondaries) ,
destroy the labyrinth directly and cau. e vertigo.
B. CENTRAL VESTIBULAR DISORDERS
1. Vertebrobasilar insufficiency. It is a common cause
of central vertigo in patients over the age of 50 years.
There is transient decrease in cerebral blood flow. Common
cause is atherosclerosis. Ischaemia in these patients may
also be preCipitated by hypotension or neck movements
when cervical os teophytes press on the vertebral a rte ries
during rotat ion and extension of head.
Vertigo is a brupt in onset, lasts several minutes and is
assoc iated with n ausea and vomiting. Other ne urological
symptoms like visual disturbances, drop attacks, diplopia,
hemianopia, dysphagia, hemiparesis resulting from ischaemia
to other areas of brain may also accompany ve rtigo.
Some patients only compla in of intermittent attacks
of d izzine s or vertigo on lateral rotation and extension of
head .
2. Posterior inferior cerebellar artery syndrome
(Wall('nberg's syndrome). Thrombos is of the posterior
in fe rior cerebellar artery cuts off blood supply to late ral
medullary area. There is violent vertigo along with diplopia,
dysphagia, hoarseness of voice, Horner's syndrome, sensory
loss on ipsilateral side of face and contralateral side of the
body, and ataxia. There may be horizontal or ro tatory
nys tagmus to the side of the les ion.
3. Basilar migraine. Migraine is a vascular syndrome,
producing recurrent headaches with symptom-free intervals.
Headache is usually unilateral and of the throbbing
type. Basilar artery migra ine produces occipital headache,
visua l disturbances, diplopia and severe vertigo which
is abrupt and may last for 5- 60 minutes. Basilar migraine
is common in adolescent girls with strong menstrual
relationship and positive family history.
4. Cerebellar disease. Cerebellum may be affected
by haemorrhage (hypertension), infarction (occlusion of
arterial supply) , infection (otogenic cerebellar abscess ) or
tumours (glioma, teratoma or haemangioma). Acute cerebellar
disease may cause severe vertigo, vomitin,g and atax ia
Simulating an ac ute periphera l laby rinthine diso rd er.
Tumours are slow grow ing and produce classical features
of ce rebellar disease, i. e. incoordination, past-pointing,
adiadokokinesia, rebound phenomenon, wide-based gait.
5. Multiple sclerosis. It is a demyelinating disease
affecting young adults. Vertigo and dizziness are common
complaints. There are other multiple neurological signs
and symptoms, e.g. blurring or loss of vision, diplopia,
dysarthria, paraestheSia and ataxia. Spontaneous n ystagmus
may be seen. AcqU ired pendular n ystagmus, dissuciated
nys tagmus and vertical upbeat nystagmus are
important features in diagnosis.
6. Tumours of brainstem and floor of IVth ventricle.
Gliomas, astrocytomas may arise from pons and midbrain;
medulloblastoma, ep idymomas, epidermoid cysts or teratomas
may arise from floor of IVth ventricle. These
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tumours cause other neurological signs and symptoms in
addition to vertigo and dizziness. Positional vertigo and
nystagmus may also be the presenting features. cr scan and
magnetic resonance imaging are useful in their diagnosis.
7. Epilepsy. Vertigo may occur as an aura in temporal
lobe epilepsy. The history of seizure and/or unconscioLlsness
following the aura may help in the diagnos is.
Sometimes, vertigo is the only symptom of epilepsy and
that may pose a difficult diagnostic problem. E.E.G. may
show abnormalities during the attack.
8. Cervical vertigo. Vertigo may follow injuries of neck
7-10 days after the accident. It is usually provoked with
movements of neck to the side of injury. Examination shows
tenderness of neck, spasrns of cervical muscles and limi tation
of neck movements. X-rays show loss of cervical
lordosis. Exact mechanism of cervical ve rtigo is not known.
It may be due to disturbed vertebrobasil ar circulation ,
DISORDERS OF VESTI BULAR SYSTEM
involvement of sympathetic vertebral plexLls or alteration
of tonic neck reflexes.
Other Causes of Vertigo
Ocular vertigo. N orma lly, balance is mai ntained by
integrated information received from the eyes , labyrinths
and somatose nsory system. A mismatch of information
from any of these organs causes vertigo and in this case
from the eyes. Ocular vertigo may occur in case of acute
extraocular muscle paresis or high errors of refraction.
Psych genic vertigo. This diagnosis is suspected in
patients suffering from emotional tension and anxiety.
Often other symptoms of neurosis, e.g. palpitation, breathlessness,
fatigue, insomnia, profuse sweating and tremors are
also present. Symptom of vertigo is often vague in the form
of floating or swim.ming sensation or light-h eadedness.
The re is no nystagmus or hearing loss. Caloric test shows
an exaggerated response .
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