PG Dhanyaa, VG Pradeep Kumarb
a. Government District Hospital, Kozhikode; b. Baby Memorial Hospital, Kozhikode

Corresponding Author: Dr. V G Pradeep Kumar, Consultant Neurologist, Baby Memorial Hospital, Kozhikode. Phone: 9447034443. Email: vgpradeep@hotmail.com

ABSTRACT

Human beings maintain equilibrium utilizing a sophisticated system. Vertigo is a very disquieting sympyom. Analysis of the symptomatology and clinical picture is needed to ascertain the cause of vertigo in any given case.

Man has developed a very sophisticated system by which perfect equilibrium is maintained. Sensory information from the eyes and vestibular apparatus together with proprioceptive information from the neck and limbs passes to the central nervous system where, at the level of the vestibular nuclei, it is integrated and    modulated by activity arising in the cerebellum, extra  pyramidal system  and  cortex. Pathways arising from the nuclei connect with five main  systems; the  cerebral cortex, occulomotor nuclei, the motor part of spinal cord, the cerebellum and the autonomic nervous system resulting  in static and  dynamic spatial   orientation and  control of locomotion and posture. Pathology   affecting the central nervous system, cardiovascular system, the eyes, the ears, the locomotor system, blood and endocrine gland may all alter this balance of neural information and result in disequilibrium.

Dizziness I VERTIGO

Table 1. Causes of Dizziness, Vertigo

Table 1. Causes of Dizziness/Vertigo

Dizziness is a term that comprises a number of symptoms of disequilibrium including light headedness, faintness, giddiness, sensations of floating, imbalance ataxia, mental confusion or  loss  of consciousness. In other words it is a feeling of “as if about to fall”.

Vertigo is a specific symptom related directly to dysfunction of the vestibular system. By definition, vertigo is a “hallucination of movement (Cawthrone 1952) or “disagreeable  sensation of instability  or disorder of orientation in  space.

It may not be always possible for the patient to differentiate between the two symptoms  and they may often complain only of a feeling of instability.

Physiology Vestibular System

Vestibular labyrinth is composed of two parts:

  • Semicircular Canals that respond to angular acceleration.
  • The Otolith Apparatus that respond to  linear
    acceleration.
Figure 1. Diagnostic approach to Dizziness,Vertigo

Figure 1. Diagnositc approach to Dizziness / Vertigo

The two halves of the vestibular system should be maintained in   perfect balance for equilibrium.

During head movements vestibular input alters along with  visual signals and  cervical and proprioceptive   input. From birth, this information is stored in the  reticular formation of the brain stem (data centre). Afferent information is  always compared with this data bank and normally there is a perfect match and equilibrium is maintained. If the function of any of these is impaired  and mismatch occur  between  the  information generated by one sensory modality and that of the other, symptoms of disequilibrium arise.

Diagnosis: is based  on

1.   A proper history

2.   Full medical examination with reference to the ears, eyes,  neurological assessment

3.   Specific special investigations.

By considering the character of complaint, duration of  illness and  presence or  absence of associated symptoms-cochlear, neurological or cardiovascular we often  get a clue to the diagnosis.

Some Generalizations:

  1. Vertigo is  commonly associated with a vestibular disorder
  2. Dizziness is commonly related to general medical disorder
  3. Sudden, unexpected, short lived episodes ofvertigo- peripheral vestibular disorders
  4. Gradual, insidious onset of continual imbalance – central disorder (exception include temporal lobe  epilepsy   and vertebrobasillar ischaemia)
  5. Duration
    BPPV- duration of individual attacks 30-40 seconds Menieres disease lasts  upto 24 hours. Labyrinthine failure vertigo lasts for many  days
  6. Associated symptoms: Audiology symptoms like hearing loss,  tinnitus, sensation of fullness in the ear and painful lesions of labyrinth or VIIIth Nerve.

Benign Paroxysmal Positional Vertigo ( BPPV)

Most common clinical syndrome following minor head injury. Symptoms develops after a symptom free interval of days  or weeks. It can also be seen after viral infections of upper respiratory tract.

Symptoms

Brief  severe  episode of rotatory vertigo lasting less  than  a  minute upon  sudden changes of head position especially on lying down and turning towards the  affected ear.

Findings:

Dix Hall pike Maneuvers

  • Latent  period 2-20 sec  followed by  vertigo/ nystagmus with or without nausea nystagmus – linear rotatory with fast  phase  towards affected ear lasts <1 minute.
  • Absence of symptoms and signs on repeated testing (fatigability)

Pathophysiology:

Thought to arise due to pathology in the posterior semi circular canal

  1. Theory of  “Cupulolithiasis”  proposed bySchuknecht in 1969.
  2. Theory of “Canalolithiasis’ proposed by Brandt and Stedden in 1993.

According to this theory, Otoconia!debris forms a freefloating clot in the posterior semicircular canal. Rapid changes  of  head  position with  respect to gravity   causes the  clot to move and   induce endolymph flow and cupular deflection

Pharmacotherapy

  1. Role not clearly established
  2. Best avoided where possible to  allow  central nervous system  compensatory mechanism
  3. Drugs employed symptomatically are
    • Phenothiazines
    • Ca++ channel antagonists
    • Antihistamines
  4. Betahistine (histamine receptor agonist) has  a prophylactic role and is widely used.

Liberatory Manoeuvre – Canalith Repositioning Procedure

  • Proposed by Epley
  • To use head position and vibration to cause free canaliths to migrate out of PSCC to the inert region of the utricle.
Table 2. Characteristics of Peripheral Vs Central Vertigo

Table 2. Characteristics of Peripheral Vs Central Vertigo

This maneuver  has produced successful results in most patients and if the symptoms recurs, the maneuver  can  be repeated.

Migrainous Vertigo

Migrainous vertigo, although not recognized in the International Headache Society Schema, is a commonly diagnosed entity among neuro-otologists.  The diagnosis requires clinical suspicion and is one of exclusion, Neuhauser et  al have  suggested diagnostic criteria

Definitive criteria

  1. Episode of  vestibular symptoms of  at  least moderate severity vertigo, positional dizziness and head motion intolerance
  2. Migraine according to International  Headache Society Criteria
  3. One or more  of the following features during at least two vertigo attacks
    Migrainous headache
    Headache
    Photophobia
    Phonophobia
    Migrainous aura
  4. Other diagnoses excluded by appropriate test

Probable:

Criterion 1 and 4 as above plus s at least ONE  of the following

  • migrainous headache
  • migraine symptoms during vertigo
  • migraine specific triggers of vertigo response of anti migraine drugs.

Migrainous vertigo is a diagnosis of exclusion and because some patients may have symptoms and signs (including nystagmus) suggestive of  central dysfunction, neuroimaging may be required at first presentation. AI though there have been no adequate randomized trials of treatment of migrainous vertigo in the clinic setting, most neurologist use standard antimigraine prophylactic drugs  (propanalol, amitryptilline etc) with reasonable success.

Investigations

The laboratory investigation, like the physical examination, should be directed particularly by the patients history. If there is a history of presyncope or syncope, the patient must have a cardiac evaluation, and an electrocardiogram. All  patients  with undiagnosed vertigo should have metabolic screening tests, including blood cell count, electrolytes, blood glucose, ESR and thyroid function test. The presence of auditory symptoms requires audiometric tests. Multiple or recurrent cranial neuropathy requires screening test for collagen vascular disease or basal skull lesions or meningitic process. Vertigo with cerebellar signs definitely requires CT scan or MRI of brain.

End Note

Author Information

  1. Dr. PG Dhanya, Consultant,  ENT Surgeon, Government District Hospital, Kozhikode
  2. Dr. V G Pradeep Kumar, Consultant Neurologist, Baby Memorial  Hospital, Kozhikode

Conflict of Interest: None declared

References

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  6. Neuhauser H, Leopold M, von Brevern M, Arnold G, Lempert T. The interrelations of migraine, vertigo, and migrainous vertigo. Neurology. 2001 Feb 27;56(4):436–41. [Pubmed] | [Source]