Monday, May 5, 2014

Vertigo: An Enigma demystified




The term vertigo has been derived from the latin word ‘ vertere’ that means ‘to turn’. 

Simply put it is a sensation that might be described as a pre-syncope, light-headedness, disequilibrium to describe that feeling of floating in our environment and losing our sense of direction.
According to a recent report by a French study, 1-year prevalence for vertigo was 48.3%, for unsteadiness 39.1%, and for dizziness 35.6%.

The vestibular system comprises of the labyrinthine part of the inner ear and its connections in the brain stem and cerebellum, which are the balance regions of the brain. 

Equilibrium Pathway:


Vertigo is caused by the abnormal functioning of the vestibular system that is responsible for managing our balance, motion perception and response of eye movements to different positions. 

Broadly, vertigo may be classified as peripheral and central in etiology.
  • Peripheral vertigo means that it is originating at the ear end of the vestibular system;
  • Central vertigo means that the causation lies some where in the brain.

Common causes of the peripheral vertigo are:

Benign paroxysmal positional vertigo (BPPV), thought to be caused by a displacement of otolith particles, calcium deposits in the inner ear, is the most common type of peripheral vertigo in the clinical practice, twice as common in women than men, usually affects older people and most often arises without a known cause (idiopathic). While most cases are spontaneous, BPPV vertigo can also follow head injury, reduced blood flow in a certain area of the brain (vertebrobasilar ischemia), labyrinthitis: inflammation of the inner ear labyrinth and vestibular nerve (the nerve responsible for encoding the body's motion and position, ear surgery, prolonged bed rest.

Other common peripheral causes of vertigo are
  • Vestibular neuronitis - this is thought to be due to inflammation of the vestibular nerve. 
  • Ménière's disease: caused by inflammation, usually infective & thought to be caused by high pressure of a fluid in a compartment of the inner ear .

Central vertigo
is a term that collects together the central nervous system causes - involving a disturbance to one of the following two areas: The parts of the brain (brainstem and cerebellum) that deal with interaction between the senses of vision and balance, or sensory messages to and from the thalamus part of the brain.
Most common of the central vertigo is Vertiginous Migraine that would be associated with the headache.
Other rare but important causes are:
                 stroke and transient ischemic attack
                 cerebellar brain tumor
                 acoustic neuroma (a non-cancerous growth on the acoustic nerve in the brain) and
                 multiple sclerosis

Let's make one thing very clear, that cervical spondylosis is not a cause of the vertigo as most of us try implying cervical spondylosis as the cause of our unexplained vertigo  though emotional upheavals may sometimes cause pre syncope type of states that may be confused with vertigo and may be misinterpreted leading to unnecessary investigation.
As described above, most of the cause of vertigo are benign and there is nothing to worry about. But we all should know the red flag signs so that we know when to call the doctor for evaluation.
Please consult a Neurologist if there is: 
  • worsening vertigo or disequilibrium, 
  • imbalance or in-coordination of the movement, 
  • associated non relieving headache, 
  • recurrent vomiting, 
  • loss of consciousness associated with vertigo, 
  • double or blurred vision, 
  • speech difficulty, 
  • limb weakness, 
  • atypical “non-peripheral” vertigo, such as vertical movement;  

Peripheral vertigo should be best evaluated by an ENT expert. So, ENT opinion is warranted if vertigo is:
  • short duration, 
  • episodic, 
  • postural vertigo 
  • associated with hearing loss and /or tinnitus

Medications are prescribed according to the etiology of the vertigo. Apart from the medicine your doctor might tell you a few exercises that might improve your vestibular system function and hence the vertigo.

Contributed by :
Dr Sweta Singla
MD, DM Neurology
 

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