Dizziness and Vertigo.

 Dizziness and Vertigo

PKGhatak, MD

Dizziness is not an uncommon symptom, specially in the elderly. Patients describe the symptoms in various ways - lightheartedness, feeling unsteady while walking, a sense of not being able to keep an upright posture while trying to get up from a bed or a chair, head spinning, about to faint and like.

Vertigo symptoms are related to a false sensation of motion of the surroundings.  Generally, head movements precipitate an attack of vertigo. Fear of falling on the ground from a bed or upright position and often associated with nausea and jerky movements of the eyes.

The distinction between dizziness and vertigo is important from diagnostic and treatment points of view. But often one term is used for the other. The task falls on the physician to get a clear history from the patient and only then proceed with the investigation.

What causes dizziness:

Many medical conditions may cause dizziness, chief among them are postural hypotension, irregular cardiac rhythm, disturbed blood flow to the hindbrain (lower posterior part of the brain) and low blood sugar.

Other conditions less commonly associated with dizziness are alcohol intoxication, antidepressant drugs, migraine, and carbon monoxide poisoning.

What causes vertigo:

Vertigo is due to abnormal signals fed to the brain from the semicircular canals of the inner ear called the vestibule.

Each vestibule contains 3 semicircular canals, positioned at 90 degrees to each other. The canals are filled with a viscous fluid called endolymph, floating on the endolymph there are tiny pebble like structures called otoconia, connected with the vestibular division of the 8^th cranial nerve. Any movement of the head displaces the otoconia and initiate signals from both ears and the signals are reciprocal to each other. The brain integrates these signals and accurately calculates the coordinates of the head position in relation to the horizon.

Diseases affecting the inner ear are the cause of Vertigo.

Common conditions causing vertigo:

Viral infection of the balance organ is commonly known as Labyrinthitis, motion sickness due to overstimulation of the brain from the constant change of head position – a common experience of passengers on a boat in a choppy sea, benign paroxysmal positional vertigo and head injury. Other conditions are:-

   Neuronitis, Meniere's disease, Tumors like meningioma pressing on the hindbrain, Vestibular migraine, and Brain cancers. Cerebral strokes, and Multiple sclerosis.

The medication also can cause Vertigo, a few examples are -  certain antibiotics, water pills, cancer drugs, and aspirin in heavy doses.

Meniere's disease:

A combination of tinnitus (low volume high pitched noise like the chirping of crickets), some loss of hearing and vertigo is known as Meniere's disease. The reason for this disease is not known. Symptoms are generally episodic but tend to be recurrent. After each attack, the hearing loss increases.

Benign Paroxysmal Positional Vertigo (BPPV):

Sudden head movement or turning the head to a certain position causes BPPV. It is very disturbing to the patients but it causes no permanent harm to the body. The sensation of the horizon tilting up and down causes the patient to grab whatever they can to avoid falling to the ground. The condition is self-limited but may be prolonged. A certain maneuver of the head position can stop vertigo and the patient can learn the technique and can self-treat. 

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