Vertigo - an overview
The term vertigo indicates a rotating or a spinning sensation. On a broader perspective it also includes the sensation of imbalance or instability. The symptoms of vertigo and imbalance are referred to in medical parlance as ‘Balance disorders’ and signifies a disorder in the balance system (also termed as the vestibular system). The maintenance of the body’s balance is a very complex mechanism and involves many different organs of the body, the most important of which are the brain, the ears, the eyes, the spinal cord, the nerves and the muscles of the limbs and trunk as well as the small muscles of the eyes. A defect in any one of them can completely jeopardize the balance system and cause vertigo/ imbalance. Over and above these, other systemic (i.e. general) causes like anemia, diabetes, thyroid disorders, heart diseases etc can cause balance disorders by inducing functional changes in the brain, eyes, ears, nerves etc. Neurological disorders like Parkinsonism, diseases of the cerebellum or that of the spinal cord, multiple sclerosis, diseases of the nerves of the limbs and the trunk, a stroke in certain parts of the brain can all present only with a balance disorder and nothing else in the initial stages. Psychological disorders / psychiatric diseases can also be the cause of balance disorders. Diagnosis and treatment of balance disorders quite often need a multi-speciality approach and in many cases a team of a neurotologist, a neurologist and a psychiatrist is needed to properly diagnose a balance disorder patient. Treatment too hence often involves a medical team of the above specialists along with psychologists/ counselors and specially trained neuro-physiotherapists who have an insight in balance disorders.
Balance disorders are pretty common and according to available international statistics about 5% of all patients seeking medical advice from the family physician and about 10% of all patients visiting neurologists and ENT doctors present with vertigo / imbalance.
The maintenance of the body's balance is primarily a function of the brain. The brain collects information about the position of the body (irrespective of whether it is stationary or, it is moving), from different sensors located in different parts of the body. The sensors are the (1) the two eyes, (2) two specialized balance organs called vestibular labyrinths, which are situated deep inside the ears, and (3) some special sensors called proprioceptors which are located in the soles of the feet, in the buttocks, in the back and in the neck. Information from the sensors are conveyed to the brain and from this information , the brain learns about the stability of the ground on which the person is standing, sitting or lying down and also about the stability of the surroundings. Once the brain has learnt about the stability of the ground and the surroundings, that is after it has accessed how much the condition of the ground and the surroundings is conducive to the subject's stability, it can ascertain very precisely how much the person is liable to be unstable or to fall and if so in which direction in that particular situation. The brain then spontaneously and instantaneously generates a corrective action which is a very precise and accurate contraction and of certain selected muscles of the body and the eyes so as to restore stability and prevent any imbalance or vertigo. This sensing of the stability of the subject in relation to the ground and the surroundings and the requisite corrective action tales every moment of our lives hundreds of times a minute. For example, if the person is tending to fall towards the left side, then the brain as soon as it recognizes this tendency of falling towards the left immediately brings about a contraction of the muscles of the right side of the body so that the fall towards the left side is prevented. This entire process occurs reflexly, that is it is automatic and the person does not have to make any conscious effort to do so. This is a unique system and the above description though a bit complicated is over-simplification of a very complex mechanism. Even a very minor defect in the any of the organs concerned with the maintenance of balance can completely jeopardize the balance system and result in vertigo or imbalance.
Since the mechanism of maintenance of balance is so very complex, the correct diagnosis and management of balance disorders is equally complicated and nowadays there is a specific medical discipline called neurotology that deals specifically with balance disorders. Doctors specializing in the diagnosis and management of balance disorders are called neurotologists. Many hospitals now have separate neurotology departments, where patients suffering from balance disorders and /or hearing disorders only are catered to.
Balance disorders can occur from are huge range of medical disorders some of which may be very trivial and some of which may be very sinister life-threatening conditions. Vertigo or imbalance is not a disease in itself. Like fever or pain, ‘vertigo’ is just a symptom or a manifestation of some underlying disease that may be due to a very simple self-limiting condition like vestibular neuritis, which is a viral inflammation of the nerve of balancing or it may be the only manifestation of a very serious disease like a tumor in the brain. So, the symptom of vertigo should never be taken lightly and should be thoroughly investigated to determine the cause and then treated scientifically. ‘Vertigo’ can never be a diagnosis; it is merely a indication and an expression of some disease, which must be identified by the treating physician. Though many medical professionals use the term ‘vertigo’ as a diagnosis this is wrong and misleading to patients. The term ‘vertigo’ is just the English translation of ‘chakkar’ or the sensation of spinning felt by the patient. The job of the medical professional is to find out the cause of the symptom of vertigo and treat the cause of the vertigo and not merely to translate the patient’s symptom of ‘chakkar’. Just like we denounce and abhor the indiscriminate use of antipyretics and pain killers to suppress the symptom of fever or pain, our objective in the management of vertigo is always to identify and correct the causative factor causing the vertigo instead of symptomatic relief only. Hence, the indiscriminate and long-continued use of anti-vertigo drugs though very prevalent is best avoided as it camouflages the actual underlying disease and gives the patient and the doctor a false sense of complacency. Treating a patient presenting with vertigo with anti vertigo medicines is the same as treating a patient presenting with fever due to malaria with anti-pyretics instead of medicines to treat malaria.
The diagnosis of vertigo is a time consuming affair as the treating doctor is expected to take a very detailed history which is the mainstay in the diagnosis of vertigo, carry out certain clinical tests and if required perform certain specialized investigations called vestibular function tests. Only then can one make a proper diagnosis and treat the cause of the vertigo. The specialized investigations that are required in a patient of vertigo are Electronystagmography (ENG) or Videonystagmography (VNG), Video Head Impulse Test (VHIT), Vestibular Evoked Myogenic Potentials (VEMP) tests, Subjective Visual Vertical (SVV) test, Dynamic Visual Acuity (DVA) test, Craniocorpography (CCG), Stabilometry, Posturography and some audiological tests like Pure tone audiometry, Electrocochleography (ECochG) and BERA. Over and above this, some other tests like blood tests, imaging studies like CT scan and / or MRI of the brain, cervical spine and the spinal cord, color Doppler studies of the blood vessels of the neck, some functional imaging studies like SPECT etc. are sometimes required. However, the role of the costly imaging studies like CT scans and MRIs is very limited and it is the functional studies like VNG, CCG, VHIT, ocular and cervical VEMP posturography and sometimes audiometry that are primarily helpful and much more informative in the diagnosis of balance disorders. Most neurotological clinics are equipped with these facilities and without these basic facilities it is impossible to diagnose and treat a patient suffering from vertigo / imbalance. Though some private and even Govt hospitals put up a signboard of ‘VERTIGO CLINIC’ to lure naïve patients or even use it as a status symbol very few if any of them actually have the infrastructure to evaluate and manage patients suffering from balance disorders. A vertigo clinic needs dedicated and trained manpower and very special sophisticated diagnostic equipment.
The management of vertigo is now done by an integrated therapy, which is a 4 pronged therapeutic protocol and consists of:-
1) Treatment of the etiological factor after a definite cause has identified through detailed history-taking, clinical neurotological tests and the relevant neurotological investigations. There are specific medications for each of the specific neurotological diseases like Meniere’s disease, vestibular neuritis, benign positional vertigo, migraine related vertigo (vestibular migraine), vertebrobasilar insufficiency, vestibular seizures, multiple sclerosis, psychogenic vertigo like Phobic Postural Vertigo and Persistent Perceptive Postural Dizziness etc.etc. There are numerous different diseases that can present with vertigo and there is no blanket therapy i.e. there is no medicine that can treat all the causes of vertigo. Each of the causative diseases has a very specific medication for it. The treating physician has to identify the precise cause of the vertigo and only then treat the disease. Whatever be the cause of the vertigo/imbalance there is a very specific remedy for it but to avail of that very specific remedy a very accurate diagnosis of the underlying disorder is mandatory.
2) Provide symptomatic relief from the vertigo with anti-vertigo drugs. This however has its limitations as discussed below and is to be done cautiously and for a very limited period of a maximum of 3-5 days if at all.
3) Physical exercises for vestibular re-education or re-calibration of the vestibular system through some specific exercises.
4) Psychological counseling and psychotherapy as and when required especially in cases of chronic / persistent vertigo where the persistence of the vertigo / imbalance and the failure of diagnosis / treatment has led to psychological disorders like helplessness, depression, anxiety and frustration. Vertigo and imbalance are not only physically distressing but mentally very traumatic too. Vertigo/ imbalance and psychological disorders often perpetuate one another and the treatment is incomplete if the frustration / anxiety / depression is not attended to.
For the proper management of vestibular disorders, a good doctor-patient relationship, explanation of the disease to the patient, justification for the therapeutic schedule prescribed by the doctor, information on the prognosis, psychological help, reduction of stress and the strict adherence to the treatment protocol by the patient is necessary. The treatment of balance disorders does not mean simply using some anti-vertigo drugs. Most of these drugs can at best provide some degree of temporary symptomatic relief only and that too not in all cases. Symptomatic relief is definitely necessary in many cases not only to ameliorate the patient’s physical distress but also to relieve the patient from the severe mental distress and the anxiety that accompanies the attack of vertigo. The flip-side of it is that trying to provide symptomatic relief not only camouflages the underlying disease as already discussed, but what is still worse is that it may (and does) jeopardize the natural vestibular compensatory mechanism which is nature’s way of restoring stability after there has been a permanent damage to the balance organ. These anti-vertigo drugs for symptomatic relief are hence best used if at all for very short spells only. Whenever there is a damage to the balance system especially the balance organs (vestibular labyrinths) in the ears, the damage is very often permanent and the damaged vestibular labyrinths cannot be regenerated by any medical or surgical means. It is the vestibular compensatory mechanism which is nature’s unique system that comes to our help and not only ameliorates the patient’s vertigo but also restores stability in spite of there being a damaged balance system. The objective of treatment should always be to enhance and expedite the vestibular compensatory mechanism and to refrain from anything that will jeopardize this natural mechanism. All anti-vertigo (also called vestibular sedatives) and all sleeping pills destroy this natural mechanism to restore balance. Balance dysfunction cannot be corrected or the balance function improved just by taking anti-vertigo drugs for an indefinite period of time. The current consensus is to restrict the use of vestibular sedatives to just 3-5 days only and definitely not beyond that; in fact most authorities recommend not using anti vertigo medicines for more than a day. A holistic approach to management of the patient’s balance disorder that comprises of (1) correcting the underlying medical disorder that is causing the vertigo rather than suppressing the symptom of vertigo by anti-vertigo drugs, (2) diligent vestibular physiotherapy which are specialized physical exercises to be done by dyuly trained vestibular physiotherapists and (3) managing any concomitant psychological or systemic disorder that is present along with the vertigo is the current mode of management.
Certain specified physical exercises have been found to play a very big role in curing a patient of vertigo and imbalance. Internationally, physical therapy i.e. some specific exercises called vestibular rehabilitation exercises (Cawthrone Cooksey exercises) is now medically recognized to play not only a major part, but probably the most effective part in the long term management of balance disorders. It is all the more effective especially in cases where the balance disorder is due to damage in one of the vestibular labyrinths (that is the organ of balance in the ear). The exercises help to enhance and expedite the vestibular compensatory mechanism. In addition to the Vestibular Rehabilitation Exercises, some specific yogic asanas and some Taichi exercises have also been found to be very helpful in enhancing the vestibular compensation and in restoring stability. Poor compensation occurs if the patient has a neurological disorder that is some disorder in the brain, is under sedative medication that is the patient is taking medicines (e.g. sleeping pills) that sedate him, is taking anti-vertigo drugs for a prolonged period, is non-ambulatory, is kept in a dark environment or has a poor motivation for recovery. Patients suffering from balance disorders need to be taught these Vestibular Rehabilitation exercises and if possible also the asanas and the taichi exercises. Physical therapy to enhance and expedite the vestibular compensatory mechanism is the mainstay of treatment in the management of vertigo. Over and above this, proper counseling to motivate the patient for recovery and some medicines for treatment of the causative disease (i.e. etiological factor) and some neurotropic agents and antioxidants to prevent further degeneration of the balance system is necessary for the management. Surgery has a very limited role in the management of vertigo / imbalance except in rare cases where the vertigo is being caused by a tumour in the brain / spinal cord. In very rare cases of Meniere’s disease and in some other intractable cases of Vertigo, ablative surgery is attempted but the results are often not very gratifying. Moreover there is a small but definite chance of a permanent hearing loss being induced by surgery and hence except in very rare and very judiciously selected cases, surgery is best avoided in vertigo.
Dr Anirban Biswas
VERTIGO and DEAFNESS CLINIC
BJ252 Salt Lake Kolkata -91
Belle Vue Clinic, Kolkata-17