Dizziness: Vertigo Unsteadiness Lightheadedness
Dizziness is a common problem. The experience of dizziness can be difficult to describe. Patients use many different words such as dizziness, giddiness, unsteadiness, imbalance, spinning, light-headedness etc. Broadly dizziness can be split into a number of types:
- Vertigo: a sensation of spinning or movement. Often the word dizziness is used to describe this type of sensation. There is no loss of consciousness. This is often due to a problem in the vestibular system (in the inner ear balance system, nerve to the inner ear and/or part of the brain involved in balance).
- Unsteadiness/imbalance: a sensation of rocking from side to side or veering off to the side often when walking. The causes of this are more varied but can include inner ear problems, problems with the balance part of the brain, abnormal sensation in the feet/ankle/legs, muscle weakness and age-related changes (or a combination of problems).
- Light-headedness or fainting: This is a sensation one experiences if their blood pressure drops. This can progress to loss of consciousness. Generally, this is not due to inner ear problems. Irregular heartbeat or low blood pressure can cause this.
Other types of descriptions may include: “spaced out feeling” or “out of body experience”. Again these tend not to be caused by inner ear balance system disorder.
For many patients, the dizziness is short-lasting and the patient does not seek any medical attention. In some cases, however, the problem can be longer-lasting and disabling. Dizziness/imbalance, particularly those due to inner ear problems, usually do eventually resolve spontaneously. Some types of dizziness/light headiness can be due to more serious problems such as an irregular heartbeat or low blood pressure. In order to determine if the problem is serious, doctors will assess patients using a combination of history taking (the story of the dizziness), examination and if required special investigations/tests. The appropriate management/treatment can then be instituted. In some cases, particularly if the problem is improving nothing but reassurance is required. In other cases, specific treatments may be required. In a number of cases, the exact cause of dizziness cannot be determined with certainty.
Control of balance and eye movements
To allow a person to maintain their balance a number of sensory structures/systems must be intact and working correctly. The sensations involved in balance include the inner ear, vision and proprioception (signals from joints (particularly the ankle and neck) and skin(particularly skin of the feet)). The brain integrates the signals from these 3 senses and sends signals to the muscles to control body movement and eye movement. The signals from the inner ear and vision help control eye movements allowing a person to keep their vision on a target while their head is moving. Signals from these senses also provide a person with a sense of orientation in space.
Causes of dizziness
The inner ear is involved in the detection of movement and gravity. This information is sent from each inner ear to the brain and integrated with information from the eyes and proprioception (sensation from joints and skin) to provide sensory information for the brain. Using this information the brain can control the movements of the eyes and body. This allows a person to keep their balance and to allow them to keep their eyes on a target whilst moving their head. In addition, the information allows patients to maintain a sense of orientation in space. Even at rest, the inner ear on each side sends signals to the brain. If the inner ear is working abnormally either sending too few signals or too many signals, a disturbance can occur causing the patient to feel dizziness. The mismatch between the information coming from the ear that is malfunctioning and the remaining normal senses can cause disturbance in balance and eye movement and nausea/vomiting. Often the dizziness in this scenario is described as a spinning sensation (medical term: vertigo) or a sensation of movement. If the inner ear malfunction on one side is permanent/long-term and does not fluctuate, the brain eventually adjusts for the problem through a process called compensation. To allow compensation a patient will need to remain active and move their head. Certain types of exercise can also help this compensation.
Causes of dizziness due to inner ear problems include:
- Benign paroxysmal positional vertigo (BPPV).
- Vestibular neuronitis (also known as viral labyrinthitis although it is unclear if this is always due to a viral infection).
- Ménière’s disease.
- Migraine associated vertigo. Although considered a brain disorder in some cases this condition can cause problems which may be perceived mainly or solely in the ear. Migraine-associated vertigo and Ménière’s disease may overlap or in fact be manifestations of the same condition. See below.
- Bilateral vestibular hypofunction. A type of rare unsteadiness occurs when the balance function in both ears stops working. Patients feel particularly unsteady when they move their heads. The causes include side effects of treatment with certain antibiotics (aminoglycosides such as Gentamicin). Often the cause is unclear.
Persistent Postural Perceptual Dizziness (PPPD)
PPPD is a symptom complex the cause of which is not clear. Patient’s have persistent unsteadiness/dizziness usually when mobilising/moving. The patient may also experience visual vertigo which is dizziness occurring when the visual environment moves e.g. when a bus or train moves past the patient. There is more information here.
Mal De Débarquement Syndrome (MDDS)
In MDDS the patient has a rocking sensation/unsteadiness when standing still. This can be triggered by boat, train, plane trip or after dizziness due to other causes and occasionally for no clear reasons. There is more information here.
Brain, Spine and Nerve Disorders causing dizziness.
There are potentially dozens of different types of brain-related disorders which could cause dizziness. In some cases, there will be evidence that the problem is not an isolated ear problem. For example, there may be headaches, blurred vision, numbness or tingling in the hands or feet or weakness of the arms/leg. Some of the conditions affecting the brain which may be accompanied by ear symptoms are described below.
Migraine (e.g. migraine-associated vertigo or vestibular migraine). This is considered a brain-related problem. During migraine, the senses can become heightened including a sense of balance making patients vulnerable to dizziness especially when they move. Some patients also develop headaches. This is a common condition. Although I have only dedicated a part of this page to migraine my experience of patients with troublesome recurrent/persistent dizziness which has been difficult to treat is that most are probably suffering from an atypical type of migraine. Unfortunately, Migraine is not a condition which is well understood. The cause and mechanisms involved are not clear. There is no proven test. The diagnosis of migraine, therefore, relies on a checklist of symptoms. If you meet the criteria for another condition such as Meniere’s disease then things become confused. My own opinion is that Migraine, Menieres’s and a number of other conditions (e.g. TMJ dysfunction and even IBS) are all manifestations of an underlying condition which has not yet been defined. All these conditions have what I would consider features of an overly sensitive sensory system. The term “Sensory Hypersensitivity Disorder” is probably a good general description of this family of disorders. I use all terms such as Migraine Spectrum Disorder or Menieres/Migraine as often features of both Meniere’s disease and Migraine co-exist.
Although most people think of Migraine as a cause of headache (and this is often the case) some patients with Migraine have no headaches. This is recognised by all Neurologists. Most patients with Migraine headaches and dizziness do not have their dizziness at the same time as the headaches. I suspect this is due to a different mechanism in the migraine process causing the pain and the dizziness. There is evidence that the mechanism causing headaches may suppress dizziness in some patients, hence the relative rarity of headaches and dizziness occurring at the same time. Many patients with Migraine are also more sensitive to various stimuli even between their attacks of headaches e.g the patient may be sensitive to light, sound, smells, dehydration or stress. The pain of a migraine can be mild and may be in other places e.g. in the ear, back of neck/head or face.
My belief is that some people are genetically predisposed to a Migraine /Sensory Hypersensitivity tendency. Often some of the patient’s relatives will have a history of Migraine, Headaches, “Sinus” pain, neck pain, IBS, TMJ dysfunction, dizziness, Meniere’s disease etc. There is also a higher rate of asthma/allergy. This is, I suspect due to the inflammatory system (which can become active in migraine and asthma) having a lower threshold to activation and hence causing more severe symptoms. Sometimes a viral infection or trauma (physical or psychological) can trigger chronic activation of the sensory system. If this involves the nerves in the ear then the patient can develop dizziness.
If my theory that Migraine and Meniere’s Disease (and possibly some other causes of dizziness) are all part of one condition is true, then it needs to explain why some patients with Meniere’s Disease develop permanent inner damage and hearing loss. Migraine typically is not supposed to cause permanent damage. This is not, I believe, true. It is well known that patients with migraine do have more “white matter lesions” in the brain. This is picked up on MRI scans. These white matter lesions represent some damage possibly related to vascular or inflammatory effects of migraine. This process, I believe can also affect the inner ear causing damage which may be reversible or permanent. Although my theory is only a theory I have noted that other specialists have also considered the possibility that Migraine and Meniere’s Disease are related (see here, here and here). I also believe that many cases of Vestibular Neurontis and even BPPV can be precipitated by an episode of migraine (with some contribution from viral infections as a co-stressor).
Patients are often worried about the possibility of brain tumours causing dizziness. Brain tumours are a rare cause of dizziness. Any tumour sufficiently large may press on part of the brain involved in balance and cause dizziness. Generally, this type of problem would cause persistent dizziness and unsteadiness. There may be a disturbance of vision (double vision) and headaches which are worse in the morning. One particular type of benign brain (i.e. non-cancerous) tumour called a Vestibular Schwannoma also known as an Acoustic Neuroma develops on the balance nerve to the inner ear. It is a benign type of tumour. This means it does not spread to other areas of the body. It is generally very slow-growing. It usually causes hearing loss and tinnitus and occasionally dizziness.
Idiopathic intracranial hypertension
This condition typically affects young women who are overweight. The symptoms include dizziness, pulsatile tinnitus (a pulse-like noise in the ears), headaches and possibly visual disturbance. The cause of the condition is not known with certainty. There is increased pressure in the fluids around the brain causing the problems. If left untreated in some cases this may cause pressure on the nerve to the eye causing visual problems.
Multiple sclerosis (MS)
This is a condition causing damage to the nervous tissue within the brain. MS can cause dizziness. The problem can fluctuate. It often causes other problems such as visual problems, numbness or tingling or problems passing urine.
Neurodegenerative Disorders including Cerebellar Disorders
In some patients part of the brain malfunction. The reasons are not always clear. In some cases, the problems are inherited. The part of the brain involved in balance and coordination may be affected causing clumsiness, slurred speech and unsteadiness.
A stroke occurs when blood flow to the brain is insufficient. This can lead to damage to nervous tissue. A stroke can cause many different types of symptoms including weakness in the arm, legs or face, numbness, slurred speech or visual loss. Some types of stroke can affect the lower part of the brain where the balance systems are located. This can lead to dizziness/unsteadiness. Usually, there are other clues that the problem is due to a stroke rather than an inner ear problem.
Dizziness is not a common feature of epilepsy. Most cases of epilepsy are fairly clear if associated with seizures which can cause shaking (tonic-clonic seizures) or altered consciousness. Occasionally epilepsy can be associated with a period of altered consciousness which does not result in the patient falling or collapsing. Generally, however the patient is not aware of what has happened. This is unusual in dizziness due to the inner ear. Patients with dizziness due to inner ear problems usually remember the episodes of dizziness.
Spinal cord problems
If the spinal cord is working incorrectly nerve signals going to or from the brain to the muscles and joints respectively do not reach their destination. This can lead to unsteadiness/imbalance or weakness/numbness of the legs. Examples of problems include a slipped disc in the back or neck pressing onto the spinal cord or Vitamin B12 deficiency (for example due to pernicious anaemia).
Sometimes the nerves supplying sensation to the legs, ankle and feet are not working correctly. This can for example happen in patients with diabetes or due to side effects of certain drugs. This causes reduced sensation and information for the brain to work out where your legs are. This can contribute to imbalance/unsteadiness.
Low blood pressure can cause disturbance of brain function and can result in dizziness or even loss of consciousness. Loss of consciousness is called faint or by the medical term “syncope”. Pre-syncope is the sensation of feeling lightheaded that may progress to fainting or syncope. Blood pressure can drop if for example there is an irregular heartbeat (arrhythmia). If the heart is beating irregularly its function can be impaired resulting in a drop in blood pressure. If the irregular heartbeat is such that blood pressure drops significantly there may be a period of loss of consciousness/fall. Other causes of the drop in blood pressure may include orthostatic hypotension. In this condition, the blood pressure drops as the patient stands up. It can occur in patients on blood pressure tablets. This can be assessed with blood pressure measurement while lying and standing. In some patients particularly young women, there appears to be a tendency to have low blood pressure which can cause dizziness.
There is evidence that on rare occasions some types of migraine can be associated with periods of loss of consciousness/syncope/faint.
The blood pressure may drop a lot when a patient stands up. This is called orthostatic hypotension. In this condition, the blood pressure drops as the patient stands up. It can occur in patients on blood pressure tablets. This can be assessed with blood pressure measurement while lying and standing. In some patients particularly young women, there appears to be a tendency to have low blood pressure which can cause dizziness.
Postural Orthostatic Tachycardia Syndrome (POTS)
In this condition, the pulse of the patient increases a lot when they stand up. There is often associated dizziness/lightheadedness. It is commoner in teenage girls. The cause of this is not clear. There may be other symptoms such as fatigue.
Some patients may have problems in multiple areas. This is more often seen in patients who are older with other conditions such as diabetes and arthritis.
Auto-Immune / Rheumatological Disorders
Auto-immune disorders occur when the body’s immune system attacks part of the patient’s own body. This can various symptoms including dizziness. The patient may have a rash, joint or eye problems.
Metabolic Hormonal Condition
Metabolic conditions including anaemia, disturbance in salts in the blood and abnormal hormone levels (e.g. abnormal thyroid function) can cause dizziness. These conditions tend to cause fairly persistent dizziness or tiredness.
Vision contributes a large proportion of information required for balance, movement and a sense of orientation. Any conditions where the vision is significantly affected can potentially contribute to dizziness/imbalance.
Arthritis/joint problems and muscle problems can contribute to a state of imbalance/unsteadiness.
Psychological problems such as anxiety, hyperventilation and panic disorder can also cause dizziness.
Older people’s balance systems do not work as efficiently as young people. A combination of minor problems in various systems can add up to cause unsteadiness.