Timothy C. Hain, MD. • Page last modified: July 31, 2022
See also: Vestibular function over age.
|System||Contribution (Davis, 1994)|
|Peripheral Vestibular (Otologic)||56|
|Proprioceptive (peripheral neuropathy)||7|
Jonsson et al (2004) found that the overall prevalence of balance problems at age 70 was 36% (women) and 29% (men). Balance symptoms were more common among women than men, and increased with increasing age. At ages 88-90 years the corresponding values were 51-45%.
Compared to younger persons, dizziness in older people is not only more common but it is also more persistent, has more causes, is less likely to be due to a psychological cause, and is more incapacitating (Davis L, 1994).
ENT clinics report a higher prevalence of peripheral dizziness (42.4% BPPV, 12.47% Menieres, 13.15% Migraine), Uneri and Polat, 2008, but this is likely due to referral bias. ENT clinics are sent patients with peripheral dizziness !
As can be seen from the table above, the main two sources of dizziness in older people are the ear (otologic -- peripheral vestibular) and the brain. This brief review of the causes of dizziness is divided into five main categories: 1) otologic; 2) central; 3) medical; 4) psychogenic; and 5) unlocalized.
|Figure 1. Current hypothesis regarding pathogenesis of BPPV. Otoconial debris displaced from the utricle becomes displaced to the bottom of the posterior semicircular canal. Treatment maneuvers relocate debris from this position back to the area of the utricle (the vestibule). The dark cells may dissolve otoconial debris.||To perform the Brandt-Daroff exercises, one spends thirty seconds in each of the positions shown. Five repetitions of these exercises should be performed each morning and evening for three weeks.|
Otologic dizziness is the most common type of dizziness in the elderly. This is mainly due to an increased tendency for the elderly to develop benign paroxysmal positional vertigo (BPPV). There is also a gradual deterioration of inner ear function with age, causing as many of 5% of unsteady older persons to have bilateral vestibular weakness. An attempt to model this process can be found here.
As a rule of thumb, about 50% of dizziness is caused by BPPV by the age of 80, compared to about 20% for all ages considered together. With BPPV, patients complain of brief bouts of vertigo provoked by changing the orientation of the head to gravity. BPPV is presently felt to be caused by dirigible otoconial debris (see Figure 1) BPPV is diagnosed by performing a Dix-Hallpike maneuver, a positional test. Vertigo and a typical twisting type of nystagmus ensue after a latency of two seconds and last about ten seconds. BPPV often responds to the Brandt-Daroff exercises performed over a three-week period (see Figure 2), but newer exercises such as the "home Epley" are much more effective. The Epley or Semont maneuvers are more complex and either require referral to physical therapy for vestibular rehabilitation, a "dizzy" specialist doctor, or use of a BPPV home-exercise. Treatment with vestibular suppressants, or antiemetics is also helpful in the week after onset (before the exercises have had a chance to work), in patients too physically limited to perform the exercises, or in patients who do not respond to the exercises. Meclizine is the most helpful of these agents.
Bilateral vestibular loss or paresis is characterized by unsteadiness and trouble seeing with the head moving (oscillopsia). It in general is most commonly caused by exposure to ototoxic medications, particularly courses of gentamicin lasting 2 weeks or longer. However, other causes include spirochete infections of the inner ear, autoimmune processes, and age-related changes. Roughly 5% of unsteady people over the age of 75 have bilateral weakness.
Although we suggest here that age reduces the vestibular system function, there is a difference between semicircular canal function (which is generally preserved), and otolithic function (which is generally lost). There appears to be a rather large redundancy in the circuitry for the canals, but a combination of a vulnerable periphery (the otoconia), and far less redundancy in the circuitry for the otoliths, that causes otolithic problems in the elderly (such as BPPV, absent VEMP tests).
Symptoms of canal impairment or otolith impairment rarely include vertigo. In the management of such a case, it is important to advise the patient to avoid any agents that may suppress the vestibular system, such as meclizine. It is also important for them to avoid anticholinergic agents such as many of the tricyclic antidepressant medications. Ototoxic agents must be avoided above all, particularly gentamicin. Vestibular rehabilitation physical therapy is usually helpful, but full recovery is never attained in many patients. Recovery depends on the degree of vestibular loss and on the individual’s ability to compensate.
Meniere’s syndrome is also a significant cause of dizziness in the older population and has its highest incidence above fifty years of age. Meniere’s syndrome usually presents as spells of rapid decline in hearing, a roaring tinnitus, vertigo, and monaural fullness. Acutely, vestibular suppressants (Table 1) and antiemetics are used. Over the long-term, a two gram salt diet combined with a mild diuretic such a Dyazide (HCTZ - triamterene) may reduce the frequency of attacks. Recently, an outpatient treatment for Meniere's involving injections of gentamicin through the eardrum has been rapidly gaining popularity. It is about 90% effective for unilateral disease.
Vestibular neuritis is a monophasic self-limited condition typified by vertigo, nausea, ataxia and nystagmus. Both vertigo at rest and positional vertigo are often present. Spontaneous nystagmus differentiates this disorder from BPPV. Severe vertigo usually only lasts two to three days. An anti-emetic, such as phenergan, may be used acutely. Vestibular suppressants such as meclizine (Table 1) should be used sparingly as they may delay central compensation to the lesion. Older patients with prior central disease, peripheral neuropathy, visual troubles, or difficulties that restrict ambulation may not recover as quickly and may benefit from vestibular physical therapy.
Central dizziness is relatively less common than otologic dizziness but, as it is most often secondary to vascular events (strokes) involving the cerebellum and brainstem, it may be a warning sign of dangerous associated conditions.
Many other neurologic disorders may cause vertigo by disruption of the brainstem/cerebellar pathways. Patients with central vertigo are often distressed by ataxia, nausea, and illusions of motion for years.
Multiple white matter lesions (periventricular leukomalacia) are a common source of unsteadiness.
Although it is uncommon for seizures to present as dizziness, epileptic vertigo deserves a special mention because it responds well to treatment with anticonvulsant medication. Historical clues include a history of very brief spinning sensations or "quick spins". The patient may also have a history of loss of consciousness.
In the treatment of central dizziness one must first attempt to address the cause. In the case of vascular events, for example, vascular risk factors should be treated. A patient with "quick spins" should have an electroencephalogram. Vestibular physical therapy is often helpful in this population.
Fortunately, dizziness caused by migraine, common in mid-adulthood, is much less prevalent in the elderly.
Sensory loss in the feet, due to diabetes, B12 deficiency, cervical spondylosis, or just peripheral neuropathy may contribute to unsteadiness in the older population.
Table : Drugs That Can Cause Ataxia
Medical etiologies of dizziness are very diverse but mainly include hypotension and cardiac events, infection, low blood glucose, and medication. Here dizziness interfaces with syncope. Both occult cardiac arrhythmias and acute myocardial infarctions may manifest as dizziness.
Medications are a common contributor to dizziness and ataxia (see Table 2) as elderly patients are often on multiple drugs, which places them at high risk for these side effects.
In fact, medications are the most common cause of symptomatic orthostatic hypotension as well as hypoglycemia. Treatment begins by removing any unnecessary agents and drug "tuning", or substituting similar, but better tolerated, medications. For example, an H2 blocker which does not cross the blood-brain barrier such as ranitidine may be better tolerated than one that does, such as cimetidine.
Psychogenic dizziness is common and includes entities such as anxiety disorders, panic attacks, agoraphobia, somatization syndrome, and malingering. This group is difficult to diagnose because organic dizziness is often accompanied by considerable and often appropriate anxiety. We advise considerable caution in diagnosing psychogenic vertigo.
Anxiety syndromes and panic syndrome often respond to treatment with benzodiazepines, but usually require larger doses than the amounts used for vestibular suppression. Somatization syndromes are difficult to treat and we routinely would refer such patients to psychiatry. In patients where malingering seems possible, it is important to carefully document objective findings and to quantify functional status, particularly where dizziness may be preventing return to work.
At all ages, in general, about one-third of patients with dizziness will go undiagnosed. These patients usually need to be followed more closely than patients in whom a clear diagnosis is available. Empirical trials of medication and vestibular physical therapy may be helpful options.
Dizziness is common in older adults and has diverse causes. The diagnostic process must distinguish between otologic, central, medical, and psychogenic etiologies. Furthermore, in a substantial fraction of patients, a clear etiology may not be determined. Medications must be used with greater caution in older adults as they may be more sensitive to side effects. Vestibular physical therapy is often helpful and should be utilized in many situations.