iVertigo.net Vertigo , Systemic or Medical Causes, B.Todd Troost

Systemic causes have been given a separate category to include more widespread conditions that secondarily affect peripheral and/or central vestibular structures to produce vertigo or dizziness. Some are outlined in (Table 5):

TABLE 5. Systemic causes of vertigo and dizziness

1. Drugs (including anticonvulsants, hypnotics, antihypertensives, alcohol, analgesics, tranquillizers)

2. Hypotension, presyncope (including primary cardiac causes and postural hypotension from a wide variety of causes)

3. Infectious diseases (including syphilis, viral and other bacterial meningitides, and systemic infection)

4. Endocrine diseases (including diabetes and hypothyroidism)

5. Vasculitis (including collagen-vascular disease, giant cell arteritis and drug-induced vasculitis)

6. Other systemic conditions (including the hematological disorders, polycythemia, anemia and dysproteinemia, sarcoidosis, granulomatous disease, and systemic toxins)

Drugs

Side effects of drug ingestion frequently cause dizziness in the broadest definition of the term. Vestibulotoxic drugs, as previously described, can produce true vertigo. The dizziness produced by other drugs is more a sense of weakness, disequilibration or "fuzzy headedness". The agents listed in Table 5 are among the most common offenders. Every attempt should be made to determine the type and quantity of medication being taken by the dizzy patient. Frequently, the elimination or reduction of medication such as a mild tranquillizer will produce improvement. The dizzy patient may have been treated with a variety of medications which themselves can add to disequilibration or dizziness.

Hypotension

The multiple causes of presyncope or postural hypotension are often responsible for complaints of vertigo or dizziness (Mathias, 1995). Again, careful historical review and documentation of physical findings such as postural hypotension or cardiac arrhythmia direct further investigation and therapy. Presyncope is described as lightheadedness, among other phrases, and is actually a common mechanism for dizziness or even vertiginous sensations. Postural hypotension is a common side effect of antihypertensive agents, diuretics, and dopaminergic agents. When the symptom is intermittent, a history of lightheadedness following change from recumbent or sitting posture to an erect position, but not the reverse, is more helpful than blood pressure measurements. In adolescents, a hyposensitive carotid sinus reflex during the growth spurt is not rare, and transient symptoms of postural dizziness might be explained by this mechanism.

Endocrine Disorders

Among the endocrinopathies that cause disorders of equilibration are diabetes and hypothyroidism. The mechanism in diabetes is probably the autonomic neuropathy and orthostatic hypotension that may accompany the disease. Though much less common as a specific cause, hypothyroidism should be considered when the symptoms of vertigo remain undiagnosed. Indeed, dizziness is not an infrequent presenting complaint in patients with thyroid deficiency. The remaining systemic conditions rarely present with isolated vertigo but are included as additional primary or secondary causes.