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Clinical Evaluation of the Dizzy Patient

Judith A. White

History

The history is the cornerstone of all medical evaluation. For the dizzy patient, it is the most valuable portion of the evaluation. Symptoms of dizziness may not be active at the time the patient is seen in the office, and the historical account may be all that is available to the clinician. An accurate and detailed history leads to the correct diagnosis in 70% of dizzy patients, when compared with final diagnostic conclusions after all evaluation is completed by a vestibular specialist.¹

Obtaining a complete, accurate, and detailed history may be challenging in the dizzy patient. Even the most conscientious, motivated patient may have difficulty describing symptoms. One reason is that equilibrium is largely an unconscious sensation. We have few words to describe its absence. The catchall term dizziness is commonly used to describe vertigo, syncope or near-syncope, imbalance or ataxia, disequilibrium, light-headedness, and poor concentration. We explain to patients that although they are being seen to evaluate their dizziness, we need to find a more exact description of their symptoms. Initial open-ended questioning can be rapidly focused onto key symptoms such as vertigo.

Vertigo is an illusion of rotatory movement. The nearly universal childhood experience of turning around rapidly and repeatedly in one location and then stopping suddenly and experiencing the illusion of the room spinning in front of your eyes can be used to describe vertigo to patients. Asking specifically “Do things move in front of your eyes when you are dizzy?” can also be helpful.

Syncope, fainting, and loss of consciousness are never vestibular in origin, and suggest the need for cardiac consultation. Even the severe drop attacks experienced by Meniere’s syndrome patients are not associated with loss of consciousness (unless patients knock themselves out inadvertently from a head injury while dropping from loss of extensor tone).

Imbalance only while walking, difficulty walking, stumbling, ataxia, and other movement disorders suggest neurologic and/ or musculoskeletal diagnoses, particularly when active head movements are well tolerated in a sitting position. In contrast, vestibular disorders (including bilateral vestibular loss) cause symptoms of visual blurring (oscillopsia) during rapid head movements, occurring both while sitting and upright/ambulating.

Light-headedness, disequilibrium, and “things moving around inside my head” are nonspecific complaints, and further diagnostic evaluation may be necessary to determine if there is an underlying vestibular component to these complaints.

After the patient and clinician have agreed on as specific a description of the symptom as possible, the duration of the specific symptom is reviewed next, which is particularly important in vestibular evaluation. Vertigo may last only seconds in benign paroxysmal positional vertigo, but the ensuing nausea or mild disequilibrium may persist for hours. Many patients may not initially differentiate between the character and the intensity of symptoms and inaccurately report “I have been dizzy for 3 weeks” when further questioning elicits a history of sudden brief vertigo with certain position changes accompanied by mild nonspecific disequilibrium. Similarly, the severe vertigo of Meniere’s syndrome may last for hours but the patient may feel “off” for days thereafter.

Patients are asked to describe in detail the first episode of dizziness, as well as the most recent episode, and to give an estimate of how many episodes in total have occurred. Details include exactly what they were doing when symptoms occurred (e.g., looking up on a high shelf, or sitting quietly at a desk) and how long each symptom lasted. Any associated symptoms, such as hearing change or loss, or tinnitus, are noted. Focal neurologic symptoms such as diplopia, visual loss, headache, numbness, and weakness are inquired about specifically. Provoking factors such as position change, pressure changes (sneezing, lifting) or loud noises are specifically reviewed.

The patient’s medical history also establishes risk factors and has impact on the likelihood of some diagnoses. Cerebrovascular pathology is more likely in patients with advanced age, valvular heart disease, smoking, hypertension, diabetes, and cardiac arrhythmias. Prior history of ear surgery, pain, and drainage makes an otologic source more likely. A history of prior transient focal neurologic deficits (such as a numb hand or visual loss) increases the possibility that imbalance or dizziness may be due to multiple sclerosis. Prior exposure to ototoxic or vestibulotoxic medications such as chemotherapeutic agents (especially cis-platinum) or aminoglycosides are important historic points suggesting bilateral vestibular hypofunction. Oncologic disease may give rise to paraneoplastic neurologic disorders such as cerebellar ataxia. Renal disease, cardiac arrhythmias, and some ophthalmologic conditions suggest syndromic vestibular disorders with or without hearing loss.

Migraine is increasingly recognized as an etiology for many episodic vestibular symptoms. Approximately 25% of patients meeting defined criteria for migraine experience otherwise unexplained episodic dizziness.2 Familiarity with migraine classification criteria may be helpful in making the diagnosis of migraine-associated dizziness, and they are outlined below. Note that migraine headaches may occur with or without classic aura such as visual loss, scintillating scotomata, and peri-oral numbness (Table 14–1).³

The International Classification of Headache Disorders (ICHD-II) has included vertigo as part of aura only in basilar-type migraine, which also requires other symptoms from the posterior circulation, such as posterior headache, bilateral visual auras, or diplopia. However, the association of the vestibular symptoms and headache may be inconsistent in migraine-associated dizziness (MAD). Vestibular symptoms may precede headache, occur variably (most commonly), or be totally unrelated to headache.⁴ The duration of vestibular symptoms may also be variable, ranging from minutes to days, and the nystagmus seen can have peripheral, central, or mixed features.⁴ Regardless of duration and association with headache, however, most investigators require discrete episodes of vestibular symptoms.

Because neither of these ICHD-II definitions includes the type of vertigo most commonly associated with migraine, additional criteria for “migrainous vertigo” or “migraine-associated dizziness” have been proposed by Neuhauser et al⁵ (Table 14–2) and have been generally accepted; these criteria form the basis of a structured diagnostic interview, the Structured Interview for Migrainous Vertigo (SIM-V).⁶

Questionnaires are often recommended for clinical evaluations of dizzy patients. We find that a one- or two-page questionnaire mailed to the patient prior to the appointment, along with a request to bring outside audiologic, vestibular, and neurologic evaluations, medication lists, and previous brain imaging studies can be time-saving and allow the patient to organize the history prior to the appointment.

Prior diagnoses that patients may have received may not be necessarily accurate. One recent review⁷ found that only 31% of consulted neurologists, 16% of otolaryngologists, and 2% of primary care providers performed positional testing in patients complaining of positional vertigo. They suggest this leads to inaccurate diagnosis and contributes to the average North American testing costs of $2000 per patient.⁸

Differential Diagnosis of Common Vestibular Disorders

The four most common vestibular syndromes have classic distinguishing historic features. A review of the pathophysiology of these disorders can be found in Chapter 27.

Benign paroxysmal positional vertigo (BPPV) is the most commonly recognized vestibular disorder. The incidence of BPPV ranges from 10.7⁹ to 64¹⁰ per 100,000, and increases by 38% with each decade of life.¹⁰ However, recent data suggest that this disorder may be more common than current population estimates indicate. In one study, Oghalai et al¹¹ noted that 9% of randomly selected geriatric patients in an urban clinic who had undergone positional testing had positive results and undiagnosed BPPV.

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