Diagnosis of vertigo

The diagnostic algorithm for dizziness can be presented as follows.

• Establishing the fact of the presence of dizziness.
• Determining the type of dizziness.
• Finding out the causes of dizziness.
• Identification of neurological or otological symptoms (examination by an ENT doctor).
• Instrumental studies depending on the identified symptoms (neuroimaging, hearing tests, evoked potentials, etc.).

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History and physical examination

Examination of a patient complaining of dizziness involves establishing the fact of dizziness itself and clarifying its topical and nosological affiliation. Quite often, patients attach a wide variety of meanings to the concept of dizziness, including, for example, blurred vision, nausea, headache, etc. In this situation, the doctor's task is to conduct differential diagnostics between dizziness and complaints of a different nature. During questioning, the patient should not be pushed to name a specific term; it is much more appropriate to obtain from him the most detailed description of the complaints. Neurological examination is of great importance, in particular, detection and determination of the nature of nystagmus (its direction, symmetry, connection with the position of the head, etc.), the state of the cranial nerves and the clarity of the performance of coordination tests, as well as detection of focal neurological deficit. Many patients require examination by an otologist or otoneurologist using instrumental methods for diagnosing the state of the vestibular apparatus, hearing, and vision. Even a full examination in some cases does not allow establishing a diagnosis, which requires dynamic observation of the patient. In particular, diagnostics of combined forms of dizziness is difficult. The rate of development of the disease, the events preceding it and the provoking factors are of significant diagnostic value: an acute onset is more typical of peripheral lesions, while gradual development is more typical of central lesions. Peripheral lesions are characterized by hearing impairment (ringing in the ear, congestion, hearing loss), while symptoms of lesions of other parts of the brain (cerebral hemispheres, trunk) indicate central lesions. Severe vestibular disorders with severe nausea, repeated vomiting are more often observed in vestibular pathological processes. The occurrence or intensification of dizziness with a change in head position in the overwhelming majority of cases indicate peripheral lesions and a relatively benign nature of the process. Information about previous inflammatory, autoimmune diseases, intoxications (including drug-induced), and head injuries can help in establishing a diagnosis.

During neurological examination, special attention should be paid to nystagmus. First, the presence of nystagmus is checked when looking straight ahead (spontaneous nystagmus), then when looking to the sides, when the eyeballs are moved 30° from the middle position (nystagmus caused by the gaze). The occurrence of nystagmus induced by intense shaking of the head (about 20 s) indicates a peripheral lesion.

Of exceptional importance in the diagnosis of BPPV is the Hallpike test. The patient sits on a couch with his eyes open, turning his head 45° to the right. Lightly supported by the shoulders, the patient quickly lies down on his back so that his head hangs over the edge of the couch by 30°. The test is then repeated with the head turned to the other side. The test is considered positive if, after a few seconds in the final position, systemic dizziness occurs and horizontal nystagmus appears.

Otiatric examination includes examination of the external auditory canal (detection of earwax, traces of recent trauma, acute or chronic infections), eardrum, study of bone and air conduction (Weber and Rinne tests).

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Laboratory and instrumental diagnostics of dizziness

CT or MRI of the head are of exceptional importance to exclude neoplasms, demyelinating process, other structural changes of acquired and congenital nature. X-ray of the skull is less informative, although it allows to identify fractures of the skull bones, expansion of the internal auditory canal in case of neurinoma of the vestibulocochlear nerve.

If a vascular etiology of the disease is suspected, ultrasound Dopplerography of the main arteries of the head and intracranial vessels (or MR angiography) should be performed. However, it should be borne in mind that the detected vascular changes are not always the cause of existing vestibular disorders. This applies to an even greater extent to changes in the cervical spine: detected osteochondrosis, osteoarthrosis, spondylosis extremely rarely have any relation to the occurrence of dizziness.

If infectious diseases are suspected, it is advisable to study the cellular composition of the blood and determine antibodies to suspected pathogens.

In case of concomitant hearing impairments, it is advisable to conduct tonal audiometry, as well as to record auditory evoked potentials. Recording an audiogram after taking glycerol (a test with dehydration, which allows to reduce the severity of endolymphatic hydrops) allows to detect an improvement in the perception of low frequencies and an improvement in speech intelligibility, which indicates in favor of Meniere's disease. Electrocochleography is also an objective method for diagnosing Meniere's disease.

One should not forget to perform an EEG to exclude paroxysmal or epileptic activity in the temporal leads or signs of brainstem dysfunction.

Diagnostic tests for complaints of dizziness

Complete blood count; fasting blood sugar; blood urea nitrogen; electrolytes (Na, K, O) and CO2; cerebrospinal fluid analysis; chest, skull and internal auditory canal radiography; cervical spine radiography; Doppler ultrasound of the main arteries of the head; compression-functional tests, duplex scanning, transcranial Doppler with pharmacological tests, CT or MRI; ECG; otoneurological examination with audiography and vestibular passport examination; ophthalmodynamometry; carotid sinus massage; cardiovascular tests. If necessary, the therapist may recommend other tests.

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Diagnostic criteria for phobic postural dizziness

This diagnosis is based primarily on the following 6 characteristic manifestations.

1. Dizziness and complaints occur while standing and walking, despite normal performance of stability tests such as the Romberg test, tandem walking, single-leg standing, and routine posturography.
2. Postural dizziness is described by the patient as a fluctuating instability, often in the form of attacks (seconds or minutes), or a sensation of illusory loss of body stability lasting a fraction of a second.
3. Attacks of dizziness occur spontaneously, but are often associated with specific perceptual stimuli (crossing a bridge, stairs, empty space) or a social situation (department store, restaurant, concert hall, meeting, etc.), which are difficult for the patient to refuse and which are perceived by him as provoking factors.
4. Anxiety and autonomic symptoms accompany dizziness, although dizziness can also occur without anxiety.
5. Typical features include an obsessive-compulsive personality type, affective lability and mild reactive depression (in response to dizziness).
6. The onset of the disease often follows a period of stress or an illness with vestibular disorders.

Similar dizziness may occur in the picture of agoraphobic disorders and (less often) panic attacks, in the picture of functional-neurological (demonstrative) disorders or be part of complex somatoform disorders along with other (gastrointestinal, pain, respiratory, sexual and other) somatic disorders that cannot be explained by any real disease. Most often in such cases there is "pseudoataxia" in the context of anxiety-phobic and (or) conversion disorders. This type of dizziness is difficult to objectify and is diagnosed based on a positive diagnosis of mental (neurotic, psychopathic) disorders and the exclusion of the organic nature of the disease.

At the same time, the presence of affective accompaniment of dizziness in the form of feelings of anxiety, fear or even horror does not exclude the organic nature of dizziness, since any dizziness: both systemic (especially paroxysmal) and non-systemic, are extremely stressful in themselves, which must always be taken into account in the process of their treatment.

When performing a differential diagnosis of dizziness, the most important thing is the analysis of the patient's complaints and accompanying somatic and neurological manifestations.

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