Diagnosis of Ménière's disease

A physical examination for suspicion of Meniere's disease is carried out depending on the concomitant pathology.

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Indications for consultation of other specialists

Given the complexity of differential diagnosis of this disease, it is necessary to conduct a comprehensive clinical examination with the participation of a therapist, neurologist, oculist (with examination of the fundus and retinal vessels, endocrinologist, and also under the advice of a traumatologist.

Laboratory research

It is necessary to carry out tests for glucose tolerance and thyroid function, as well as general clinical and biochemical blood testing according to generally accepted methods.

Instrumental diagnosis of Ménière's disease

Since the changes in Meniere's disease are localized in the inner ear, the evaluation of the condition of the hearing and balance organ is of the greatest importance in the diagnosis of this disease. When otoscopy is determined by unchanged tympanic membranes. A primary study of auditory function may be performed by an otorhinolaryngologist. In the tuning fork, the lateralization of sounds in the Weber test is determined. With a change in the auditory function, at the early stages, lateralization is determined by the type of neurosensory changes (toward the hearing ear). In tests, Rinne and Federici also reveal typical changes in neurosensory hearing loss - both tests are positive both on the side of the hearing ear, and worse than hearing,

Further, to study the auditory function, a tone threshold audiometry is performed. At the initial stage, a typical audiometric pattern, usually of an ascending or horizontal type, is revealed with the greatest damage in the low frequency region and the presence of a bone-air interval of 5-15 dB at frequencies of 125-1000 Hz. Hearing loss does not exceed I degree. In the future there is a progressive increase in tonal thresholds of hearing by sensory type, up to the fourth degree in the III stage of the disease. Methods of hearing research also include the use of supra-threshold audiometry, with all patients, as a rule, exhibiting a positive phenomenon of accelerated increase in loudness.

To assess the state of the equilibrium system, vestibulometric tests are carried out, such as coulometry with threshold and supra-threshold stimuli, bithermal calorization, post-angiography, indirect selective otolithometry. The study of the vestibular analyzer during an attack is limited to recording spontaneous nystagmus as the most stable and objective sign of a dizziness attack. In this case, the nystagmus is horizontally rotated and sharply pronounced (grade III or II). In the stage of irritation, the fast component of the nystagmus is directed to the sore side, and in the interictal period - to the healthy one (a symptom of oppression or deactivation of the function). With the index sample, a miss is made on the side of the slow component.

The study of the vestibular apparatus during the interictal period can give completely normal data, but a known number of cases shows a decreased sensory sensitivity of the patient ear (elevated thresholds during rotation and calorization). As instilled, in patients in the interictal period vestibular hyporeflexia is detected on the affected side. With supra-threshold stimulation, vegetative reactions can be intensified. Very often an asymmetry is observed in the caloric reaction, namely, a decreased reflex excitability of the patient ear with respect to the nystagmic reaction. Vestibular asymmetry increases with the development of the disease (from 30% or more). For the final stage of the disease, an equilibrium disorder is more characteristic than dizziness attacks.

To verify the diagnosis of Meniere's disease, it is necessary to establish the presence of zindolymphatic hydrops. At present, two instrumental methods for diagnosing inner ear hydroids are the most widely used in the clinic: dehydration tests and electrochlearography.

When performing dehydration, glycerol is used at a dose of 1.5-2.0 g / kg of a patient's weight with an equal volume of lemon juice to potentiate the action. The hearing test is performed immediately before taking the drug and then after 1, 2, 3, 24 and 48 hours. Of the study after 48 hours is determined in each patient individually, depending on the rate of rehydration.

Evaluation of the results of dehydration is carried out by several criteria. The sample is considered "positive" if 2-3 hours after taking the drug, hearing thresholds drop by no less than 5 dB in the whole range of frequencies studied or by 10 dB at three frequencies and speech intelligibility improves by at least 12%. The sample is considered to be "negative" if the thresholds of tonal hearing increase 2-3 hours later and the intelligibility of speech relative to the initial level worsens. Intermediate options are regarded as "dubious".

Sufficiently informative is the use of the UAE as an objective non-invasive method for assessing the state of sensory structures of the inner ear during dehydration, which increases the sensitivity of the technique to 74%. With a positive dehydration sample, the amplitude of the otocoustic response increases by no less than 3 dB. The most informative application of the UAE at the frequency of the product distortion. Moreover, in order to monitor the state of the equilibrium function, it is advisable to use dynamic post-uricography in conducting dehydration tests to detect the hydrops of the vestibular part of the inner ear.

The electrocholecography technique, also used to detect the labyrinth hydrops, allows one to record the electrical activity of the cochlea and auditory nerve that occurs in the interval 1-10 ms after the stimulus is presented. This activity consists of presynaptic activity, represented by the microphone and summation potentials generated at the level of the inner ear, as well as post-silaptic activity, which includes the potential of the auditory nerve action generated by the peripheral part of this nerve. In the presence of gidrops in the inner ear, the following symptoms are revealed:

• negative sum-potential wave preceding the action potential. There is an increase in the amplitude of the summation potential with increasing intensity, with a corresponding increase in the ratio of the amplitudes of the summation potential and the action potential of more than 0.4.
• shift of the latent period of the action potential upon stimulation by clicks of alternating polarity of more than 0.2 ms.
• The change in the amplitude of the total potential in the study of tonal sends.

In addition, a number of researchers confirm the effectiveness of the low-frequency masking method in detecting the inner ear gidrope. Normally, when a low-frequency tone is presented, the basal membrane of the inner Uxa synchronously moves throughout its entire length. In this case, the sensitivity of the Corti organ for tones changes with a certain periodicity.

The perception of tonal parcels of a different frequency that are normally heard by a normally hearing person against a background of a low-frequency mask, varies considerably depending on the phase into which the signal enters. Even at the end of the 20th century, studies were carried out with modeling of the experimental inner ear hydrograph, suggesting that the disguise of tonal parcels by presentation of low frequency tone does not depend on the phase of presentation of tone in the endolymphatic gypsum of the inner ear, in contrast to the norm. In clinical practice, a masking tone and a short tone are applied to the auditory passage of the examinee using a tightly fixed liner. As a masking tone, you can apply a tone frequency of 30 Hz and an intensity of up to 115 dB. As a tone, the frequency is 2 kHz. The test signal is presented to the phase from 0 to 360 deg. In relation to the mascara, step and 30 degrees. In the presence of a hydrops, there is practically no oscillation in the perception of the 2 kHz test signal against the background of the mask, depending on the presentation phase. The method has a number of limitations in the application.

In a comprehensive examination, chest X-ray examination, temporal bones in the projections of Stenvers, Schueller and Mayer are performed, the most informative is the CT and MRI of the head. To study cerebral hemodynamics, extracranial and transcranial ultrasound dopplerography of the main vessels of the head or duplex scanning of cerebral vessels is performed. All patients need an audiological, vestibulometric and complex stabilometric study to assess the condition of the organ of hearing and balance.

Differential diagnosis of Meniere's disease

In Meniere's disease, there is a known triad of symptoms caused by the formation in the inner ear of the gidrops. In the case of non-detection of gidrops during specific tests, a comprehensive examination is needed to determine other causes that can cause bouts of system dizziness and changes in hearing.

Differential diagnosis is carried out with pathological conditions that also cause systemic dizziness. Among them:

• acute disturbance of cerebral circulation in vertebrobasilar insufficiency;
• benign paroxysmal positional dizziness;
• tumors in the region of the cerebellopontine angle;
• dizziness with a trauma to the skull;
• fistula labyrinth;
• vestibular neuronitis;
• multiple sclerosis.

In addition, it must be remembered that dizziness can also occur when taking certain groups of medications; when CNS is affected; as a complication of acute middle or chronic otitis media; with otosclerosis; as a consequence of hyperventilation, as well as in psychogenic disorders.

[2], [3], [4], [5]