RU2484769C1 - Method of diagnosing vestibulocochlear nerve dysfunction, induced by vasculonervous conflict - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to field of medicine, in particular to otoneurology. Examination of patient is performed and in case if cochleovestibular syndrome symptoms are detected in form of peripheral level of affection and hemorrhagic and/or hemodynamic disorders, MRT examination of brain is additionally performed in mode of simultaneous neurovisualisation of vessels and vestibulocochlear nerve in the area of cerebellopontine angle or internal auditory canal. If intimate adjoining of vessel in form of loop or part of vessel to vestibulocochlear nerve on the side of peripheral cochleovestibular syndrome is present at the background of increased blood pressure and/or blood viscosity, and/or impairment of venous outflow from posterior cranial fossa, dysfunction of vestibulocochlear nerve resulting from nerve compression by vessel is diagnosed.

EFFECT: method makes it possible to specify etiology of vestibulocochlear nerve in a reliable way.

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Description

The invention relates to medicine, in particular to otoneurology, and can be used to diagnose dysfunction of the auditory maxillary nerve.

Part of the inner ear (cochlea) is used for hearing, the other part is used for balance (labyrinth). If there are abnormalities in the labyrinth or in the nerve connecting it to the brain, then this leads to dizziness, which is a symptom of various pathological conditions, in particular Meniere's disease, labyrinthitis, positional dizziness, vestibular neuronitis and nerve tumors. Typically, these pathological phenomena cause imbalance, a sense of rotation of objects and nausea. Also, these phenomena can be accompanied by ear noise and hearing loss on the corresponding side.

To date, nerve dysfunction as a result of a neurovascular conflict has been detected only for the trigeminal nerve (Lebedeva M.A. Otoneurological symptoms in trigeminal neuralgia and hemifascial spasm in the perioperative period. Abstract on the degree of candidate of medical science. , M., 2010). The work shows that a neurovascular conflict in the area of the brain bridge is the main cause of trigeminal neuralgia due to compression of the trigeminal nerve by the blood vessel in the area of its entry into the brain stem.

In addition, an imbalance is known due to compression of the acoustical-nerve nerve by a tumor that arises from the Schwann sheath of this nerve, due to an asymmetry of the functional activity of the vestibular apparatus on the affected and healthy side. At the same time, a one-sided decrease in hearing and taste on the side of the tumor is also noted. And due to the fact that the tumor grows slowly and gradually squeezes the root of the acoustical nerve, these patients have no complaints of paroxysmal dizziness (Blagoveshchenskaya N.S. Otoneurological symptoms and syndromes, Moscow, 1990, 230 p.).

There is also a method for diagnosing dysfunction of the auditory-pre-nerve nerve by means of an otoneurological examination of a patient (caloric and rotational tests) and samples with a tuning fork, in particular, Rinne, Weber and Schwabach (B. Lebedev and other Neuritis (neuropathy) of the vestibulo-cochlear nerve. Posted on 05.26.2007 Found on 09.21.2012 on the Internet at http://www.lor.inventech.ru/neurology/reference-0394.shtml). This method is considered by us as the closest analogue. However, it does not have sufficient informativeness about the nature of dysfunction of the auditory maxillary nerve and, therefore, about the causes of peripheral dizziness and hearing loss and does not provide accuracy in the differentiation of peripheral dizziness of various origins.

In contrast, in the method we developed when compressing the auditory pre-nerve nerve with a vessel in patients, complaints of isolated dizziness, noise and hearing loss are noted and other cranial nerves are not involved. Thus, to date, peripheral cochleovestibular syndromes have not been sufficiently studied. The purpose of this work was to determine the main characteristics of the peripheral cochleovestibular syndrome caused by arterial hypertension and atherosclerosis, to elucidate the pathogenetic features of its formation. Dizziness, noise and hearing loss occur against a background of various causes that are difficult to diagnose in a large number of cases. An isolated attack of dizziness can occur as a result of various diseases associated with pathology of the inner ear (Meniere's disease), damage to the peripheral vestibular formations in the internal auditory canal (viral lesions of the vestibular ganglion, inflammation of the root of the auditory pre-nerve, neurinoma). Unlike Meniere's disease, dizziness due to a neurovascular conflict can occur without concomitant auditory symptoms (ear noise and hearing loss), or auditory symptoms may be without dizziness.

Vascular-neural conflict is a syndrome of hyperactive dysfunction of the auditory-pre-nerve nerve due to compression by its vessel at the entrance to the brain stem in the area of the cerebellopontine or internal auditory canal. We have made the assumption that dysfunction of the auditory pre-nerve nerve can occur when the intracranial branch of the vertebral-basilar system (CHD) is intimate, more often the anteroposterior or mid-lower cerebellar arteries, to the auditory pre-nerve, which, against the background of increased blood pressure and / or blood viscosity, and / or difficulties in the venous outflow from the posterior cranial fossa can lead to its compression and the development of an attack of isolated peripheral dizziness, ear noise, hearing loss. To date, the study of neurovascular conflict in this area for the detection of dysfunction of the auditory pre-nerve has not been conducted.

The technical result of the method we developed consists in the fact that the possibility of detecting dysfunction of the auditory maxillary nerve as a result of neurovascular conflict allows us to more accurately determine the nature of peripheral dizziness and hearing loss and thereby provides a more accurate differentiation of peripheral dizziness of various origins.

The technical result is achieved by conducting a patient examination for hemorheological, hemodynamic indicators and revealing the symptoms of cochleovestibular syndrome and in the presence of hemorheological and hemodynamic disorders and symptoms of peripheral cochleovestibular syndrome in the form of a peripheral level of damage, an additional MRI scan of the brain in the mode of simultaneous neuroimaging of vascular and auditory vessels nerve in the area of the cerebellopontine angle or internal about the auditory meatus and when revealing intimate dilution of the vessel in the form of a loop or a portion of the vessel to the auditory-nerve nerve against the background of high blood pressure and / or blood viscosity, and / or obstruction of the venous outflow from the posterior cranial fossa, the auditory-nerve dysfunction is diagnosed as a result of nerve compression by the vessel.

The method is as follows.

On admission to a patient with complaints of dizziness, hearing loss, on the one hand, an otoneurological examination is performed. A complete otoneurological examination includes: determination of corneal reflexes, sensitivity of the nasal cavity and oral cavity, soft palate mobility, smell, taste, spontaneous vestibular symptoms, the nature of caloric and rotational tests, as well as the study of hearing in whisper and colloquial speech, tuning forks. Additionally, auditory and vestibular myogenic evoked potentials were studied to diagnose peripheral cochleovestibular syndrome. A study was also conducted of hemorheological, hemodynamic parameters, in particular blood pressure, blood viscosity and venous outflow from the posterior cranial fossa. When detecting hemorheological and hemodynamic disorders in the form of high blood pressure and / or blood viscosity, and / or difficulty in venous outflow from the posterior cranial fossa and otoneurological symptoms of peripheral cochleovestibular syndrome in the form of unilateral spontaneous nystagmus, increasing the duration of post-rotational experimental nystagmus and unilateral sensory MRI of the area of the cerebellar cerebellar angle and the internal auditory canal in simultaneous mode zualizatsii sluhopreddvernogo vessels and nerve. The study was carried out on the apparatus "Magnetom Symphony" with a capacity of 1.5 T ("Siemens", Germany). The standard research protocol included obtaining T2 weighted images in axial projection with a slice thickness of 1 mm and the subsequent construction of multiplanar reconstructions. If there is a vascular loop or a portion of the vessel intimately adjacent to the auditory-pre-nerve nerve on the side of the formation of the peripheral cochleovestibular syndrome in the area of the cerebellopontine angle or the internal auditory meatus, and against the background of an increase in blood pressure and / or blood viscosity, and / or difficulty in the venous outflow from the posterior cranial the fossa was diagnosed with dysfunction of the auditory pre-nerve as a result of vascular compression of the nerve - a neurovascular conflict.

Method implementation examples

Example 1

Patient Z., 23 years old, was admitted with complaints of hearing loss in her right ear for 5 years. Diagnosed with sensorineural hearing loss on the left. Appealed to the FSBI NTSN RAMS in connection with dizziness attacks. During the study, the patient revealed high blood pressure, and a history of hypertension was noted. An otoneurological examination revealed symptoms from the right cerebellopontine angle in the form of unilateral spontaneous nystagmus to the left, hearing loss by type of sensorineural hearing loss of 2-3 degrees in the range of all frequencies without a bone air interval, with a rotational test revealed a bilateral decrease in vestibular excitability, more to the left. Taking into account the fact that auditory and vestibular objective indices revealed during otoneurological examination are characteristic of both lesions of the inner ear and the auditory-pre-nerve nerve, we performed an additional electrophysiological examination of the auditory and vestibular functions using evoked potentials (EP) to clarify the level of damage to the auditory-pre-nerve a nerve. It was revealed: 1) there are no signs of violation of intra-trunk conduction; 2) there is a deterioration in the parameters of peripheral responses of auditory EPs on the left; 3) vestibular airspace revealed an increase in amplitude on the left. These results confirmed that the patient has a lesion of the auditory maxillary nerve on the left. Due to the presence of hemodynamic disturbances and the presence of symptoms of the peripheral cochleovestibular syndrome, an MRI scan of the brain was performed in the area of the bridge-cerebellar angle and the internal auditory canal in the mode of simultaneous neuroimaging of the vessels and the auditory-nerve nerve, in which a vascular loop is detected that enters the internal auditory canal, causing compression root of the auditory pre-nerve nerve on the left (see Fig. 1). Conducted pathognomonic therapy aimed at lowering blood pressure, allowed to improve hemodynamic parameters in this patient, and during the course of treatment the frequency of dizziness attacks decreased and hearing was improved. This confirmed the cause of the noise, hearing loss and dizziness due to dysfunction of the auditory-vestibular nerve as a result of neurovascular conflict amid increased pressure.

Example 2

Patient S., 30 years old, turned to the center of neurology with complaints of dizziness, hearing loss in her left ear. Sick for 6 months. The decrease in hearing on the left was in the form of two episodes, against which noise and lightheadedness appeared. Conducted a course of treatment in the ENT department with a diagnosis of acute left-sided sensorineural hearing loss of unknown origin. When conducting MRI of the brain, foci of ischemia were not detected. In the study of hemorheological blood parameters, the patient showed difficulty in the venous outflow from the posterior cranial fossa, an increase in blood viscosity, and a periodic increase in blood pressure was noted in the anamnesis. The patient underwent a complete otoneurological examination, in which the symptoms of peripheral cochleovestibular syndrome on the left were revealed in the form of spontaneous nystagmus to the left, hyperreflexion after rotational nystagmus (increased amplitude and duration of nystagmus after a rotational test on the left, more pronounced than on the right), and also persisted to a small extent sensorineural hearing loss on the left, with a predominant increase in the threshold by 4 kHz. Given the violation of hemorheological, hemodynamic parameters and peripheral lesions of the auditory pre-nerve nerve, the patient underwent an MRI scan of the brain in the mode of simultaneous neuroimaging of the intracranial vessels of the vertebral-basilar system and the auditory pre-nerve nerve, as a result of which a situation of the neurovascular conflict on the left - the vascular loop in the inner auditory loop on the left (see Fig. 2), adjacent to the auditory-pre-nerve nerve, against the background of increased blood viscosity, vein obstruction ozone outflow from the posterior cranial fossa and high blood pressure. The pathognomonic therapy aimed at lowering blood pressure, improving venous outflow from the posterior cranial fossa and lowering blood viscosity allowed us to improve hemorheological and hemodynamic parameters in this patient, and dizziness and hearing improved during the course of treatment. This confirmed the cause of dizziness and hearing loss due to dysfunction of the auditory-pre-nerve as a result of neurovascular conflict against the background of high blood pressure, high blood viscosity and obstructed venous outflow from the posterior cranial fossa.

Example 3

Patient Sh., 54 years old, turned to the NCH RAMS with complaints of dizziness, increased blood pressure, numbness in the hands, sleep disturbance. Sick since 2011, when there was dizziness, weakness in the legs, increased blood pressure. Conducted a course of neurometabolic therapy with a positive effect, which was not long-lasting. When examining hemorheological blood parameters, the patient showed an increase in blood viscosity (platelet aggregation under the influence of adrenaline and ADP) to 84% and 71%, respectively, and a history of transient hypertension was noted. The patient underwent a complete otoneurological examination, in which the symptoms of peripheral cochleovestibular syndrome were detected in the form of hearing loss and increased vestibular excitability on the right, while studying vestibular myogenic evoked potentials - signs of impaired function of the vestibular analyzer at the peripheral level on the right.

These signs characterize the violation of hemorheological, hemodynamic parameters and the presence of symptoms of peripheral cochleovestibular syndrome. In this regard, an MRI scan of the brain was performed in the area of the cerebellopontineal angle and the internal auditory canal in the mode of simultaneous neuroimaging of the vessels and the auditory-nerve nerve, in which an intimate adherence of the portion of the intracranial vertebral artery to the right in the region of the cerebellopontine nerve in the medulla oblongata and the latter (see Fig. 3).

The patient was treated with vascular preparations (pyrocetam, cavinton, mexidol, cardiomagnyl, etc.), after which the patient's condition improved: numbness in the hands and sleep disturbance regained, dizziness decreased, which confirmed the cause of dizziness and hearing loss due to dysfunction of the auditory pre-nerve as a result neurovascular conflict against a background of high blood pressure and high blood viscosity.

Under our supervision, there were 25 patients aged 23 to 54 years with complaints of dizziness, noise and hearing loss, who studied hemodynamic and hemorheological parameters, namely blood pressure, blood viscosity, venous outflow from the posterior cranial fossa, and a complete neurological examination , including the study of auditory and vestibular evoked potentials to assess the level of lesion of the auditory and vestibular analyzers, excluding demyelinating lesion in the brain stem RSA; MRI of the brain to exclude ischemic lesions and MRI in the mode of simultaneous visualization of intracranial vessels of the vertebral-basilar system and cranial nerves. All examined patients showed clinical and otoneurological peripheral cochleovestibular syndromes (PCVS) in the form of unilateral spontaneous nystagmus, an increase in the duration of experimental nystagmus, unilateral sensorineural hearing loss of varying severity, and changes in hemorheological and hemodynamic parameters. When conducting MRI of the brain, foci of ischemia were not detected in any patient. However, with MRI in the mode of neuroimaging of blood vessels and nerves, vascular abnormalities were detected, most often in the form of vascular loops or a section of the vessel directly adjacent to the auditory pre-nerve or extending into the internal auditory canal, against the background of either high blood pressure and / or increased blood viscosity, and / or difficulty in venous outflow from the posterior cranial fossa.

Thus, in patients with complaints of dizziness, noise and hearing loss in the absence of foci of cerebral ischemia and signs of demyelination of the trunk and the presence of peripheral cochleovestibular syndrome during an MRI scan in the mode of simultaneous visualization of blood vessels and nerves, it was revealed in the area of the cerebellopontine or inner ear the presence of a vascular loop or part of the vessel that compresses the auditory-pre-nerve as a result of a violation of hemorheological and hemodynamic parameters. This allowed us to assess peripheral dizziness and hearing loss due to dysfunction of the auditory pre-nerve caused by a neurovascular conflict due to an increase in blood pressure, and / or an increase in blood viscosity, and / or difficulty in venous outflow from the posterior cranial fossa, which was further confirmed by pathognomonic therapy , the result of which was an improvement in hemodynamic and hemorheological parameters and a decrease or absence of symptoms of peripheral cochleovestibular syndrome ohms.

Claims (1)

A method for the diagnosis of auditory pre-nerve dysfunction due to a neurovascular conflict, including examining a patient, characterized in that, when symptoms of cochleovestibular syndrome are detected in the form of a peripheral level of lesion and hemorheological and / or hemodynamic disturbances, an additional MRI scan of the brain is performed in the mode of simultaneous neuroimaging of blood vessels and the auditory pre-nerve in the area of the cerebellopontine angle or internal auditory meatus and in the presence of intimate diligence the vessel in the form of a loop or a section of the vessel to the auditory-nerve nerve on the side of the peripheral cochleovestibular syndrome against the background of increased blood pressure and / or blood viscosity, and / or difficulty in venous outflow from the posterior cranial fossa, the auditory-nerve dysfunction is diagnosed as a result of vascular compression.

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