RU2730991C1 - Method for neurophysiological analysis of the pudendal nerve in females with chronic urethral pain syndrome - Google Patents

Abstract

FIELD: medicine.SUBSTANCE: invention refers to medicine, namely neurology and functional diagnostics. Two catheter electrodes are inserted into the urethra and vagina, one of them is inserted into the urethra to a depth of up to the middle one-third of the urethra, the second electrode is placed so that it faces the anterior vaginal wall. Fixtures corresponding to the active and reference discharge electrodes are attached to the catheter electrodes. Inductor center is located at the level of the I sacral vertebra at the center; the current in the inducer coil is directed cranially; the stimulation is performed until the correct M-response is obtained. If the M-response from the urethral sphincter latency values are 6.82 ms, the conductivity of the pudendal nerve is within the normal range; more than 6.93 ms, the conductivity is disturbed; and if the values are from 6.82 ms to 6.93 ms, that condition is boundary.EFFECT: method is non-traumatic, non-invasive, painless and enables diagnosing the injured pudendal nerve, including before the appearance of neurovisual and ultrasonic signs of nerve compression.4 cl, 6 tbl, 4 ex

Description

The proposed invention relates to medicine, namely to neurology and functional diagnostics, and can be used in real time to determine damage to the pudendal nerve in chronic urethral pain syndrome (UBS).

Urethral pain syndrome is characterized by the appearance of persistent or recurrent pain in the urethra in the absence of a confirmed infectious process and other obvious local pathological changes. Until now, the causes of this pathology remain unclear, there are no clear recommendations for the prevention and treatment of UBS.

In the absence of objective data for inflammatory and oncological processes in the pelvic organs, trauma and operations in the pelvic region in the history, the most likely cause of pelvic pain is damage to the pudendal nerve due to its compression.

Neuralgia of the pudendal nerve due to compression can be determined clinically, but such a vivid clinical picture develops after a long time from the onset of the initial symptoms, when conservative treatment is already ineffective. Very often, a similar clinical picture precedes sensitive prolapse and dysfunction of the sphincters (i.e., neuropathy of the pudendal nerve).

There are instrumental methods for diagnosing lesions of the pudendal nerve, which, however, give only an indirect idea of its involvement in the pathological process:

Ultrasound of the internal genital artery, which follows as part of the neurovascular bundle of the Alcock canal; with a decrease in the linear blood flow velocity (LFV), one can assume its compression, and, consequently, compression of the nerve;

Ultrasound of the pudendal nerve: it is possible to visualize the nerve only if there is an expert-class apparatus, a highly qualified specialist, there are no clear criteria for compression.

MRI of Alcock's canal and adjacent structures, which will help visualize perineural fibrosis, thickening of the genital, thickening and fibrosis of the fascia of the internal obturator muscle, mass effect of any adjacent formations, bone injuries and their consequences, fatty infiltration, edema and atrophy of the internal obturator muscle, fibrosis and thickening sacro-tuberous and sacrospinous ligaments.

The use of the above methods for the most part allows you to obtain additional information about the possible causes of the patient's condition only at the later stages of the pathological process, require expensive equipment and the appropriate qualifications of the specialist conducting the study.

Another way to diagnose the condition of the pudendal nerve is neurophysiological research, but the information content of the available methods is a subject of discussion: some experts consider it high, others low.

The main disadvantage of the existing methods of neurophysiological diagnostics is that they can be used to assess the functional state of only sufficiently large myelinated nerve fibers.

Today, the following neurophysiological techniques are traditionally used to assess the state of the pudendal nerve:

1) somatosensory evoked potentials (SSEP);

2) electromyography of the muscles of the perineum (EMG);

3) electroneuromyography of the bulb-cavernous reflex (BCR).

BKR electromyography is performed as follows (https://www.androlog03.ru/bkr/, accessed 06.04.2020):

The patient is in a horizontal position, with the lower limbs bent at the knee joints and spread apart. The head of the penis is treated with electrode paste and 2 annular irritating electrodes are tightly installed on it. The skin of the perineum is treated with an iodine solution. With a needle withdrawal electrode, the skin of the perineum is punctured, retreating 0.5 cm to the right or left from the middle suture, and, passing through the subcutaneous tissue, the end of the needle is inserted into the bulbocavernosus muscle. The lead electrode is connected to the electromyograph, and the irritating electrode is connected to the stimulator. Electrocutaneous irritation of the penis is produced by impulses with a frequency of 1 Hz, duration 0.2 ms, voltage from 0 to 500. By increasing the voltage, the threshold of psychosensory perception and the reflex threshold of the muscle are determined. The latency period is determined as the interval between stimulation and the response recorded electromagnetic impulse, when its value is 30-40 ms, the norm is determined. Then, having increased the electrical stimulation by 1.2-1.5 times in comparison with the reflex threshold, they achieve a stable and constant EMG discharge in the bulbocavernosus muscle and process and record 10 consecutive discharges. Then the electrodes are removed and the skin of the perineum is re-treated with an antiseptic.

The disadvantages of this method include: soreness, invasiveness, extreme technical difficulty in women, which is associated with gender differences in the structure of the bulbous-cavernous muscles; they are not palpable, have a fine-fiber structure and therefore are difficult to access, the absence of responses to stimulation occurs even in the absence of pathology.

The objective of the proposed invention is the development of an atraumatic, non-invasive, painless and inexpensive method for studying the conduction along the genital nerves in women, which makes it possible to obtain M-responses suitable for analysis in all cases,

The technical result of the method for examining the pudendal nerve in women with chronic urethral pain syndrome is the diagnosis of damage to the pudendal nerve, including before the appearance of neuroimaging and ultrasound signs of compression of the nerve trunk.

The technical result is achieved by the fact that in the method of neurophysiological study of the pudendal nerve in women with chronic urethral pain syndrome, including electroneuromyographic study in response to stimulation, analysis of the latency of the M-response, a magnetic stimulator is used as stimulation equipment, two catheter electrodes are inserted into the urethra and vagina , one of them is inserted into the urethra to a depth of up to the middle third of the urethra, the second electrode is installed so that it adjoins the anterior wall of the vagina, attachments corresponding to the active and reference withdrawal electrodes are attached to the catheter electrodes, the center of the inductor is placed at the level of the I sacral vertebra along to the center, the current in the inductor coil is directed cranially, stimulation is carried out until the correct M-response is obtained, with values of the latency of the M-response from the urethral sphincter up to 6.82 ms, it is considered that the conductivity along the pudendal nerves is within the normal range, more than 6.93 ms, which conductivity is broken, and when At readings from 6.82 ms to 6.93 ms, the state is considered to be borderline.

Preferably, a circular inductor with a diameter of 15 cm is used for segmental magnetic stimulation, the magnetic field strength is set to 2.6 Tesla.

Catheter electrodes of the KEU-2 type are preferably used, an electrode with a diameter of 16 Ch is inserted into the urethra, and an electrode with a diameter of 20 Ch is inserted into the vagina.

Preferably, stimulation with each lead is performed no more than three times until the correct M-response is obtained.

The method is carried out as follows.

The study is carried out in a warm room equipped with a screen behind which the patient undresses, in the absence of unauthorized persons (only the doctor and the patient) and irritating factors.

The patient is placed on a couch, lying on her back. Before the examination, the doctor puts on gloves, treats them with an alcohol solution of chlorhexidine, and treats the patient's external genital organs with an aqueous solution of 0.02% chlorhexidine.

Two catheter electrodes of the KEU-2 type are inserted into the urethra and vagina. One of them (16 Ch in diameter) is inserted into the urethra to a depth of up to the middle third of the urethra, 1.5-2 cm, that is, to the zone of the internal sphincter. When drops of urine appear, the catheter is pulled slightly towards itself until they disappear. The second electrode (20 Ch in diameter) is positioned so that it is adjacent to the anterior vaginal wall. The distal ends of the electrodes are fixed to the skin of the thigh with an adhesive plaster.

A Neuro-MS / D magnetic stimulator combined with a Neuro MVP-4 electroneuromyograph (Neurosoft Company, Russia, Ivanovo) is used as stimulation equipment. For segmental magnetic stimulation, a round inductor (coil) with a diameter of 15 cm is used. The magnetic field power is 2.6 Tesla.

After moistening with isotonic sodium chloride solution, a grounding strip electrode is applied to any leg, to the region of the lower third of the lower leg. Alligator attachments corresponding to the active (black) and reference (red) lead electrodes are attached to the catheter electrodes in any order. If the active (black) electrode is connected to the urethral catheter electrode, the impulse is read from the urethral sphincter, if to the vaginal one - from the vaginal muscles. The electrodes are swapped once.

The center of the inductor is located at the level of the I sacral vertebra in the center. The current in the inductor coil is directed cranially. Stimulations are performed at each lead until the correct M-response is obtained, but no more than three to prevent synaptic exhaustion.

The response time is 1-2 ms. The research time is 10-15 minutes. Type of information received: graphic and numerical. Processing of the obtained result: the program of the myograph and the magnetic stimulator "Omega" ("Neurosoft" company, Russia, Ivanovo).

Analyze the latency and amplitude of the received M-responses.

With values of the latency of the M-response from the sphincter of the urethra up to 6.82 ms, it is considered that the conductivity along the pudendal nerves is within the normal range, more than 6.93, that the conductivity is impaired, and with values from 6.82 to 6.93, it is considered that the state is borderline ... If the condition is classified as borderline, the study is repeated.

The proposed method for neurophysiological examination of the pudendal nerve can become a component of the algorithm for diagnosing chronic pelvic pain in women, in particular, with urethral pain syndrome. Using the proposed method, it is possible to identify among patients with chronic urethral pain syndrome those who have impaired conduction along the pudendal nerve, which is characterized by an increase in the latency of the M-response. Such changes in indicators indicate damage to the myelin sheath, which is caused by compression of the nerve in places of "traps" - in the Alcock canal, or between the sacrospinous and sacro-tuberous ligaments, or under the influence of a tense piriformis muscle. Based on the results of this neurophysiological study, it is possible to determine one of the pathogenetic bases of UBS, which is currently a “diagnosis of exclusion”. The data obtained can be used not only for diagnostics, but also for determining the prognosis of the disease and monitoring the effectiveness of treatment, i.e. to implement the principle of "personalized therapy".

Examples of application of the method

Example 1. Patient Sh., 35 years old. She was hospitalized in the urology department. Diagnosis: chronic pelvic pain similar to urethral pain syndrome. Concomitant diseases: Bilateral nephrolithiasis. Myoma of the uterus. Adenomyosis. Complaints of burning, cramps, pain in the urethra and in the labia.

The epidemiological history is calm. Heredity is not burdened. History of 2 births: independent and cesarean section due to a critically narrow pelvis. Profession - ballet master, choreographer. The nature of labor is physical.

Medical history. Considers himself a patient from the age of 18, when passing and short-term pains in the urethra appeared. She associated exacerbations with sexual intercourse, as a result of which she began to avoid them. In 2017, against the background of stress, her condition worsened, pain in the urethra increased. In 2018, ultrasound revealed endometriosis of the postoperative uterine scar, and received hormonal treatment.

Physical examination data. The condition is satisfactory. Skin and mucous membranes of a physiological color. In the lungs, vesicular breathing, no wheezing, respiratory rate 16 per minute, clear heart sounds, rhythmic, blood pressure 116/60 mm Hg. Art., heart rate 70 beats per minute. The abdomen is soft, painless, there are no peritoneal signs. Stool, urine output are normal. There is a postoperative scar after a cesarean section, with palpation, the pain over the bosom increases. Signs of hemorrhoids and venous congestion of the lower extremities.

The external genitals are formed correctly, according to the female type. Pervaginum - sharply painful points along the front wall of the vagina, more to the left of the urethra; soreness in the neck of the bladder.

In the neurological status: decreased sensitivity in the area of innervation of the pudendal nerve on the left, the anal reflex is somewhat reduced, the bulbocavernous reflex is absent.

According to the DN4 questionnaire, 6 points were scored, which characterizes the neuropathic component of pain.

In laboratory tests of blood, urine, vaginal smears and urine culture for bacuria, no pathological changes were revealed.

A study was carried out according to the proposed method (the stimulation zone is segmental, the stimulation point is at the level of the I sacral vertebra in the center):

Indicators Abduction from the vaginal muscles Abduction from the urethral sphincter Latency, ms 7.01 6.94 Amplitude, mV 0.498 0.447 Duration, ms 4.76 8.8 Area, mV × ms 1.7 2

The latency of the M-response from the urethral sphincter is 6.94 ms, which is more than 6.93 ms; therefore, it was concluded that the conduction along the pudendal nerves is disturbed, i.e. about damage to the myelin sheath due to external compression.

According to the Doppler study of the internal genital artery: the blood flow of the main type on both sides, a slight tortuosity of the course of the arteries on both sides, the linear blood flow velocity is reduced, more on the left; violation of blood flow in the walls of the urethra, blood flow with increased spectral characteristics of IR - 0.81.

MRI of the small pelvis: signs of adhesions in the small pelvis. Aimed MRI of the Alcock canal: perineural fibrosis, fibrous structure of the genital nerves, fatty infiltration of the internal obturator muscles on both sides.

Thus, using the proposed method, conduction disturbances along the pudendal nerve were detected, which were confirmed radiologically. The defeat of the pudendal nerve was due to its compression in the Alcock's canal, which coincides with the MRI data. Other causes of neuropathy of the pudendal nerve (damage during childbirth, pelvic trauma and malignant neoplasms) were excluded by history and during the study.

Example 2. Patient A., 44 years old. She was hospitalized in the urology department. Diagnosis: chronic pelvic pain similar to urethral pain syndrome. Concomitant diseases: Varicose veins of the lower extremities. Chronic external hemorrhoids. Chronic sinusitis without exacerbation. Vertebral lumbodynia. Small uterine myoma, right ovarian cyst, scar deformity of the cervix. Prolonged depressive episode of moderate severity.

Complaints of discomfort, burning sensation in the urethra, aggravated at the end of the act of urination, shooting pains in the perineum, more on the left.

The epidemiological history is calm. Heredity is not burdened. The profession is an accountant, a sedentary lifestyle, the nature of work is mental.

Medical history. Considers herself sick for about a year, when she began to notice the gradual appearance of the above complaints. About 5 years ago she suffered severe stress. For pain in the genital area, she was examined and treated by a urologist at the place of residence.

Physical examination data. The condition is satisfactory. In the lungs, vesicular breathing, no wheezing, RR 17 per minute, clear heart sounds, rhythmic, blood pressure 120/80 mm Hg. Art., heart rate 72 beats per minute. The abdomen is soft, painless, there are no peritoneal signs. Stool, urine output are normal.

The external genitals are formed correctly, according to the female type. Pervaginum - sharply painful points in the area of the sacrospinous ligaments, soreness in the proximal segment of the urethra and the neck of the bladder.

In the neurological status: decreased sensitivity in the area of innervation of the pudendal nerve on the left, anal and bulbocavernous reflexes are somewhat reduced.

According to the DN4 questionnaire, 4 points were scored, which characterizes the neuropathic component of pain.

In laboratory tests, gram-positive cocci were found in the vagina in a moderate amount, degree of purity III, otherwise without deviations from the norm.

A study was carried out according to the proposed method (the stimulation zone is segmental, the stimulation point is at the level of the I sacral vertebra in the center)

Indicators Abduction from the vaginal muscles Abduction from the urethral sphincter Latency, ms 2.12 6.96 Amplitude, mV 1.26 2.02 Duration, ms 7.98 4.98 Area, mV × ms 5.9 4.9

The latency of the M-response from the urethral sphincter is 6.96 ms, which is more than 6.93 ms, therefore it was concluded that the conduction along the pudendal nerves is disturbed, i.e. about damage to the myelin sheath due to external compression.

Instrumental survey data.

Ultrasound of the internal genital artery: blood flow of the main type on both sides, a slight tortuosity of the course of the arteries, the linear blood flow velocity is not reduced.

MRI of the lumbosacral spine: MRI picture of degenerative-dystrophic changes, protrusion of L1-S1 discs, moderate edema of the subcutaneous fat. Schmorl's hernia at the level of Th12-L3, L5-S1.

MRI of the small pelvis: small uterine myoma, right ovarian cyst.

Sighting MRI of Alcock's canal: pudendal nerves and adjacent structures were normal.

Thus, when the potentials are withdrawn from the urethral sphincter, the latency of the M-response is increased in comparison with the normative indicators, which indicates a violation of the conduction along the pudendal nerves, i.e. about damage to the myelin sheath due to external compression.

However, despite the data obtained, the patient was taken under dynamic observation by the attending physician without appropriate medication support, with a recommendation to return to the appointment after 4 months. At the second appointment, the patient reported that the pain did not disappear, but, on the contrary, intensified. Repeated studies were carried out:

A study was carried out according to the proposed method (the stimulation zone is segmental, the stimulation point is at the level of the I sacral vertebra in the center):

Indicators Abduction from the vaginal muscles Abduction from the urethral sphincter Latency, ms 2.12 6.98 Amplitude, mV 1.26 2.01 Duration, ms 7.98 5.01 Area, mV × ms 5.9 5.1

The latency of the M-response from the urethral sphincter is 6.98 ms, which is more than 6.93 ms and more than the previous value of this indicator is 6.96 ms, which indicates an aggravated compression of the pudendal nerve.

Ultrasound of the internal genital artery: blood flow of the main type on both sides, a slight tortuosity of the course of the arteries, the linear blood flow velocity is slightly reduced on the left.

Sighting MRI of Alcock's canal: adjacent structures without features, initial signs of perineural fibrosis on the left.

The patient was prescribed treatment in accordance with the treatment standards for compression-ischemic neuropathies, with control of the condition after 2 months.

Research data after 2 months from the start of the study:

Magnetic stimulation according to the proposed method:

Indicators Abduction from the vaginal muscles Abduction from the urethral sphincter Latency, ms 2.12 6.88 Amplitude, mV 1.26 2.02 Duration, ms 7.98 4.97 Area, mV × ms 5.9 4.5

The latency of the M-response from the urethral sphincter is 6.88 ms, which is less than 6.93 ms and less than the previous value of this indicator of 6.96 ms, which indicates a decrease in the phenomena of compression of the pudendal nerve.

The patient reported that she began to feel better, the burning sensation in the urethra decreased, the shooting pains in the perineum became less frequent.

This clinical example illustrates the high value of the proposed method in the early diagnosis of a lesion of the pudendal nerve by assessing its conductance in conditions when neither ultrasound nor neuroimaging research methods allow revealing the interest of the pudendal nerve in the pathological process. This increases the effectiveness of conservative treatment methods.

Example 3. Patient R., 62 years old. Was being treated in a urological hospital. Diagnosis: chronic pelvic pain similar to urethral pain syndrome. Concomitant diseases: Chronic gastritis without exacerbation. Varicose veins of the lower extremities.

The epidemiological history is calm. Heredity is not burdened. Complaints of a burning sensation in the urethra, not dependent on the act of urination, frequent urination in small portions (up to 21 times a day), painful intercourse, a feeling of dryness in the vagina, tearfulness, poor sleep.

Medical history. Considers himself a patient since 55 years. For a long time she was observed by a urologist with a diagnosis of "Cystitis", however, she did not notice any particular effect from the prescribed treatment. The pain persists and prompts the refusal to have sexual intercourse. Repeatedly passed urine culture for flora - the results are negative. History at the age of 30 - resection of the left ovary for a cyst.

Physical examination data. The condition is satisfactory. In the lungs, vesicular breathing, no wheezing, BH 16 per minute, clear heart sounds, rhythmic, blood pressure 140/70 mm Hg. Art., heart rate 88 beats per minute. The abdomen is soft, painless, there are no peritoneal signs. Stool, urine output are normal.

The external genitals are formed correctly, according to the female type. Pervaginum - when trying to research, there is a sharp pain, the patient interferes with the research. The urethra is in a typical place, soft, sharply painful on palpation with one finger. Bimanual examination is not possible due to the patient's restless behavior.

Neurological status: cranial nerves without pathology, coordination tests are satisfactory, no paresis, tendon reflexes are symmetrical, no pathological signs, sensitivity is not impaired, mood background is reduced, emotionally labile.

In laboratory tests, there is a slight erythrocyturia (single in the field of view), otherwise without deviations.

A study was carried out according to the proposed method (the stimulation zone is segmental, the stimulation point is at the level of the I sacral vertebra in the center):

Indicators Abduction from the vaginal muscles Abduction from the urethral sphincter Latency, ms 8.33 6.71 Amplitude, mV 0.218 0.83 Duration, ms 12.3 7.75 Area, mV × ms 4,3 3.1

The latency of the M-response from the urethral sphincter is 6.71, which is less than 6.82, so it was concluded that the conduction along the pudendal nerves is normal.

Instrumental survey data.

Uroflowmetry: urine volume - 234 ml, Qmax - 36 ml / s, Qav. - 19 ml / s.

Cystoscopy: the urethra is freely passable. Bladder capacity 150 ml. The mucous membrane is clean, pink; mouths on rollers. In the neck for 6 hours there is a small small zone of whitish mucous membrane (0.3 × 0.4 cm).

Ultrasound of the internal genital artery (transperineal access): the main type of blood flow from both sides, the linear blood flow velocity is not reduced.

MRI of the small pelvis: condition after resection of the left ovary. Signs of an adhesive process.

Sighting MRI of Alcock's canal: pudendal nerves without features.

From this example, it follows that the amplitudes and latencies of M-responses during abduction from the urethral sphincter and from the vaginal muscles are within normal limits, which excludes the involvement of the genital nerves in the pathological process.

The patient was recommended to visit a psychotherapist to exclude anxiety-depressive disorder and prescribe therapy aimed at stopping it. She was scheduled to appear again in three months.

On repeated observation, the patient noted that the background of the mood improved, excessive tearfulness and emotional lability disappeared, intercourse ceased to bring the previous discomfort, the burning sensation in the urethra became less intense.

Example 4. Patient M., 48 years old. She was hospitalized in the urology department. Diagnosis: Urolithiasis: calculus of the pelvis of the left kidney. Concomitant diseases: hypertension, grade II, risk 4; chronic gastroduodenitis with duodeno-gastric reflux; polyp in the area of the gatekeeper; small uterine fibroids.

The epidemiological history is calm. Heredity is not burdened.

Complaints of lower back pain on the left.

Medical history. Considers himself sick for about 3 years, when the first pain in the lower back arose. She was treated for a long time by a neurologist without obvious improvement. I went to the urologist at the place of residence, an ultrasound of the kidneys was prescribed. A calculus of the left kidney 1 cm in size was revealed. Then she continued treatment with a urologist with a slight improvement. Hospitalization in the urological hospital is planned for remote lithotripsy.

Physical examination data. The condition is satisfactory. In the lungs, vesicular breathing, no wheezing, BH 16 per minute, clear heart sounds, rhythmic, blood pressure 130/70 mm Hg. Art., heart rate 77 beats per minute. The abdomen is soft, painless, there are no peritoneal signs. Stool, urine output are normal.

Examination in a chair: the external genitals are formed correctly, according to the female type, the urethra is in a typical place, painless, there are no pain points in the vagina.

Neurological status: cranial nerves without pathology, coordination tests are satisfactory, no paresis, tendon reflexes are symmetrical, there are no pathological signs, sensitivity is not impaired, sacral reflexes are preserved, symmetric, sphincter function is not impaired.

In laboratory tests - leukocyturia (up to 15 in the field of view), slight erythrocyturia, otherwise the norm.

A study was carried out according to the proposed method (the stimulation zone is segmental, the stimulation point is at the level of the I sacral vertebra in the center)

Indicators Abduction from the vaginal muscles Abduction from the urethral sphincter Latency, ms 1.85 6.81 Amplitude, mV 0.564 0.462 Duration, ms 24.2 29.4 Area, mV × ms five 6

The latency of the M-response from the urethral sphincter is 6.81, which is less than 6.82, therefore it was concluded that the conduction along the pudendal nerves is normal.

Instrumental survey data

Plain urography: a shadow, suspicious of calculus in the projection of the pelvis of the left kidney 10 × 7 mm.

Excretory urography: function of both kidneys on both sides, timely, urodynamics is not impaired.

Ultrasound of the kidneys: a 10 × 7 mm calculus is visualized in the pelvis of the left kidney. Kidney parenchyma 15mm, calyx-pelvic system of the left kidney: cups are not dilated, pelvis 17mm.

MRI of the pelvis: small uterine fibroids.

It follows from this example that the conduction along the pudendal nerves is normal (the latencies and amplitudes of the M-responses are within the standard values).

Clinical cases illustrate the high value of magnetic stimulation in diagnosing lesions of the peripheral neuromotor apparatus in patients with chronic urethral pain syndrome.

In conditions of a large flow of patients, the method makes it possible to differentiate patients into those who need expensive additional examinations (in the case of obtaining values related to pathology), those who do not need them (in the case of obtaining normative indicators) and those who need to be examined more deeply and be under closer control by doctors (in case of obtaining borderline values).

Unlike other methods, the one proposed by us is non-invasive and allows you to get answers in all cases, which allows you to standardize the results. The method makes it possible to detect compression of the pudendal nerve in the places of its most probable compression at the early stages of the pathological process. The use of catheter electrodes makes it possible to standardize the position of the derivation of electrical potentials and makes it possible to reliably obtain responses from the muscles innervated by the pudendal nerve. The method is absolutely painless.

The proposed research technique can become a component of the research algorithm for patients with chronic pelvic pain, in particular, with urethral pain syndrome, and will also allow timely initiation of pathogenetic treatment, monitoring the effectiveness of therapy.

The proposed method makes it possible to assess conduction disturbances along the pudendal nerves more reliably, at an earlier stage and cheaper than other existing techniques, while being painless and non-invasive.

Claims (4)

1. A method of neurophysiological examination of the pudendal nerve in women with chronic urethral pain syndrome, including an electroneuromyographic study in response to stimulation, analysis of the latency of the M-response, characterized in that a magnetic stimulator is used as stimulation equipment, two catheter electrodes are inserted into the urethra and vagina, one of them is inserted into the urethra to a depth of the middle third of the urethra, the second electrode is set so that it adjoins the anterior wall of the vagina, attachments corresponding to the active and reference abduction electrodes are attached to the catheter electrodes, the center of the inductor is placed at the level of the I sacral vertebra in the center , the current in the inductor coil is directed cranially, stimulation is carried out until the correct M-response is obtained, with values of the latency of the M-response from the urethral sphincter up to 6.82 ms, it is considered that the conductivity along the pudendal nerves is within the normal range, more than 6.93 ms, that the conductivity violated, and at values from 6.82 ms to 6.93 ms consider the state to be borderline. 2. The method according to claim 1, characterized in that a round inductor with a diameter of 15 cm is used for segmental magnetic stimulation, the power of the magnetic field is set to 2.6 T. 3. A method according to claim 1 or 2, characterized in that catheter electrodes of the KEU-2 type are used, an electrode with a diameter of 16 Ch is inserted into the urethra, and an electrode with a diameter of 20 Ch is inserted into the vagina. 4. A method according to any claim. 1-3, characterized in that stimulation at each lead until the correct M-response is obtained no more than three times.