Cerebral echinococcosis

Introduction to echinococcosis Human infection with hydatidosis is a chronic brain, liver, lung, heart and kidney, etc. caused by the echinococcosis of the echinococcosis, and the brain worm accounts for about 1% of patients with hydatid disease. The disease is a natural epidemic disease and is widely distributed throughout the world, mainly in animal husbandry areas. basic knowledge The proportion of illness: 0.03% Susceptible people: no special people Mode of infection: non-infectious Complications: brain abscess anaphylactic shock cerebral infarction epilepsy

Causes of echinococcosis

(1) Causes of the disease

Echinococcus is a disease caused by the larvae of the genus Echinococcus. In China, Echinococcus granulosus is the most common, and Echinococcus granulosus is only 1.5 to 6 mm long and consists of 1 head section and 3 individual sections. The final host is a canine, a wolf, a fox, etc., and the intermediate host is mainly a sheep. When the eggs of the echinococcosis are swallowed by the sheep, the hooks can be hatched in the duodenum. The intestinal wall, the mesenteric vein enters the liver with blood flow, and the lung develops into a hydatid cyst (Echinococcus). The capsule is filled with transparent or milky white cyst fluid. The cyst fluid does not coagulate and has strong antigenicity. The capsule also contains a number of original head lice, and can produce ascus, sun sac, when the fresh viscera of the infected sheep is swallowed by dogs and other canines, the original sputum inside the capsule can be in the small intestine. It develops into an adult, matures and lays eggs, and humans are also intermediate hosts of hydatid.

(two) pathogenesis

Central nervous system hydatidosis has primary and secondary. The primary system refers to the aphid through the liver, lung, and internal carotid artery into the brain to develop into the echinococcosis, entering the central nervous system. At the end of the 3rd week, it develops into a hydatid, and it can grow to 1cm in the 5th month. Most of the larvae die in about 5 years, but some of them can continue to grow into huge cysts. The wall is divided into two layers, the inner capsule. Insect sac, the outer capsule is a layer of fibrous envelope formed by brain tissue. The blood vessels between the two contain nutrients. Because of the little adhesion between the two layers of the capsule, it is easily peeled off during surgery. The inner capsule wall is made up of the stratum corneum and hair growth. Layer composition, the former has elasticity, like powder skin, plays a protective and nutritive role, and the germinal layer is a parasite body, which can form a sac, an ascus, a scorpion scorpion (collectively called echinococcosis), when the capsule is ruptured, the original sputum New cysts can be formed again, and the hydatid can form a occupying effect in the brain, which can compress the ventricular system, leading to increased intracranial pressure, and can cause seizures and hemiplegia, hemianopia, hemiparesis, aphasia, etc. Focal symptoms, huge cysts can still be pressed Skull damage, spinal echinococcosis in compression occupying main pathological changes, if the violation of nerve roots can cause severe pain.

Cerebral hydatidosis prevention

It is mainly necessary to strengthen the handling and control of endemic areas, strictly control the quarantine of meat and food, and vigorously carry out health education.

Cerebral echinococcosis complications Complications, brain abscess, anaphylactic shock, cerebral infarction, epilepsy

Can be complicated by intracapsular infection, resulting in brain abscess, trauma can cause cerebral hydatid rupture, leading to anaphylactic shock, echinococcosis can cause cerebral infarction, preoperative or intraoperative hydatid cyst rupture, multiple planting lesions can appear after surgery , sequelae may have hemiparesis or single sputum, blindness, epilepsy and so on.

Symptoms of echinococcosis common symptoms sensory disorder visual impairment increased intracranial pressure eosinophilia nausea

1. The original type of echinococcosis gradually increases, causing intracranial space occupying effect, and the ventricular system compression and obstruction, and even increased intracranial pressure, due to the expansion of hydatid cyst growth, stimulating the cerebral cortex, causing seizures, cysts Larger headaches, nausea, vomiting, vision loss and optic disc edema, etc., according to the location of the cyst to produce focal symptoms such as hemiplegia, aphasia, partial sensory disturbance, etc., the main clinical features are increased intracranial pressure and seizures.

2. Following the symptoms of the hair is more complicated, generally divided into the original echinococcosis into the intracardiac period, latent quiescent period, and increased intracranial pressure, secondary echinococcosis into the heart, due to a large number of contents of the hydatid Into the bloodstream, there may be symptoms such as collapse, respiratory urgency, cardiovascular dysfunction and allergic reactions. Because of the continuous growth of the hydatid, and the multiple distribution, the clinical features of this type are similar to those of brain metastases.

Examination of echinococcosis

1. Half of the patients with eosinophilia, even up to 70%, eruption of the hydatid cyst or after surgery, eosinophils can often be significantly increased.

2. Intradermal test capsule fluid 0.1ml injection inside the forearm, 15 ~ 20min after observation of the reaction, positive red local papules, may have pseudo-foot (immediate reaction), if there is a sufficient amount of antibodies in the blood, delayed response does not appear, The positive rate of intradermal test is between 80% and 95%, but false positives can occur.

3. Complement binding test 70% ~ 90% of echinococcosis is positive, human or amniotic fluid cyst as an antigen (including the first section of the hydatid cyst fluid effect), cystic fluid antigenic or echinococcosis When the outer membrane of the capsule is very thick until the antigen is not easy to overflow, it may be a false negative reaction, the cyst is worn out, and the positive or secondary infection may increase the positive rate. After the complete removal of the cyst, the complement binding test may turn negative if the worm is One year after the removal of the capsule surgery, the test is still positive and can be regarded as recurrence.

There is a cross-reaction between this disease and schistosomiasis and cysticercosis.

4. Skull X-ray film Skull echinococcosis lesions start from the barrier, destroy the skull, and easily break the bone plate, forming intracranial, external soft tissue mass, the skull is limited or extensive expansion of polycystic or single-capsule morphology Sexual lesions, polycystic-type grape-like, single-capsule internal plate displacement, dural transposition and calcification, cyst itself can also be calcified, limited to the skull base, lack of single or multi-vesicular characteristics, but osteosclerosis Performance, generally no periosteal reaction.

Cerebral hydatid cysts produce increased intracranial pressure, posterior bed bone bone absorption, saddle enlargement, children can still appear finger indentation, skull thin, and even can cause skull defects, hydatid cysts out of the skull, can also see pine cones Body displacement, superficial cyst caused localized convexity of the adjacent skull, thinning of the bone plate, sometimes curved on the flat sheet, ring or eggshell and agglomerate calcification, if found, can be qualitative.

5. Cerebral angiography Cerebral hydatid cysts are common in the middle cerebral artery supply area, especially in the parietal lobe. Cerebral angiography can best show this cystic lesion on the screen, causing the arcuate displacement of the surrounding vessels, which is generally expressed as:

(1) There is no vascular area in the cyst.

(2) The blood vessels around the cyst are compressed and displaced, and the surrounding avascular area is a sign of hand holding the ball.

(3) The cerebral blood vessels are straightened and thin, and the diameter of the tube is the same, which is like a "spider foot" sign.

(4) Increased intracranial pressure, the location of the midline and under the coverworm is not as good as ventriculography.

6. Brain CT scans the brain with a net-like or round-like cyst, with sharp borders (occasionally incomplete thin-shell calcification), no periorbital edema, no peripheral enhancement, obvious signs of space, water density of the contents of the capsule, Generally, the ascus may not be distinguished (if the infection, the density of the mother cyst fluid and the hand capsule fluid are different, the ascus may have a number of particles, the density of the ascus is lower than the mother capsule has diagnostic significance), and multiple cysts in the adjacent site should be considered for cyst rupture, CT scan The examination of the brain worms, the image is clear, qualitative, accurate positioning, and the cost can be accepted by the majority of patients.

7. MRI scan MRI image quality is more clear than CT scan, its image features: fault morphology with CT, shell-like calcification no signal, intra-capsule fluid signal with cerebrospinal fluid or slightly higher than cerebrospinal fluid, hydatid with larger ascus Cysts, factor cyst fluid is lower than the density of the mother cyst fluid, showing the number and arrangement of the ascus in the mother capsule, which can be diagnosed. MRI is superior to CT in density discrimination.

Diagnosis and diagnosis of echinococcosis

Diagnostic criteria

More common in pastoral areas, patients have close contact with dogs and sheep, clinical symptoms are characterized by increased chronic intracranial pressure and epilepsy, blood eosinophilia, intradermal test positive rate of 80% to 95%, but can have false positives The positive combination of complement fixation test and indirect hemagglutination test and cerebral angiography are helpful for diagnosis. CT or MRI is the best method for the diagnosis of echinococcosis.

Differential diagnosis

Intracranial tumor

The increase of intracranial pressure and localization symptoms caused by echinococcosis are similar to those of intracranial tumors, so they are often misdiagnosed as intracranial tumors and surgery. Therefore, patients with increased intracranial pressure from endemic areas should be vigilant and must be detailed. For a comprehensive physical examination, special attention should be paid to the presence of liver or lung hydatid. If necessary, the echinocarbone test and various immunological tests should be performed. CT and MRI can confirm the diagnosis.

2. Intracranial arachnoid cyst

Arachnoid cysts are generally thought to be caused by arachnoid dysplasia in the embryonic stage. They are highly prevalent in children and young adults, and often occur in related parts of the brain pool, such as lateral fissure pools. CT and MRI examinations show a low boundary. Density, low-signal cystic lesions, density or signal same as cerebrospinal fluid, no calcification, long T1 length T2, no enhancement.

3. Other parasitic diseases in the brain

(1) Cerebral cysticercosis: generally have common clinical symptoms such as increased intracranial pressure, seizures and localized signs, but this disease may be associated with subcutaneous nodules, and specimens are taken for biopsy to confirm the diagnosis, feces Examination of the segment, eggs, can also be used as a proof of diagnosis, brain CT and MRI can make an accurate diagnosis of most cysticercosis, but for vesicular cerebral cysticercosis, especially the huge single vesicle sac The worm, because its CT and MRI performance is basically consistent with the brain echinococcosis, it is easy to be misdiagnosed as cerebral echinococcosis, but vesicle cerebral cysticercosis is sometimes seen with other types of cysticercosis, and the cerebral hydatid cyst is more rounded than the cysticercosis cyst. A few rounds, the brain wall of the brain worm is milky white, powdery, about 2mm thick, the vesicle wall of the cysticercosis is thin and transparent.

(2) Pneumococcosis: Most of them are accompanied by lung and other parts of the disease. Usually, the abdominal symptoms appear first, the lung symptoms are second, and the symptoms of the lungs last longer. They are often valued by patients and physicians, from rust. In the color sputum, the eggs and the Shaker Ryden crystals can be found, combined with the X-ray film of the lungs, and the typical schistosomiasis changes, which is not difficult to identify.

(3) cerebral schistosomiasis: advanced patients showed schistosomiasis granuloma, and its reactive extensive cerebral edema, increased intracranial pressure, often accompanied by hemiplegia, partial sensory disturbances, aphasia and other local signs, similar to brain spines Where the ball is sick, the patient is usually from the epidemic area, has a history of wading, liver and intestinal involvement, fecal sedimentation and hatching can be found in eggs and edulis, sigmoidoscopy can be seen in superficial mucosal ulcers, polyps, scars When the lesions were taken, the living tissue was taken and the positive rate of the eggs was found to be extremely high.

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