Cerebral schistosomiasis

Introduction to cerebral schistosomiasis Cerebral schistosomiasis (cerebralschistosomiasis) is an egg granuloma and inflammatory reaction caused by the deposition of schistosome eggs in brain tissue, accounting for about 2% to 4% of schistosomiasis patients. It is generally believed to be mainly derived from lung lesions. The brain tissue deposited by the eggs has brain softening, granuloma formation, and cerebral edema around. Common in the parietal lobe and occipital lobe, more in the cortex and subcortical area to form abscess, eosinophilic granuloma. The lesion can be multiple, scattered or dense. After the egg is dead, it can be calcified. If it is tired, it can cause dura mater, arachnoid hypertrophy and adhesion. Cerebral schistosomiasis is divided into acute and chronic types. The number of patients is more than farmers and fishermen, more men than women. There is only partial immunity after infection, and repeated infections often occur. The disease can be divided into acute and chronic two types, which are more common in young people. Acute type is more than 6 months after infection, manifested as meningoencephalitis symptoms: fever, disturbance of consciousness, paralysis, convulsions and hyperreflexia, meningeal irritation, pyramidal tract signs. Chronic type is more common in patients with chronic early schistosomiasis. The main symptoms are seizures, which are more common in localized epilepsy. Some patients also have increased intracranial pressure and localized signs. basic knowledge The proportion of illness: 0.003% Susceptible people: more common in young people Mode of infection: parasitic infection Complications: epilepsy

Causes of cerebral schistosomiasis

Causes:

The life history of schistosomiasis includes six stages of adult worms, eggs, edulis, cell mites, cercariae, and larvae. After the eggs enter the water with the faeces, the mites invade the intermediate host freshwater snails (Schistosoma japonicum is snail) at a suitable temperature. In the snail, the scorpion develops into the tail scorpion and releases water. When the terminal host of the schistosomiasis or other mammals is exposed to the infected water, the cercaria can invade the host body from the skin or mucous membrane and become a child worm. The child worm flows through the lungs with the blood, and the heart is dirty. The device enters the portal system and develops into adult worms. It begins to hug and mates to lay eggs. Among them, Schistosoma japonicum can lay 1000 to 3000 eggs per day, which is 10 times that of Schistosoma mansoni and Schistosoma japonicum.

Pathogenesis:

Egg granuloma is a basic pathological change of schistosomiasis. It is believed that the formation of granuloma of Schistosoma mansoni is a cell-mediated immune response (late-type allergic reaction), which is soluble by the hairy mites in mature eggs. Egg antigen (SEA) sensitized T cells, T cells and various cytokines released by them play an important role in the formation of egg granuloma. IL-2 and IFN-, Th2 released by T cell subtype Th1 cells. IL-4, IL-5 and IL-10 released by cells, TNF-2 and IL-1 released by macrophages, and other cytokines, Schistosoma japonicum granuloma is similar in some respects to Schistosoma mansoni, but Many unique features: the egg mass of Schistosoma japonicum is 10 times that of Schistosoma mansoni, and the eggs are clustered in the host tissue, while the eggs of Schistosoma mansoni are more single. The acute granuloma is easy to liquefy and is abscess-like. Damage, infiltrating cells are mostly polymorphonuclear leukocytes; more plasma cells are seen in granuloma, because a large number of eggs are deposited in the tissue, so the granuloma is formed, and the surrounding cells are infiltrated. In the blood of patients with acute schistosomiasis The detection rate of cyclic immune complexes and heterophilic antibodies is very high, so acute schistosomiasis is a mixed manifestation of humoral and cellular immune responses, while the immune response of chronic and advanced schistosomiasis is a delayed allergic reaction.

The granuloma of cerebral schistosomiasis is more common in the parietal lobe and temporal lobe, mainly distributed in the cerebral gray matter junction, and the surrounding tissue may be accompanied by gliosis and mild cerebral edema. So far, autopsy and surgery have not been performed in the cerebral vein. Found in adults, the central nervous system damage of Schistosoma mansoni is rare, more common in the compression of the spinal cord, while Schistosoma japonicum is more common in the brain.

Cerebral schistosomiasis prevention

1. Control the source of infection: conduct a general survey of patients in endemic areas, thoroughly treat patients and sick animals.

3. Cut off the transmission route: It is necessary to strengthen the management of manure and protect the water source. The intermediate host snail in the elimination of Schistosoma japonicum in China is an important measure to control schistosomiasis.

3. Protect susceptible populations: Strengthen health education and avoid contact with infected water.

Cerebral schistosomiasis complications Complications

Patients with cerebral schistosomiasis may have seizures, and schistosomiasis may be complicated by spinal dysfunction.

Symptoms of cerebral schistosomiasis Common symptoms Increased intracranial pressure, convulsions, local signs, epilepsy and epileptic seizures, hyperreflexia, conscious disturbance, nodules

Cerebral schistosomiasis

The disease can be divided into acute and chronic two types, which are more common in young people. The acute type is more than 6 months after infection. It is characterized by meningoencephalitis: fever, disturbance of consciousness, paralysis, convulsions and hyperreflexia , meningeal irritation, pyramidal tract signs, etc., cerebrospinal fluid examination normal or protein and white blood cells slightly increased, with the patient's body temperature decreased, the symptoms can be relieved; chronic type is more common in chronic early schistosomiasis patients, the main symptoms are seizures, It is more common in patients with localized epilepsy. Some patients have increased intracranial pressure with localized signs. When the eggs cause arterial embolism in the brain, there may be sudden hemiplegia and aphasia. This type of patient has no fever, CT scan of the head. It is shown that the lesion is often located in the parietal lobe, and can also be seen in the occipital lobe. It is a unilateral multiple high-density nodule shadow. It is surrounded by cerebral edema and even deforms the lateral ventricle to deform it. The visceral lesions of patients with cerebral schistosomiasis are generally not obvious. Fecal examination can find eggs, and serum immunological examination has a positive finding. If early diagnosis and treatment have a good prognosis, most of them will recover without surgery.

2. Spinal cord schistosomiasis

Mainly found in Mann's schistosomiasis, causing cross-sectional myelitis, cerebrospinal fluid examination showed increased lymphocytes and protein, immunological tests of adult or egg antibodies can be positive, spinal cord patients can be gradually recovered if diagnosed and treated early, However, long-term compression causes ischemic spinal cord damage, which is difficult to recover.

Examination of cerebral schistosomiasis

Fecal examination

Eggs can be found in the feces or hatch can be hatched.

2. Blood routine examination

The total number of white blood cells in patients is mostly between (10 ~ 30) × 10 ⁹ / L, showing leukemia-like reactions, eosinophils increased significantly, generally accounting for 20% to 40%, eosinophilia is one of the characteristics of this disease.

3. Cerebrospinal fluid examination

Sometimes eggs can be found in the cerebrospinal fluid. The number of white blood cells is between several hundred and several billion per liter, mainly lymphocytes.

4. Immunological examination

Intradermal test, ring egg sedimentation test (COPT), indirect hemagglutination test (IHA), enzyme-linked immunosorbent assay (ELISA) and other tests can be applied. Among them, COPT is the most commonly used method in China, with high sensitivity and Specificity, while ELISA is the most sensitive and specific method in immunology with a positive rate of 95%.

CT scan in the acute type is mainly cerebral edema. In the brain parenchyma, low-density lesions of different sizes and degrees can be seen. There is no enhanced manifestation. The chronic type shows localized granuloma, which is equal or slightly high density. The position was manifested, the boundary was unclear, the surrounding edema, and the enhanced scan showed that the lesion was enhanced.

Diagnosis and diagnosis of cerebral schistosomiasis

diagnosis

The diagnostic criteria are:

1. First determine that you have been infected with Schistosoma japonicum according to:

1 history of exposure to the source;

2 clinical features;

3 stool examination;

4 immunological examination.

2. Brain symptoms: after schistosomiasis infection.

3. Other diseases: Exclude brain symptoms caused by other diseases.

4. Tincture, praziquantel treatment is effective sometimes requires the discovery of eggs during surgery to confirm the diagnosis.

Differential diagnosis

Cerebral schistosomiasis needs to be differentiated from the following diseases:

1. Other cerebral parasitic diseases such as echinococcosis, cerebral cysticercosis, cerebral amoebiasis, and toxoplasmosis, mainly rely on epidemiological characteristics, specific immunodiagnosis and typical imaging examination the difference.

2. Non-parasitic infectious diseases of the brain such as encephalitis, brain abscess, brain tuberculosis, etc.

3. Non-infectious diseases of the brain such as cerebral infarction, cerebral vascular malformation, tuberous sclerosis and multiple sclerosis.

4. Brain tumors and brain metastases.

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