Definition.
Cerebralcysticercosis (cerebral cysticercosis) is a disease caused by the larvae of pork tapeworm (cysticercus or cysticercus) parasitizing in the brain, and is the most common disease of the central nervous system. It is the most common disease of the central nervous system. It is common in northeast and north China, followed by northwest China and Yunnan Province, and rare south of the Yangtze River.
Etiology and pathogenesis.
Humans are both end-hosts of pork tapeworms (pork tapeworm disease) and intermediate hosts (cysticercosis). There are two routes of infection, the most common of which is exogenous infection, i.e., human ingestion of food unoccupied by eggs (exogenous allogeneic infection), or autologous exogenous infection caused by contamination of the hands of tapeworm patients with eggs, i.e., vomiting by tapeworm-infected patients or retrograde entry of tapeworm nodules into the stomach. The eggs enter the duodenum and hatch into the larvae, which are distributed throughout the body via the bloodstream and develop into cysticercus larvae, which parasitize the brain parenchyma, spinal cord, ventricles, and subarachnoid space to form cysts.
The cysts are caused by compression and destruction of the surrounding brain tissue, metamorphosis and inflammation of brain tissue caused by heterogeneous proteins, and increased intracranial pressure caused by obstruction of the cerebrospinal fluid circulation pathway.
Clinical manifestations.
Cerebral cysticercosis is mostly seen in young adults, more males than females, and the number of male and female cases is about 2~5:1. Clinical symptoms are complex and varied, mainly depending on the location, scope and number of eggs parasitized, the living state of the cysticercus, changes in the reaction of the surrounding tissues, and the degree of blood circulation and cerebrospinal fluid circulation disorders. There are usually three major symptoms: epilepsy, increased intracranial pressure and mental disorders. According to their clinical manifestations, they can be divided into the following clinical types.
Epileptic type.
1, the most common, with seizures as the prominent symptom. The seizure types commonly include generalized tonic clonic seizures, partial motor seizures and compound partial seizures, etc. A patient may have more than two seizure forms. The seizures usually appear after six months of subcutaneous cysticercosis nodules, or after many years of seizures. Increased intracranial pressure: The main symptoms include headache, vomiting, vision loss, optic papillary edema and increased cerebrospinal fluid pressure, which may be accompanied by impaired consciousness or even coma. If accompanied by hemiplegia, hemianopia, aphasia and other limited neurological signs, it can be called brain tumor-like type.
2.A few patients suddenly appear severe vertigo, vomiting, respiratory and circulatory dysfunction and consciousness disorder when the head position is changed, which is called Brun syndrome and is a sign of cysticercus parasitic in the ventricles of the brain.
3.Psychiatric disorders: mental confusion, hallucinations, cycloplegia, language disorders as the prominent symptoms, serious cases may produce dementia.
4.Meningoencephalitis type: It is caused by cysticercus stimulating meninges and diffuse cerebral edema. Acute or subacute onset, mainly manifested as headache, vomiting, fever, often accompanied by mental disorders, cervical ankylosis, inflammatory changes in cerebrospinal fluid.
5. Neurotic type: insomnia, dreaminess, nervousness, dizziness, irritability, emotional instability, memory loss, and reduced work ability. Objective examination CT, MRI confirms cysticercosis parasites in the brain and positive blood or cerebrospinal fluid immunological examination.
6, Stroke type: similar to ischemic stroke or transient ischemic attack, manifesting hemiparesis, aphasia, sensory impairment, etc.
7.Spinal cord type cysticercosis: less common clinically, cysticercosis causes symptoms by compressing the spinal cord in the spinal canal.
8.Mixed type: those who appear more than two kinds of manifestations above.
9.Incognito type: clinically asymptomatic, with cysticercosis infection confirmed by CT or MRI or by surgery.
Auxiliary examinations.
1.Blood routine Total white blood cell count is mostly normal, eosinophils are elevated, up to 15%~50%.
2, cerebrospinal fluid pressure is elevated, the white blood cell count can be normal or mildly increased, and eosinophils predominate, protein quantification is normal or mildly elevated, sugar and chloride are normal.
3, immunological examination ELISA, indirect hemagglutination test and complement binding test to detect serum and (or) cerebrospinal fluid cysticercosis IgG antibodies for the diagnosis of the disease has qualitative significance with ELISA method has the highest sensitivity and specificity.
4, EEG mainly in the frontal, central, parietal and temporal areas appear more irregular mixed slow waves, with epileptic seizures can be traced spike waves, spike waves, spike slow integrated waves, etc..
5. Typical cranial CT images are single or multiple round low-density foci, with visible cephalic nodes, or multiple high-density foci, 0.5~1.5 cm in size; nodular or dotted ring-like lesions after enhancement. Sometimes grape-like cysts are seen on the brain surface or in the brain pool.
6.Cranial MRI is important for the diagnosis of this disease, which can clearly reflect the location, disease duration and number of cysts. It can be divided into four types: parenchymal type, ventricular type, meningeal type and mixed type.
(1) Brain parenchymal type: According to different stages of cysticercosis development, it can be divided into active stage, metamorphosis death stage, inactive stage and mixed stage.
a The active stage shows multiple small round or ovoid long T1 and long T2 cystic signals scattered in the brain parenchyma, with thin cystic wall and dotted cephalic nodes visible in the cystic wall on one side.
b Metastatic death stage shows slightly long T1 slightly long T2 abnormal signal, obvious ring enhancement after enhancement, edema area without enhancement is seen around the lesion, cephalic nodes disappear in this stage, cyst wall becomes thicker and surrounding edema increases.
c Inactive stage refers to cysticercosis, which shows low signal in both T1 and T2-weighted images, and the lesion is not enhanced or mildly annularly enhanced after enhancement.
d The mixed stage refers to the combined presence of the above 3 stages of lesions.
(2) Ventricular type: the worm is larger, the cyst wall is thinner, it shows long T1 and T2 abnormal signal, the FLAIR image shows clear cyst wall and cephalic ganglion, and it is often accompanied by obstructive hydrocephalus.
(3) Meningeal type: It shows grape bunch cystic signal shadow on the brain surface or in the brain pool. Mild enhancement or non-enhancement of soft meninges or fibrous separation is seen after enhancement.
(4) Mixed type: a mixture of the above types is present.
Diagnosis.
Diagnostic criteria for cerebral cysticercosis: a corresponding clinical symptoms and signs; b positive immunological examination (positive serum and/or cerebrospinal fluid cysticercosis IgG antibody or antigen); cerebrospinal fluid eosinophilia; c cranial CT or MRI showing cysticercosis image changes; d subcutaneous, intramuscular or intraocular cysticercosis nodules, confirmed by biopsy pathology as cysticercosis; e patients from tapeworm endemic areas, fecal excretion of tapeworm The history of nodules or eating “rice pork” can be used as a reference basis for diagnosis.
The diagnosis can be confirmed if there are 4 or more of them; or if there are a, b, c or a, b, e or a, c, e. The diagnosis can also be confirmed.
Treatment.
1.Etiological treatment
(1) Albendazole: It is the drug of choice for the treatment of cerebral cysticercosis. The commonly used dose is 15-20mg/(kg.d), divided into 2 oral doses, for 10 days, rest 10-15 days and then take the second course, usually 3-5 courses. The apparent efficiency is more than 85%.
(2) Praziquantel: It is a broad-spectrum anti-helminthic drug and has good therapeutic effect on cysticercus. If the number of cysts is small, the total amount of 180mg/kg should be divided into 4 days (divided into 2 doses per day). If the number of cysticercus is large and the condition is heavy, a small dose and long course of treatment, i.e. 180mg/kg, divided into 9 days, and the second course of treatment will be started in 2~3 months, with a total of 3~4 courses of treatment.
2.Symptomatic treatment
Choose antiepileptic drugs according to the type of seizure for epileptic type of cerebral cysticercosis.
3.Surgical treatment
Diagnosed ventricular type should be treated surgically.
4.Treatment of tapeworm expulsion
Prevention.
The traditional source of cerebral cysticercosis is pork tapeworm patients, so the primary measure to prevent cysticercosis is to eradicate pork tapeworm patients in order to prevent others and themselves from contracting cysticercosis.