Neurocysticercosis: Causes, Symptoms and Treatment

Neurocysticercosis is a parasitic disease of the nervous system caused by larvae of the pork chain. A person becomes infected when eggs of pork chopsticks get into the gastrointestinal tract. The first symptoms most often appear 5-7 years after infection. More often manifested by convulsions, increased intracranial pressure, a violation of intellectual functions, but can be asymptomatic. Characteristic wave-like flow with periods of exacerbation and relative improvement in the state. Diagnosis is rather difficult. For treatment, both medical methods and surgical interventions are used.

Causes

The cause of the disease is one: the ingress of eggs of pork chopsticks into the gastrointestinal tract, followed by the spread of blood through the organs and tissues (including the brain). Pork Chain is a tapeworm.

The adult form of the pork chain lives in the human intestine (and most often the person does not even suspect it). A sick person emits millions of eggs of pork chopsticks into the environment with feces, contaminating household objects, food, etc., with them. (especially when non-compliance with personal hygiene rules). This, contaminated with eggs, food and becomes a source of infection. Sometimes autozaraction is possible (when a person infects himself) - when throwing the contents of the intestine with eggs of pork chopsticks in the stomach (for example, when vomiting). After falling into the stomach, the egg shell dissolves under the action of gastric juice, the released embryos spread through the body through the blood vessels. Most often, embryos settle in the brain (60%), striated muscles and eyes (3%).

After entering the brain, the embryo becomes a larval form - cysticerc (finnu). Cysticerc is a vial with a diameter of 3-15 mm with a clear liquid inside. The shell of the Finn is quite dense, and inside is a small head with hooks and suckers. Such cysticerci can be as many as you like - from one to several hundred (even thousands are described). Around themselves, they form a hotbed of inflammation, resulting in a fibrous capsule, clearly separating the brain tissue from the larva. Over time (at least 1 year after infection), larvae may die, and the remaining blister-like formations are subjected to calcification (cystic cavities with calcium deposition are formed), supporting chronic inflammatory process. The average life of cysticerci is 5-7 years.

In the brain, cysticercises are localized on the surface of the cortex of the cerebral hemispheres, at the base of the brain, in the soft meninges, inside the ventricles of the brain (they can freely swim there). They not only cause an inflammatory process, but also interfere with normal circulation of the CSF, irritate and squeeze the brain tissue.

Symptoms

Clinical manifestations of neurocysticercosis are very diverse. It depends on many factors:

• location;
• the amount of cysticerci;
• stage of their development (whether the larvae are alive, dying or dead);
• individual immunological features of the body.

A total of 6 major forms of neurocysticercosis are distinguished: parenchymal (with cyst localization in the brain), subarachnoid (located in subarachnoid space), intraventricular (cysts in the ventricles of the brain), spinal (in the spinal cord), asymptomatic and neurocysticercosis eye. Forms can be combined. The course of the disease is slow, progressive. There is no spontaneous cure.

Parenchymal neurocysticercosis

At the patient with neurocysticercosis, speech may be disturbed.

With this form of the disease, the cysts are located on the border of the gray and white matter of the brain, in the thickness of the brain tissue. With this arrangement, they manifest themselves clinically:

• convulsions - develops an episyndrome. Epiprids, different in their flow, which confirms the multifaceted defeat, with the death of the parasite accompanied by increased epiactivity in connection with the release of toxic products;
• paresis - a decrease in muscle strength in one or more limbs;
• a violation of sensitivity in the limbs (for example, the patient does not feel a touch or cold with a hand);
• violation of speech (a person loses the ability to speak or understand the speech addressed to him. Often speech is not completely lost, and individual functions suffer. For example, sounds that are similar in sound are confused, and the person replaces them in words and does not notice it);
• violation of visual fields - when a person does not see the left or right half of the image;
• defeat of cranial nerves (often facial);
• impaired coordination - dizziness, shakiness and instability in walking;
• the appearance of involuntary movements in the limbs (which are not controlled and not eliminated by effort of will. For example, trembling of hands, slow alternating bending - extension of fingers);
• a violation of mental abilities right up to dementia (described the case of complete dementia in a 15-year-old girl due to massive cysticercic brain damage);
• disturbances in the psycho-emotional sphere - periodic excitement, neuroticism, sometimes hallucinations, delirium.

Subarachnoid neurocysticercosis

This form of the disease is characterized by the appearance of mildly expressed meningeal symptoms (increased sensitivity to light, headache, nausea, sometimes vomiting, tension of the neck muscles) and increased intracranial pressure. The degree of increase in intracranial pressure depends on the size of cysticerci, their number and location. The larger the size and quantity, the more pronounced the symptoms. Patients complain of a bursting headache, nausea and vomiting, pain in eye movement. Gradually, the compression of the optic nerves develops, which is manifested by impaired vision. The movements of the eyes are limited to the sides.

Intraventricular neurocysticercosis

This form of the disease is also accompanied by increased intracranial pressure. But, unlike the previous form, often occurs with a paroxysmal, even sudden deterioration of the condition. This is due to the fact that cysticerci, freely floating inside the ventricles of the brain, can cover the openings for normal circulation of the cerebrospinal fluid. The occlusion of the opening is accompanied by a sharp increase in intracranial pressure. Most often affects the IV ventricle. There may be a so-called Bruns syndrome: sudden strong dizziness, until the fall, a sharp headache, vomiting, impairment of consciousness, pallor, slowing of the heartbeat, violation of breathing, forced position of the head, sweating, sometimes fainting.

Spinal neurocysticercosis

Rather rare form, is only 1% of all cases. The cervical and thoracic parts of the spinal cord are most often affected. It is manifested by paresis of limbs, sensitivity disorders, shooting pains in hands and feet, girdling pains on the trunk, impaired urination (and, more rarely, defecation).

Asymptomatic neurocysticercosis

This form is found when examining a person for another disease or at an autopsy as a result of death from another disease, i.e., is an accidental find. Data from different countries differ significantly in the number of asymptomatic forms of neurocysticercosis and range from 1 to 25%.

Neurocysticercosis of the eye

It causes the development of such symptoms as the lowering of the eyelid, chronic conjunctivitis, the displacement of the eyeball relative to its axis. The movement of the affected eye is disturbed. Perhaps the sensation of a foreign body, prolonged swelling in the eye area, violation of the fields of vision, sometimes sudden total blindness. If, with such a localization, the cysticercus perishes, then the development of abscess or atrophy of the optic nerve is possible.

Principles of diagnostics

Clinical manifestations of neurocysticercosis are nonspecific (that is, they can occur in other diseases), therefore additional diagnostic methods are needed for diagnosis.

Since cysticerci are a larval form of the helminth, the disease causes an increase in the content of eosinophils in the blood. Doctors know that the presence of parasitic worms in the body always provokes a similar reaction from eosinophils.

In the study of cerebrospinal fluid, an increase in protein content, a decrease in glucose, an increase in lymphocyte count, and eosinophils are found.

Serological diagnostic methods are of particular value. The complement binding reaction is most often used, its informativeness is 83-90% when studying CSF. There are both false-positive and false-negative results.

Methods of neuroimaging can be used to confirm the diagnosis of neurocysticercosis. On the radiographs of the skull, intracerebral calcified cysticerci are detected, as well as signs of increased intracranial pressure. Computed tomography (CT) or magnetic resonance imaging (MRI) reveals calcifications, granulomas, foci with edema in the form of a ring or knot when introducing contrast, multiple nodal lesions, cysts. Of course, these changes do not have 100% specificity in neurocysticercosis, but the account of clinical symptoms, eosinophilia, Serological tests with similar changes on CT or MRI in most cases allow you to correctly establish a diagnosis.

If suspected of cysticercosis of the eye, the examination of the fundus may be informative. Sometimes you can even see free floating cysticercles in the anterior chamber of the eye or in the vitreous.

Principles of treatment

Treatment of neurocysticercosis can be carried out in two ways: conservative with the use of drugs and surgical. The choice of method depends on the clinical form of the disease.

The asymptomatic course of the disease causes controversy regarding the tactics of conducting such patients: to apply or not to use medicines? Often, treatment is not carried out so as not to provoke a deterioration in the state of larval decay.

Drug treatment involves the use of specific drugs - antiparasitic. Assign Praziquantel (Azinox, Cestoks) at a dose of 50 mg / kg / day in 3 divided doses for 2-4 weeks or Albendazole (Nemosol, Sanoxal) to, mg / kg 2 r / day for 1 month. Preparations cause the death of the parasite and the release into the blood of a large number of toxic products, which can accompanied by an increase in the inflammatory reaction, allergic manifestations, an increase in convulsive seizures, brain edema. To avoid these phenomena, along with antiparasitic drugs, hormones (Dexamethasone), non-steroidal anti-inflammatory drugs (Ibuprofen, Diclofenac, etc.), anticonvulsants (Depakin).Drugs penetrate only to the "fresh" cysticerci, the shell with calcium interferes with the penetration of the drug.

Cysticercosis of the eyes and malignant course of neurocysticercosis require surgical treatment. Malignant course is characterized by a fairly rapid increase in intracranial hypertension, multiple cysts, the development of acute hydrocephalus. Intracranial hypertension and hydrocephalus are eliminated by ventricular shunting. If access permits, then the available cysts are removed. Neurocysticercosis of the eye requires surgical treatment prior to the use of drugs, since inflammatory changes that occur during the decay of cysts during drug treatment can cause irreversible loss of vision.

Forecast

Neurocysticercosis is a disease whose prognosis can not always be foreseen, since it is not known how many larvae are in the brain (after all, not all of them can be detected during the examination). Late diagnostics, multiple foci of lesions, the lack of the possibility of surgical treatment are adverse factors of the course. Sometimes, a fatal outcome is possible during epipriposition or with occlusion of the IV ventricle with the development of acute occlusive hydrocephalus.

Thus, we can summarize the above: neurocysticercosis is a treacherous disease. Infection occurs unnoticed for a person. The disease can not be felt for a long time, sometimes it is asymptomatic. The unfolded clinical picture does not have specific symptoms, and the diagnosis requires a whole range of studies. Treatment is not always effective. In order not to become infected with neurocysticercosis, it is necessary to strictly observe the rules of personal hygiene, to overload the products carefully before eating them.