There are cysts in the brain, what causes it?

Neurocysticercosis is a cystic disease caused by the larvae (cysticerci or cysticerciae) of pork tapeworm parasitizing in the brain, and is the most common parasitic disease
of the central nervous system in China.
The clinical symptoms are extremely complex and diverse, mainly depending on the location range, number and living status of cysticerci parasitism
.
Neurocysticercosis can be cured
after regular diagnosis and treatment.
The author met this patient in the clinic and summarized the relevant knowledge points for peers to learn
.

Author: Wang Lulu

This article is authorized by the author to be published by Yimaitong, please do not reprint
without authorization.

Case profile

Current medical history: Patient male, 47 years old
.
He was admitted to hospital
for "episodic loss of consciousness with limb convulsions for 2 years, aggravated for 2 weeks".
The patient had no obvious cause 2 years ago to look to the right side of both eyes, then lost consciousness, foaming at the mouth, convulsions in the limbs, anuria incontinence, lasted about 10 minutes and then relieved on its own, and then had 2-3 similar seizures, which were not diagnosed
.
Similar symptoms occur frequently 2 weeks before admission, 2-3 times a day, lasting 2-15 minutes to relieve themselves, and symptoms
such as headache, dizziness, fatigue and numbness of fingers appear.
Normal
temperature during and between episodes.
Local head CT shows multiple intracranial low-density foci with edema
.
For further diagnosis and treatment, we visit our outpatient clinic
.

Anamnesis: The patient consumed "rice pork"
20 years ago.
Appendicitis removal surgery
was performed at a local hospital 33 years ago.


Physical examination: clear consciousness, indifference, no dysarthria, normal high-level cortical function, slow response
.
Cranial nerve examination is generally normal, limb muscle strength grade 5, muscle tone is normal, ataxia is normal, and gait is normal
.
Sensory examination is generally normal, tendon reflexes are symmetrical, and bilateral Pussep signs are suspiciously positive
.
Strong three transverse fingers of the neck, left Kernig sign (+).

The patient's back and calves can palpate several subcutaneous nodules with a diameter of 0.
5-1.
0 cm, which are tough, non-tender, and have no adhesion with
surrounding tissues.

✔ Trivia: Pussep sign - drawn upwards along the dorsal lateral margin of the foot, all the way to the base of the little toe or above the toe, suggesting damage
to the pyramidal tract.

Examine:

Blood routine: white blood cells 8.
6*10⁶/L, eosinophil proportion 8.
5%.

Urine and stool routine are normal, and blood biochemistry is normal
.

Then look for eggs (-).

Serum tumor marker (-).

Lumbar puncture: pressure 300mmH₂O, colorless and transparent, Paneth test (+), cerebrospinal fluid conventional WBC40x10⁶/L, RBC0, mononuclear cells 70%, multiple nuclear cells 30%, protein 1010mg/L, chloride 123mmol/L, Sugar 3.
5mmol/L
.

Serum and cerebrospinal fluid cytomegalovirus, herpes simplex virus type 1/2, rubella virus, coxsackievirus type B antibody (-).

Toxoplasma haematosis DNA is below the lower limit of
detection.
Serum tuberculosis antibody and tuberculosis confirmation test (-).

Serum and cerebrospinal fluid cysticerin enzyme label (+).

Serum hydatid antibodies, Toxoplasma gondii antibodies, and strongyloides cantonica antibodies are all (-).

MRI of the head showed multiple scattered small round or oval long T1 long T2 sac-like signals in the brain parenchyma, the cyst wall was thin, a point-like head segment was visible on one side of the cyst wall, and the FLAIR head segment was clearly
displayed.
Gd-DTPA enhanced scan showed mild enhancement of the cyst wall and cephalic segment; Meningeal enhancement
may also be seen in the left lateral fissure.

Fig.
1 MRI of the head is enhanced

Diagnosis: neurocysticercosis
.

Positioning diagnostics

The patient has seizures, and the interictal period is manifested by unresponsiveness, apathy, localization in the bilateral cerebral cortex; Bilateral Pussep sign is suspicious and localised to bilateral corticospinal tracts; Meningeal signs are localized to the meninges
.
In addition, there are manifestations
of subcutaneous muscle involvement.

Epidemiological features of neurocysticercosis

Worldwide, neurocysticercosis is common in tropical and underdeveloped regions such as Mexico, Central and South America, Southeast Asia, China, and India
.
It is more common in northeast China, north China, Shandong and other regions, followed by northwest China and Yunnan Province, and rare south of the Yangtze River
.
It is more common in young adults, more males than females, and the cases in males and females are about 2-5:1
.
Humans are both the final host of pork tapeworm (pork tapeworm disease) and an intermediate host (cysticercosis).

Cysticercosis is caused
by ingestion of pork tapeworm eggs.
Eating "rice pork" is one of
the ways to get cysticercosis.

Classification of neurocysticercosis

Tapeworm eggs that enter the stomach through a variety of routes hatch into cysticerci in the duodenum, drill into the intestinal wall through the intestinal veins into the systemic circulation and choroid, and thus enter the brain parenchyma, subarachnoid space and ventricular system, called cysticercosis cerebral type
.
Neurocysticercosis accounts for about 80%
of all cysticercosis.
In addition, cysticerci can also enter the voluntary muscles and retina, vitreous and other parts, causing muscle and eye damage, which are called dermatomyotype and eye type
, respectively.

Imaging findings of neurocysticercosis

Typical images of cerebral CT with neurocysticercosis include single or multiple round low-density foci, 0.
5-1.
5 cm in size, visible head segments, or multiple high-density foci, the same size as before; Upon intensification, it appears as single or multinodular or dotted annular lesions
.
Grape-shaped cysts on the surface of the brain or in the cistern, cystic lesions
in the ventricles.

MRI of the head is of great significance for the diagnosis of this disease, which can clearly reflect the location, course and number of
cysts.
According to the location of cysts, MRI of the head of neurocysticercosis can be divided into four types
: parenchymal type, ventricular type, meningeal type and mixed type.

MRI of active cysticerpillar lesions showed multiple scattered small round or oval long TT long T2 sac-like signals in the brain parenchyma, the cyst wall was thin, a point-like head segment was visible on one side of the cyst wall, the FLAIR head segment was clearly displayed, and Gd-DTPA enhanced scanning showed slight enhancement of the cyst wall and head segment; Cysticercosis lesions in the metamorphosis death stage, manifested as slightly longer T1, slightly longer T2 abnormal signal, obvious annular enhancement after enhancement, no enhancement of edema areas visible around the lesion, the cephalic segment disappears in this stage, the cyst wall becomes thicker, and the surrounding edema is intensified
.

Laboratory features of labeled neurocysticercosis laboratory

1.
Blood routine parasitic infection mostly leads to elevated blood eosinophils, up to 15%-50%.

2.
Some patients with pococysticercosis can be combined with pork tapeworm disease at the same time, and tapeworm eggs
can be found by stool examination.

3.
Lumbar puncture examination of patients with neurocysticercosis patients can increase intracranial pressure; The number of white blood cells in cerebrospinal fluid is normal or mildly elevated, generally not more than 100x10⁶/L, and eosinophils may be elevated; normal or mildly elevated protein; Sugars and chlorides did not change
significantly.

4.
Serum and cerebrospinal fluid cyst immunological detection ELISA, indirect hemagglutination test and complement binding test to detect serum and/or cerebrospinal fluid cyst IgG antibody have qualitative significance
for the diagnosis of this disease.
ELISA has the highest
sensitivity and specificity.

5.
Subcutaneous nodule biopsy confirmed that cysticercosis is one of the bases for the diagnosis of
cysticercosis.

Diagnostic criteria for neurocysticercosis in China

• There are corresponding clinical signs and symptoms, such as seizures, increased intracranial pressure, mental disorders and other brain symptoms and signs, basically excluding other diseases
  that need to be differentiated.
  

• positive immunological tests (positive for serum and/or cerebrospinal fluid cystis IgG antibodies or circulating antigen CAg); Cerebrospinal fluid is routinely biochemically normal, or there may be leukocytes, particularly eosinophilia
  .
  

• CT or MRI of the head shows changes
  in cyst imagery.
  

• Subcutaneous, muscular or intraocular cyst nodules, confirmed by biopsy pathological examination
  .
  

• The patient is from an area where cysticercosis is endemic, and the stool has a history of tapeworm nodules or eating "rice pork", which can be used as a reference for
  diagnosis.
  

• Those with more than 4 can be diagnosed; Or with 1.
  2.
  3 or 1.
  2.
  5 or 1.
  3.
  5 can also be diagnosed
  .
  

  
  

Pharmacological treatment of neurocysticercosis

Albendazole is preferred, and it is a broad-spectrum antihelminthic drug
.
The mechanism of action may be related to
its inhibition of the absorption of insect progens and inhibition of butenedioate reductase.
The efficacy is definite, the obvious efficiency is more than 85%, and the side effects are light, which is currently the preferred drug
for the treatment of neurocysticercosis.
Now more than one course of treatment is used, the usual dose is 15-20mg/(kg*d), for 10 days
.
Cerebral patients have 3-5 courses of treatment, with an interval of 2-3 months
.

Praziquantel, a broad-spectrum anti-helminth drug, also has a good therapeutic effect
on cysticercosis.
The usual total dose is 180mg/kg, divided into 3-5 days, and the daily dose is divided into 2-3 times
.
After taking the drug, cysts can appear swelling, degeneration and necrosis, resulting in inflammatory reactions and allergic reactions of brain tissues around cysts, and even the risk of
intracranial pressure increase in severe cases.

Mebendazole, the commonly used dose is 200mg, 3 / day, for 3 consecutive days, common toxic side effects are abdominal pain, diarrhea, skin itching and headache
.

Neurocysticercosis has involved more than 20 provinces in China, of which the northeast region and the Yellow River Basin are high-incidence areas, and it is not uncommon in individual provinces in the southwest, so the disease urgently needs to be strengthened in China
.
Prevention of the disease should begin
with the elimination of the source of infection and the cutting off of the transmission route.
Do a good job in publicizing and popularizing medical knowledge of cysticercosis, so that people understand the importance of dietary hygiene habits, change the habit of eating half-cooked pork, and strictly prevent "rice pork" from entering the body
.