Clinical presentation, diagnosis, stages, types and current treatment guidelines for Neurocysticercosis.

1. Neurocyscticercosis
Dr.Yusuf Imran
M.D Pediatrics
J.N Medical College, Aligarh, India

2. Introduction
Neurocysticercosis (NCC) is the infection of the CNS by the larval stage of the
pork tapeworm Taenia solium.
Infection may develop in any organ- CNS (parenchyma, subarachnoid spaces,
ventricles and spinal cord), eyes and muscles are the most commonly involved.
Most common manifestation is epilepsy but can have several other neurological
manifestations.

3. Epidemiology
NCC is endemic in most Latin American countries, sub-Saharan Africa, and large
regions of Asia (including Indian subcontinent and China).
Rare in developed countries, can occur in travelers/immigrants.
A study from North India found point prevalence of NCC - 4.5/1000. In pig farming
community it is upto 15 %.
Proportion of NCC among patient with epilepsy is estimated @ 29 %. In those with
partial seizures it was >50 %.

4. Life cycle of Taenia solium
Taenia solium requires two hosts to complete its life cycle.
Pigs (intermediate host) contain the cystecerci, primarily in muscle.
Humans (definitive host) infected by consuming undercooked pork containing live
T.solium cysticerci.
Cysticerci develop into adult tapeworm which releases eggs in human feces.
Eggs contaminate soil/vegetation, when ingested by pigs/humans eggs develop into
larvae which pass through intestinal mucosa and reach various tissues.

5. LifecycleofTaeniasolium

6. Growth stages ofTaenia solium:
A-InfectiveT.solium eggs, B-Larva or
cysticercus, C-Evaginating cysticercus,
D-Tapeworm scolex, E-Tapeworm strobila
LifecycleofTaeniasolium

7. Modes of infection
Sources of infection- persons withTaeniasis (acquired from pork).
Transmission ways-
 not spread from person to person directly
 persons withTaeniasis will shed tapeworm eggs in their bowel movements

8. Modes of infection
Infection can happen by accidentally swallowing pork tapeworm eggs
Through-
 drinking contaminated water or food
 by putting contaminated fingers to mouth (external autoinfection)
 by internal autoinfection

9. Disease spectrum of T.solium
Taeniasis = adult tapeworm in small intestine
• Usually asymptomatic (eggs or proglottids in feces)
• Vague abdominal symptoms
Cysticercosis = T. solium larvae in human tissues (eg, muscle)
• Usually asymptomatic
• Painless subcutaneous nodules in arms and chest
Neurocysticercosis (NCC) = cysts in the central nervous system
• Most severe manifestation

10. Etiopathogenesis
Clinical expression, management and prognosis of NCC varies depending on
the number of CNS lesions, their stage, size, location and host inflammatory
response.
Studies have identified a number of mechanisms used by the cycticercus to
modulate host’s immune response.
• Protease inhibitor-Taeniaestatin
• Sulfated polysaccharides
• Parasite paramyosin
• Prostaglandins
• Stimulate antibody production

11. Etiopathogenesis
Although, cysticerci reach mature size within a few weeks, there a period
of several years between exposure and onset of symptoms.
When parasite degenerates there is a brisk inflammatory response.
The seizures are thought to result not from the parasitic infection per se,
but from the host response.

12. Types of Neurocysticercosis
1. Intraparenchymal NCC
Most common form, seen at grey white matter junction.
Single or Multiple.
Range in size from a few mm to 1 to 2 cm.
Commonly seen in children >5 years but can occur in toddlers and infants.

13. Types of Neurocysticercosis
Intraparenchymal NCC cont…
Seizures are most common manifestation of intraparenchymal NCC.
1/3rd may have associated headache and vomiting.
Papilloedema occurs in 2 to 7 %.
Neurological deficits seen in 4 to 6 %.
Seizures respond well to monotherapy.
Cysticercal Encephalitis- results from large number of cysticeci in brain parenchyma
with diffuse inflammation and edema.

14. Types of Neurocysticercosis
The parenchymal cysts evolve through 4 stages-
 The vesicular cyst
 Colloidal stage
 Granular nodular stage
 Nodular calcified stage

15. StagesofIntraparenchymalNCC

16. Types of Neurocysticercosis
2. Extraparenchymal NCC
Ventricular NCC- can obstruct CSF flow causing hydrocephalus. CT may
reveal only hydrocephalus and no cysticerci.
Subarachnoid NCC- can occur in the gyri, fissures, basilar cisterns.

17. TypesofNeurocysticercosis

18. Types of Neurocysticercosis
Other forms of Cysticercosis
Spinal Cysticercosis (intramedullary/extramedullary)
Ocular Cysticercosis
In Muscles
In Subcutaneous tissue
Other organs
A single patient may have multiple types and locations of cysticercus.

19. TypesofCysticercosis

20. Clinical Manifestations
Asymptomatic.
Most common manifestation is Seizure (focal, secondary generalized or
generalized). (80%)
Headache is common (unilateral/bilateral)- may reflect raised ICT or vasculitis.
Focal neurological deficits (16%)
Symptoms/signs of raised ICT-nausea, vomiting, altered mental status, visual
changes, dizziness, cerebral edema. (12%)
Neurocognitive defects- leaning disability, psychosis, depression. (5%)

21. Imaging
CT
 Parenchymal cysts- usually appear as single, small (<20mm) with ring/disk
enhancement and eccentric hyper dense scolex. Multiple lesions give ‘starry
sky’ appearance. (colloidal stage).
 Enhancement indicates inflammation. Live vesicular cysts are non-enhancing.
 Extra-parenchymal cysts- may show hydrocephalus, enhancement of
tenctorium and basal cisterns and occasionally infarcts.

22. Imaging
MRI
 Superior to CT in detecting cysts in ventricles, posterior fossa, brainstem,
small cysts.
 Small calcified lesions may be missed.
 Magnetization transfer images (MT) and magnetization transfer ratio (MTR),
recovery (FLAIR) and fast imaging employing steady-state acquisition
(FIESTA) sequences for lesions not visible on routine MRI.

23. SerologicalTests
Seropositivity depends on parasite load and endemicity. False positive and false
negative results can occur.
False-negative result:
Single lesions
Calcification
False-positive:
Other parasitic infections
High percentage of false positive for patients from endemic area

24. SerologicalTests
EITB assay- uses lentil lectin purified glycoprotein antigens (LLGP) to detect
antibodies to T soliumin in serum. Sensitivity 98% (multiple parasites), 50-70 %
(solitary cysticercus).
Detection of anticysticercal antibodies in the CSF by ELISA.
Detection of circulating parasitic antigens in serum by ELISA with monoclonal
antibodies is experimental.
In patients with reliable diagnosis of NCC by imaging studies, immunological test is not
required, since a negative test will not discard a NCC.

25. Other lab tests…
Eosinophilia may occur.
CSF-
 Usually done to rule out other causes.
 Can be normal in inactive disease.
 Moderate pleocytosis (mostly mononuclear cells; upto 300/mm3), increased
protein (50-300 mg/dl). Correlate with disease activity and whether or not the
parasites are located in sub-arachnoid space.

26. Other lab tests…
Biopsy of subcutaneous nodules.
Radiographs of skeletal muscles.
Specific coproantigen detection by ELISA for screening forT solium carriers.
Stool examination forT.solium eggs has poor sensitivity.

27. Diagnosticcriteria Definitive diagnosis- one
absolute criterion or two major
plus one minor and one
epidemiologic criteria
Probable diagnosis- one major
plus two minor criteria, one major
plus one minor and one
epidemiologic criteria, three
minor plus one epidemiologic
criteria.

28. Differential diagnosis
Tuberculoma
(presence of raised ICT, progressive
focal neurodeficit, size >20mm,
lobulated irregular shape, midline shift
& marked edema, lesions at base of
brain)
Special MRI sequences – diffusion
weighted MRI and proton magnetic
resonance spectroscopy (MRS) are
being tried.
 Case discussion- A two month old child was referred for
evaluation of fever associated with fits. Plain CT brain showed
a 1.1.x 1.0 cms. round hypodense lesion in the right frontal
lobe. There was dilatation of all the ventricles, basal cisterns.
The anterior fontanalle was bulging. On contrast study there
was dense enhancement of basal meninges, dense ring
enhancement ( 4 mm thick ) of the the right frontal lobe
lesion.

29. Differential diagnosis
Microabscesses
Toxoplasmosis
Fungal lesions
Low grade astrocytoma
Cystic cerebral metastasis
CNS lymphoma

30. Management
Emergency care
Manage seizure activity
Supportive care (A-B-C)
Monitor, and correct metabolic abnormalities
Anticonvulsants are effective.
Evidence of increased ICP- Steroids, osmotic agents, and/or diuretics
Initiate proper diagnostic procedures
Blood work and imaging

31. Management
Intraparenchymal NCC- Symptomatic treatment, anti-parasite treatment or
surgery ?
Calcified cysts only- antiepileptic, analgesic, and anti-inflammatory drugs; for
seizures relapses, repeat imaging looking for peri-calcification oedema. AED for at least
2yrs since last seizure. No anti-parasite drugs.
*One or more cystic or degenerating lesions- antiepileptic, analgesic, and anti-
inflammatory drugs; antiparasitic treatment under hospital conditions with steroid
treatment. DiscontinueAED in single lesions after they resolve (without calcification).
*Level 1 evidence
Cysticercal encephalitis- Manage intracranial hypertension; do not use antiparasitic
drugs.

32. Management
Asymptomatic parenchymal lesions
• Prophylactic AED not justified in calcified lesions without seizures.
• Viable cysts- Give prophylactic AED when antiparasite treatment is also
planned.
Repeat neuroimaging after 3-6 m to document lesion resolution. Repeat
course of cysticidal therapy if persistent lesion.

33. Management
Drugs:
• Albendazole- 15mg/kg/day in 2-3 divided doses for 2-4 weeks. Shorter
courses of 3 to 14 days tried in single lesions.
• Praziquintal- 50mg/kg/day, less effective than albendazole.
• Combinations of two antiparasitic drugs- increased cyst clearance in
multiple lesions.
• Steroids-
Dexamethasone- 0.1 mg/kg/day i.v starting one day before antiparasite
drugs, give for 1 to 2 weeks then taper.
Prednisolone- 1 to 2 mg/kg/day.

34. Management

35. Management
Extraparenchymal NCC

36. Management
Other forms of NCC
Spinal- Intramedullary cysts are treated with surgery, albendazole with
steroids is being tried. Subarachnoid cysts can migrate so imaging is done
just before surgery.
Ocular- Surgical management is the standard of care.

37. Prognosis
Single lesions- good prognosis, disappears in >60% at 6m.
Seizure recurrence is 10-20% with single lesions, multiple lesions have
more frequent seizures.
Prognosis is poorer in cysticercal encephalitis and extraparenchymal
NCC.

38. Prevention
T solium infection is one of a few diseases targeted for focal
elimination and eventual eradication by the International Task Force
for Disease Eradication.
Public education, proper hygiene, provision for toilets.
Safe handling of meat, strict animal husbandry and meet inspections
procedures.

39. Prevention
Mass deworming of population with Niclosamide or Praziquintal.
Mass vaccination of pigs and treatment of pigs with Oxfendazole.
Community interventions reduce rate of epilepsy in hyper-endemic areas.

40. Conclusion
NCC is a common cause of seizures and other neurological manifestations
and needs to be considered in D/D of many neurological conditions.
Treatment with cycticidal therapy leads to reduction in seizure frequency
and faster resolution of lesions.
Children with a single or few lesions have a good outcome.
Prevention of NCC is important and feasible.

41. Thank you