AM Report 03/07/17: Neurocysticercosis

Cysticercosis 

-Caused by the larval stage of the pork tapeworm (Taenia Solium)
-Humans get cysticercosis by drinking/eating water/food contaminated by tapeworm eggs (eg: infected pork)
-See life cycle below

Cysticercosis_LifeCycle

Clinical syndromes

Neurocysticercosis
Parenchymal
Extra-Parenchymal (Intraventricular/sub-arachnoid/intraocular/spinal)
-Extraneural cysticercosis

Clinical presentation

Parenchymal cysts
Seizures/headache-Most common cause of adult onset seizures in many countries (70 % of patients)-esp. Latin America, India, Africa, and China
-Can be YEARS after infection. Most never cause symptoms and identified incidentally

Extraparenchymal cysts:
-Increased ICP- HYDROCEPHALUS, headache, nausea, vomiting, AMS
-Intraventricular cysts can cause obstructive hydrocephalus (nausea/vomiting/headache), subarachnoid cysts, spinal (<1%), ocular, extra-neural (subQ/intramuscular)

How do you make the diagnosis?

-Stool O&P usually negative as chronic infection
-Peripheral eosinophilia is NOT commonly seen
-If you have a patient from an endemic area with seizure and enhancing lesion on MRI-very likely to be Taenia Solium. 
-See criteria below as definitive diagnosis requires at least one absolute criterion or two major plus one minor and one epidemiologic criterion

diagnostic criteria
Reference: UpToDate

Note that identification of the Scolex (anterior end with hooks) in cystic lesion is pathognomonic. 
-Serology with EITB (enzyme linked immunoelectrotransfer blot)antibody to T.solium, 83-100 % sensitive, 100 % specific but lab dependent)-takes a while to come back
-A detailed eye exam should be done to rule out ocular cysticercosis 
-Brain biopsy rarely done as can be diagnosed by above 

Differential Diagnosis (not complete) but do not miss other infectious causes!
Toxoplasmosis
-Cryptococcus
-Brain abscess
-Nocardiosis
-Septic emboli
-TB/fungal
-Meningeal carcinomatosis
-Glioblastoma

Treatment 

Seizure control (controversial but esp. if multiple lesions, parenchymal involvement, or presenting with seizure)
-Treatment of increased ICP
Antiparasitic therapy (Albendazole + Praziquantel with better efficacy, always given with or after anti-inflammatory therapy (steroids) due to inflammation with dying cysts. Can RECUR after treatment so needs to be tailored to imaging and symptoms.
-Surgical management if ocular or spinal lesions

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