Submitted by Dr LAU Chun Wing Arthur on 21 Feb 2009
Department of Intensive Care, Pamela Youde Nethersole Eastern Hospital
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CT Brain {morfeo 12} |
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MRI Brain {morfeo 13} |
What is this brain lesion?
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Answer: This patient had recurrent neurocysticercosis with hydrocephalus and repeated VP shunt revision done, and was on Praziqantel and Dilantin. He has had craniotomy + Lt temporal cyst excision in 5 years ago. He was admitted this time for craniotomy + complete excision of left cerebellar cyst for recurrent brain cyst, with post-operative ICU care. Yellowish slimmy cysticercosis ova with turbid fluid was seen at the left quadrigeminal multiloculated cyst, and frozen section confirmed neurocysticercosis
Discussion
For a more complete review, see:
Epidemiology
See: O. H. Del Brutto, et al. Neurocysticercosis: A Clinical Handbook (Preview only)
Neurocysticercosis is the most common parasite infection of the brain. It is a leading cause of epilepsy in the developing world, including China.
Life cycle as related to clinical manifestations
1. Humans ingested human feces with eggs from Taenia solium >> Human cysticerci in brain (HUMAN NEUROCYSTICEROCIS), eyes and muscle >> life cycle blind end
2. Humans ingested raw pork with porcine cysticerci in muscle >> HUMAN TAENIAISIS >> eggs passed out in human fecese and go to step 3 or 1
3. Pigs ingested human feces with eggs from Taenia solium >> PORCINE CYSTICERCOSIS >> eggs passed out in pig feces and go to step 2
Neuroimaging findings in parenchymal neurocysticerosis depend on the stage of the parasite. There are four stages of cysts within the parenchyma of the brain:
1. VESCICULAR CYST (= viable larval cyst): scolex can be identified within the cyst. Little or no immune response, and there is minimal or no enhancement on contrast study
2. COLLOIDAL CYST: Results from degeneration of vesicular cyst. Fluid leaks out and causes immune response, therefore there is enhancement in contrast CT/MRI studies. Scolex not seen.
3. NODULAR/GRANULAR CYST: results from further degeneration, there is also contrast enhancement
4. CALCIFIED GRANULOMA: non-enhancing, punctate calcification
(Our patient is having colloidal cyst)
Neurological symptoms and signs
Seizures (vesicular cysts and colloid cysts more epileptogenic than nodular/granular cyst and calcified granuloma); headaches, hydrocephalus, stroke-like syndromes
Principles of treatment of neurocysticercosis
1. All patients require adequate symptomatic therapy (anti-convulsants, anti-inflammatory drugs, treatment for intracranial hypertension like CSF diversion, other individualised treatment)
2. Vesicular cysts (viable cysts): albendazole 15mg/kg/D PO for >= 7D + dexamethasone 0.1 mg/kg/D PO for >= 7D; or praziquantel 25mg/kg PO q2H for 3 doses or 50 – 100mg/kg/D for 15 D + dexamethasone)
3. Enhancing intraparenchymal lesions (Colloidal cysts and nodular/granular cysts): favourable course whether or not treatment with anti-epileptic drugs is given
4. Dead/calcified cysts: no need for anti-parasitic drugs
5. Subarachnoid cysticercosis: no controlled trials, anti-parasitic drugs +/- steroids +/- shunting. E.g. Albendazole 15 mg/kg/D for 4 weeks (Proano et al, NEJM 2001), for several courses
6. Cerebrovascular complications: no published trials, may use steroids for inflammatory reactions
Treatment of Taeniasis (i.e. worm in human)
Niclosamide 2g for 1 dose or Praziquantel (5mg/kg) for 1 dose; Niclosamide preferred, 95% effective, but no FU studies exist
Also give osmotic purgative before and after anti-parasitic drugs to confirm excretion of the worm scolex, otherwise it will regenerate to a full tapeworm within 2 months.