====== Cysticercosis ======
  * A parasitic infection caused by the larval stage of the pork tapeworm //Taenia solium//
  * Caused by ingesting food or water contaminated by the worm's eggs (frequently fecal-oral transmission) which hatch in the gut and larvae migrate to the tissues then form cysts in the tissue. 
    * Cysts can be viable (dormant), degenerating (non-viable) or resolved with calcification
  * The larvae spread hematologically and settle in tissues, especially the CNS and eye.
  * Neurocysticercosis is the leading cause of epilepsy in endemic areas
  * Endemic areas 
    * Latin America, sub-Saharan Africa, Indian Subcontinent, Southeast Asia and China. 
    * In the USA (not endemic) cases are more often seen among immigrant populations 
=====Diagnosis====
    * Neuroimaging
      * MRI
        * T2-hyperintesnse and T1-hypointense showing cyst morphology (scolex, cyst fluid and surrounding inflammation) 
      * CT
        * Complementary to MRI, more sensitive for detecting calcified lesions 
    * Ocular imagining 
      * B-scan 
        * Well defined cystic lesion with eccentric intracystic echogenic focus (nidus) representing the scolex, thick cyst wall, surrounding inflammation and retinal detachment 
    * Serologic testing- enzyme linked immunoelectrotransfer blot assay (EITB) 

====Ocular manifestations====
  * 1-3% of all cases have ocular infection but //T. solium// is the most common intraocular parasite worldwide 
  * Intraocular cysts
    * Free floating in vitreous (60%) 
    * Subretinal space (40%) 
    * Vitreous inflammation 84%
    * Anterior segment inflammation 30%
    * Retinal detachment +/- PVR 50%
    * cyst rupture causes more inflammation than intact cysts
  * Orbital/Extraocular involvement common
    * Most often superior rectus affected causing restriction, proptosis, diplopia and ptosis 
    * Retro-orbital cysts can affect optic nerve and cause proptosis
  * Vision loss from CNS disease
    * papilledema, or chiasmal compression 
====Treatment====
  * Intraocular cysts require surgical removal
    * Vitrectomy and cyst removal and repair of retinal detachment 
  * Subconjunctival cysts are usually removed as well. 
  * Cysticidal therapy can cause severe ocular inflammation
    * Extraocular cysts are more amenable to medical treatment alone
    * Albendazole + cortiosteroids >90% resolution
      * Standard regimen: 
        * albendazole PO (15mg/kg/day usually about 400 mg BID, max 1200 mg/day) for 10-14 days (FDA label permits up to 30 days but some evidence supports shorter courses 3-7 days for example)
        * prednisone PO (1mg/kg/day) given for the duration and the tapered. 
      * possible persistent motility restriction, proptosis or ptosis
    * Treatment response monitored by vision exam, and repeat imaging. 
    * If cystic lesions persist beyond 6-12 months, retreatment is recommended. 
      * albendazole can be repeated, praziquantel can be added or switched to. 
      * a combination may be superior if ≥ 3 cysts 
    * Monitor: liver enzymes, CBC
      * Hepatotoxicity occurs in 16%
      * Leukopenia in 10%
      * Reversable alopecia may occur 
      * More common to have above with more prolonged treatment 

====References====
  - [[https://1drv.ms/b/c/31d83ae8e55e0542/ESPvY4XqC1BPg1_kzYOcbUQBgRAIUlsb7_eISmJBNaZHLQ?e=ANUFCJ| Pujari A. et al. Cysticercosis in ophthalmology. Surv Ophthal. 2022;67:544-569]]
  - [[https://pubmed.ncbi.nlm.nih.gov/20060168/|Rath S. et al. Orbital cystercosis: clinical manifestations, diagnosis, management, and outcome. Ophthalmology 2010;117(3):600-605.]]