Neurocysticercosis (NCC), caused by infestation of the human central nervous system with the tissue cyst of Taenia solium, is the most common parasitic disease of the human nervous system. Seizures are by far the most common clinical manifestation.
During March 2008 to May 2009, the serological test was carried out in a series of 90 cases of seizure disorders aged more than 14 years presented to B. P. Koirala Institute of Health Sciences, Nepal using an enzyme linked immunosorbent assay for circulating antigen (Ag-ELISA).
Taenia solium antigen was detected in 15% of the patients. Seropositivity was associated with neuroimaging studies consistent with NCC (OR=13.2 95% CI 1.43- 305.79, P= 0.014). It is significant for multiple ring enhancing lesions (P= 0.00935 for CT Head and 0.00274 for MRI Head). Living in kachha house, family members >5 and age > 60 years have higher odds ratio for positive serology of cysticercosis although there was no statistical significance.
On the basis of clinical and imaging findings, the serological test was found to have sensitivity of 41.5% and specificity of 98.4% with the positive predictive value of 92.3% and negative predictive value of 81.8%. So, in the settings where imaging facilities are not available a positive serological test could qualify to start the treatment for NCC. In conditions of negative serological test but if NCC is suspected on clinical grounds then neuroimaging is advocated and could be the reason for referral for neuroimaging.
Posted by: bickram pradhan, Additional Professor, B P Koirala Institute of Health Sciences, Nepal (14-Feb-2013)