ObjectiveThe diagnosis of neurocysticercosis (NCC) remains problematic because of the heterogeneity of its clinical, immunological, and imaging characteristics. Our aim was to develop and assess a new set of diagnostic criteria for NCC, which might allow for the accurate detection of, and differentiation between, parenchymal and extraparenchymal disease.MethodsA group of Latin American NCC experts developed by consensus a new set of diagnostic criteria for NCC. A multicenter, retrospective study was then conducted to validate it. The reference standard for diagnosis of active NCC was the disappearance or reduction of cysts after anthelmintic treatment. In total, three pairs of independent neurologists blinded to the diagnosis evaluated 93 cases (with NCC) and 93 controls (without NCC) using the new diagnostic criteria. Mixed‐effects logistic regression models were used to estimate sensitivity and specificity.ResultsInter‐rater reliability (kappa) of diagnosis among evaluators was 0.60. For diagnosis of NCC versus no NCC, the new criteria had a sensitivity of 93.2% and specificity of 81.4%. For parenchymal NCC, the new criteria had a sensitivity of 89.8% and specificity of 80.7% and for extraparenchymal NCC, the new criteria had a sensitivity of 65.9% and specificity of 94.9%.InterpretationThese criteria have acceptable reliability and validity and could be a new tool for clinicians and researchers. An advantage of the new criteria is that they consider parasite location (ie, parenchymal or extraparenchymal), which is an important factor determining the clinical, immunological, and radiological presentation of the disease, and importantly, its treatment and prognosis. Ann Neurol 2016;80:434–442

Cognitive impairment was ubiquitous in this sample of patients with active neurocysticercosis (NCYST). Antiepileptic drug use and seizure frequency could not account for these features. Dementia was present in a significant proportion of patients. These data broaden our knowledge on the clinical presentations of NCYST and its impact in world public health.

Neurocysticercosis (NC) is a neglected disease that contributes substantially to neurological morbidity/mortality in lower-income countries and increasingly among high-income countries due to migration. Many advances have been made in understanding NC, but unanswered questions remain Areas covered: This review discusses the epidemiology, pathophysiology, immunology, diagnosis, treatment, and eradication of NC. Expert commentary: The global NC prevalence remains unknown and needs proper ascertainment. Further understanding of the pathophysiology of extraparenchymally located cysts is needed to improve management. The role of inflammation, which is required for parasite death and reabsorption, but may lead to severe complications, must be better understood. Valid screening tools including immunological and molecular tests need to be developed to reduce the reliance on neuroimaging which is not usually accessible in endemic areas. Prognosis for people with parenchymal NC is generally good after treatment, but there are no sufficiently powered randomized trials evaluating antiparasitic treatment for extraparenchymal NC. Most people with seizures do not develop epilepsy. Overemphasizing NC as the main cause of epilepsy could increase stigmatization with potential medico/social implications. Several tools for prevention and control of taeniasis/cysticercosis are available, but strategies to eradicate NC must be created with the involvement of all stakeholders.

Independently of its phase, NC leads to a spectrum of cognitive abnormalities, ranging from impairment in a single domain, to CIND and, occasionally, to dementia. These findings are more conspicuous during active vesicular phase and less prominent in calcified stages.

Neurocysticercosis is the most frequent parasitic infection of the CNS and the main cause of acquired epilepsy worldwide. Seizures are the most common symptoms of the disease, together with headache, involuntary movements, psychosis and a global mental deterioration. Absolute diagnostic criteria include the identification of cysticerci, with scolex, in the brain by MRI imaging. We demonstrate here, for the first time, that T. solium DNA is present in the cerebrospinal fluid of patients. The PCR amplification of the parasite DNA in the CSF enabled the correct identification of 29/30 cases (96.7 %). The PCR diagnosis of parasite DNA in the CSF may be a strong support for the diagnosis of neurocysticercosis.