Neurocysticercosis: relationship between Taenia antigen levels in CSF and MRI

Abstract

Objective: To determine the relationship between Taenia antigen (TA) detection in cerebrospinal fluid (CSF) and magnetic resonance imaging (MRI) findings in patients with definite diagnosis of neurocysticercosis (NC). Method: Sixty-three patients with definite diagnosis of NC were submitted to a MRI of the brain, and to a CSF examination, with a meticulous search for TA by ELISA. results: TA detection was positive in 36 patients (57.1%). A total of 836 lesions were analyzed, greatly within the cerebral parenchyma (98.7 of the lesions). Intact or non-degenerating cysts were the most common evolutive phase observed (50.4% of all lesions), 22.1% were degenerating cysts and 19.5% calcified cysts. We observed a significant relationship between TA levels detected and the total number of lesions and the number of non-degenerating cysts, but not with calcified lesions. conclusion: According to our results, we propose at least four important types of contribution: (1) TA detection may allow etiologic diagnosis in transitional phases of NC, with non-characteristic images; (2) in final stages of evolution of cysticercoids in the CNS, lesions may not appear on CT or MRI, and TA detection may contribute to a definite etiologic diagnosis; (3) TA detection may permit diagnosis of NC in some patients with previous negative tests for antibody detection in CSF; (4) TA detection may represent an accurate marker of disease activity in the epileptic form of NC. Key words: central nervous system, cerebrospinal fluid, enzyme-linked immunosorbent assay, magnetic resonance imaging, neurocysticercosis, Taenia antigens detection.Neurocisticercose: relação entre antígeno da Taenia no líquido cefalorraquidiano e ressonância magnética resuMO Objetivo: Determinar a relação entre a detecção de antígeno de Taenia (TA) no líquido cefalorraquidiano (LCR) e achados de ressonância magnética (RM) em pacientes com diagnóstico definitivo de neurocisticersose. Método: Sessenta e três pacientes com diagnóstico de NC foram submetidos a exame de RM e exame de LCR com pesquisa de antígeno de Taenia por método imunoenzimático. resultados: A detecção de TA foi positiva em 36 pacientes (57,1%). Um total de 836 lesões foram analizadas sendo 98,7% intraparemquimatosas, 50,4% dos cistos encontravam-se íntegros, 22,1% degenerados e 19,5% calcificados. Foi observada relação significativa entre a presença dos níveis de TA detectados com o número total dos cistos e também com o número de cistos íntegros. Não foi observada relação com cistos calcificados. conclusão: (1) a detecção de TA permite o diagnóstico etiológico em formas transicionais na NC com imagem pouco característica; (2) em estágio evolutivo final de um cisticerco no sistema nervoso, este pode não aparecer na tomografia computadorizada ou RM sendo a presença do antígeno importante para confirmação diagnóstica; (3) a detecção do TA permite também o diagnóstico de NC nos casos em que as reações inumológicas são negativas; (4) a detecção do TA representa um marcador de atividade da doença nas forma...

Added Value of Antigen ELISA in the Diagnosis of Neurocysticercosis in Resource Poor Settings

“…Analyzing CSF could be a helpful tool to localize cysts within the central nervous system. A recent study indicates a significant relationship between antigen levels in CSF and total number of lesions as well as number of non-degenerating cysts as identified by MRI [27]. In our study, all patients with viable cysts on CT scan had a positive CSF Ag-ELISA and all patients with only calcified lesions had a negative result.…”

Cerebrospinal fluid analysis in infectious diseases of the nervous system: when to ask, what to ask, what to expect

“…• The results that can be expected from CSF analysis in NC cases are as shown in Tables 1 and 2 10 : • Taenia antigen searches have been found to be positive in 57.1% of parenchymal NC cases 11,12 .…”

New diagnostic criteria for neurocysticercosis: Reliability and validity

“…[16][17][18]30 Further studies with these new MRI sequences, however, as well as a wider use of CSF analysis, are needed. 31,32 Forty-one people had extraparenchymal parasites, of whom only 18 (43.9%) would have been diagnosed with definitive NCC using the 2001 criteria. 8 In contrast, the new diagnostic criteria allowed an accurate diagnosis of definitive extraparenchymal NCC in the majority of them.…”