Neurocysticercosis and microscopic hippocampal dysplasia in a patient with refractory mesial temporal lobe epilepsy

Abstract

Médico, Doutorando do Depart a m e n t o de Neurologia e Neuro c i ru rgia da UNIFESP-EPM;7 D o u t o r, Professor do Departamento de Patologia da UNIFESP-EPM; 8 D o u t o r, P rofessor do Departamento de Neurologia e Neuro c i ru rgia da UNIFESP-EPM. This work was supported by FA P E S P, CNPq and CAPES from Brazil. Dr. Alexandre Valotta da Silva received a postdoctoral grant from FAPESP (2003/01195-8 ABSTRACT -Epidemiologic studies suggest that neuro c y s t i c e rcosis (NC) is the main cause of symptomatic epilepsy in developing countries. The association between NC and mesial temporal lobe epilepsy (MTLE) has been re p o rted by several authors. Recent data have shown that the presence of NC does not influence the clinical and pathological profile in MTLE patients and suggest that not all cysticercotic lesions are inevitably epileptogenic. We describe a 50-years-old woman with partial seizures due to NC which evolve to MTLE. The patient was submitted to a corticoamygdalohippocampectomy to treat re f r a c t o ry epilepsy. An immunohistochemical study using neuronal markers was made on hippocampal formation. Besides the typical aspects of Ammon's horn sclerosis (AHS), the microscopic examination demonstrates cellular feat u res of hippocampal malformation including dysmorphic neurons and focal bilamination of granular cell l a y e r. We suggest that, in this case, a developmental disorder lowered the threshold for the NC-induced seizures and contributed to the establishment of refractory epilepsy.KEY WORDS: refractory epilepsy, neurocysticercosis, dysmorphic neurons. N e u ro c i s t i c e rcose e displasia hipocampal microscópica em paciente com epilepsia do lobo temporal mesial refratária.RESUMO -Estudos epidemiológicos sugerem que a neurocisticercose (NC) é a causa principal de epilepsia sintomática em países em desenvolvimento. A associação entre NC e epilepsia do lobo temporal mesial ( E LTM) tem sido relatada por vários autores. Estudos recentes mostraram que a presença de NC não influên-cia o perfil clínico e patológico em pacientes com ELTM e sugere que nem todas as lesões cisticerc ó t i c a s são inevitavelmente epileptogênicas. No presente estudo, descrevemos uma mulher de 50 anos com crises epilépticas parciais associadas à NC que evolui para ELTM. A paciente foi submetida à cort i c o a m i g d a l ohipocampectomia para tratamento de epilepsia refratária. O estudo imunohistoquímico, utilizando marc a d o res neuronais, foi realizado em seções da formação de hipocampal. Além dos aspectos típicos da esclerose hipocampal, o exame microscópico demonstrou características celulares de malformação hipocampal, incluindo neurônios dismórficos e bilaminação focal da camada granular do giro denteado. Sugerimos que, neste caso, um transtorno do desenvolvimento reduziu o limiar para as crises epilépticas induzidas pela NC e contribuiu para o estabelecimento da epilepsia refratária.PALAVRAS-CHAVE: epilepsia refratária, neurocisticercose, neurônios dismórficos.It has been estimated that 50 million people are i...

On the relationship between neurocysticercosis and mesial temporal lobe epilepsy associated with hippocampal sclerosis: coincidence or a pathogenic relationship?

“…35 da Silva et al described anatomopathological aspects of a patient with partial seizures due to NCC that evolved to refractory MTLE-HS. 40 Resected tissue analysis demonstrated cellular features of hippocampal malformation, including dysmorphic neurons and focal bilamination of the granular cell layer. The authors suggested that a developmental disorder of the hippocampus could eventually have led to a low seizure threshold for NCC-induced seizures, causing or contributing to the establishment of hippocampal sclerosis and refractory epilepsy.…”

“…48 If the cysticercus is located inside the hippocampus, direct physical damage might also occur and the entireprocess might be more intense. 40 Moreover, based on animal models (Fig. 1).…”

Small calcified lesions suggestive of neurocysticercosis are associated with mesial temporal sclerosis

“…The authors speculated that inflammatory lesions or repetitive seizures might play a role in disease pathogenesis 6,7 . Isolated case reports and small case series have suggested a possible association between NC and mesial temporal sclerosis, in which typical mesial temporal sclerosis developed after cysticercosis-related acute symptomatic seizures 8,9,10 . Two case-control studies evaluated the prevalence of NC in refractory epilepsy patients 11,12 .…”

Isolated amygdala neurocysticercosis in a patient presenting with déjà vu and olfactory auras

“…Similar findings have been observed in patients with spontaneous seizures. 7 With or without afterdischarge, experiential phenomena are not as common in the temporal neocortex. The role of the neocortex is further elucidated by the fact that the early spread of an electrical discharge to the neocortex actually appears to prevent hallucinations or illusions, further emphasizing the role of the mesial temporal structures in experiential phenomena.…”