Cognitive and surgical outcome in mesial temporal lobe epilepsy associated with hippocampal sclerosis plus neurocysticercosis: a cohort study

PLoS One. 2013 Apr 22;8(4):e60949. doi: 10.1371/journal.pone.0060949. Print 2013.

Abstract

Background: Where neurocysticercosis (NCC) is endemic, chronic calcified neurocysticercosis (cNCC) can be observed in patients with mesial temporal lobe epilepsy associated with hippocampal sclerosis (MTLE-HS). Considering that both disorders cause recurrent seizures or cognitive impairment, we evaluated if temporal lobectomy is cognitively safe and effective for seizure control in MTLE-HS plus cNCC.

Methods: Retrospective cohort study of neuropsychological profile and surgical outcome of 324 MTLE-HS patients submitted to temporal lobectomy, comparing the results according to the presence or absence of cNCC.

Findings: cNCC occurred in 126 (38.9%) of our MTLE-HS patients, a frequency higher than expected, more frequently in women than in men (O.R. = 1.66; 95% C.I. = 1.05-2.61; p = 0.03). Left-side (but not right side) surgery caused impairment in selected neuropsychological tests, but this impairment was not accentuated by the presence of cNCC. Ninety-four (74.6%) patients with MTLE-HS plus cNCC and 153 patients (77.3%) with MTLE-HS alone were Engel class I after surgery (O.R. = 1.16; 95% C.I. = 0.69-1.95; p = 0.58). However, the chances of Engel class IA were significantly lower in MTLE-HS plus cNCC than in patients with MTLE-HS alone (31.7% versus 48.5%; O.R. = 2.02; 95% C.I. = 1.27-3.23; p = 0.003). Patients with MTLE-HS plus cNCC showed higher rates of Engel class ID (15.1% versus 6.6%; O.R. = 2.50; 95% C.I. = 1.20-5.32; p = 0.012).

Interpretation: cNCC can be highly prevalent among MTLE-HS patients living in areas where neurocysticercosis is endemic, suggesting a cause-effect relationship between the two diseases. cNCC does not add further risk for cognitive decline after surgery in MTLE-HS patients. The rates of Engel class I outcome were very similar for the two groups; however, MTLE-HS plus cNCC patients achieved Engel IA status less frequently, and Engel ID status more frequently. Temporal lobectomy can be safely performed in most patients with MTLE-HS plus cNCC without affecting cognitive outcome. Long-term surgical seizure control in MTLE-HS plus cNCC is still satisfactory, as long as selected patients remain under medication.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Child
  • Cognition*
  • Cohort Studies
  • Decision Making
  • Epilepsy, Temporal Lobe / complications
  • Epilepsy, Temporal Lobe / pathology
  • Epilepsy, Temporal Lobe / physiopathology*
  • Epilepsy, Temporal Lobe / surgery*
  • Female
  • Hippocampus / pathology*
  • Humans
  • Male
  • Neurocysticercosis / complications*
  • Sclerosis / complications
  • Treatment Outcome

Grants and funding

This study was fully supported by Brazilian Government research grant agencies FAPESP/CINAPCE (http://www.fapesp.br), CNPq (http://www.cnpq.br) grants #306644/2010-0 and #483108/2010-3, and FAPERGS/CNPq/PRONEM (http://www.fapergs.rs.gov.br). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.