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Network evolution in mesial temporal lobe epilepsy revealed by diffusion tensor imaging
Author(s) -
Wang Helen,
Huang Yuegao,
Coman Daniel,
Munbodh Reshma,
Dhaher Roni,
Zaveri Hitten P.,
Hyder Fahmeed,
Eid Tore
Publication year - 2017
Publication title -
epilepsia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.687
H-Index - 191
eISSN - 1528-1167
pISSN - 0013-9580
DOI - 10.1111/epi.13731
Subject(s) - epileptogenesis , hippocampal formation , neuroscience , hippocampus , diffusion mri , corpus callosum , entorhinal cortex , epilepsy , neocortex , white matter , external capsule , temporal lobe , psychology , fractional anisotropy , medicine , magnetic resonance imaging , radiology
Summary Objective The objective of the present study is to identify novel, time‐indexed imaging biomarkers of epileptogenesis in mesial temporal lobe epilepsy ( MTLE ). Methods We used high‐resolution brain diffusion tensor imaging ( DTI ) of the translationally relevant methionine sulfoximine ( MSO ) brain infusion model of MTLE . MSO inhibits astroglial glutamine synthetase, which is deficient in the epileptogenic hippocampal formation of patients with MTLE . MSO ‐infused (epileptogenic) rats were compared with phosphate‐buffered saline ( PBS )–infused (nonepileptogenic) rats at early (3–4 days) and late (6–9 weeks) time points during epileptogenesis. Results The epileptogenic rats exhibited significant changes in DTI ‐measured fractional anisotropy ( FA ) in numerous brain regions versus nonepileptogenic rats. Changes included decreases and increases in FA in regions such as the entorhinal‐hippocampal area, amygdala, corpus callosum, thalamus, striatum, accumbens, and neocortex. The FA changes evolved over time as animals transitioned from early to late epileptogenesis. For example, some areas with significant decreases in FA early in epileptogenesis changed to significant increases late in epileptogenesis. Finally, the FA changes significantly correlated with the seizure load. Significance Our results suggest (1) that high‐resolution DTI can be used for early identification and tracking of the epileptogenic process in MTLE , and (2) that the process identified by DTI is present in multiple brain areas, even though infusion of MSO is restricted to the unilateral entorhinal‐hippocampal region.