Volume changes of medial temporal lobe structures in patients with genetic generalized and temporal lobe epilepsy in relation to neuropsychological functions

Purpose
In patients with epilepsy (PWE), cognitive and behavioural dysfunctions are associated with abnormalities in various brain areas. The aim of the study was to compare the volume of the hippocampus (VHIP), amygdala (VAMG) and parahippocampal gyrus (VPHG) with the results of neuropsychological assessment in patients with temporal lobe epilepsy (TLE) and genetic gene­ralized epilepsy (GGE).

Methods
33 PWE were enrolled in the study (mean age 37.3), 10 with TLE and 23 GGE (12 with GGE with tonic-clonic seizure [GGE-GTCS], and 11 with juvenile myoclonic epilepsy). 19 healthy persons (mean age 32.2) were enrolled as the control group (CG). Measurements of VHIP, VAMG and VPHG were made with 3D completely balanced steady state (CBASS) and 3D T1-weighted sequence. All participants underwent a neuropsychological assessment using a multi-domain cognitive battery and emotional state questionnaires.

Results
The left hippocampus was significantly smaller in patients with left TLE (LTLE) and with GGE-GTCS, compared to the CG (p = 0.0069). In LTLE a significant enlargement of the right amygdala in comparison to the CG and other types of epilepsy were found (p = 0.0015). Among patients with LTLE and GGE-GTCS, impairment of attention and executive functions was statistically more common than in the CG. VHIP right (r = 0.25 p < 0.01) and VHIP left (r = 0.26 p < 0.04) were positively correlated with phonetic verbal fluency.

Conclusions
PWE showed changes in the volume of selected medial temporal lobe (MTL) structures. Selective impairment of attention and executive functions was found. Some neuropsychological findings correlate with volume changes in MTL structures. Antiseizure medications therapy could have an impact on the severity of neuropsychological dysfunctions.