Alertness network in patients with temporal lobe epilepsy: a fMRI study

Patients with temporal lobe epilepsy (TLE) often suffer from cognitive deficits. However, it remains elusive whether the performance of TLE patients in the attentional networks test (ANT) is impaired. Functional magnetic resonance imaging (fMRI) can accurately reflect the hemodynamics and functional activities in certain regions of the brain. In the current study, we aimed to investigate the characteristics and neural mechanisms of the functions of the alertness network in patients with TLE using the ANT and fMRI. A total of 12 patients with TLE and 8 healthy controls underwent the ANT behavioral tests and subsequent block-design fMRI scanning. The results showed that the response times of the alertness network had no significant difference between the TLE group and the healthy control group. The fMRI data showed that the activation of the cerebellum, right occipital lobe, right frontal and brainstem was significantly weaker in TLE patients than in healthy control. Our data indicate that despite neuropsychological test performance is normal; the alerting network is deficient in the TLE patients. The decreased activation of brain regions of right occipital lobe, cerebellum, right frontal lobe, brain stem and temporal lobe may be the neural basis of altering network impairment in TEL patients.