Abstracts

Rationale: Juvenile myoclonic epilepsy (JME) patients exhibit characteristic limb myoclonus, with some patients showing photosensitivity and varying degrees of higher cognitive function impairment. This study uses transcranial magnetic stimulation-electroencephalogram (TMS-EEG) technology to identify brain regions with abnormal excitability and map the causal "dynamic" brain network information flow characteristics of JME, providing a multidimensional explanation of the neural network mechanisms of JME.

Methods: In this prospective observational study, JME patients were recruited from December 2020 to December 2022 as the experimental group, and healthy individuals (HC) matched for age, gender, and education level were recruited as the control group. All participants received TMS at the F3 region, and EEG responses and transcranial magnetic stimulation evoked potentions (TEPs) were recorded. Time-frequency characteristics of EEG signals were obtained using wavelet transform, and adaptive directed transfer function (ADTF) was used to identify the propagation patterns of EEG signals in brain regions. Comparison of means between the two groups was performed using the t-test, and comparison of proportions was performed using the chi-square (χ²) test.

Results: The study included 22 JME patients (mean age 23.93±7.46 years, 10 males) and 22 healthy controls (mean age 23.94±7.22 years, 10 males). The mean age of onset for JME patients was 12.64 years, with a mean disease duration of 11.30 years. TEP analysis revealed that peak-to-peak values in frontal, central, and parietal regions were lower in the JME group than in the HC group (p-values 0.004, 0, 0.005, 0.014, 0.026, 0.002, 0.009, 0.045). Point-by-point analysis showed that early amplitudes in the JME group were lower than those in the HC group, while mid-to-late amplitudes were higher than those in the HC group. Time-frequency analysis revealed that the energy in the alpha, beta, and theta bands was lower in the JME group compared to the HC group (p< 0.05). ADTF analysis showed that when time-varying brain network connections were enhanced, the inflow from the F3 and parieto-occipital regions to the frontal area was reduced in the JME group compared to the HC group, while the inflow from the frontal area to the parieto-occipital regions was increased. When time-varying brain network connections were weakened, the influx from posterior temporal and parieto-occipital regions to the frontal area decreased in the JME group compared to the HC group after TMS stimulation during the early, middle, and late phases. After stimulation, the inflow of information flow to the occipital region increased in patients compared to the healthy group.