Quantification of stroke lesion volume using epidural EEG in a cerebral ischaemic rat model

We uploaded the EEG dataset of the auditory cortical stroke rat model in response to specific sound stimuli. We are planning to submit a manuscript, titled "Quantification of stroke lesion volume using epidural EEG in a cerebral ischaemic rat model " in the future. The dataset will be finalized after the paper is accepted All the dataset was analyzed offline using MATLAB software. EEG signals without the auditory stimuli were also analysed. First, the recorded EEG data were band-pass filtered between 0.05 and 60 Hz. We used the zero-phase forward and reverse Infinite Impulse Response Butterworth filter of 4th order⁷³. Further, we averaged the last 300 ms of the signal before stimulus onset as a baseline correction. Next, we down-sampled the data from 1,200 to 600 Hz. Subsequently, we conducted the PSD analysis using signals obtained from the target stimulus or silent period onset to 1 s using Welch’s method, which is one of the most widely used periodogram methods for determining the power density of EEG frequency components⁷⁴. The parameter was set to divide the EEG signals into eight sections of equal length, each with a 50% overlap based on the Hamming window. We defined the frequency range for each band as follows: Delta (1-4 Hz), theta (4-8 Hz), alpha (8-12 Hz), and beta (12-30 Hz). We calculated the relative power for each frequency band by summing all of the absolute PSD values across the four bands to compute the total power followed by dividing the absolute value for each frequency band with the total power. Finally, we calculated the DAR (delta/alpha ratio) and the DTABR ((delta + theta) / (alpha + beta) ratio), which were computed by the relative power of the relevant frequency bands. Further, we analysed AEPs in response to the target sound stimuli by averaging all of the epochs between 300 ms before the stimuli onset to 500 ms after it. The AEP amplitude was defined as the highest recorded voltage following the sound stimulus. The latency of the components of the AEPs was defined as the duration from stimulus onset to the peak amplitude.