P300 in mesial temporal lobe epilepsy and its correlation with cognition - A MEG based prospective case-control study

Area of Science:

• Neuroscience
• Epilepsy Research
• Cognitive Assessment

Background:

• Temporal Lobe Epilepsy (TLE) with hippocampal sclerosis (HS) often involves cognitive deficits.
• Objective biomarkers for cognitive impairment in TLE are needed.

Purpose of the Study:

• To evaluate the role of P300, a cognitive event-related potential, in TLE patients with unilateral HS.
• To correlate P300 measures with neuropsychological test performance.

Main Methods:

• Thirty TLE-HS patients and 15 healthy controls underwent magnetoencephalography (MEG) with auditory and visual oddball tasks.
• Independent Component Analysis (ICA) and Classical LORETA Analysis Recursively Applied (CLARA) were used for P300 detection and source localization.
• Cognitive function was assessed using the Indian Council of Medical Research (ICMR) cognitive test battery.

Main Results:

• Visual P300 amplitude was significantly lower in the TLE group compared to controls.
• The right HS subgroup showed lower visual P300 amplitudes than the left HS and control groups.
• No significant differences in auditory P300 were observed.
• A negative correlation was found between visual P300 amplitude and the duration of the Indian Trial Making Test-B.

Conclusions:

• Patients with TLE-HS exhibit decreased visual P300 amplitude.
• Visual P300 amplitude is significantly correlated with visuospatial attention and working memory.
• MEG-based visual P300 holds potential as a complementary objective test for cognitive assessment in TLE.