Psychogenic seizures and frontal disconnection: EEG synchronisation study

Area of Science:

• Neuroscience
• Clinical Neurology
• Psychiatry

Background:

• Psychogenic non-epileptic seizures (PNES) are events with psychological origins, distinct from epileptic seizures, lacking epileptiform EEG changes.
• Current models suggest PNES result from multifactorial influences, including psychiatric features and brain vulnerability.
• The interaction between psychiatric aspects and brain susceptibility is crucial but not fully understood in PNES.

Purpose of the Study:

• To investigate functional cerebral network abnormalities in PNES patients.
• To characterize functional connectivity in individuals with PNES.
• To explore the relationship between brain network function and PNES clinical presentation.

Main Methods:

• Analysis of whole-head surface topography of multivariate phase synchronisation (MPS) in high-density EEG.
• Comparison of MPS maps between 13 PNES patients and 13 matched controls during interictal periods.
• MPS mapping used to visualize functional connectivity changes associated with cortical abnormalities.

Main Results:

• Between-group comparisons revealed limited, non-uniform MPS changes.
• Significant inverse correlations were observed between PNES frequency and MPS in prefrontal and parietal cortices.
• These findings suggest individual differences in functional connectivity relate to PNES severity.

Conclusions:

• PNES is associated with diminished synchronisation in prefrontal and parietal brain networks.
• This decreased synchronisation may indicate network dysfunction in these specific cortical regions.
• Functional connectivity alterations could be a key factor in the pathophysiology of PNES.