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Published on: August 16, 2024
Improvement of brain function after surgery in infants with posterior quadrant cortical dysplasia
Riyo Ueda1, Masaki Iwasaki2, Yosuke Kita3
1Department of Child Neurology, National Center Hospital, National Center of Neurology and Psychiatry, 4-1-1 Ogawahigashi-cho, Kodaira, Tokyo 187-8551, Japan; Department of Developmental Disorders, National Institute of Mental Health, National Center of Neurology and Psychiatry, 4-1-1 Ogawahigashi-cho, Kodaira, Tokyo 187-8553, Japan.
Insights
Electroencephalography (EEG) functional connectivity analysis using the phase lag index (PLI) can quantify neurodevelopmental improvements in infants after epilepsy surgery. Postoperative connectivity normalized and correlated with better developmental outcomes.
Area of Science:
- Neuroscience
- Pediatric Neurology
- Medical Imaging
Background:
- Epilepsy surgery in infants can impact neurodevelopmental outcomes.
- Quantitative assessment of these outcomes is crucial for evaluating treatment efficacy.
Purpose of the Study:
- To determine if electroencephalography (EEG) functional connectivity analysis can quantitatively assess neurodevelopmental outcomes in infants following epilepsy surgery.
- To investigate the relationship between brain connectivity and developmental quotient (DQ) after posterior quadrantectomy.
Main Methods:
- 13 infants (<2 years) with posterior quadrant dysplasia underwent posterior quadrantectomy.
- EEG and developmental quotient (DQ) assessments were performed pre- and post-surgery.
- Phase lag index (PLI) was calculated to measure functional connectivity in different electrode pairs.
Main Results:
- 77% of infants achieved seizure freedom post-surgery.
- Preoperative hyper-connectivity (beta and gamma bands) in posterior short distance (PSD) pairs normalized postoperatively.
- A significant association was found between postoperative DQ and postoperative beta-band PLI in anterior short distance (ASD) pairs.
Conclusions:
- Postoperative normalization of abnormal hyper-connectivity to control levels was observed.
- Increased postoperative hyper-connectivity correlated with long-term neurodevelopmental improvements.
- Phase lag index (PLI) effectively quantifies neurodevelopmental improvements after posterior quadrantectomy.
Objective:
To reveal whether neurodevelopmental outcome of infants after epilepsy surgery can be quantitatively assessed by electroencephalography (EEG) functional connectivity analysis.
Methods:
We enrolled 13 infants with posterior quadrant dysplasia aged <2 years who were treated using posterior quadrantectomy and 21 age-matched infants. EEG was performed both before and one year after surgery. Developmental quotient (DQ) was assessed both before and 3 years after surgery. The phase lag index (PLI) of three different pairs of electrodes in the nonsurgical hemisphere, i.e., the anterior short distance (ASD), posterior short distance (PSD), and long distance (LD) pairs, were calculated as indices of brain connectivity. The relationship between the PLI and DQ was evaluated.
Results:
Overall, 77% infants experienced seizure freedom after surgery. The beta- and gamma- range PLI of PSD pairs increased preoperatively. All these pairs normalized postoperatively. Simple linear regression analysis revealed a significant relationship between the postoperative DQ and the postoperative beta-band PLI of ASD pairs.
Conclusion:
Preoperative abnormal hyper-connectivity was normalized to the control level after surgery. The postoperative hyperconnectivity was associated with long-term neurodevelopmental improvement.
Significance:
PLI quantifies neurodevelopmental improvements after posterior quadrantectomy.
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