Seizure-induced neuronal injury: human data

Area of Science:

• Neuroscience
• Radiology
• Epileptology

Background:

• Clinical observations suggest recurrent epileptic seizures can cause neuronal injury.
• Previous cross-sectional studies offer conflicting results, hindering causal conclusions.
• In vivo biochemical evidence supports the link between seizures and neuron damage.

Purpose of the Study:

• To explore the potential of longitudinal neuroimaging to objectively identify structural brain changes indicating neuronal injury from seizures.
• To discuss the complexities and requirements for designing effective longitudinal neuroimaging studies in epilepsy.

Main Methods:

• Longitudinal neuroimaging studies with age-matched controls are proposed.
• Quantitative analysis of MRI T(1)-weighted volumetric datasets for detecting subtle volume changes (1-3%).
• Consideration of functional imaging (MR spectroscopy, PET, SPECT) and diffusion tensor imaging for detecting abnormalities and secondary damage.

Main Results:

• Longitudinal studies can objectively identify structural brain changes, serving as markers of neuronal injury.
• Quantitative MRI can detect small but potentially significant volume changes in individual subjects.
• Functional imaging may be more sensitive but has lower test-retest reliability.

Conclusions:

• Longitudinal neuroimaging studies are crucial for establishing causation between seizures and neuronal injury.
• Detecting treatment effects for neuroprotective agents requires large, long-term (≥3 years) studies with neuroimaging endpoints.
• Heterogeneity in epilepsy and patient factors complicate uniform conclusions.