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Parasympathetic alteration during sub-clinical seizures.
Ruth Brotherstone1, Ailsa McLellan
1Department of Clinical Neurophysiology, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, United Kingdom. ruth.brotherstone@luht.scot.nhs.uk
Seizure
|April 13, 2012
Summary
This study found that parasympathetic activity changes during sub-clinical seizures, potentially indicating autonomic instability. Generalised seizures showed increased parasympathetic activity, while temporal lobe seizures showed a decrease.
Area of Science:
- Neurology
- Cardiology
- Autonomic Nervous System Research
Background:
- Autonomic instability is a suspected factor in sudden unexpected death in epilepsy (SUDEP).
- Sub-clinical seizures may contribute to autonomic dysfunction.
- Measuring parasympathetic activity offers insight into autonomic control during seizures.
Purpose of the Study:
- To quantify parasympathetic activity during sub-clinical seizures.
- To investigate autonomic instability in epilepsy.
- To differentiate autonomic responses between generalised and focal (temporal lobe) sub-clinical seizures.
Main Methods:
- Prospective study utilizing Video-EEG, ECG, and SpO2 monitoring.
- Analysis of R-R intervals from ECG during sub-clinical seizures and matched non-ictal periods.
- Utilized NeuroScope and BioSignal HRV software to assess cardiac index of parasympathetic activity (CIPA) and heart rate variability (HRV).
Main Results:
- Parasympathetic activity was significantly altered during sub-clinical seizures (p<0.001 for CIPA, p=0.026 for 5-min HRV HF %).
- Generalised sub-clinical seizures were associated with increased cardiac parasympathetic activity.
- Temporal lobe sub-clinical seizures were linked to decreased parasympathetic activity.
Conclusions:
- Sub-clinical epileptic seizures are associated with measurable changes in parasympathetic activity.
- Generalised sub-clinical seizures may indicate a higher degree of autonomic instability compared to temporal lobe seizures.
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