Seizures in patients with temporal lobe epilepsy can be anticipated more than 30 minutes before they start, a new study finds.
Authors of the publication in the NEJM Evidence say that these findings could lead to the development of electrical or drug therapies for seizure prevention.
Previous studies on continuous electroencephalography (EEG) — the measurement and recording of electrical activity in different brain parts — have suggested that seizures in people with focal-onset epilepsies tend to occur during periods of heightened risk. Called "pro-ictal states," these periods are represented by pathologic brain activities.
To distinguish these pro-ictal states, the researchers examined a consecutive series of 15 temporal lobe epilepsy patients who underwent routine skull EEG and recordings of limbic thalamic–brain structures on both sides of the thalamus. In total, 1,800 patient hours of continuous EEG were analyzed.
The researchers detected pro-ictal states at least 35 minutes before the start of seizures. In most patients (13 out of 15), pro-ictal states were distinguished at least 45 minutes before seizure onset, while in two patients, they were detected up to 35 minutes prior.
"These findings are significant because they suggest that we may be able to develop more effective therapies for epilepsy, which could greatly improve the quality of life for patients who suffer from this condition," says study lead-author Sandipan Pati, M.D., associate professor in the Department of Neurology with McGovern Medical School at UTHealth Houston.
Temporal lobe epilepsy is the most common seizure disorder affecting about 50 million people globally and is usually diagnosed within the first 20 years of life. About 60% of all epilepsy forms are focal in origin, with the majority originating in the temporal lobe, a part of the brain that helps to process sensory input, such as pain and auditory stimuli.
This seizure disorder s drug-resistant and is often treated with microsurgery, laser ablation, and neuromodulation. However, less than half of patients achieve seizure freedom following surgical interventions.
The study authors say that modulation of the brain regions during pro-ictal states may be effectively used to treat temporal lobe epilepsy; however, further research is needed.
- NEJM Evidence. Pro-Ictal State in Human Temporal Lobe Epilepsy.
- UTHealth Houston. Study: Seizures can be predicted more than 30 minutes before onset in patients with temporal lobe epilepsy.
- CDC. Types of Seizures.
- National Library of Medicine. Temporal Seizure.