Related Experiment Video
Updated: Apr 27, 2026
Network Analysis of Foramen Ovale Electrode Recordings in Drug-resistant Temporal Lobe Epilepsy Patients
Published on: December 18, 2016
Mirror focus in a patient with intractable occipital lobe epilepsy
Jiyoung Kim1, Hae Kyung Shin1, Kyoung Jin Hwang2
1Department of Neurology, Pusan National University Hospital, Pusan National University School of Medicine, Busan;
Abstract:
Mirror focus is one of the evidence of progression in epilepsy, and also has practical points for curative resective epilepsy surgery. The mirror foci are related to the kindling phenomena that occur through interhemispheric callosal or commissural connections. A mirror focus means the secondary epileptogenic foci develop in the contralateral hemispheric homotopic area. Thus mirror foci are mostly reported in patients with temporal or frontal lobe epilepsy, but not in occipital lobe epilepsy. We have observed occipital lobe epilepsy with mirror focus. Before epilepsy surgery, the subject's seizure onset zone was observed in the left occipital area by ictal studies. Her seizures abated for 10 months after the resection of left occipital epileptogenic focus, but recurred then. The recurred seizures were originated from the right occipital area which was in the homotopic contralateral area. This case can be an evidence that occipital lobe epilepsy may have mirror foci, even though each occipital lobe has any direct interhemispheric callosal connections between them.
Insights
Mirror foci, secondary epileptogenic zones, can occur in occipital lobe epilepsy. This challenges previous understanding and offers new insights for epilepsy surgery.
Area of Science:
- Neuroscience
- Epileptology
Background:
- Mirror foci, secondary epileptogenic zones in the contralateral hemisphere, are linked to kindling via interhemispheric connections.
- They are typically observed in temporal or frontal lobe epilepsy, not commonly in occipital lobe epilepsy.
Observation:
- A case of occipital lobe epilepsy with a mirror focus was observed.
- Initial seizure onset was in the left occipital lobe; post-resection, seizures recurred originating from the right occipital lobe.
Findings:
- This case provides evidence that occipital lobe epilepsy can exhibit mirror foci.
- It suggests mirror foci may develop even without direct interhemispheric connections between occipital lobes.
Implications:
- Findings expand the understanding of mirror foci in epilepsy progression.
- This has potential implications for surgical planning in occipital lobe epilepsy treatment.
