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Hippocampal seizure-onset laterality can change over long timescales: A same-patient observation over 500 days.

Smart O, Rolston JD, Epstein CM, Gross RE - Epilepsy Behav Case Rep (2013)

Bottom Line: This study describes seizure laterality and localization changes over 500 consecutive days in a patient with bilateral temporal lobe epilepsy (BTLE) and implanted NeuroPace RNS™ System.During a continuous two-year time period, the RNS™ device stored 54 hippocampal electrocorticography (ECoG) seizures, which we analyzed to determine their distribution and time variance across hippocampi.This case suggests that hippocampal seizures dynamically progress over extensive timescales.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurosurgery, Emory University School of Medicine, Woodruff Memorial Research Building, 101 Woodruff Circle, Room 6329, Atlanta, GA 30322, USA.

ABSTRACT
This study describes seizure laterality and localization changes over 500 consecutive days in a patient with bilateral temporal lobe epilepsy (BTLE) and implanted NeuroPace RNS™ System. During a continuous two-year time period, the RNS™ device stored 54 hippocampal electrocorticography (ECoG) seizures, which we analyzed to determine their distribution and time variance across hippocampi. We report nonrandom long-term seizure laterality and localization variations, especially in the first 200 days postimplant, despite equivalent total seizure counts in both hippocampi. This case suggests that hippocampal seizures dynamically progress over extensive timescales.

No MeSH data available.


Related in: MedlinePlus

Tracking (A, C), tallying (B, D), and clustering (E–F) the ECoG seizures. Tracking the SOZ laterality (A, B) and localization (C, D) shows shifts from the left (L1 and L2) to the right (R1 and R2) side over daily (A, C) and monthly (B, D) timescales for the seizures (black asterisk) unrelated to changes in RNS™ detection or stimulation parameters (solid vertical lines). Total seizure preponderance does not indicate lateralization (A) but may indicate localization (C). (E) Seizure clusters mostly occur within a week, where (F) time between consecutive seizures models a negative binomial distribution.
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f0015: Tracking (A, C), tallying (B, D), and clustering (E–F) the ECoG seizures. Tracking the SOZ laterality (A, B) and localization (C, D) shows shifts from the left (L1 and L2) to the right (R1 and R2) side over daily (A, C) and monthly (B, D) timescales for the seizures (black asterisk) unrelated to changes in RNS™ detection or stimulation parameters (solid vertical lines). Total seizure preponderance does not indicate lateralization (A) but may indicate localization (C). (E) Seizure clusters mostly occur within a week, where (F) time between consecutive seizures models a negative binomial distribution.

Mentions: We examined whether one side had greater seizure preponderance than the contralateral side. We found no statistically significant difference in total seizure counts on the left and right sides (p = 0.893, χ2 test) (Fig. 3A) but found a statistically significant difference in seizure counts (Fig. 3C) across the signals (p < 0.001, χ2 test), suggesting that the SOZ localized to a specific brain area despite ambiguous laterality. Further analysis showed more seizures in L1 than in L2 or R1 (p < 0.004, χ2 test) but not R2 (p = 0.058, χ2 test). Signal L2 exhibited the fewest seizures (versus R1: p < 0.035, others: p < 0.003, χ2 test). We found no statistically significant difference in seizure counts between R1 and R2 (p = 0.297, χ2 test).


Hippocampal seizure-onset laterality can change over long timescales: A same-patient observation over 500 days.

Smart O, Rolston JD, Epstein CM, Gross RE - Epilepsy Behav Case Rep (2013)

Tracking (A, C), tallying (B, D), and clustering (E–F) the ECoG seizures. Tracking the SOZ laterality (A, B) and localization (C, D) shows shifts from the left (L1 and L2) to the right (R1 and R2) side over daily (A, C) and monthly (B, D) timescales for the seizures (black asterisk) unrelated to changes in RNS™ detection or stimulation parameters (solid vertical lines). Total seizure preponderance does not indicate lateralization (A) but may indicate localization (C). (E) Seizure clusters mostly occur within a week, where (F) time between consecutive seizures models a negative binomial distribution.
© Copyright Policy - CC BY-NC-SA
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4150592&req=5

f0015: Tracking (A, C), tallying (B, D), and clustering (E–F) the ECoG seizures. Tracking the SOZ laterality (A, B) and localization (C, D) shows shifts from the left (L1 and L2) to the right (R1 and R2) side over daily (A, C) and monthly (B, D) timescales for the seizures (black asterisk) unrelated to changes in RNS™ detection or stimulation parameters (solid vertical lines). Total seizure preponderance does not indicate lateralization (A) but may indicate localization (C). (E) Seizure clusters mostly occur within a week, where (F) time between consecutive seizures models a negative binomial distribution.
Mentions: We examined whether one side had greater seizure preponderance than the contralateral side. We found no statistically significant difference in total seizure counts on the left and right sides (p = 0.893, χ2 test) (Fig. 3A) but found a statistically significant difference in seizure counts (Fig. 3C) across the signals (p < 0.001, χ2 test), suggesting that the SOZ localized to a specific brain area despite ambiguous laterality. Further analysis showed more seizures in L1 than in L2 or R1 (p < 0.004, χ2 test) but not R2 (p = 0.058, χ2 test). Signal L2 exhibited the fewest seizures (versus R1: p < 0.035, others: p < 0.003, χ2 test). We found no statistically significant difference in seizure counts between R1 and R2 (p = 0.297, χ2 test).

Bottom Line: This study describes seizure laterality and localization changes over 500 consecutive days in a patient with bilateral temporal lobe epilepsy (BTLE) and implanted NeuroPace RNS™ System.During a continuous two-year time period, the RNS™ device stored 54 hippocampal electrocorticography (ECoG) seizures, which we analyzed to determine their distribution and time variance across hippocampi.This case suggests that hippocampal seizures dynamically progress over extensive timescales.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurosurgery, Emory University School of Medicine, Woodruff Memorial Research Building, 101 Woodruff Circle, Room 6329, Atlanta, GA 30322, USA.

ABSTRACT
This study describes seizure laterality and localization changes over 500 consecutive days in a patient with bilateral temporal lobe epilepsy (BTLE) and implanted NeuroPace RNS™ System. During a continuous two-year time period, the RNS™ device stored 54 hippocampal electrocorticography (ECoG) seizures, which we analyzed to determine their distribution and time variance across hippocampi. We report nonrandom long-term seizure laterality and localization variations, especially in the first 200 days postimplant, despite equivalent total seizure counts in both hippocampi. This case suggests that hippocampal seizures dynamically progress over extensive timescales.

No MeSH data available.


Related in: MedlinePlus