Evidence map›Paper›PMID 42577060›Full record

ReviewJMA journal2026

Pathological and Physiological Significance of Hippocampal Ripples in Epilepsy.

Takamitsu Iwata

Abstract readReview
In one paragraph

Review in JMA journal, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

1 author.

Takamitsu IwataDepartment of Neurosurgery, Graduate School of Medicine, The University of Osaka, Suita, Osaka, Japan.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Ripple activity is defined as a high-frequency synchronous neural activity that has emerged as an important biomarker of epilepsy, both in research and clinical practice. In intracranial electroencephalography, ripple-band activity is closely linked to epileptogenicity and has been investigated as a marker to guide localization of epileptogenic tissue and predict surgical outcomes. Simultaneously, in the hippocampus, ripple activity additionally includes physiological sharp-wave ripples (SWRs), which play essential roles in memory consolidation, retrieval, and the selection of experiences for long-term storage. This overlap gives hippocampal ripple activity dual clinical significance: it may indicate pathological synchrony related to epilepsy, and it can also indicate the physiological processes that support memory and other higher cognitive functions. This review summarizes the current knowledge regarding the dual significance of hippocampal ripple activity in epilepsy. First, the pathological relevance of high-frequency oscillations as biomarkers of epileptogenicity and the physiological role of SWRs in hippocampal-cortical information processing are outlined. Subsequently, the methodological challenges involved in distinguishing pathological ripples from physiological SWRs in human intracranial recordings are discussed. Recent advances in consensus-based criteria, spatiotemporal analyses, and machine learning-based detection methods are further reviewed. Mechanistic frameworks further indicate that ripples reflect a shared synchrony-generating substrate, whose meaning depends on the network state, behavioral context, and spatial relation to the epileptogenic focus. Finally, ripple activity could be interpreted not only as a local hippocampal event but also as a marker of hippocampo-neocortical network state, with potential implications for epileptogenicity assessment, surgical planning, and function-preserving treatment strategies. Understanding the dual role of the hippocampal ripple activity may provide a basis for more precise epilepsy therapies that balance seizure control and memory preservation.

Indexed as

epilepsyhigh-frequency oscillationshippocampusintracranial electroencephalography (EEG)memorysharp-wave ripple

Identifiers

PMID42577060
PMCPMC13453656

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.