Evidence map›Paper›PMID 33564915›Full record

SynthesisJournal of neurology2022

Functional connectivity of hippocampus in temporal lobe epilepsy depends on hippocampal dominance: a systematic review of the literature.

Camille K Milton, Christen M O'Neal, Andrew K Conner

Abstract readSystematic Review
PubMed Publisher
In one paragraph

Synthesis in Journal of neurology, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 7 papers, 1 of them a synthesis that pooled it.

0numbers the graph read from it
0cells of the map it votes in
7citing papers in PubMed, 1 pooled it
–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

7 citing papers in PubMed, 1 synthesis or guideline pooled it.

  1. Pooled it
  2. Article
  3. Article
  4. Article
  5. Review
  6. Article
  7. Article
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

3 authors.

Camille K MiltonDepartment of Neurosurgery, University of Oklahoma Health Sciences Center, 1000 N Lincoln Boulevard, Suite 4000, Oklahoma City, Oklahoma, 73104, USA.ORCID http://orcid.org/0000-0001-7883-5612
Christen M O'NealDepartment of Neurosurgery, University of Oklahoma Health Sciences Center, 1000 N Lincoln Boulevard, Suite 4000, Oklahoma City, Oklahoma, 73104, USA.ORCID http://orcid.org/0000-0001-8412-4040
Andrew K ConnerDepartment of Neurosurgery, University of Oklahoma Health Sciences Center, 1000 N Lincoln Boulevard, Suite 4000, Oklahoma City, Oklahoma, 73104, USA. Andrew-Conner@ouhsc.edu.ORCID http://orcid.org/0000-0002-7878-4461

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundLateralized alterations in hippocampal function in the resting-state have been demonstrated for patients with temporal lobe epilepsy (TLE). However, resting-state fMRI of the hippocampus has yet to be substantiated as an adjunct to standard pre-operative assessments of the seizure focus.

objectiveHere we report the results of a systematic review of resting-state fMRI studies investigating laterality of hippocampal network connectivity in TLE patients.

methodsA search of the PubMed, SCOPUS, Web of Science, and Embase databases for full-length articles written in English was conducted through June 2020 using the following terms: 'resting state fMRI,' 'hippocampus,' 'epilepsy,' and 'laterality.'

resultsOur literature search yielded a total of 42 papers. After excluding studies that did not include patients with epilepsy, utilize resting-state fMRI, or explore the relationship between functional connectivity and disease lateralization, 20 publications were selected for inclusion. From these studies, a total of 528 patients, 258 with left TLE and 270 with right TLE, and 447 healthy controls were included. Of the 20 studies included, 18 found that patients with TLE demonstrated decreased hippocampal functional connectivity ipsilateral to the epileptogenic focus and 10 additionally reported increased hippocampal functional connectivity contralateral to the epileptogenic focus. Several studies demonstrated that the duration of disease was correlated with these changes in functional connectivity. This implies that a compensatory mechanism may be present in patients with treatment-refractory TLE.

conclusionThe consistency of this hippocampal connectivity pattern across multiple studies suggests resting-state fMRI may be useful as a non-invasive diagnostic tool for preoperative evaluation of TLE patients.

Indexed as

Epilepsy, Temporal LobeFunctional LateralityHippocampusHumansMagnetic Resonance ImagingTemporal LobeFunctional connectivityHippocampusRs-fMRITemporal lobe epilepsyWada testing

Identifiers

PMID33564915

What OpenQuestion holds

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Registered trials

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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.