Evidence map›Paper›PMID 41915254›Full record

SynthesisNeurosurgical review2026

Deep brain stimulation of the fornix for Alzheimer's disease: A systematic review and meta-analysis of cognitive outcomes.

Farzan Fahim, MohammadAmin Farajzadeh, Behnaz Rahatijafarabad, Abdul Majeed Mohammadi, Ali Khorram, Mehrsa Mostafaei, Omidreza Nikbakht, Raziyeh Zamiri, Nikoo Sepehrian, Sayeh Oveisi and 1 more

Abstract readSystematic ReviewMeta-Analysis
PubMed Publisher
In one paragraph

Synthesis in Neurosurgical review, 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

11 authors.

Farzan Fahim *Shohada-E-Tajrish Hhospital , Shahid Beheshti University of Medical Science, Tehran, Iran. Farzn.fahim@gmail.com.ORCID http://orcid.org/0000-0003-0591-674X
MohammadAmin Farajzadeh *Functional Neurosurgery Research Center, Research Institute of Functional Neurosurgery, Shohada Tajrish Comprehensive Neurosurgical Center of Excellence, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Behnaz RahatijafarabadFunctional Neurosurgery Research Center, Research Institute of Functional Neurosurgery, Shohada Tajrish Comprehensive Neurosurgical Center of Excellence, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Abdul Majeed MohammadiFunctional Neurosurgery Research Center, Research Institute of Functional Neurosurgery, Shohada Tajrish Comprehensive Neurosurgical Center of Excellence, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Ali KhorramFunctional Neurosurgery Research Center, Research Institute of Functional Neurosurgery, Shohada Tajrish Comprehensive Neurosurgical Center of Excellence, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Mehrsa MostafaeiFunctional Neurosurgery Research Center, Research Institute of Functional Neurosurgery, Shohada Tajrish Comprehensive Neurosurgical Center of Excellence, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Omidreza NikbakhtFunctional Neurosurgery Research Center, Research Institute of Functional Neurosurgery, Shohada Tajrish Comprehensive Neurosurgical Center of Excellence, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Raziyeh ZamiriFunctional Neurosurgery Research Center, Research Institute of Functional Neurosurgery, Shohada Tajrish Comprehensive Neurosurgical Center of Excellence, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Nikoo SepehrianFunctional Neurosurgery Research Center, Research Institute of Functional Neurosurgery, Shohada Tajrish Comprehensive Neurosurgical Center of Excellence, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Sayeh OveisiFunctional Neurosurgery Research Center, Research Institute of Functional Neurosurgery, Shohada Tajrish Comprehensive Neurosurgical Center of Excellence, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Alireza ZaliFunctional Neurosurgery Research Center, Research Institute of Functional Neurosurgery, Shohada Tajrish Comprehensive Neurosurgical Center of Excellence, Shahid Beheshti University of Medical Sciences, Tehran, Iran.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Deep brain stimulation of the fornix (fornix-DBS) has been proposed as a potential neuromodulatory strategy for Alzheimer’s disease (AD), based on its role within the Papez memory circuit and reported effects on hippocampal metabolism and network connectivity. However, clinical studies vary substantially in design, disease stage, stimulation parameters, and outcome assessment, and the consistency of cognitive benefit remains uncertain. To systematically evaluate the clinical cognitive effects of fornix-targeted DBS in Alzheimer’s disease and to quantitatively synthesize available evidence from controlled and observational studies. This systematic review was conducted in accordance with PRISMA-2020 guidelines and registered in PROSPERO (CRD420251175724). PubMed, Embase, Scopus, Web of Science, and the Cochrane Database of Systematic Reviews were searched for randomized controlled trials and observational studies investigating fornix-targeted DBS in patients with Alzheimer’s disease. Meta-analyses were performed for ADAS-Cog and MMSE outcomes using random-effects models. Subgroup analyses by study design (RCT vs. observational) and sensitivity analyses were conducted to assess robustness. Structural and metabolic issues were narratively synthesis. Ten studies encompassing mild, moderate, and severe AD populations met inclusion criteria. Individual studies reported heterogeneous and predominantly short-term cognitive responses, with transient improvements mainly observed in small severe-AD cohorts. In contrast, randomized trials in mild AD consistently demonstrated no clinically meaningful benefit.

Indexed as

Alzheimer DiseaseCognitionDeep Brain StimulationFornix, BrainHumansTreatment OutcomeADAS-CogAlzheimer’s diseaseCognitive declineDeep brain stimulationFDG-PETFornixHippocampal volumeMeta-analysisMMSENeuromodulation

Identifiers

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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.