Evidence map›Paper›PMID 40846657›Full record

ArticleEuropean journal of neurology2025

Diagnostic Value of the "Insular Knife-Cut" Sign in Patients With Suspected Herpes Simplex Virus Encephalitis.

Sofia Marini, Maria Luisa Usai, Silvia Falso, Davide Turilli, Sabrine Othmani, Rossella Meloni, Pietro Businaro, Giacomo Greco, Mariangela Puci, Martina Marini and 9 more

Abstract read
In one paragraph

Article in European journal of neurology, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing 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

1 citing paper in PubMed.

  1. 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

19 authors.

Sofia MariniDepartment of Neuroscience, Catholic University of the Sacred Heart, Rome, Italy.ORCID 0009-0002-4982-1662
Maria Luisa UsaiNeurology Unit, University Hospital of Sassari, Sassari, Italy.
Silvia FalsoDepartment of Neuroscience, Catholic University of the Sacred Heart, Rome, Italy.
Davide TurilliRadiology Unit, University Hospital of Sassari, Sassari, Italy.
Sabrine OthmaniNeurology Unit, University Hospital of Sassari, Sassari, Italy.
Rossella MeloniNeurology Unit, University Hospital of Sassari, Sassari, Italy.
Pietro BusinaroNeuroimmunology Laboratory and Neuroimmunology Research Section, IRCCS Mondino Foundation, Pavia, Italy.
Giacomo GrecoDepartment of Brain and Behavioural Sciences, University of Pavia, Pavia, Italy.ORCID 0000-0001-8097-0565
Mariangela PuciClinical Epidemiology and Medical Statistics Unit, University Hospital of Sassari, Sassari, Italy.
Martina MariniDepartment of Neuroscience, Catholic University of the Sacred Heart, Rome, Italy.
Anna PichiecchioNeuroradiology Department, IRCCS Mondino Foundation, Pavia, Italy.
Matteo PaolettiNeuroradiology Department, IRCCS Mondino Foundation, Pavia, Italy.
Pietro ZaraNeurology Unit, University Hospital of Sassari, Sassari, Italy.
Salvatore MasalaRadiology Unit, University Hospital of Sassari, Sassari, Italy.
Giovanni SotgiuClinical Epidemiology and Medical Statistics Unit, University Hospital of Sassari, Sassari, Italy.
Matteo GastaldiNeuroimmunology Laboratory and Neuroimmunology Research Section, IRCCS Mondino Foundation, Pavia, Italy.ORCID 0000-0003-2288-2000
Paolo SollaNeurology Unit, University Hospital of Sassari, Sassari, Italy.
Raffaele IorioDepartment of Neuroscience, Catholic University of the Sacred Heart, Rome, Italy.ORCID 0000-0002-6270-0956
Elia SechiNeurology Unit, University Hospital of Sassari, Sassari, Italy.ORCID 0000-0003-4698-663X

Funding

Ministero della Salute Ricerca Corrente 2022-2024
6 · The paper itself

Abstract

backgroundThe "insular knife-cut" sign is a sharp demarcation between hyperintense insular lesions on fluid-attenuated inversion recovery axial images and the basal ganglia, detected on brain MRI. This sign has been associated with herpes simplex virus encephalitis (HSVE); however, its specificity remains unknown. We assessed the frequency and specificity of the insular knife-cut sign in a real-life cohort of patients with suspected HSVE.

methodsWe retrospectively identified patients admitted for suspected HSVE over the past 10 years at three Neurology Units in Italy. Inclusion criteria were cerebrospinal fluid (CSF) tested for HSV-1/2 PCR and acute brain MRI available.

resultsA total of 188 patients were included: HSVE, 44; alternative diagnoses, 144 (autoimmune encephalitis, 51; infectious encephalitis, 22; other acute encephalopathies, 71). The insular knife-cut sign was present on the initial brain MRI in 23/44 (52.3%) HSVE patients and 1/144 (0.7%) patients with alternative diagnoses (p < 0.001). The specificity and sensitivity of the sign were 99.3% (95% CI, 96-100) and 52% (95% CI, 38-66), respectively. In eight HSVE patients, the insular knife-cut sign appeared on subsequent MRIs obtained acutely, raising the sensitivity to 70.5% (95% CI, 56-82). On multivariate regression, the insular knife-cut sign was the strongest independent predictor (odds ratio [95% CI]) of HSVE (68.9 [11.42-415.54]), followed by temporal pole involvement (8.44 [2.06-34.6]), and CSF pleocytosis (6 [1.7-21.18]).

conclusionsIn patients with suspected encephalitis, the insular knife-cut sign on MRI strongly predicts a diagnosis of HSVE. Its detection should prompt consideration of HSVE, even when other diagnostic tests are equivocal/unavailable.

Indexed as

Basal GangliaEncephalitis, Herpes SimplexMagnetic Resonance ImagingAdultAgedAged, 80 and overFemaleHumansMaleMiddle AgedRetrospective StudiesSensitivity and SpecificityYoung Adultdiagnostic valueencephalitisherpes simplex virusMRInervous system

Identifiers

PMID40846657
PMCPMC12373480

What OpenQuestion holds

Textmetadata
LicenceCC BY-NC-ND
Read underepoch 390

Registered trials

None linked

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.