Epilepsia
September 12, 2026 Β· via Europe PMC
Relationship between cognitive functioning and diffusion tensor imaging analysis along perivascular spaces as a diffusion magnetic resonance imaging marker of perivascular directional diffusivity in functional seizures after traumatic brain injury.
Szaflarski JP, Nenert R, Allendorfer JB, LaFrance WC.
AI summary β for doctors, generated from the abstract only
In patients with functional seizures following traumatic brain injury, a specialized brain MRI measure of perivascular fluid movement (related to the brain's waste-clearance system) was reduced compared with TBI patients without functional seizures, and lower values correlated with worse overall functioning, suggesting a potential biological marker linking brain fluid dynamics to this condition.
What was studied
A study of 173 participants (40 healthy controls, 74 with functional seizures after traumatic brain injury [TBI-FS], 59 with TBI only) underwent diffusion MRI to calculate the DTI-ALPS index, a marker of perivascular fluid movement related to the brain's glymphatic (waste-clearance) system, examining relationships between this marker and cognitive/functioning measures (Montreal Cognitive Assessment, Quality of Life in Epilepsy scale, Global Assessment of Functioning).
Key findings
- Cognitive and functioning measures were significantly worse in TBI-FS patients than TBI-only patients on all measures assessed
- Global Assessment of Functioning showed a significant positive correlation with the DTI-ALPS index in the combined patient sample (r=.228, p=.009)
- The DTI-ALPS index was significantly lower in TBI-FS patients than TBI-only patients (p=.026), with significant hemispheric asymmetry (right hemisphere values lower than left) and sex as a significant covariate (females higher)
Clinical relevance
The findings suggest that reduced perivascular fluid dynamics, as measured by the DTI-ALPS index, may be a biological correlate of functional seizures after traumatic brain injury and relates to overall patient functioning, which could eventually support using this noninvasive MRI marker to better understand or identify this condition, though this remains an early-stage biomarker finding rather than a diagnostic tool ready for clinical use.
Who should care
Limitations
This is a cross-sectional study that can identify associations but cannot establish whether altered perivascular fluid dynamics causes functional seizures or results from the underlying condition, and the DTI-ALPS index is an indirect measure of glymphatic function whose precise biological interpretation remains debated in the broader neuroimaging literature.
Patients with functional seizures after traumatic brain injury showed reduced perivascular fluid dynamics on specialized MRI compared with TBI patients without functional seizures, with lower values linked to worse overall functioning, suggesting a potential biological marker warranting further investigation in this condition.
This is an AI-generated summary of the published abstract, not a clinical recommendation. It may not reflect the full text or subsequent updates β verify against the original source before acting on it.
Abstract
Objective
Patients with functional seizures (FS) frequently exhibit deficits in cognitive and functioning measures (CFM) similar in magnitude to those present in epilepsy. An association between glymphatic system function and CFM in various neuropsychiatric conditions has been reported. Our objective was to investigate the relationships between CFM and diffusion tensor imaging analysis along perivascular spaces (DTI-ALPS) index as a measure of perivascular directional diffusivity related to neurofluid dynamics in FS after traumatic brain injury (TBI-FS), TBI without functional seizures (TBI-only), and healthy controls (HCs).
Methods
A total of 173 participants (40 HCs, 74 TBI-FS, 59 TBI-only) underwent diffusion magnetic resonance imaging at 3 T to establish their DTI-ALPS index. CFM acquired in patient groups were Montreal Cognitive Assessment, Quality of Life in Epilepsy-31 (total score and cognitive subscale), and Global Assessment of Functioning (GAF). Group differences were analyzed using linear mixed models with hemisphere as a within-subject factor. The primary group comparison was adjusted for age and sex. Correlations between CFM and DTI-ALPS index were examined in patient groups.
Results
CFM were significantly worse in TBI-FS than TBI-only on all measures. GAF showed a significant positive correlation with DTI-ALPS index in the combined patient sample (rβ=β.228, pβ=β.009). In the primary analysis, there was a significant main effect of group on DTI-ALPS index (F2, 330β=β3.51, pβ=β.031, Ξ·2 pβ=β.021). DTI-ALPS index was lower in TBI-FS than in TBI-only (pβ=β.026), and biological sex was a significant covariate (F1, 330β=β5.71, pβ=β.017; females higher). A significant hemispheric asymmetry was found, with right hemisphere DTI-ALPS index values lower than left (F1, 340β=β35.30, pβ2 pβ=β.094).
Significance
TBI-FS participants showed reduced CFM across all measures, with lower global functioning associated with lower DTI-ALPS index values in the combined patient sample, suggesting a positive relationship between perivascular directional diffusivity related to neurofluid dynamics and global functioning. Patients with TBI-FS showed reduced DTI-ALPS index compared to TBI-only participants, suggesting potential differences in perivascular function.
DOI
10.1002/epi.70490
PMID
42730507
Research metadata (titles, abstracts, authors, publication dates) is sourced from Europe PMC, which aggregates content from PubMed/MEDLINE, PubMed Central, and other providers under the U.S. National Library of Medicine (NLM/NCBI). NLM does not claim copyright on abstracts; the original journal publishers or authors may hold rights to the full articles. AI-generated summaries are derived only from the abstract, never the full text, and are always labeled as AI-generated.
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