Masseter muscle quality in acute ischemic stroke: Associations with functional outcome, dysphagia, and cerebral small vessel disease burden.

BACKGROUND

The masseter muscle-a surrogate of systemic muscle mass and quality-has been linked to dysphagia and mortality in oncology, but evidence in acute ischemic stroke (AIS) is limited. Cerebral small vessel disease (SVD), via oxidative stress and inflammation, may contribute. We investigated the prognostic value of masseter status in AIS, its relation to dysphagia, and association with SVD.

METHODS

Consecutive AIS patients admitted between January 2022 and March 2024 within one week of onset were screened. Unfavorable outcome was defined as mRS 3-6 at 3 months. On contrast-enhanced CT, masseter cross-section 2 cm below the zygomatic arch was measured to calculate masseter muscle index (MMI = area/height2; cm2/m2, quantity) and masseter muscle density (MMD = mean attenuation; HU, quality). Lower HU indicated greater intramuscular fat. Dysphagia was defined as Functional Oral Intake Scale ≤ 5 at day 7. SVD burden was assessed by total SVD score.

RESULTS

Among 100 patients (72 [72%] male; median age, 69 years), 24 had unfavorable outcomes. Lower MMD was significantly associated with unfavorable outcomes in multivariable analysis (p < 0.05). ROC analysis identified an MMD cutoff of 55.5 HU (AUC, 0.663; sensitivity, 0.908; specificity, 0.375). Higher SVD burden was associated with lower MMD in multivariable linear regression (p < 0.05). Both lower MMI and MMD were associated with acute dysphagia in multivariable analysis (p < 0.05).

CONCLUSIONS

Masseter muscle quality may serve as a prognostic marker in AIS, potentially influenced by SVD. Both quantity and quality were linked to acute dysphagia.