Dynamic suprahyoid muscle ultrasound in acute stroke: a prospective observational study for developing a dysphagia severity score.

Five key predictors of severe dysphagia were identified: brainstem lesion, bilateral lesion, NIHSS score, SHM difference, and total duration.

• Predictors were identified using Least Absolute Shrinkage and Selection Operator (LASSO) and logistic regression analyses.
• The study enrolled 212 patients with acute ischemic stroke, split into mild dysphagia (n=146) and severe dysphagia (n=66) groups.
• Group assignment was based on need for dietary modifications, videofluoroscopic swallowing study results, and occurrence of aspiration pneumonia during hospitalization.
• The study population was randomly split into training (70%) and test (30%) sets for model development and validation.

The dysphagia severity scoring system demonstrated excellent discriminative performance in both training and test sets.

• AUC for the training set was 0.963 and for the test set was 0.935.
• A cutoff of ≥3 points yielded sensitivity of 97.9% and specificity of 86.4% for the training set.
• The same cutoff yielded sensitivity of 78.9% and specificity of 95.3% for the test set.
• The scoring system integrated both ultrasound (SHM difference, total duration) and clinical variables (brainstem lesion, bilateral lesion, NIHSS score).

Dynamic M-mode ultrasound of the suprahyoid muscle (SHM) yielded six quantifiable parameters during swallowing.

• The six parameters were: SHM thickness (baseline thickness), SHM displacement (peak-to-peak amplitude of SHM movement), SHM difference (SHM displacement minus SHM thickness), SHM ratio (SHM displacement divided by SHM thickness), peak-to-peak time, and total duration.
• Of the six ultrasound parameters, SHM difference and total duration were identified as significant predictors of severe dysphagia.
• Ultrasound was performed prospectively during the acute inpatient phase in a university-affiliated hospital neurology department.

The study population consisted of 212 acute ischemic stroke patients with a higher proportion classified as mild dysphagia than severe dysphagia.

• The mild dysphagia group comprised 146 patients (68.9% of total) and the severe dysphagia group comprised 66 patients (31.1% of total).
• The study used a prospective, cross-sectional observational design.
• Patients were enrolled from the inpatient neurology department of a university-affiliated hospital.

Clinical variables including brainstem and bilateral lesion location, along with NIHSS score, were significant predictors of severe dysphagia alongside ultrasound parameters.

• Brainstem lesion and bilateral lesion were included as binary clinical predictors in the final scoring system.
• NIHSS score, a standard clinical measure of stroke severity, was retained as a predictor.
• The combination of clinical and ultrasound variables in the scoring system was designed to enable early identification of patients at increased risk for severe dysphagia.