Table e-1 and e-references for: Neurogenic dysphagia: a systematic review and proposal of a classification system

Objective: Introduction of a phenotypic classification of dysphagia with
differential diagnostic implications and its validation in different
disease groups using videos of flexible endoscopic evaluation of
swallowing (FEES). Methods: A systematic literature review was performed
to summarize disease-typical FEES-findings. In an interdisciplinary team,
a FEES-based classification of neurogenic dysphagia was developed which
distinguishes different dysphagia phenotypes. The classification was
validated using 1012 randomly selected FEES videos of patients with
various neurological disorders. Chi-square tests were applied to
investigate the relationship between the disease groups and each dysphagia
phenotype. Results: Seven dysphagia phenotypes were defined and all
phenotypes were significantly  associated with specific
neurological disease groups: (1) “Premature bolus spillage” and (2)
“delayed swallowing reflex” occurred mainly in stroke patients, (3)
“predominance of residue in the valleculae” was most common in
Parkinson's disease, (4) “predominance of residue in the piriform
sinus” occurred only in myositis, motoneuron disease and brainstem stroke
patients, (5) “pharyngolaryngeal movement disorder” was found in atypical
Parkinsonian syndromes and stroke patients, (6) “fatigable swallowing
weakness” was common in patients with myasthenia gravis, and (7) “complex
disorder” with a heterogeneous dysphagia pattern was the leading mechanism
in amyotrophic later sclerosis. The interrater reliability showed a strong
agreement (kappa = 0.84). Conclusion: Neurogenic dysphagia is not a mere
symptom, but a multi-etiological syndrome with different phenotypic
patterns depending on the underlying disease. Dysphagia phenotypes can
facilitate differential diagnosis in patients with dysphagia of unclear
etiology.