Objective: This study aimed to determine the diagnostic utility of clinician speech ratings and patient self-report for detecting early bulbar changes associated with amyotrophic lateral sclerosis (ALS), compared to instrumentation-based speech measures.
Methods: Thirty-six individuals with ALS and 17 healthy control participants were included. Patients' awareness of early bulbar motor involvement was assessed using self-reported scores on the Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised (ALSFRS-R). Clinicians' detection of early bulbar motor involvement was assessed through perceptual speech ratings by two experienced speech-language pathologists. Participants with ALS were grouped as 'bulbar pre-symptomatic' or 'bulbar symptomatic' based on self-report and clinician ratings, and compared to healthy controls on six instrumentation-based speech measures. ROC analysis was used to compare the sensitivity and specificity of perceptual and instrumentation-based measures for detecting bulbar changes in pre-symptomatic individuals.
Results: Early bulbar changes that were documented using instrumentation-based measures were undetected by both patients and clinicians. ROC analyses indicated that instrumentation-based measures outperformed clinicians' scaled severity ratings, and that percent pause time was the best measure for differentiating healthy controls from bulbar pre-symptomatic individuals with ALS.
Conclusions: Findings suggested that instrumentation-based measures of speech may be necessary for early detection of bulbar changes due to ALS.
Keywords: Bulbar; early detection; speech motor impairment.