The “Spoke Sign”

Abstract

OBJECTIVE To determine the prevalence and diagnostic usefulness of the "spoke sign" (SS), a specific otoscopic finding, in detecting the presence of pediatric middle ear effusion (MEE). METHODS The SS was defined as a dull gray appearance of the tympanic membrane with engorged vasculature in an arrangement similar to the spokes of a bicycle wheel, covering 50% or more of the inferior tympanic membrane by area. An observational screening test study was performed prospectively with enrollment of consecutive pediatric patients scheduled for tympanostomy tube placement. Intraoperatively, the presence or absence of SS was noted before myringotomy and that of MEE was noted after myringotomy. Statistical analysis was performed to determine the value of SS as a predictor of MEE, with myringotomy as the criterion standard. Videos taken before myringotomy were subsequently shown to independent pediatricians and otolaryngology residents to analyze interrater concordance in evaluating the presence of SS. RESULTS Seventy-six patients (150 ears) were included in the study. Forty-nine patients (64%) had SS in at least 1 ear. The sensitivity, specificity, positive predictive value, and negative predictive value for the SS for MEE were 100% (79/79), 93% (66/71), 94% (79/84), and 100% (64/64), respectively. The Fleiss κ score for interrater concordance among pediatricians was 0.21 (residents) to 0.24 (staff), and that among otolaryngology residents was 0.61 (all P < .001). CONCLUSIONS The presence of SS may represent a useful adjunct in the detection of pediatric MEE, with high measured sensitivity and specificity. Incorporation of SS in clinical practice may require focused training to detect this specific examination finding.