Vocal cord edema, which was observed in 100% of patients with cluster headache, should continue to be explored in research settings, according to the study authors.
Using a digital voice analysis, investigators found patients with cluster headache (CH) to have significantly lower second harmonic values compared to healthy controls (HC), suggesting they can be characterized by a creaky voice phonation. This type of “creaky voice” was associated with vocal cord edema underlined by laryngopharyngeal reflux.
The cross-sectional study led by Marcello Silvestro, MD, resident, University of Campania, evaluated whether it was possible to identify typical voice quality in male patients with CH (n = 20) by matching them with HCs (n = 13). Clinical experiences with patients with CH who’ve demonstrated this low voice quality also played a factor into the reasoning behind the study.
Patients had voice quality examined using traditional measures of fundamental frequency, calculations of jitter and shimmer, and noise-to-harmonics ratios as well as quantities related to the spectral tilt (ie, H1-H2, H1-A1m H1-A2, and H1-A3). These measures were calculated based on the production of stressed vowels extracted from digitally recorded reading tasks done inside of a soundproof insulated cabin in the laboratory of the Audiology Department at the University of Campania.
At the conclusion of the study, patients with CH showed a significantly lower difference between the amplitude of the first harmonic (H1) and the amplitude of the second harmonic (H2) compared with HC (–6.9 [±7.6] vs 2.1 [±6.7]; P = .002). Even after using age and smoking status as covariates, Quade’s rank analysis confirmed the pattern seen in these patients (Quade’s test = 7.84; P ≤.001).
"Creaky voice phonation can be due to a vocal fold's reduced capability to become slack or flaccid secondary to vocal cord edema underpinned by laryngopharyngeal reflux affecting the phonatory mechanisms in patients with CH,” the study authors wrote. "The laryngopharyngeal reflux may represent a dysautonomic sign related to the increased parasympathetic tone during in-bout period, reinforcing the hypothesis of an extracranial autonomic dysfunction as part of CH clinical picture."
After undergoing videolaryngostroboscopy, 100% of patients with CH had chordal edema, compared to 15% of HC (P <.001). Furthermore, all patients with CH showed marked signs of laryngopharyngeal reflux, 14 of the 15 patients with CH showed a marked bilateral chordal edema and 6 showed a mild bilateral chordal edema.
Of note, 1 patient had signs of asymmetrical chordal vibration and insufficient chordal adduction. In contrast, 10 of the 13 HCs demonstrated a normal laryngeal picture, while 2 had mild bilateral chordal edema, and 1 was excluded due to the poor quality of the laryngoscopic examination. Moderate signs of laryngopharyngeal reflux were observed in just 2 HCs.
"These findings reinforce the hypothesis of extracranial autonomic dysfunctions as part of the CH syndrome presenting with laryngopharyngeal reflux and highlight the need to explore the presence of vocal cord edema in these patients," Silvestro et al wrote.