Studies of UCC/RCC with abnormalities of cough hypersensitivity and laryngeal findings

First author [ref.]Subjects evaluated and number studiedAbnormal cough triggers In RCC/UCCLaryngeal paresthesiaThroat clearing in UCC/RCCVoice abnormalities and upper airway dyspnoea in UCC/RCCLaryngeal abnormalities on endoscopyOther findings
Vertigan [6]111 chronic cough patients (55 out of 111 with PVFM also)Average of 8 triggers noted for each participant41% reported warning sensations with most identifying throat as the site of triggerNoted but percentage of patients with this symptom not specifiedAbnormal voice and dyspnoea scores in chronic cough and cough plus PVFM patients55 chronic cough with PVFM included in analysisTalking, cigarette smoke, cold air and irritability in throat identified as most frequent triggers.
Ryan [21]24 subjects with chronic persistent coughNot reportedNot reportedNot reportedNot reported14/24 noted with PVFMAbnormal extrathoracic airway hyper-reponsiveness using hypertonic saline in cough+PVFM group
Vertigan [22]53 RCC patients100% with one or more cough triggersSeen in 94%Not reportedNot reportedShortness of breath reported as a cough triggerCategorised tussive and non-tussive triggers to capture hypertussia and allotussia
Bucca [23]61 UCCNot reportedNot reportedNot reportedNot reported66% of UCC patients had abnormal LHRLHR seen not only in UCC but also in GORD (62) asthma (41), rhinosinusitis (208)
Ryan [24]62 patients50% with laryngeal hypersensitivity63% with central reflex sensitisationNot reported76% with voice changesNot reportedThis was a placebo-controlled study of gabapentin in chronic cough that showed higher cough improvement in those with central sensitisation.
Vertigan [25]33 RCCNot reportedRCC patients had worse laryngeal paresthesia scores compared to controlsNot reportedWorse VHI scores and DSI as compared to controlsNot reported57% of RCC had abnormal fall in forced inspiratory flow (FIF50)following hypertonic saline and worse compared to control groups
Hilton [26]100 consecutive chronic cough patients79% with hypertussia 72% with allotussia75% with neck sensations∼50% with throat clearingNot reportedNot reportedCorrelation between urge-to-cough sensation intensity and total LCQ score.
Vertigan [27]20 patients with RCCNot reportedAbnormal LHQ with correlation with cough frequencyNot reportedAbnormal mean VHI values in RCC group compared to controlsLaryngeal motor dysfunction with breathing in 47% RCC (67% with odour challenge). Mediolateral constriction of false vocal cords in 45% with incomplete or abnormal vocal cord closure in 75% of RCC group.Specialised voice testing and timed swallow test different in RCC group as compared with controls. 69% with of 27 out of 69 patients that had abnormal cough had PVFM
Won [28]62 patients with RCC100% of patients with two or more cough triggers100% of patients with at least one abnormal sensationNot reportedNot reportedNot assessedCorrelations between LCQ and number of laryngeal sensations, number of cough triggers, CHQ score
Current study60 patients RCC/UCC100% with one or more cough triggersSeen in 97%Seen in 45% of patientsVHI abnormal in 43% and DI in 75% of patientsFunctional laryngeal abnormalities in 88% patientsCorrelations between LCQ and VHI and DI noted

RCC: chronic refractory cough; UCC: unexplained chronic cough; PVFM: paradoxical vocal fold motion; LHR: laryngeal hyper-responsiveness; LHQ: laryngeal hypersensitivity questionnaire; LCQ: Leicester Cough Questionnaire; CHQ: Cough Hypersensitivity Questionnaire; DSI: Dyspnea Symptom Index; VHI: Voice Handicap Index; DI: dyspnoea index.