TABLE 4.

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

First author [ref.]	Subjects evaluated and number studied	Abnormal cough triggers In RCC/UCC	Laryngeal paresthesia	Throat clearing in UCC/RCC	Voice abnormalities and upper airway dyspnoea in UCC/RCC	Laryngeal abnormalities on endoscopy	Other findings
Vertigan [6]	111 chronic cough patients (55 out of 111 with PVFM also)	Average of 8 triggers noted for each participant	41% reported warning sensations with most identifying throat as the site of trigger	Noted but percentage of patients with this symptom not specified	Abnormal voice and dyspnoea scores in chronic cough and cough plus PVFM patients	55 chronic cough with PVFM included in analysis	Talking, cigarette smoke, cold air and irritability in throat identified as most frequent triggers.
Ryan [21]	24 subjects with chronic persistent cough	Not reported	Not reported	Not reported	Not reported	14/24 noted with PVFM	Abnormal extrathoracic airway hyper-reponsiveness using hypertonic saline in cough+PVFM group
Vertigan [22]	53 RCC patients	100% with one or more cough triggers	Seen in 94%	Not reported	Not reported	Shortness of breath reported as a cough trigger	Categorised tussive and non-tussive triggers to capture hypertussia and allotussia
Bucca [23]	61 UCC	Not reported	Not reported	Not reported	Not reported	66% of UCC patients had abnormal LHR	LHR seen not only in UCC but also in GORD (62) asthma (41), rhinosinusitis (208)
Ryan [24]	62 patients	50% with laryngeal hypersensitivity	63% with central reflex sensitisation	Not reported	76% with voice changes	Not reported	This was a placebo-controlled study of gabapentin in chronic cough that showed higher cough improvement in those with central sensitisation.
Vertigan [25]	33 RCC	Not reported	RCC patients had worse laryngeal paresthesia scores compared to controls	Not reported	Worse VHI scores and DSI as compared to controls	Not reported	57% 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 patients	79% with hypertussia 72% with allotussia	75% with neck sensations	∼50% with throat clearing	Not reported	Not reported	Correlation between urge-to-cough sensation intensity and total LCQ score.
Vertigan [27]	20 patients with RCC	Not reported	Abnormal LHQ with correlation with cough frequency	Not reported	Abnormal mean VHI values in RCC group compared to controls	Laryngeal 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 RCC	100% of patients with two or more cough triggers	100% of patients with at least one abnormal sensation	Not reported	Not reported	Not assessed	Correlations between LCQ and number of laryngeal sensations, number of cough triggers, CHQ score
Current study	60 patients RCC/UCC	100% with one or more cough triggers	Seen in 97%	Seen in 45% of patients	VHI abnormal in 43% and DI in 75% of patients	Functional laryngeal abnormalities in 88% patients	Correlations 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.