Laryngeal hypersensitivity and abnormal cough response during mannitol bronchoprovocation challenge.

BACKGROUND AND OBJECTIVE: Inhalational challenge with dry mannitol powder may potentially induce cough by two mechanisms: airway bronchoconstriction or laryngeal irritation. This prospective observational study investigated laryngeal and bronchial components of cough induced by mannitol challenge. METHODS: We recruited consecutive patients referred for clinical mannitol challenge. The Newcastle Laryngeal Hypersensitivity Questionnaire (LHQ) was administered. Throughout testing, coughs were audio-recorded to derive a cough frequency index per time and dose of mannitol. Relationships between cough indices, laryngeal hypersensitivity and bronchial hyperresponsiveness (BHR) were examined. Participants were classified by cough characteristics with k-means cluster analysis. RESULTS: Of 90 patients who underwent challenge, 83 completed both the questionnaire and challenge. Cough frequency was greater in patients with abnormal laryngeal hypersensitivity (p = 0.042), but not in those with BHR. There was a moderate negative correlation between coughs per minute and laryngeal hypersensitivity score (r = -0.315, p = 0.004), with lower LHQ scores being abnormal. Cluster analysis identified an older, female-predominant cluster with higher cough frequency and laryngeal hypersensitivity, and a younger, gender-balanced cluster with lower cough frequency and normal laryngeal sensitivity. CONCLUSION: Cough frequency during mannitol challenge in our cohort reflected laryngeal hypersensitivity rather than BHR. Laryngeal hypersensitivity was more often present among older female patients. With the incorporation of cough indices, mannitol challenge may be useful to test for laryngeal hypersensitivity as well as BHR.

Amphetamine-induced cardiomyopathy complicated by embolic stroke: a case report.

BACKGROUND: Amphetamine use causes cardiomyopathy via catecholamine-mediated effects such as tachycardia, hypertension, vasoconstriction, and direct cardio-toxic effects. Traditionally, an increased risk of haemorrhagic stroke is associated with amphetamine use. However, up to one-third of stimulant-associated cardiomyopathy patients have left ventricular (LV) thrombus formation leading to an increased risk of systemic embolization. We report a case of amphetamine-induced cardiomyopathy complicated by embolic stroke secondary to LV thrombus. CASE SUMMARY: A 38-year-old man with 6-month history of sustained amphetamine use presented to the emergency department with left-sided weakness, facial droop, and dysarthria. Angiography confirmed right middle cerebral artery thrombus. Prompt mechanical thrombectomy yielded full neurological recovery. Dyspnoea prompted transthoracic echocardiography showing dilated cardiomyopathy with an ejection fraction of 5% and LV thrombus. Anticoagulation was initiated with warfarin as well as pharmacological therapy for heart failure with reduced ejection fraction including bisoprolol, spironolactone, loop diuretic, and sacubitril/valsartan. He was discharged successfully following resolution of ventricular thrombus and medical management of heart failure. Clinical recovery was hampered by psychosocial factors resulting in non-adherence to medical therapy and continued amphetamine use. CONCLUSION: Sustained amphetamine use can result in severe dilated cardiomyopathy with LV thrombus formation and embolic complications such as ischaemic stroke. Avoidance of amphetamines in conjunction with guideline-directed pharmacological management are key components of therapy. However, psychosocial factors can exert significant influence on recovery.