Objective: The purpose of this study was to assess the effect of acute unilateral middle cerebral artery (MCA) infarctions in right-handed subjects on their ability to elicit voluntary cough (VC), and separately to assess the laryngeal cough reflex using the reflex cough test.
Design: This prospective, clinical study involved 30 right-handed, alert subjects with no previous history of stroke or asthma and with an infarction of the MCA distribution as seen on computed tomographic or magnetic resonance images. Subjects could follow verbal commands. A total of 16 subjects had right MCA infarcts and 14 had left MCA infarcts. VC responses and reflex cough test results were compared with the side of the infarct. The reflex cough test used nebulized tartaric acid.
Results: The laryngeal cough reflex was normal in all 30 subjects, irrespective of side of MCA infarction, and none developed aspiration pneumonia. Eleven of the 14 subjects who had a left MCA infarct had an abnormal VC (78.6%) and showed cough apraxia. All 16 subjects with right infarcts produced a VC. Subjects with left infarcts were more likely to have an abnormal VC than those subjects with right lesions (P < 0.001).
Conclusions: VC is of limited use in screening subjects for aspiration pneumonia risk. A normal laryngeal cough reflex indicated a neurologically protected airway.