Prevalence and Clinicoradiological Profiles of Respiratory Dysfunction in Patients with Medullary Infarction: Retrospective Case Study and Review of Literature

Background: Respiratory dysfunction occurs in stroke patients. Little is known about the prevalence, clinical features and lesion topography in patients with dyspnea due to medullary infarction (MI). We aimed to evaluate the frequency and the clinicoradiological profile in dyspnic MI patients.

Methods: We serially reviewed clinical records and magnetic resonance imaging (MRI) findings in 2144 inpatients (1211 men and 933 women) with acute ischemic stroke from 2007 to 2013. The clinicoradiological features were studied in MI patients with respiratory dysfunction. The prevalence of dyspnic MI was estimated among patients with cerebral infarction or MI. Patients with extensive infarction in the brainstem or the posterior circulation area, and cerebral hernia were excluded.

Results: Ninety-five patients (47 men and 48 women) were diagnosed as MI. Six patients (2 men and 4 women) developed respiratory dysfunction. The prevalence was 6.3% (4.3% in men and 8.3% in women) in MI patients, and 0.3% (0.2% in men and 0.4% in women) in patients with cerebral infarction. Age was ranged from 38 to 78 years and the mean age (SD) was 70.0 (22.3) years. Abnormal respiration patterns included hyperventilation in 4 patients, dyspnea in one and apnea in one. Initial neurological examination revealed absent pharyngeal reflex and soft palatal palsy in all patients. Cough syncope, hiccup, dysphagia, circulatory failure, sensory deficits or dysuria was present simultaneously in several patients. MRI disclosed three types of lesion topography: 1) The bilateral medial and the right tegmental regions in the upper and the middle medulla oblongata, 2) The right-predominant extensive regions in the lower medulla oblongata, and 3) The left lateral and tegmental regions in the lower medulla oblongata. Magnetic resonance angiography or cerebral angiography showed severe degree of atherosclerosis, dural arteriovenous fistula or dissection in the vertebral artery. The prognosis was fatal in 2 patients, poor in 2 patients, and recovered in each one patient with and without intervention.

Conclusion: The present study indicated that the prevalence of dyspnic MI was 0.3% in ischemic stroke patients and 6.3% in MI patients. The neurological profile suggested cough, hiccup, circulatory instability, absent pharyngeal reflex, soft palatal palsy and dysuria. Lesion topography disclosed the tegmentum in unilateral or bilateral MI. Atherothrombotic mechanism and circulatory failure might predict high mortality.