Lesional location of intractable hiccups in acute pure lateral medullary infarction

ABSTRACT

Background & Objective: Hiccups is a disabling condition of lateral medullary infarction (LMI). Unlike other symptoms of LMI, the anatomical lesions of hiccups are not well known. Few studies have evaluated the relationship between the lesional location of LMI and hiccups. We performed this study to correlate hiccups and magnetic resonance imaging (MRI)-based lesional location in pure LMI. Methods: Between January 1997 and February 2013, we identified 24 patients with pure LMI who presented with hiccups in addition to typical lateral medullary syndrome. Sixty six pure LMI patients without hiccups were included as a control group. Clinical and radiologic findings were compared between the two groups. MRI-identified lesions were classified rostrocaudally as rostral, middle and caudal, and horizontally as typical, ventral, large, lateral and dorsal. Results: The pure LMI patients with hiccups had significantly more frequent aspiration pneumonia (P = 0.001) and longer hospital stay (P = 0.03). The patients with hiccups significantly more often had dorsal rather than ventral lesion at horizontal levels (P = 0.012). But, there were no rostro-caudal differences at vertical levels (P = 0.162). Conclusions: We suggest that pure LMI associated with hiccups often locates in the dorsal medulla at horizontal correlation. This MRI-based comparative study has advanced the understanding of the neural substrate for hiccups in LMI, and indicates that hiccups become predictable when specific lesional locations in the lateral medulla are considered.