Cruciate paralysis or man-in-the-barrel syndrome? Report of a case of brachial diplegia.

A patient who developed isolated brachial diplegia following cardiac surgery is described. The underlying cerebral lesion could not be localized using magnetic resonance imaging (MRI). Evoked potentials disclosed normal findings, while pathological latencies were seen on cortical magnetic stimulation. Their marked improvement over the following year was accompanied by almost complete clinical recovery. The preserved arm reflexes, together with the observed slow firing motor units in electromyography argued against bilateral lesions of the brachial plexus. We attribute the observed diplegia to a medullary lesion at the level of the pyramidal decussation, presumably caused by an intraoperative embolic occlusion of the anterior spinal artery. Cruciate paralysis and man-in-barrel-syndrome (MIBS) both are terms used to describe brachial diplegia; cruciate paralysis when caused by medullary lesions, MIBS when caused either by supratentorial or by medullary lesions. Exclusive use of the term MIBS for bilateral frontal lobe lesions, as in the original description, would provide more clarity in terminology.