Conduction block and axonal degeneration co-occurring in a patient with axonal Guillain-Barré syndrome

Guillain-Barré syndrome can present as demyelinating or axonal subtypes. Recent studies suggest that the neurophysiology of the axonal subtype not only exhibits axonal degeneration but can also show reversible conduction failure at the early stages. It is less certain if reversible conduction failure is evident in only a minority of patients with a specific subtype associated with better prognosis. We describe a 73-year-old man with Guillain-Barré syndrome and electrodiagnostic features of both reversible conduction block and possible axonal degeneration. Initial features of conduction failure were seen in both median nerves. This was followed by features of axonal degeneration, with corresponding weakness in the left abductor pollicis brevis and lumbricalis muscles, which are innervated by the median nerve, but rapid resolution of conduction block with corresponding rapid clinical recovery in the right. The presence of both features in a single patient provides further evidence that early conduction failure can be followed by either rapid resolution or axonal degeneration in the electrophysiological spectrum of axonal Guillain-Barré syndrome.