Chronic inflammatory demyelinating polyneuropathy or subacute Guillain-Barré syndrome? Not always an easy differential diagnosis

Guillain-Barré syndrome (GBS) is an immuno-mediated disorder of the peripheral nervous system with an acute onset of 2–4 weeks, and a monophasic course. In the subacute variant the symtpoms nadir is reached in 4–8 weeks. However, in sporadic cases the onset and the evolution of the disease may be different than expected, leading to significant diagnostic difficulties.

Case report: A 78-yrs old man presented at our Hospital with a 4-month history of progressive, diffuse motor and sensory deficit. He had previously undergone two electrophysiological examinations with uncertain findings. At hospitalization the nerve conduction study (NCS) and the cerebrospinal fluid examination were consistent with inflammatory demyelinating polyradiculoneuropathy. While a 5-day high-dose of intravenous methylprednisolone proved to be ineffective, a single intravenous immunoglobulin cycle risulted in a significant clinical improvement without relapse after an 18-month follow-up. Based on clinical and neurophysiological findings, a diagnosis of atypical subacute GBS was finally made.

Conclusion: Although generally accepted that GBS has an acute onset within a few weeks, with a maximum of 8 weeks in the subacute variant, this case report shows that it may initially present with a very slow clinical progression and inconsistent NCS findings. However, its recognition and differentiation from the chronic inflammatory nerve disorders, which have a chronic, long-term evolution, is mandatory to provide the correct therapy protocol.