Upper limb-predominant variant of Guillain-Barre Syndrome (GBS) following diarrhoea.

Guillain-Barre syndrome (GBS) is an acute immune-mediated polyneuropathy classically presenting with ascending lower limb weakness; however, rare regional variants may pose diagnostic challenges. We report a case of an unusual upper limb-predominant variant of GBS following a self-limiting diarrhoeal illness, presenting with acute shoulder pain, progressive bilateral hand paraesthesia and upper limb weakness without lower limb, bulbar or cranial nerve involvement. Neurological examination demonstrated proximal and distal upper limb weakness with upper limb hyporeflexia. Cerebrospinal fluid analysis revealed albumin-cytologic dissociation; anti-GM1 antibodies were positive; cervical spine MRI excluded structural pathology and nerve conduction studies confirmed an axonal motor neuropathy consistent with the acute motor axonal neuropathy variant of GBS. The patient was treated with a 5-day course of intravenous immunoglobulin alongside physiotherapy, resulting in gradual neurological recovery and functional improvement. This case emphasises the importance of recognising atypical regional presentations of GBS to facilitate timely diagnosis and prompt initiation of immunomodulatory therapy.