An Atypical Descending Variant of Guillain-Barré Syndrome With Bulbar Palsy, Autonomic Instability, and Delayed Colonic Pseudo-Obstruction: A Case Report.

Guillain-Barré syndrome (GBS) is an acute, immune-mediated polyradiculoneuropathy that is the most common cause of acute flaccid paralysis worldwide. The classical form manifests as an ascending, symmetrical weakness, but atypical variants, including descending presentations, have been increasingly recognized. Such variants often pose diagnostic challenges and are associated with more severe disease and prolonged recovery. We describe a 70-year-old woman with well-controlled hypertension who presented with progressive dysphagia, pooling of saliva, and upper limb weakness. Clinical examination revealed bulbar dysfunction, areflexia in the upper limbs, and motor power in the upper limbs was markedly reduced to grade 1/5 on the Medical Research Council (MRC) scale, while lower limb strength was preserved. Within hours of admission, the weakness progressed to quadriplegia with respiratory distress, necessitating intubation and mechanical ventilation. Cerebrospinal fluid analysis demonstrated albumin cytological dissociation, and nerve conduction studies revealed changes consistent with GBS. Intravenous immunoglobulin was initiated but discontinued due to anaphylaxis; therapeutic plasma exchange was subsequently performed. The patient had marked cardiovascular lability and, after one month, acute colonic pseudo-obstruction (ACPO), which resolved with conservative management. Around the 40th day, she experienced complete left lung collapse due to mucus plugging, which was successfully managed with bedside bronchoscopy. Persistent bulbar dysfunction delayed decannulation until day 80. Remarkably, full neurological recovery was achieved only after six months of follow-up. This case highlights several atypical and severe features of GBS: descending onset with bulbar involvement at presentation, multisystem autonomic dysfunction extending to the gastrointestinal tract, and a protracted course despite early immunotherapy and supportive care. The unusually delayed onset of ACPO and persistent bulbar palsy underscores the need for vigilance beyond the acute phase. Hence, clinicians should maintain a high index of suspicion for atypical variants of GBS in patients with acute, progressive weakness, even when the presentation deviates from the classical ascending pattern. A structured, multimodal diagnostic approach and timely initiation of therapy are essential to prevent complications. Severe variants may follow a prolonged recovery trajectory, requiring sustained multidisciplinary management.