Acute motor-sensory axonal neuropathy with brain death-like manifestations: two case reports and literature review

Acute motor-sensory axonal neuropathy (AMSAN) presenting with brain death-like features is rare, rapidly progressive, and easily mistaken early in the course for brain death of unclear cause or for locked-in syndrome. Misdiagnosis may delay timely immunotherapy and supportive care. We describe two such patients from a single center and summarize the published adult literature to improve recognition of this fulminant presentation. We retrospectively reviewed two patients treated at Yichang Central People’s Hospital between 2016 and 2024 who developed brain death-like manifestations in the setting of AMSAN. We also searched CNKI, Wanfang Data, and PubMed for relevant reports published up to June 2025. Both patients developed rapidly progressive generalized paralysis, external and internal ophthalmoplegia, respiratory failure, and disappearance of brainstem reflexes, thereby simulating brain death. Electrophysiological studies showed severe motor-sensory axonal neuropathy and cerebrospinal fluid findings supported the diagnosis. One patient improved after intravenous immunoglobulin (IVIG), whereas the second showed no early response to IVIG but improved after subsequent plasma exchange. Our literature review identified 28 adult patients with fulminant Guillain-Barré syndrome presenting with brain death-like manifestations, most of whom required prolonged mechanical ventilation and experienced slow, incomplete motor recovery. AMSAN presenting with brain death-like features is characterized by acute onset and complete systemic paralysis, typically initially manifesting as limb weakness and paralysis of both extraocular and intraocular muscles, followed by respiratory muscle paralysis. All patients require prolonged mechanical ventilation and intensive care treatment, rapidly presenting with clinical manifestations resembling “brain death.” At this stage, electrophysiological studies and lumbar puncture are particularly crucial for definitive diagnosis. Early initiation of immunotherapy, such as IVIG infusion or plasma exchange, is critical. Patients often show gradual recovery of extraocular and intraocular muscles first; however, most experience poor recovery of respiratory muscle paralysis and limb weakness, significantly prolonging hospitalization and severely impacting patients’ work and daily life, highlighting the need for prospective studies to evaluate therapeutic strategies beyond standard IVIG and plasma exchange. While emerging agents such as efgartigimod show preliminary promise in refractory GBS, current evidence is limited to small case reports, and prospective studies are critically needed.