Abstract Background Hopkins syndrome (HS) is a rare neuromuscular disorder characterized by poliomyelitis-like flaccid paralysis occurring in children after an acute asthma attack. This report describes the multimodal neurophysiological and ultrasonographic evaluation of a child presenting with post-asthmatic lower limb weakness and discusses the differential diagnosis of flaccid paralysis in childhood. Case presentation A 2-year-old boy presented with left leg weakness two weeks after an asthma exacerbation; one month after symptom onset, he was unable to walk without assistance. The child’s past medical history was significant only for asthma, and his vaccination schedule, including for poliomyelitis, was up to date. Neurological examination revealed left lower limb weakness with areflexia (absent reflexes) and moderate atrophy. Electroneuromyography and muscle ultrasound indicated a chronic, asymmetric anterior horn cell disease without evidence of acute denervation. Conclusion HS is a rare neuromuscular disorder characterized by poliomyelitis-like paralysis that occurs in children following an acute asthma attack. Given its rarity, the pathophysiology and optimal management strategies for HS remain poorly understood. A multimodal assessment combining ultrasound and neurophysiological studies is valuable for improving the characterization of this phenotype.
Camelo‐Filho et al. (2026) studied this question.