Iatrogenic botulism after botulinum meurotoxin exposure: A contemporary case series with clinical and electrophysiological insights

Abstract

Backgorund & Objective: Iatrogenic botulism is a rare but potentially serious complication of botulinum neurotoxin (BoNT) use, increasingly recognized in association with cosmetic and therapeutic applications. This study aimed to describe the clinical characteristics, diagnostic challenges, electrophysiological findings, management strategies, and outcomes of patients with iatrogenic botulism.

Methods: We retrospectively analyzed ten patients diagnosed with iatrogenic botulism who were evaluated and followed at a tertiary neurology center between 2019 and 2025. Demographic characteristics, indications for BoNT administration, time to symptom onset, initial clinical manifestations, electrophysiological findings, treatments, and clinical outcomes were systematically reviewed.

Results: The cohort consisted predominantly of female patients, with therapeutic and cosmetic indications—most commonly migraine prophylaxis and facial aesthetic procedures—being the leading causes of BoNT exposure. Initial symptoms included cranial nerve involvement such as ptosis, diplopia, dysarthria, and dysphagia, frequently accompanied by generalized weakness, blurred vision, nausea, and vomiting. Electrophysiological studies revealed presynaptic neuromuscular junction dysfunction, characterized by low-frequency decremental responses and high-frequency or post-exercise incremental responses on repetitive nerve stimulation, as well as increased jitter on single-fiber electromyography. Treatment strategies included botulinum antitoxin administration and adjunctive pyridostigmine therapy, along with supportive care. Clinical outcomes were favorable in all patients, with gradual and complete neurological recovery observed over days to weeks.

Conclusion: This case series highlights the evolving clinical spectrum of iatrogenic botulism and emphasizes the importance of early clinical recognition, appropriate electrophysiological evaluation, and timely management. Increased awareness and stricter regulation of BoNT use are essential to prevent this potentially avoidable complication.