Single institution experience with efgartigimod in patients with myasthenia gravis: Patient selection, dosing schedules, treatment response, and adverse events.

INTRODUCTION/AIMS: Efgartigimod is a neonatal Fc receptor blocker and was the first approved medication in its class for the treatment of generalized myasthenia gravis (gMG). As a novel therapy, little is known about the use of efgartigimod in clinical practice. This study aims to describe how efgartigimod is being incorporated into the current therapeutic landscape of MG. METHODS: We reviewed the charts of 17 patients with gMG treated with efgartigimod at the University of Pennsylvania between January 2022 and June 2023. RESULTS: Efgartigimod was selected mainly for patients who were treatment refractory, had side effects to other treatments, and/or required quick improvement in their symptoms. All patients had been previously treated with at least one medication for MG and had an average baseline Myasthenia Gravis Activities of Daily Living (MG-ADL) score of 9.1. The patients treated with efgartigimod improved their MG-ADL score by an average of 5.5 points at 3 months (p < .001) and 7.1 points by 6 months (p < .001). Forty percent of patients achieved minimal symptom expression. Adverse events (AEs) were reported in 43.7% of patients on efgartigimod, the most common being mild infection (urinary tract infection and thrush). There were no serious AEs. DISCUSSION: This study found efgartigimod to be efficacious, well tolerated, and safe in patients with MG. Efgartigimod should be considered as an add-on therapy, a bridge therapy, or as a monotherapy if patients have difficulty tolerating other treatments.

Head drop after botox: Electrodiagnostic evaluation of iatrogenic botulinum toxicity.

BACKGROUND: Botulinum is a potent neurotoxin with increasing indications for neurologic disorders. While clinical benefit manifests primarily due to local actions at the neuromuscular junction, regional and systemic effects do occur. Rarely, systemic symptoms including weakness, dysarthria, dysphagia and other side effects occur as a result of iatrogenic botulinum neurotoxicity. CASE: A 72 year-old female with right leg dystonia developed head drop, bulbar and systemic weakness following right lower extremity botulinum toxin injection. Routine nerve conduction studies were normal. Repetitive stimulation of the spinal accessory nerve showed decrement; electromyography (EMG) demonstrated slightly small units with subtle signs of denervation, and single fiber EMG revealed increased jitter with blocking, all of which are consistent with systemic botulism. CONCLUSION: This case highlights and reviews the important electrodiagnostic features of iatrogenic systemic botulinum neurotoxicity.