title: Secondary nonresponsiveness to new bulk botulinum toxin A (BCB2024).
abstract: We report on a patient with cranio-cervical dystonia injected with the new, lower protein formulation of botulinum toxin A who developed secondary resistance to this toxin. Subsequent injections with botulinum toxin B provided substantial reduction of blepharospasm. This is the first reported case of secondary resistance to the new preparation of botulinum toxin A.
mesh_terms: D001764:Blepharospasm / Q000188:drug therapy; D001767:Blinking / Q000187:drug effects*; D019274:Botulinum Toxins, Type A / Q000494:pharmacology* / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008875:Middle Aged; D016896:Treatment Outcome
chemical_list: D019274:Botulinum Toxins, Type A