Formation of antibodies against botulinum toxin B after treatment of drooling in two children with cerebral palsy

Introduction: Is formation of antibodies a clinically relevant issue in the treatment of drooling with intraglandular injections of botulinum toxin B?

Methods: retrospective case report about two patients with cerebral palsy who had recieved sonography-guided injections of parotide and submandibular glands on both sides.

Patient 1: male, 17 years of age, 4 injections within 12 months with botulinum toxin B with a total dose of 10.800 Units (Neurobloc®). With initially good response secondary non-response occured after the third injection.

Patient 2: female, 9 years of age, 5 injections of botulinum toxin B within 24 months with a total dose of 12.000 Units (Neurobloc®). After four successful treatments non-response occured after the fifth injection. Both patients were tested for antibodies using the mouse diaphragm assay to assure the clinical diagnosis.

Results: Both patients showed positive antibody titres against botulinum toxin B: patient 1 >20 mU/ml, patient 2 >10 mU/ml.

Conclusion: This is the first case report about two patients who formed antibodies after repeated injections of the salivary glands to reduce drooling. The formation of antibodies against botulinum toxin B seems to be as clinical relevant as publised for the treatment of cervical dystonia