Assessing the risk of developing secondary resistance in patients receiving botulinum toxin injections at a frequency interval of less than 3 months
Author: Ameerah Ilyas
Base Hospital / Institution: Newcastle NHS trust
ePoster presentation
Abstract ID: 25-436
Purpose
Injection of botulinum neurotoxin A is considered a first-line treatment for a number of diverse conditions. It is a potent neurotoxin produced by Clostridium botulinum, inducing muscle paralysis through synaptic neurotransmission blockade. Since the effects of botulinum toxin wear off over time, repeated injections are required to maintain the treatment effect.The study conducted in the Department of Ophthalmology at the RVI aimed to assess the risk of developing secondary resistance in patients receiving botulinum toxin injections more frequently than every 3 months
Methods
Restrospective review of 154 patients who underwent botulinum toxin treatment for hemifacial spasm, blepharospasm, apraxia of eyelid opening, a combination of apraxia and blepharospasm, aberrant regeneration of the 7th nerve, myokymia, entropion, epiphoria, Meige Syndrome (oromandibular dystonia), non-epileptic lid closure, hemifacial spasm, and entropion with the inter-treatment period varying between 8 weeks and 3 months
Results
During a 4-month period, we identified a total of 154 patients who underwent botulinum toxin treatment.Blepharospasm and hemifacial spasm patients had the longest followup – this is not surprising given the incurable nature of these disorders.Out of the 154 patients, only one (0.65%) showed likely signs of secondary resistance following botulinum toxin treatment with an inter-treatment interval of less than 3 months.
Conclusion
Our results show that primary poor response/ resistance has a relatively low prevalence, only presenting in 1.9% (3/154) of patients undergoing botulinum toxin treatment in our clinic. 1-2/154 (0.6-1.2%) of the total population developed features in keeping with our definition of secondary resistance. This is below the 2.5% literature benchmark . The patient most likely to have secondary resistance on a background of poor primary response was undergoing 2 monthly botulinum toxin treatment but no definite conclusions relating secondary resistance to treatment frequency more than 3 monthly can be drawn
Additional Authors
| First name | Last name | Base Hospital / Institution |
|---|---|---|
| Saba | Ishrat | Newcastle RVI hospital |
| Benjamin | Dowell | Newcastle RVI hospital |
| Margaret | Dayan | Newcastle RVI hospital |
