Intraoral Administration of Botox in Patients With Dentoalveolar Neuropathic Pain

Intraoral Administration of Onabotulinum Toxin A for Continuous Neuropathic Pain: a Single Subject Experimental Design

Onabotulinum toxin type A (BoNT-A) is a potent neurotoxin that has been reported to have an effect on afferent (sensory) neurons independent of its action on muscle tone and secretory glands at the periphery.In human studies, the use of BoNT-A has proven to reduce the severity and intensity of attacks in chronic tension type headaches and chronic neck pain. The PREEMPT study concluded that BoNT-A could be used as a preventive therapy in chronic migraine patients and FDA approval was obtained. According to the International Association for the Study of Pain (IASP), BoNT-A is recommended for the management of peripheral neuropathic pain with subcutaneous administration of 50-200 units (50-200U) to onabotulinum toxin A to the painful neuropathic area every 3 months as a third line of treatment. To our knowledge, there are no clinical trials published investigating the effect of intraoral administration of BoNT-A in continuous dentoalveolar neuropathic pain. The aim of this pilot study is to investigate the potential therapeutic effect of intraoral administration of BoNT-A in patients suffering from continuous neuropathic pain.

HYPOTHESIS:

There will be statistically significant differences in reported pain intensity after the intraoral administration of BOTOX® in patients suffering from chronic continuous dentoalveolar neuropathic pain.

A single subject experiment will be conducted with 10 patients where 50 U of BonT-A will be injected into the painful dentoalveolar area. Eligible subjects will complete a pain diary indicating their pain intensity by means of a visual analog scale during one month to establish a baseline. After the first injection, subjects will continue to monitor the VAS daily for 3 months and the infiltration will be repeated a second time following the same protocol. Patient's response will be monitored with the daily pain diary.

Inclusion Criteria:

• History of continuous dentoalveolar pain with clinically evident positive (hyperalgesia, allodynia) and/or negative (hypoaesthesia, hypoalgesia) signs of trigeminal nerve dysfunction and where other possible pain sources have been ruled out.
• Intractable pain to conventional oral and/or topical pharmacotherapy for neuropathic pain according to the recommendations published by NeuPSIG (Neuropathic Pain Special Interest Group) including anticonvulsants, SNRIs (serotonin and norepinephrine reuptake inhibitors) and/or tricyclic antidepressants.
• Subject consent to participate in the study.

Exclusion Criteria:

• hypersensitive to any onabotulinum toxin preparation or any component in the formulation.
• systemic nerve or muscle disorders
• bleeding disorders
• dysphagia
• breathing problems
• pregnancy or breastfeeding
• previous treatment with botulinum toxin in the last 4 months.