[The effectiveness of botulinum therapy of trigeminal neuralgia]

To evaluate the treatment protocol with the use of onabotulinum toxin type A (botox) and the efficacy of a single botulinum therapy procedure for clinical manifestations in patients with trigeminal neuralgia (TN).

We studied 90 patients (57 women, 33 men), including 80 people with primary TN and 10 people with secondary TN. Then 20 patients with primary TN (11 women and 9 men, mean age 61.8 years) received local injections of onabotulinum toxin type A (botox). Clinical examination included taking anamnesis, assessment of pain on a visual analogue scale (VAS), assessment of the frequency of pain paroxysms, taking into account the average indicator (0 to 100 seizures during the day); neurosensory examination according to the developed protocol with the definition of pain, temperature, tactile sensitivity, the study of stimulus-dependent pain; MRI of the brain to diagnose neurovascular conflict.

A month after the injections, the pain intensity practically did not change (8.5 versus 7.2 points on the VAS), but the number of paroxysms decreased (31.2 versus 22.5 seizures per day). Two months after the use of botox, the number of pain attacks continued to decrease (31.2 versus 17.7; Mann-Whitney U-test, p=0.006). At the same time, there was a decrease in pain intensity according to the VAS (8.5 versus 6.1, t-test 2.75 points; p=0.02). After three months, there was a decrease in the number of paroxysms from 31.2 to 9.2 (paired Student's test, p<0.001) and the severity of pain (8.85 versus 4.0 points on the VAS, paired t-test 3.95 points, p<0.001). There were significant differences in the average dose of carbamazepine (867.5 versus 670.8 after 3 months, t-test 196.7 mg, p=0.02). In TN patients who underwent destructive operations with exposure to the peripheral branches of the trigeminal nerve, signs of severe neurosensory deficit on the face and burning pain are added to the main symptoms, which corresponds to the clinical criteria of post-traumatic trigeminal neuropathy.

Local injections of type A onabotulinum toxin (botox) are minimally invasive, safe and effective symptomatic therapy for patients with TN. Persistent sensory disturbances that develop in patients after destructive surgeries call into question the safety of these therapies for TN.