Title : Change of functional state of the brain at the time of botulinum toxin therapy of generalized spasticity in patients with disorders of consciousness
Introduction and Objectives: Previously we found that botulinum toxin therapy of generalized spasticity in patients with disorders of consciousness after coma improves the functional state of the brain and consciousness. However, when do these central changes start and how they develop remains unclear. The aim of the current study was to analyze the changes of bioelectric activity of the brain (BEA) during botulinum toxin therapy of generalized spasticity.
Methods: Botulinum toxin therapy of generalized spasticity was performed under electroencephalography and clinical monitoring in 17 patients with disorders of consciousness after coma (including permanent vegetative state). IncobotulinumtoxinA (Xeomin) was successively injected in all hypertonic muscles. The dose into each muscle did not exceed the mean-recommended (the total dose up to 1400 u). Additionally, a test with injection of saline was done in 2 patients.
Results: Changes of BEA that are associated with Xeomin were detected within 1 to 2 minutes after the first injection of Xeomin in all patients and have initially caught the motor cortex in 16 patients. The more muscles were injected, the more widespread changes of BEA were registered with an appearance of beta and other rhythms (P<0.05). Fewer oscillations of rhythms and a tendency to return to the initial background of BEA were observed. Both an initial transient decrease of muscle tone (in all patients) and an improvement of consciousness (in 10 patients) appeared immediately after injections into all muscles; the changes of BEA covered all parts of the brain and remained present for 30-60 minutes.
Conclusions: The central effect of botulinum toxin therapy of generalized spasticity starts immediately with the beginning of the reduction of afferentation from the muscles. We believe that the early transient clinical effect reflects the appearance of the process of liberation of neurons formaintaining other functions, including consciousness.
Audience take away: New data, shown in this poster presentation, are helpful for a better understanding of the central effect of botulinum toxin therapy. They could be used in the designing of future research and in teaching.