Abstract Details

Title The effect of botulinum toxin injections on EMG

Topic Neuromuscular and Clinical Neurophysiology (EMG)

Presentation(s) P4 - Poster Session 4 (5:30 PM-6:30 PM)

Poster/Presentation
Number 12-041

Objective This study looks at patients with spasticity receiving botulinum toxin injections and periodically surveys the H-reflex and M-wave to standardize the changes that occur, so that they can be controlled for in future experimentation.

Background Many conditions lead to spasticity, including cerebral palsy, traumatic brain injury, multiple sclerosis, stroke and spinal cord injury. Many of these patients are treated with intramuscular botulinum toxin injections. These patients may also benefit from operant conditioning of the H-reflex. Currently, we do not know what effect intramuscular botulinum toxin injections have on EMG values, which precludes their inclusion in studies on operant conditioning.

Design/Methods Patients were included with the following criteria: clinically stable injury, ability to ambulate at least 10m, clinical signs of spasticity in plantarflexion at least unilaterally, and currently receiving intramuscular botulinum toxin injections for spasticity. Patients with lower motor neuron disease or cognitive deficits were excluded. Pre-treatment and several periodic post-treatment H-reflex and M-wave measurements, including H-max and M-max were collected by NCS. H/M ratios were calculated and recruitment curves were created with slopes calculated. PT evaluations and kinematic gait analysis were performed pre-treatment, at 4 weeks and at 12 weeks post-treatment.

Results Based on the data we have collected, the H-max and M-max both decreased with intramuscular botulinum toxin injections, then increased as the toxin wore off. The H-reflex and M-wave were lowest 2-4 weeks after the treatment was administered, then slowly trended up until they returned to around baseline at 10 weeks. Likewise, the amount of current required to elicit an H-reflex increased initially, then returned to baseline after 10 weeks.

Conclusions According to this data, botulinum toxin injections typically wear off at about the 10 week mark. This supports the practice of administration every 10 weeks instead of the conventional Q12 week interval.

Authors/Disclosures
Robin Warner, DO (Robin Warner Neurology, PLLC) PRESENTER	Dr. Warner has nothing to disclose.
	No disclosure on file

��ɫ��

��ɫ��