Using peripheral nerves that branch from the spinal cord, the central nervous system tells a muscle to contract by sending signals to activate that muscle. Nerve and muscle connect at a neuromuscular junction and the nerve signal travels across to the muscle in the form of the neurotransmitter acetylcholine. BOTOX injections inhibit acetylcholine release from vesicles at the neuromuscular junction.

Typically, injections are required at several sites in the muscles that cause spasticity with the expectation that enough toxin will travel to the neuromuscular junctions and act on those muscles. Dr. Mayer reasoned that lower BOTOX dosages might be needed if the toxin could be injected directly into the neuromuscular junctions.

No clinical tool pinpoints the exact location of the neuromuscular junction, but standard electrical stimulation techniques pinpoint the motor point, which may be close to it. Therefore, Dr. Mayer proposed injecting a lower BOTOX dosage directly into the motor point region to target the neuromuscular junction and minimize the amount of the drug for any given muscle.

In collaboration with Alberto Esquenazi, MD, Medical Director, MossRehab and John Whyte, MD, PhD, Director, Moss Rehabilitation Research Institute, Dr. Mayer developed a clinical research protocol now being tested on 36 patients with spasticity caused by traumatic brain injury. In the randomized study, half of the patients will receive four BOTOX injections into the four quadrants of the biceps, and two injections into the brachioradialis muscle. The other group will receive the same dosage in a single injection at the motor point for each spastic muscle. Both approaches will administer the lowest BOTOX dosage typically used to treat spasticity, as reported in the medical literature to be 30 or 60 units per site depending on muscle size. The BOTOX injection will be diluted, resulting in a greater fluid volume than standard BOTOX injections.