(NaturalNews) The botulinum toxin injected into the face from the popular drug Botox can move into the brain, where it may cause damage to the central nervous system, according to a study published in the Journal of Neuroscience.
Allergan Inc.'s best-selling drug Botox, used to smooth out wrinkles by relaxing facial muscles, is actually botulinum neurotoxin type A. The toxin functions by disrupting the signals of the nervous system. Botox and a different variety of botulinum toxin, marketed as Myobloc by Solstice Neurosciences, are also used to treat muscular stiffness or spasms caused by conditions such as cerebral palsy.
After reports surfaced of people experiencing trouble breathing or swallowing after receiving injections of the toxin, the FDA added warnings to the labels of Botox and Myobloc about these effects. While the FDA has only warned of the effects in patients with neuromuscular disorders, it has acknowledged that a risk might also be posed in other people and has launched an investigation.
The reason for the danger is that the botulinum toxin might migrate from its injection site into other parts of the nervous system.
In the current study, researchers injected botulinum toxin into one side of the hippocampus into the brains of rats, and observed it to migrate to the other side of the brain. When the toxin was injected into the brain's superior colliculus, which is involved in vision, it migrated into the animals' eyes.
Six months after the initial injection into the hippocampus, the researchers could still observe the toxin's effects.
Botulinum toxin is produced by the bacteria Clostridium botulinum, which is known to infect wounds and contaminate food. Approximately 110 cases of botulism poisoning occur in the United States each year. Because of the toxin's tendency to paralyze the respiratory system, botulism contamination can be fatal if not treated.