The American Food and Drug Administration (FDA) has approved Allergan’s Botox as a treatment for upper limb spasticity.

The anti-wrinkle drug is the first neurotoxin to be approved by the regulator to treat the particular disorder. Botox can also be used for therapy to treat abnormal head positions and neck pains related to cervical dystonia and eye muscle problems.

The drug will be injected into the affected muscle to block overactive nerve impulses that can cause contractions. This will reduce the severity of upper limb spasticity, which is present in over one million Americans. The condition is commonly triggered by any of the following: stroke, spinal cord complications, and traumatic brain injuries.

The condition is unpredictable, and it can develop anywhere from weeks to years after the original injury.

To back up its newly approved application, Allergan has conducted several studies on the drug’s use. The results have been positive, and results indicate that Botox can improve the muscle tone affected patients.