Botulinum toxin (or Botox/Dysport/Xeomin) is used in neurology/rehabilitation medicine to treat muscle stiffness / tightness disorders, such as dystonia, spasticity, cerebral palsy, and hemifacial spasms. These disorders cause abnormal muscle tone or spasms that cause pain, discomfort, and difficulty with movement. BT can be used to reduce pain and improve mobility by relaxing the muscles that cause abnormal muscle tone or spasms.