Botox therapy is widely used in treating movement disorders and for cosmetic purpose.
"Movement Disorders" is a subspecialty of Neurology. Movement disorders are neurological conditions that affect the speed, fluency, quality and ease of an individual movement. Most of the symptoms are finally relayed in the way of abnormal excessive contraction of the muscles. One of the well recognized current day's state of art treatment is chemodenervation. Chemodenervation is a process, in which signals from the nerves to the muscles are modified using various medications. There are various medications which include chemicals and neurotoxins used in a controlled manner to achieve a desired action. This effect is used to control unwanted and excessive muscular contractions due to various etiologies and disease process. Chemodenervation using Botulinum toxin, is currently a well-recognized and accepted treatment in management of various medical disorders. Even though there are various therapeutic indications for Botulinum toxin injections, in neurology it commonly used for dystonia, spasticity (stiffness of muscle following stroke), and chronic migraine.
Botulinum Neurotoxin, is a biological product which has revolutionized the treatment of various neurological symptoms, being derived from the bacterium Clostridium botulinum. There are various serotypes of this toxin, but commonly used are the Type – A and Type – B. Botulinum toxin (Brand names : Botox, Dysport, Xeomin, etc) is a nerve "blocker" that binds to the nerves that lead to the muscle and prevents the release of acetylcholine, a neurotransmitter that activates muscle contractions. If the message is blocked, muscle spasms are significantly reduced or eliminated.
The various disorders wherein Botulinum is currently used are:
- a. Focal dystonias - Involuntary, sustained, or spasmodic patterned muscle activity, Cervical dystonia (spasmodic torticollis), Blepharospasm (eyelid closure), Laryngeal dystonia (spasmodic dysphonia), Limb dystonia (writer's cramp), Oromandibular dystonia, Orolingual dystonia, Truncal dystonia.
- b. Spasticity - following Stroke, Traumatic brain injury, Cerebral palsy, Multiple sclerosis, Spinal cord injury.
- c. Nondystonic disorders of involuntary muscle activity, Hemifacial spasm, Tremor, Tics, Nocturnal bruxism, etc.
- d. Trismus, Strabismus (disorder of conjugate eye movement) and nystagmus.
- e. Chronic pain and disorders of localized muscle spasms, Chronic low back pain, Myofascial pain syndrome.
- f. Tension headache, Chronic migraine headache, Medication overuse headache.
- g. Lateral epicondylitis, Knee pain, Shoulder pain.
- h. Neuropathic pain.
- i. Smooth muscle hyperactive disorders, Neurogenic bladder – Detrusor hyperreflexia, Detrusor-sphincter dyssynergia, Benign prostatic hypertrophy, Achalasia cardia, Hirschsprung disease, Sphincter of Oddi dysfunctions.
- j. Cosmetic use: Hyperkinetic facial lines (glabellar frown lines, crow's feet), Hypertrophic platysma muscle bands, Sweating, salivary, and allergy disorders.
- k. Axillary and palmar hyperhidrosis.
- l. Drooling in cerebral palsy and other neurological disorders.
PROCEDURE
The medication is directly injected into the area of the body where benefit is intended for, e.g. in to cervical muscles in cervical dystonia and ocular muscles for blepharospasm. For selected areas of the body, and particularly when injecting muscles that are difficult or impossible to palpate, guidance using an electromyograph (EMG) may be necessary. For instance, when injecting the deep muscles of the jaw, neck, or vocal cords, an EMG-guided injection may improve precision since these muscles cannot be readily palpated. An EMG measures and records muscle activity and may help the physician locate overactive muscles. The procedure is done with a very fine needle and most of the people do not complain of any discomfort. At most the pain can be as that or less of a small mosquito bite.
DURATION
It is given as an outpatient therapy. Patients who respond well to botulinum neurotoxin may continue treatment over the course of many years without side effects from long-term use.
RECOVERY
It normally takes several days for the effects of the botulinum neurotoxin to become apparent. The benefit peaks in approximately four weeks and lasts three to four months. In some cases the benefits can last between 6 to 12 months.
RISKS
Temporary side effects for both types A and B may include muscle weakness, mild pain, bruising or swelling at the injection site, and dry mouth. Temporary difficulty in swallowing may occur in patients injected for laryngeal or cervical dystonias, but is highly unlikely for someone getting injected for writer's cramp. If a patient experiences side effects, adjusting the dosage or site of injection for future treatments may help avoid these effects. As Botulinum toxin effects are temporary, most of the side effects usually resolve within days to weeks.
Contributed by:
Dr. Prashanth LK
DM (Neurology) Fellowship in Movement Disorders (Toronto))
Consultant Neurologist.
Specialist : Parkinson's Disease & Other Movement Disorders