Since their introduction into clinical medicine in 1989, Botox injections have been used in several fields. They were initially used for the non-surgical management of strabismus. These injections are now widely used in plastic and reconstructive surgery; however, the non-aesthetic uses of Botox have expanded greatly over the past two decades and cover many fields, such as urology, dermatology, ophthalmology, otolaryngology, gynecology, general surgery, and neurology.
Botox is a powerful neurotoxin produced by the bacterium Clostridium botulinum. It causes muscle paralysis by blocking the release of acetylcholine at the neuromuscular junction. This toxin also affects the release of other neurotransmitters and neuropeptides, which has significantly contributed to the increase in alternative uses. Seven different types of the toxin have been reported, with various subtypes that have unique protein sequences and distinct molecular identities.
All Botox products available on the market consist of serotype A1 (botulinum toxin type A), except for a serotype B product, which has been shown to have lower activity in humans than in experimental animal studies. The three widely used botulinum toxin type A products—which differ in their final composition and potency units—are onabotulinumtoxin A (Botox; Allergan, Inc., Dublin, Ireland), abobotulinumtoxin A (Dysport; Ipsen, Paris, France), and incobotulinumtoxin A (Xeomin; Merz, Frankfurt am Main, Germany).
Many non-aesthetic uses have emerged over the past two decades. Although aesthetic applications have been more extensively studied, this article aims to provide a comprehensive yet concise review of the most common non-aesthetic uses.
Source: https://www.medscape.com
Chronic Migraine
Chronic migraine is defined as a headache occurring on 15 or more days per month, for more than 3 months, with at least 8 days per month meeting the criteria for migraine and responding to migraine-specific treatment. It occurs in a patient with a history of at least five previous migraine attacks that cannot be attributed to another disorder or excessive use of medication. Chronic migraine affects approximately 2% of the population, leading to reduced quality of life, increased analgesic overuse, higher healthcare costs, and more missed workdays.
Botox is a non-invasive treatment approved by the U.S. Food and Drug Administration, with high effectiveness supported by three large-scale studies. Phase 3 research evaluating migraine treatment concluded that botulinum toxin significantly improved chronic migraine, with continued improvement observed over 56 weeks of follow-up. The “Chronic Migraine OnabotulinumToxin A Prolonged Efficacy Open Label study” reported significant improvement after nine sessions, with favorable results at 24 months.
With continued use of the toxin for the symptomatic treatment of adults with chronic migraine—measuring healthcare resource usage and patient-reported outcomes—long-term benefits were observed in preliminary studies across 78 clinics in Europe and the United States. Although the therapeutic mechanism of botulinum toxin in preventing migraines is still being investigated, it appears to act both at the injection site and in distant areas through axonal transport. The toxin inhibits the release of neurotransmitters and neuropeptides other than acetylcholine and reduces the release of substance P and calcitonin gene-related peptide, which likely contributes to its therapeutic effect in chronic migraine. Botulinum toxin also modifies cell surface receptors associated with chronic migraine.
Osteoarthritis
Patients with osteoarthritis often seek surgeons due to pain arising from joint inflammation, changes in the articular surface of the cartilage, and loss of joint volume. Inhibition of substance P, calcitonin gene-related peptide, and neurokinin A release may allow the toxin to reduce osteoarthritis-related pain.
A systematic review showed that Botox helps in treating osteoarthritis, but the studies reviewed were highly heterogeneous, and the optimal method, dilution, and dosage require further investigation. A recent analysis of controlled trials found significant short-term reduction in joint pain with intra-articular botulinum toxin injection. However, it again highlighted the need for additional studies comparing the toxin with conventional therapeutic methods.
Trigeminal Neuralgia
Trigeminal neuralgia is characterized by paroxysmal episodes of sudden pain in the distribution of the trigeminal nerve—usually unilateral—with various possible causes, although in many patients it is idiopathic. The use of Botox for trigeminal neuralgia was first reported in 2002 for pain relief, and its effectiveness in reducing the frequency and severity of episodes has been confirmed by multiple studies. Effective doses ranged from 70 to 100 U of type A toxin for single-dose regimens or 50 to 70 U per treatment for repeat-dose regimens.
Postherpetic Neuralgia
Postherpetic neuralgia is a form of neuropathic pain caused by peripheral nerve damage from shingles (herpes zoster). Although topical or subcutaneous lidocaine and systemic treatment with tricyclic antidepressants or anticonvulsants have been beneficial, these treatments are limited by variable tolerance and side effects. Several reports and controlled trials found that up to 200 U of type A toxin injected subcutaneously throughout the affected area is beneficial in postherpetic neuralgia, reducing pain, lowering opioid use, and improving sleep duration and quality.
Temporomandibular Joint Syndrome (TMJ Disorders)
TMJ disorders, which can be classified as myo-fascial or arthrogenic, have many causes and affect up to 10% of the population. These disorders respond well to pharmacologic therapy and behavioral changes, though persistent cases can be difficult to treat. Limited research on the use of type A Botox has produced encouraging results, with effective dosages ranging from repeated injections of 100 U to a single injection of 500 U of type A toxin.
Additional studies found that 90 U of type A toxin reduced pain by at least 50% in 79% of patients. Similar promising results were observed using type A toxin for correcting disc displacement in arthrogenic TMJ disorders through lateral pterygoid muscle injection.
Cervical Dystonia
Cervical dystonia is the most common focal dystonia, characterized by involuntary head and neck postures that can lead to severe pain. A 2017 study showed significant pain improvement after a single session with type A Botox. Another 2016 analysis showed similarly promising results for type B toxin. All botulinum toxin products—type A and type B—are now FDA-approved for the treatment of cervical dystonia.
Hemifacial Spasm
Hemifacial spasm, generally caused by vascular compression of the facial nerve near the brainstem, is characterized by involuntary facial contractions and can cause major cosmetic and functional impairment.
Several trials have supported the use of Botox as a first-line treatment. Success rates ranged from 76% to 100%, with duration of effect lasting between 2.6 and 4 months. No systemic side effects were observed, and minor adverse events were temporary. Despite the lack of extensive high-quality studies, hemifacial spasm remains an indication for Botox based on clinical experience.
Blepharospasm
Blepharospasm is a dystonia affecting the orbicularis oculi muscle, leading to excessive eyelid closure. Patient education, avoidance of triggering factors (such as dopamine antagonists), and prevention of corneal injury are essential in managing blepharospasm. Oral medications—including benzodiazepines, baclofen, tetrabenazine, and clozapine—have shown therapeutic effects due to their activity on GABA-ergic or dopaminergic receptors. Multiple evidence-based clinical trials have shown that Botox is a safe and effective treatment option.