Neuromuscular blockade and ventilatory failure after cyclosporine

Therapeutic applications of botulinum neurotoxins in head and neck disorders

Objective

The aim of this article is to review the mechanism of action, physiological effects, and therapeutic applications of botulinum neurotoxins in the head and neck area.

Study design

An extensive literature search was performed using keywords. The resulting articles were analyzed for relevance in four areas: overview on botulinum neurotoxins, the role of botulinum neurotoxins in the management of salivary secretory disorders, the role of botulinum neurotoxins in the management of facial pain, and the role of botulinum neurotoxins in head and neck movement disorders. Institutional review board approval was not needed due the nature of the study.

Results

Botulinum neurotoxin therapy was demonstrated to be a valuable alternative to conventional medical therapy for many conditions affecting the head and neck area in terms of morbidly, mortality, and patient satisfaction with treatment outcomes.

Conclusion

Botulinum neurotoxin therapy provides viable alternatives to traditional treatment modalities for some conditions affecting the head and neck region that have neurological components. This therapy can overcome some of the morbidities associated with conventional therapy. More research is needed to determine the ideal doses of botulinum neurotoxin to treat different diseases affecting the head and neck regions.

Botulinum toxin A for the treatment of cervical dystonia

Idiopathic cervical dystonia (ICD) is the most common adult-onset focal dystonia. It is characterised by relatively sustained, involuntary contractions of neck muscles. Injections of botulinum toxin (BTX)-A are safe and effective for the treatment of ICD, and have substantially improved its treatment. BTX-A is manufactured by Allergan Pharmaceuticals in the US and Ireland, and is distributed as Botox. In Europe, BTX-A is manufactured and distributed by Ipsen Pharmaceuticals as Dysport. Success rates for BTX-A injections for ICD ranges 64-90%, with 76-93% of injected patients experiencing pain reduction. Side effects are generally mild and include dysphagia and neck weakness.

Complications of botulinum toxin A use in facial rejuvenation

The esthetic application of botulinum toxin type A (Botox) is a safe treatment modality; nevertheless complications can occur as a result of patient-and physician-related factors. Fortunately, adverse effects and undesirable sequelae after Botox injections are temporary. Complications may be more serious in patients who have more severe rhytids (which require more Botox), previous facial plastic surgery (altered anatomy), and those who have pre-existing neuromuscular disease. The physician can reduce complications by using proper injection techniques, appropriate regional Botox dosing, and by being conservative in the overall approach to Botox-mediated facial rejuvenation.

Complications of botulinum toxin A use in facial rejuvenation

The esthetic application of botulinum toxin type A is a safe treatment modality; nevertheless, complications can occur as a result of patient- and physician-related factors. Fortunately, adverse effects and undesirable sequelae after Botox injections are temporary. Complications may be more serious in patients who have more severe rhytids (which require more Botox), have undergone previous facial plastic surgery (altered anatomy), and those who have preexisting neuromuscular disease. The physician can reduce complications by using proper injection techniques, appropriate regional Botox dosing, and by being conservative in the overall approach to Botox-mediated facial rejuvenation.

Pharmacology of botulinum toxin

BACKGROUND

Botulinum toxin has a well-defined role among dermatologists for the treatment of facial wrinkling, brow position, and palmar and axillary hyperhidrosis.

OBJECTIVE

The purpose of this study is to educate dermatologists on the pharmacology of botulinum toxin.

METHODS

A retrospective review of the literature on botulinum toxin from 1962 to the present was conducted. We examined the clinical applications of botulinum toxin, cholinergic neuromuscular transmission, the toxin's structure and molecular actions, drug and disease interactions at the neuromuscular junction, toxin assays, determinants of clinical response, and adverse side effects.

RESULTS

Botulinum toxin blocks the release of acetylcholine from the presynaptic terminal of the neuromuscular junction. Several drugs and diseases interfere with the neuromuscular junction and the effects of botulinum toxin. The mouse bioassay, the most sensitive and specific measurement of toxin activity, is the gold standard for botulinum toxin detection and standardization. The major determinants of clinical response to treatment are the toxin preparation, individual patient's anatomy, dose and response relationships, length of toxin storage after reconstitution, and immunogenicity. To minimize potential antibody resistance, one should use the smallest effective dose, utilize treatment intervals of more than 3 months, and avoid booster injections. Uncommon adverse effects include ptosis, ectropion, diplopia, bruising, eyelid drooping, hematoma formation, and temporary headaches.

CONCLUSION

Botulinum toxin is a safe and effective treatment. Knowledge of the pharmacologic basis of therapy will be useful for standardizing techniques and achieving consistent therapeutic results in the future.