Dystonias, Treatment with botulinum

A patient treated with botulinum toxin using a superficial approach into the tongue for lingual dystonia induced by speaking had excellent results [22 ]. The authors concluded that lingual botulinum toxin injection is a fairly simple, safe and viable treatment option. 

Botulinum toxin is used clinically in the treatment of blepharospasm, writer s cramp, spasticities of various origins, and rigidity due to extrapyramidal disorders. It is also used to treat gustatory sweating and cosmetically to decrease facial wrinkles. Botulinum toxin A Botox, Oculinum) injected intramuscularly produces functional denervation that lasts about 3 months. Clinical benefit is seen within 1 to 3 days. Adverse effects range from diplopia and irritation with blepharospasm to muscle weakness with dystonias. 

The pharmacologic basis of these disorders is unknown, and there is no satisfactory medical treatment for them. A subset of patients respond well to levodopa medication (dopa-responsive dystonia), which is therefore worthy of trial. Occasional patients with dystonia may respond to diazepam, amantadine, antimuscarinic drugs (in high dosage), carbamazepine, baclofen, haloperidol, or phenothiazines. A trial of these pharmacologic approaches is worthwhile, though often not successful. Patients with focal dystonias such as blepharospasm or torticollis often benefit from injection of botulinum toxin into the overactive muscles. The role of deep brain stimulation for the treatment of these conditions is being explored. 

Botulinum toxin has been used for some time to control localized muscle dystonias, including conditions such as spasmodic torticollis, blepharospasm, laryngeal dystonia, strabismus, and several other types of focal dystonias.6 25,26,87 93 When used therapeutically, small amounts of this toxin are injected directly into the dystonic muscles, which begin to relax within a few days to 1 week. This technique appears to be fairly safe and effective in many patients, but relief may only be temporary. Symptoms often return within 3 months after each injection, necessitating additional treatments.40 Still, this technique represents a method for treating patients with severe, incapacitating conditions marked by focal dystonias and spasms. 

Botulinum toxin type A is approved for use in humans for the treatment of strabismus, blepharospasm associated with dystonia, head position and neck pain associated with cervical dystonia (a movement disorder characterized by involuntary muscle contractions), as well as for the temporary improvement in the appearance of moderate to severe glabellar lines in adult men and women 65 years or younger. Clinical trials have noted few adverse effects associated with use of botulinum toxin type A for these conditions. 

A total of 182 patients (73 male, 109 female) with various facial region disorders were retrospectively studied using botulinum toxin injection for the treatment of facial region disorders [19 j. Improvement in symptoms was marked and good in subjects treated for blepharospasm, hemifacial spasm, facial s5mkinesis and Meige syndrome, and moderate for oromandibular dystonia and hypersalivation. Ptosis was the most common side effect. 

A review of published trials in the use of botulinum toxin in the treatment of dystonia demonstrated that adverse events associated with chronic, periodic exposure to botulinum toxin injections are generally minor and self-limiting [211 ]. 

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