[Focal or Segmental Dystonia Resistant to Botulinum Toxin: Re-Evaluation, Surgery, and Botulinum Again].

Botulinum toxin is effective in most patients with focal/segmental dystonia. A minority of these patients show primary or secondary resistance to this therapy. After excluding technical reasons, such as inappropriate dosage or injection sites, neutralizing antibodies against the toxin may be suspected. If the patient tests positive for the anti-toxin antibody, changing the toxin type may be effective. The next step in treatment is local surgical approaches or stereotactic surgery, depending on the type of dystonia. Stereotactic surgery can be the first-line treatment for some types of dystonia because of its high efficacy or because of the absence of official approval for botulinum toxin treatment in Japan. If the clinical efficacy of surgery is insufficient, retreatment with botulinum toxin should be considered for remaining symptoms when the patient is negative for the anti-toxin antibody. Adjunctive therapies include oral medication, rehabilitation, or the use of devices that alleviate symptoms via sensory tricks or other mechanisms. Any of these may be applied simultaneously with the main procedure. The shortage of expert doctors providing botulinum toxin therapy is the most urgent issue in Japan, as this limits patients' access to therapy and potentially undermines the quality of disease management.