[Long-term evolution of the doses of Botulinum toxin used in laryngeal and cervical dystonias].
BACKGROUND
Dystonia is a neurological condition characterised by involuntary movements that give rise to abnormal postures. Different strategies have been used in the treatment of focal dystonias, but the most widely accepted at the present time involves the use of botulinum toxin type A (BTA) injections. Yet, despite its widespread use, the ideal dosages for long-term treatment are still not known with precision.


OBJECTIVE
The purpose of this study is to report on our experience with long-term BTA therapy in laryngeal (LD) and in cervical dystonia (CD).


METHODS
We reviewed the data concerning the dosages of BTA injected in 10 patients with LD who received treatment in our centre over a period of eight years. We also analysed the data regarding the doses of BTA injected over an eight-year period in 17 patients with CD. The data were analysed using an ANOVA for paired data.


RESULTS
No significant differences were found in the highest dosages of BTA needed for the treatment of LD throughout the progression of the disease (p=0.84). These data contrast with those obtained from the analysis of the treatment of CD, which do show a gradual increase in the dose of toxin that is required (p<0.0001).


CONCLUSIONS
These findings suggest that the long-term response to treatment is different in the two conditions.
García-Torres
M A
MA
Fundación Jiménez Díaz, 28040 Madrid, España. maleligarcia@yahoo.es
Echeverría-Urabayen
A
A
Contreras
A
A
Carnal-Martín
P
P
García-Ruiz Espiga
P J
PJ
D000704:Analysis of Variance; D001905:Botulinum Toxins / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D020821:Dystonic Disorders / Q000188:drug therapy*; D006801:Humans; D007830:Larynx / Q000503:physiopathology*; D009334:Neck Muscles / Q000503:physiopathology*; D012189:Retrospective Studies; D016896:Treatment Outcome
D001905:Botulinum Toxins