Effects of Botulinum Toxin in Cervical Dystonia
Condition: Torticollis; Cervical Dystonia
MeSH terms: Dystonia; Dystonic Disorders; Torticollis
Study type: Observational

Summary: 
      Botulinum toxin injection in the contracting muscles has proven to be a safe and effective
      method of relieving pain and lessening dystonic posturing. The current hypothesis is that
      botulinum toxin works on altering sensory input in the central nervous system in addition to
      its effects on the neuromuscular junction.

      Magnetoencephalography (MEG)of brain has been used in dystonia such as writer's cramp and
      musician's hand dystonia. However, no study has investigated the correlation of central
      signal changes via magnetoencephalography before and after treatment with botulinum in
      torticollis patients. Prior studies using somatosensory potentials indicated the possibility
      of differential activation of precentral cortex in patients with cervical dystonia. Cervical
      dystonia may result from a disorder of both cortical excitability and intracortical
      inhibition. The investigators hypothesis is that botulinum injection modulates central
      inhibition which improves clinical outcome for torticollis.
    

Detailed description: 
      This study of MEG neuro-imagery will increase the understanding of the central pathway
      involvement in the efficacy of botulinum toxin treatment for torticollis. Cervical dystonia
      (spasmodic torticollis) patients will be selected from the Neurology clinic. Subjects will
      range in age from 18 years old through 90 years old. Subjects are expected to be ambulatory
      and independent. Patients are generally expected to be in good health. Exclusion criteria
      include significant intracranial metal (typically fixed dental bridges or braces) generating
      significant magnetic artifact, medical instability, pregnancy, and certain other factors such
      as severe head tremors that would produce magnetic artifact. Clinical states of torticollis
      patients will be assessed by using Tsui scale. Every torticollis patient will have
      magnetoencephalography on the day of botulinum treatment beforehand and approximately 2-8
      weeks after botulinum treatment. We will compare the results of magnetoencephalography
      between control subject and torticollis patient before botulinum treatment aiming to find any
      difference between the two populations. We also compare the results of magnetoencephalography
      in individual torticollis patient before and after botulinum treatment, aiming to detect the
      changes between these two conditions in the same individual and possibly between the average
      of data from each condition before and after botulinum treatment.
    

Intervention name(s): Botulinum Toxin A
Intervention type(s): Drug
Intervention description(s): Not exceeding a total dose of 400 units, once every three months.
Other intervention name(s): Botox, Botulinum toxin A
Intervention MeSH terms: Botulinum Toxins; Botulinum Toxins, Type A; abobotulinumtoxinA
Observational model: Case-Control
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Subjects meeting the criteria for cervical dystonia (torticollis) who are receiving
        botulinum toxin injections in the Neurology Clinic
      
Keywords: cervical dystonia; torticollis; Botulinum toxin; magnetoencephalography; MEG; cortical organizational changes detected by MEG after botulinum toxin in patients with torticollis, correlating with improvement in the symptoms