Hypothesis & Theory ARTICLE

Front. Neurol., 28 April 2014 | http://dx.doi.org/10.3389/fneur.2014.00054

Cervical dystonia: a disorder of the midbrain network for covert attentional orienting

imageMichael Hutchinson1,2*, imageTadashi Isa3, imageAnna Molloy1,2, imageOkka Kimmich1,2, imageLaura Williams1,2, imageFiona Molloy4, imageHelena Moore5, imageDaniel G. Healy6, imageTim Lynch7, imageCathal Walsh8, imageJohn Butler9, imageRichard B. Reilly9, imageRichard Walsh10 and imageSean O’Riordan1,2
  • 1Department of Neurology, St. Vincent’s University Hospital, Dublin, Ireland
  • 2School of Medicine and Medical Science, University College Dublin, Dublin, Ireland
  • 3Department of Developmental Physiology, National Institute for Physiological Sciences, Okazaki, Japan
  • 4Department of Neurophysiology, Beaumont Hospital, Dublin, Ireland
  • 5Cork University Hospital, Cork, Ireland
  • 6Department of Neurology, Beaumont Hospital, Dublin, Ireland
  • 7Dublin Neurological Institute, Mater Misericordiae Hospital, Dublin, Ireland
  • 8Department of Statistics, Trinity College Dublin, Dublin, Ireland
  • 9Trinity Centre for Bioengineering, Trinity College Dublin, Dublin, Ireland
  • 10Department of Neurology, The Adelaide and Meath Hospital, Dublin, Ireland

While the pathogenesis of cervical dystonia remains unknown, recent animal and clinical experimental studies have indicated its probable mechanisms. Abnormal temporal discrimination is a mediational endophenotype of cervical dystonia and informs new concepts of disease pathogenesis. Our hypothesis is that both abnormal temporal discrimination and cervical dystonia are due to a disorder of the midbrain network for covert attentional orienting caused by reduced gamma-aminobutyric acid (GABA) inhibition, resulting, in turn, from as yet undetermined, genetic mutations. Such disinhibition is (a) subclinically manifested by abnormal temporal discrimination due to prolonged duration firing of the visual sensory neurons in the superficial laminae of the superior colliculus and (b) clinically manifested by cervical dystonia due to disinhibited burst activity of the cephalomotor neurons of the intermediate and deep laminae of the superior colliculus. Abnormal temporal discrimination in unaffected first-degree relatives of patients with cervical dystonia represents a subclinical manifestation of defective GABA activity both within the superior colliculus and from the substantia nigra pars reticulata. A number of experiments are required to prove or disprove this hypothesis.

Keywords: cervical dystonia, temporal discrimination, covert attention, GABA, superior colliculus

Citation: Hutchinson M, Isa T, Molloy A, Kimmich O, Williams L, Molloy F, Moore H, Healy DG, Lynch T, Walsh C, Butler J, Reilly RB, Walsh R and O’Riordan S (2014) Cervical dystonia: a disorder of the midbrain network for covert attentional orienting. Front. Neurol. 5:54. doi: 10.3389/fneur.2014.00054

Received: 03 February 2014; Paper pending published: 22 March 2014;
Accepted: 03 April 2014; Published online: 28 April 2014.

Edited by:

Marina Tijssen, Academic Medical Centre, Netherlands

Reviewed by:

Bart P. C. Van De Warrenburg, Radboud University Nijmegen Medical Centre, Netherlands
Maria Stamelou, University of Athens, Greece

Copyright: © 2014 Hutchinson, Isa, Molloy, Kimmich, Williams, Molloy, Moore, Healy, Lynch, Walsh, Butler, Reilly, Walsh and O’Riordan. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

*Correspondence: Michael Hutchinson, Department of Neurology, St. Vincent’s University Hospital, Elm Park, Dublin 4, Ireland e-mail: mhutchin2@mac.com