Endophenotyping in idiopathic adult onset cervical dystonia

Georg Kägi; Diane Ruge; Florian Brugger; Petra Katschnig; Rafael Sauter; Mirta Fiorio; Michele Tinazzi; John Rothwell; Kailash P Bhatia

doi:10.1016/j.clinph.2017.04.007

Endophenotyping in idiopathic adult onset cervical dystonia

Clin Neurophysiol. 2017 Jul;128(7):1142-1147. doi: 10.1016/j.clinph.2017.04.007. Epub 2017 Apr 23.

Authors

Georg Kägi¹, Diane Ruge², Florian Brugger³, Petra Katschnig⁴, Rafael Sauter⁵, Mirta Fiorio⁶, Michele Tinazzi⁷, John Rothwell⁸, Kailash P Bhatia⁹

Affiliations

¹ Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, Queen Square, London, United Kingdom; Department of Neurology, Kantonsspital St.Gallen, St.Gallen, Switzerland. Electronic address: [email protected].
² Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, Queen Square, London, United Kingdom; Department of Psychology and Neurosciences, Leibniz Research Centre for Working Environment and Human Factors, Technical University (TU) Dortmund, D-44139 Dortmund, Germany. Electronic address: [email protected].
³ Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, Queen Square, London, United Kingdom; Department of Neurology, Kantonsspital St.Gallen, St.Gallen, Switzerland. Electronic address: [email protected].
⁴ Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, Queen Square, London, United Kingdom; Department of Neurology, Division of Special Neurology, Medical University Graz, Graz, Austria. Electronic address: [email protected].
⁵ Clinical Trials Unit, Kantonsspital St. Gallen, St. Gallen, Switzerland. Electronic address: [email protected].
⁶ Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy. Electronic address: [email protected].
⁷ Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy; Neurology Unit, Borgo Trento Hospital, Verona, Italy. Electronic address: [email protected].
⁸ Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, Queen Square, London, United Kingdom. Electronic address: [email protected].
⁹ Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, Queen Square, London, United Kingdom. Electronic address: [email protected].

PMID: 28511126
DOI: 10.1016/j.clinph.2017.04.007

Abstract

Objective: Idiopathic adult onset cervical dystonia (IAOCD) is considered to be a partially penetrant autosomal dominant genetic condition. Dystonia may result from genetic and environmental factors. In this view, part of the physiology should be an endophenotype stemming from the genetic background. We assessed the most discriminative test to separate patients with IAOCD and healthy controls for further endophenotyping in non-affected 1st degree relatives.

Methods: We included patients with IAOCD, their 1st degree relatives and healthy controls. Tests performed: (1) Sensory temporal discrimination (visual, tactile, visuo-tactile), (2) Paired pulse paradigms using transcranial magnetic stimulation (TMS), (3) Mental rotation paradigms.

Results: 45 patients with IAOCD, 23 healthy controls and 14 non-affected 1st degree relatives were recruited. Visuo-tactile temporal discrimination separated best between controls and patients as well as between controls and 1st degree relatives. 36% of the latter had an abnormal visuo-tactile temporal discrimination. No difference between patients and healthy controls was found for the other paradigms.

Conclusions: Visuo-tactile temporal discrimination separates controls from patients with IAOCD and its 1st degree relatives. 36% of the latter had abnormal visuo-tactile thresholds supporting the role of visuo-tactile temporal discrimination as an endophenotype for IAOCD.

Significance: Even though the study was of exploratory design, our findings expand the understanding of endophenotypes in IAOCD.

Keywords: Dystonia; Endophenotype; Mental rotation; Temporal discrimination; Transcranial magnetic stimulation.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adult
Aged
Discrimination Learning / physiology
Dystonic Disorders / diagnosis
Dystonic Disorders / physiopathology
Endophenotypes*
Female
Humans
Male
Middle Aged
Photic Stimulation / methods
Random Allocation
Torticollis / diagnosis*
Torticollis / physiopathology*
Touch / physiology*
Transcranial Magnetic Stimulation / methods*
Visual Perception / physiology*
Young Adult