Pınar Demirayak1, Onur Emre Onat2, Aslıhan Örs Gevrekci3, Süleyman Gülsüner4, Hilmi Uysal5, Rengin S Bilgen6, Katja Doerschner7, Tayfun S Özçelik2, Hüseyin Boyacı7. 1. Neuroscience Graduate Program, Bilkent University; A.S. Brain Research Center and National Magnetic Resonance Research Center, Bilkent University, Ankara, Turkey. 2. Department of Molecular Biology and Genetics, Bilkent University, Ankara, Turkey. 3. Department of Psychology, Başkent University, Ankara, Turkey. 4. Department of Genome Sciences, University of Washington, Seattle, WA, USA. 5. Department of Neurology, Akdeniz University School of Medicine, Antalya, Turkey. 6. Department of Neurology, Bezmialem University School of Medicine, İstanbul, Turkey. 7. Neuroscience Graduate Program, A.S. Brain Research Center and National Magnetic Resonance Research Center and Psychology, Bilkent University, Ankara, Turkey; Department of Psychology, JL Giessen University, Giessen, Germany.
Abstract
PURPOSE: Congenital mirror movement disorder (CMMD) is characterized by unintended, nonsuppressible, homologous mirroring activity contralateral to the movement on the intended side of the body. In healthy controls, unilateral movements are accompanied with predominantly contralateral cortical activity, whereas in CMMD, in line with the abnormal behavior, bilateral cortical activity is observed for unilateral motor tasks. However, task-related activities in subcortical structures, which are known to play critical roles in motor actions, have not been investigated in CMMD previously. METHODS: We investigated the functional activation patterns of the motor components in CMMD patients. By using linkage analysis and exome sequencing, common mutations were revealed in seven affected individuals from the same family. Next, using functional magnetic resonance imaging (fMRI) we investigated cortical and subcortical activity during manual motor actions in two right-handed affected brothers and sex, age, education, and socioeconomically matched healthy individuals. RESULTS: Genetic analyses revealed heterozygous RAD51 c.401C>T mutation which cosegregated with the phenotype in two affected members of the family. Consistent with previous literature, our fMRI results on these two affected individuals showed that mirror movements were closely related to abnormal cortical activity in M1 and SMA during unimanual movements. Furthermore, we have found previously unknown abnormal task-related activity in subcortical structures. Specifically, we have found increased and bilateral activity during unimanual movements in thalamus, striatum, and globus pallidus in CMMD patients. CONCLUSION: These findings reveal further neural correlates of CMMD, and may guide our understanding of the critical roles of subcortical structures for unimanual movements in healthy individuals.
PURPOSE:Congenital mirror movement disorder (CMMD) is characterized by unintended, nonsuppressible, homologous mirroring activity contralateral to the movement on the intended side of the body. In healthy controls, unilateral movements are accompanied with predominantly contralateral cortical activity, whereas in CMMD, in line with the abnormal behavior, bilateral cortical activity is observed for unilateral motor tasks. However, task-related activities in subcortical structures, which are known to play critical roles in motor actions, have not been investigated in CMMD previously. METHODS: We investigated the functional activation patterns of the motor components in CMMD patients. By using linkage analysis and exome sequencing, common mutations were revealed in seven affected individuals from the same family. Next, using functional magnetic resonance imaging (fMRI) we investigated cortical and subcortical activity during manual motor actions in two right-handed affected brothers and sex, age, education, and socioeconomically matched healthy individuals. RESULTS: Genetic analyses revealed heterozygous RAD51 c.401C>T mutation which cosegregated with the phenotype in two affected members of the family. Consistent with previous literature, our fMRI results on these two affected individuals showed that mirror movements were closely related to abnormal cortical activity in M1 and SMA during unimanual movements. Furthermore, we have found previously unknown abnormal task-related activity in subcortical structures. Specifically, we have found increased and bilateral activity during unimanual movements in thalamus, striatum, and globus pallidus in CMMD patients. CONCLUSION: These findings reveal further neural correlates of CMMD, and may guide our understanding of the critical roles of subcortical structures for unimanual movements in healthy individuals.
Authors: M Krams; R Quinton; M J Mayston; L M Harrison; R J Dolan; P M Bouloux; J A Stephens; R S Frackowiak; R E Passingham Journal: Brain Date: 1997-07 Impact factor: 13.501
Authors: K Kullander; S D Croll; M Zimmer; L Pan; J McClain; V Hughes; S Zabski; T M DeChiara; R Klein; G D Yancopoulos; N W Gale Journal: Genes Dev Date: 2001-04-01 Impact factor: 11.361
Authors: Stuart A Royal; R Shane Tubbs; Michael G D'Antonio; Michael J Rauzzino; W Jerry Oakes Journal: AJNR Am J Neuroradiol Date: 2002-04 Impact factor: 3.825