TY - JOUR
T1 - Primary somatosensory cortical plasticity and tactile temporal discrimination in focal hand dystonia
AU - Conte, Antonella
AU - Rocchi, Lorenzo
AU - Ferrazzano, Gina
AU - Leodori, Giorgio
AU - Bologna, Matteo
AU - Li Voti, Pietro
AU - Nardella, Andrea
AU - Berardelli, Alfredo
PY - 2014/3
Y1 - 2014/3
N2 - Objective: To investigate whether theta burst stimulation (TBS) applied over primary somatosensory cortex (S1) modulates somatosensory temporal discrimination threshold (STDT) and writing performances in patients with focal hand dystonia (FHD). Methods: Twelve patients with FHD underwent STDT testing and writing tasks before and after intermittent, continuous, or sham TBS (iTBS, cTBS, sham TBS) over S1 contralateral to the affected hand. Twelve healthy subjects underwent iTBS and cTBS over S1 and STDT values were tested on the right hand before and after TBS. Results: Baseline STDT values were higher in patients than in healthy subjects on both the affected and unaffected hand. In patients and healthy subjects iTBS decreased, whereas cTBS increased STDT values and did so to a similar extent in both groups. In patients, although STDT values decreased after iTBS, they did not normalize. S1 modulation did not improve the writing performance. Conclusions: In patients, S1 responds normally to protocols inducing homotopic synaptic plasticity. The inhibitory interneuron activity responsible for STDT is altered. Significance: The pathophysiological mechanisms underlying abnormal temporal discrimination differ from those responsible for motor symptoms in FHD.
AB - Objective: To investigate whether theta burst stimulation (TBS) applied over primary somatosensory cortex (S1) modulates somatosensory temporal discrimination threshold (STDT) and writing performances in patients with focal hand dystonia (FHD). Methods: Twelve patients with FHD underwent STDT testing and writing tasks before and after intermittent, continuous, or sham TBS (iTBS, cTBS, sham TBS) over S1 contralateral to the affected hand. Twelve healthy subjects underwent iTBS and cTBS over S1 and STDT values were tested on the right hand before and after TBS. Results: Baseline STDT values were higher in patients than in healthy subjects on both the affected and unaffected hand. In patients and healthy subjects iTBS decreased, whereas cTBS increased STDT values and did so to a similar extent in both groups. In patients, although STDT values decreased after iTBS, they did not normalize. S1 modulation did not improve the writing performance. Conclusions: In patients, S1 responds normally to protocols inducing homotopic synaptic plasticity. The inhibitory interneuron activity responsible for STDT is altered. Significance: The pathophysiological mechanisms underlying abnormal temporal discrimination differ from those responsible for motor symptoms in FHD.
KW - Cortical plasticity
KW - Focal hand dystonia
KW - Primary somatosensory cortex
KW - Somatosensory temporal discrimination
KW - Theta-burst stimulation
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U2 - 10.1016/j.clinph.2013.08.006
DO - 10.1016/j.clinph.2013.08.006
M3 - Article
C2 - 24012050
AN - SCOPUS:84894334731
VL - 125
SP - 537
EP - 543
JO - Clinical Neurophysiology
JF - Clinical Neurophysiology
SN - 1388-2457
IS - 3
ER -