Lorenzo Rocchi1, Roberto Erro2, Elena Antelmi3, Alfredo Berardelli4, Michele Tinazzi5, Rocco Liguori6, Kailash Bhatia7, John Rothwell7. 1. Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, WC1N 3BG London, United Kingdom; Department of Neurology and Psychiatry, University of Rome "Sapienza", Viale dell'Universita' 30, 00185 Rome, Italy. Electronic address: l.rocchi@ucl.ac.uk. 2. Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, WC1N 3BG London, United Kingdom; Department of Neuroscience, Biomedicine and Movement Science, University of Verona, Piazzale L.A. Scuro 10, 37134 Verona, Italy. 3. Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, WC1N 3BG London, United Kingdom; Department of Biomedical and Neuromotor Sciences, Alma Mater Studiorum, University of Bologna, 40123 Bologna, Italy. 4. Department of Neurology and Psychiatry, University of Rome "Sapienza", Viale dell'Universita' 30, 00185 Rome, Italy; IRCCS Neuromed Institute, Via Atinense, 18, 86077 Pozzilli, Italy. 5. Department of Neuroscience, Biomedicine and Movement Science, University of Verona, Piazzale L.A. Scuro 10, 37134 Verona, Italy. 6. Department of Biomedical and Neuromotor Sciences, Alma Mater Studiorum, University of Bologna, 40123 Bologna, Italy; IRCSS Institute of Neurological Sciences, Via Altura 3, 40139 Bologna, Italy. 7. Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, WC1N 3BG London, United Kingdom.
Abstract
OBJECTIVE: High frequency repetitive somatosensory stimulation (HF-RSS), which is a patterned electric stimulation applied to the skin through surface electrodes, improves two-point discrimination, somatosensory temporal discrimination threshold (STDT) and motor performance in humans. However, the mechanisms which underlie these changes are still unknown. In particular, we hypothesize that refinement of inhibition might be responsible for the improvement in spatial and temporal perception. METHODS: Fifteen healthy subjects underwent 45min of HF-RSS. Before and after the intervention several measures of inhibition in the primary somatosensory area (S1), such as paired-pulse somatosensory evoked potentials (pp-SEP), high-frequency oscillations (HFO), and STDT were tested, as well as tactile spatial acuity and short intracortical inhibition (SICI). RESULTS: HF-RSS increased inhibition in S1 tested by pp-SEP and HFO; these changes were correlated with improvement in STDT. HF-RSS also enhanced bumps detection, while there was no change in grating orientation test. Finally there was an increase in SICI, suggesting widespread changes in cortical sensorimotor interactions. CONCLUSIONS: These findings suggest that HF-RSS can improve spatial and temporal tactile abilities by increasing the effectiveness of inhibitory interactions in the somatosensory system. Moreover, HF-RSS induces changes in cortical sensorimotor interaction. SIGNIFICANCE: HF-RSS is a repetitive electric stimulation technique able to modify the effectiveness of inhibitory circuitry in the somatosensory system and primary motor cortex.
OBJECTIVE: High frequency repetitive somatosensory stimulation (HF-RSS), which is a patterned electric stimulation applied to the skin through surface electrodes, improves two-point discrimination, somatosensory temporal discrimination threshold (STDT) and motor performance in humans. However, the mechanisms which underlie these changes are still unknown. In particular, we hypothesize that refinement of inhibition might be responsible for the improvement in spatial and temporal perception. METHODS: Fifteen healthy subjects underwent 45min of HF-RSS. Before and after the intervention several measures of inhibition in the primary somatosensory area (S1), such as paired-pulse somatosensory evoked potentials (pp-SEP), high-frequency oscillations (HFO), and STDT were tested, as well as tactile spatial acuity and short intracortical inhibition (SICI). RESULTS:HF-RSS increased inhibition in S1 tested by pp-SEP and HFO; these changes were correlated with improvement in STDT. HF-RSS also enhanced bumps detection, while there was no change in grating orientation test. Finally there was an increase in SICI, suggesting widespread changes in cortical sensorimotor interactions. CONCLUSIONS: These findings suggest that HF-RSS can improve spatial and temporal tactile abilities by increasing the effectiveness of inhibitory interactions in the somatosensory system. Moreover, HF-RSS induces changes in cortical sensorimotor interaction. SIGNIFICANCE: HF-RSS is a repetitive electric stimulation technique able to modify the effectiveness of inhibitory circuitry in the somatosensory system and primary motor cortex.
Keywords:
Cortical inhibition; Evoked potentials; High frequency oscillations; Tactile stimulation; Temporal discrimination; Transcranial magnetic stimulation
Authors: Lorenzo Rocchi; Jaime Ibáñez; Alberto Benussi; Ricci Hannah; Vishal Rawji; Elias Casula; John Rothwell Journal: Front Neurosci Date: 2018-06-12 Impact factor: 4.677
Authors: Ana Dumitru; Lorenzo Rocchi; Fedal Saini; John C Rothwell; Jonathan P Roiser; Anthony S David; Raphaelle M Richieri; Gemma Lewis; Glyn Lewis Journal: Cogn Affect Behav Neurosci Date: 2020-09-30 Impact factor: 3.282