title: Changes in intracortical circuits of the human motor cortex following theta burst stimulation of the lateral cerebellum.
abstract: OBJECTIVE
  The cerebellum takes part in several motor functions through its influence on the motor cortex (M1). Here, we applied the theta burst stimulation (TBS) protocol, a novel form of repetitive Transcranial Magnetic Stimulation (rTMS) over the lateral cerebellum. The aim of this study was to test whether TBS of the lateral cerebellum could be able to modulate the excitability of the contralateral M1 in healthy subjects.
  
  
  METHODS
  Motor-evoked potentials (MEPs) amplitude, short intracortical inhibition (SICI), long intracortical inhibition (LICI) and short intracortical facilitation (SICF) were tested in the M1 before and after cerebellar continuous TBS (cTBS) or intermittent TBS (iTBS).
  
  
  RESULTS
  We found that cTBS induced a reduction of SICI and an increase of LICI. On the other hand, cerebellar iTBS reduced LICI. MEPs amplitude also differently vary following cerebellar stimulation with cTBS or iTBS, resulting in a decrease by the former and an increase by the latter.
  
  
  CONCLUSIONS
  Although the interpretation of these data remains highly speculative, these findings reveal that the cerebellar cortex undergoes bidirectional plastic changes that modulate different intracortical circuits within the contralateral primary motor cortex.
  
  
  CONCLUSIONS
  Long-lasting modifications of these pathways could be useful to treat various pathological conditions characterized by an altered cortical excitability.
authors.affiliation: Laboratorio di Neurologia Clinica e Comportamentale, Fondazione Santa Lucia IRCCS, Via Ardeatina, 306, 00179 Rome, Italy. g.koch@hsantalucia.it
authors.forename: Giacomo
authors.initials: G
authors.lastname: Koch
authors.forename: Francesco
authors.initials: F
authors.lastname: Mori
authors.forename: Barbara
authors.initials: B
authors.lastname: Marconi
authors.forename: Claudia
authors.initials: C
authors.lastname: Codecà
authors.forename: Cristiano
authors.initials: C
authors.lastname: Pecchioli
authors.forename: Silvia
authors.initials: S
authors.lastname: Salerno
authors.forename: Sara
authors.initials: S
authors.lastname: Torriero
authors.forename: Emanuele
authors.initials: E
authors.lastname: Lo Gerfo
authors.forename: Pablo
authors.initials: P
authors.lastname: Mir
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Oliveri
authors.forename: Carlo
authors.initials: C
authors.lastname: Caltagirone
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D002531:Cerebellum / Q000502:physiology / Q000528:radiation effects*; D004056:Differential Threshold / Q000502:physiology; D004558:Electric Stimulation / Q000379:methods*; D004576:Electromyography / Q000379:methods; D019054:Evoked Potentials, Motor / Q000502:physiology*; D005260:Female; D007839:Functional Laterality; D006225:Hand / Q000294:innervation; D006801:Humans; D008297:Male; D009044:Motor Cortex / Q000502:physiology*; D009334:Neck Muscles / Q000294:innervation; D009433:Neural Inhibition / Q000502:physiology / Q000528:radiation effects; D011597:Psychomotor Performance; D013826:Theta Rhythm; D013997:Time Factors; D050781:Transcranial Magnetic Stimulation; D055815:Young Adult