Effect of coil orientation on strength-duration time constant and I-wave activation with controllable pulse parameter transcranial magnetic stimulation

Kevin D'Ostilio, Stefan M. Goetz, Ricci Hannah, Matteo Ciocca, Raffaella Chieffo, Jui Cheng A Chen, Angel V. Peterchev, John C. Rothwell

Research output: Contribution to journalArticle


Objective: To compare the strength-duration (S-D) time constants of motor cortex structures activated by current pulses oriented posterior-anterior (PA) or anterior-posterior (AP) across the central sulcus. Methods: Motor threshold and input-output curve, along with motor evoked potential (MEP) latencies, of first dorsal interosseus were determined at pulse widths of 30, 60, and 120. μs using a controllable pulse parameter (cTMS) device, with the coil oriented PA or AP. These were used to estimate the S-D time constant and we compared with data for responses evoked by cTMS of the ulnar nerve at the elbow. Results: The S-D time constant with PA was shorter than for AP stimulation (230.9. ±. 97.2 vs. 294.2. ±. 90.9. μs; p

Original languageEnglish
JournalClinical Neurophysiology
Publication statusAccepted/In press - 2015



  • Current direction
  • Input-output curve
  • Motor threshold
  • Pulse width
  • Strength-duration time constant
  • Transcranial magnetic stimulation

ASJC Scopus subject areas

  • Clinical Neurology
  • Neurology
  • Physiology (medical)
  • Sensory Systems

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