Comparison of 100 Hz hdTBS and Conventional iTBS
In the rat motor cortex study you provided, 100 Hz high density theta burst stimulation (100 Hz hdTBS) produces after effects that are about three times stronger than conventional intermittent TBS (iTBS) .[:cite[1]{l...
In the rat motor cortex study you provided, 100 Hz high density theta burst stimulation (100 Hz hdTBS) produces after effects that are about three times stronger than conventional intermittent TBS (iTBS) .[:cite[1]{ln=3}] What’s different vs conventional iTBS (protocol level) Conventional iTBS delivers 3 pulses per burst at 50 Hz , with bursts delivered every 200 ms , totaling 600 pulses per session .[:cite[2]{ln=3}] 100 Hz hdTBS delivers 6 pulses per burst at 100 Hz , while keeping the 200 ms inter burst interval , totaling 1200 pulses per session .[:cite[2]{ln=7}] What they found (outcome level) Using MEP measurements and comparing 100 Hz hdTBS vs iTBS (and also “prolonged iTBS” controls), the authors report that 100 Hz hdTBS induces after effects three times stronger than conventional iTBS .[:cite[1]{ln=3}] They quantified overall response using AUC of post TBS MEP signals and report that the AUC values were 19.3 ± 12.6 for 100 Hz hdTBS vs 5.9 ± 2.9 for conventional iTBS .[:cite[3]{ln=1}] They also report a significant difference between the 100 Hz hdTBS and iTBS groups: “100 Hz hdTBS group were significantly higher than that of the iTBS group (p = 0.04)” .[:cite[3]{ln=7}] Important control for “more pulses” vs “temporal structure” Because 100 Hz hdTBS and iTBS differ in pulse count ( 1200 vs 600 per session ), the paper includes prolonged iTBS (two back to back conventional iTBS sessions to match the 1200 pulses ) to test whether the enhancement is just due to total pulses.[:cite[1]{ln=4}] They say that prolonged iTBS decreased MEP response , whereas 100 Hz hdTBS increased MEP signals even though both deliver the same total number of pulses .[:cite[4]{ln=4}] So, based on this study’s results, 100 Hz hdTBS is superior to conventional iTBS not only in magnitude (≈3× stronger after effects), but also in direction relative to pulse count matched prolonged iTBS—supporting an effect of pulse temporal structure rather than just having more pulses. [:cite[1]{ln=3}], [:cite[4]{ln=4}]