Can a patient who has had one course of repetitive Transcranial Magnetic Stimulation (rTMS) and experienced improvement have another course a few months later?

Repeat rTMS Course After Initial Success

Yes, a patient who responded to an initial course of rTMS can and should receive another course a few months later, particularly if symptoms have returned or worsened during the interval between treatments.

Evidence Supporting Repeat Treatment Courses

The literature directly supports repeated rTMS courses in responders:

• Maintenance of response typically lasts 3-6 months after a standard acute treatment course, making repeat treatment at "a few months later" an appropriate timeframe 1.

• A study of 35 patients with treatment-resistant depression who had responded to two courses of rTMS demonstrated that repeated courses are both safe and effective, with patients tolerating multiple treatment series well 2.

• The strongest predictor for benefit from a second course is symptom worsening during the intertreatment interval - patients who experienced deterioration between treatments showed the most improvement with repeat rTMS, regardless of their response to the first course 3.

Optimal Timing and Protocol

Repeat treatment should be initiated when:

• Symptoms begin to return or worsen after the initial response (typically 3-6 months post-treatment) 1, 3
• The patient demonstrates motivation for the daily treatment burden 1, 4

Standard repeat course protocol:

• Use the same parameters as the initial successful course: typically 20-30 daily sessions over 4-6 weeks 4
• Apply high-frequency stimulation (10 Hz) to the left dorsolateral prefrontal cortex at 100-120% of resting motor threshold 4
• Deliver approximately 1800 pulses per daily session 4

Alternative: Maintenance Treatment Strategy

Rather than waiting for symptom return, consider proactive maintenance rTMS to extend the duration of response:

• Some protocols use twice-weekly maintenance sessions for 3 months following the acute treatment phase 1
• Clustered maintenance (monthly sessions of five treatments over two days) substantially delayed relapse compared to no maintenance, extending wellness from <3 months to a mean of 10.5 months 2
• This approach may be preferable to waiting for full symptom return before retreating 2

Important Clinical Considerations

Key factors for success with repeat courses:

• At least 4-6 weeks of daily treatment is required for significant clinical improvement - shorter courses (3 weeks) show no benefit over sham 1
• Protocols with 8-14 sessions or more show better sustained outcomes 5
• Only highly motivated patients should be selected given the requirement for frequent onsite visits (typically 5 sessions per week) 1, 4

Common pitfall to avoid:

• Do not assume lack of response to a second course based on initial response - the degree of symptom worsening between courses, not the initial response magnitude, predicts second course efficacy 3

Safety Profile

Repeated courses are well-tolerated:

• Both first and second treatment courses in the tinnitus study were well tolerated with no significant adverse events 3
• The aggregate literature shows only minimal and manageable adverse events with rTMS 4
• Long-term safety data from patients receiving multiple courses supports this approach 2