TMS: Indications, Contraindications, and Medications to Avoid
What TMS Treats
TMS has definite efficacy (Level A evidence) for treating major depressive disorder and chronic neuropathic pain, with probable efficacy for several other psychiatric conditions. 1, 2
FDA-Approved and Evidence-Based Indications:
- Major depressive disorder (resistant depression) - Level A evidence 3, 1
- Migraines - FDA-approved 3
- Obsessive-compulsive disorder (OCD) - FDA-approved 3
- Chronic neuropathic pain - Level A evidence for high-frequency rTMS of contralateral primary motor cortex 1, 2
- Negative symptoms of schizophrenia - Level B (probable efficacy) for high-frequency rTMS of left DLPFC 1
- Tinnitus - Level C (possible efficacy) for low-frequency rTMS of left temporoparietal cortex 1
- Auditory hallucinations - Level A evidence 2
- Chronic motor stroke - Level B evidence for low-frequency rTMS of contralesional M1 1
- Substance use disorders/addiction - emerging evidence for craving reduction 4
Special Considerations and Contraindications
Absolute Contraindications:
The primary absolute contraindication is metallic hardware in or near the head (excluding the mouth) that could be affected by the magnetic field. 5
- Ferromagnetic implants in the head/neck (cochlear implants, aneurysm clips, electrodes, stimulators) 5
- Cardiac pacemakers or implantable cardioverter-defibrillators near the stimulation site 5
Relative Contraindications and Risk Factors:
Sleep deprivation is a critical modifiable risk factor that significantly increases seizure risk and must be screened for before each session. 6, 5
High-Risk Factors for Seizures:
- Sleep deprivation - present in multiple reported seizure cases 6
- Polypharmacy with seizure threshold-lowering medications 6, 2
- History of traumatic brain injury or neurological insult 6
- Exceeding recommended stimulation parameters - most seizures occurred when guidelines were violated 2, 5
- Alcohol use - affects seizure threshold 3
Patient Populations Requiring Extra Caution:
- Epilepsy patients - TMS has been successfully used but requires careful parameter selection 3, 5
- Bipolar disorder - case reports exist but TMS has been used successfully 3
- History of traumatic brain injury - increased risk but not absolute contraindication 3, 6
- Pregnancy - insufficient safety data 5
- Children and adolescents - limited data, requires specialized protocols 3, 5
Medications to Avoid or Use with Caution
Seizure Threshold-Lowering Medications:
Despite historical concerns, bupropion is NOT contraindicated for TMS, as systematic review found no seizures in patients taking bupropion alone during TMS. 6
Medications Requiring Careful Consideration:
- Tricyclic antidepressants - lower seizure threshold 5
- Antipsychotics (particularly clozapine) - lower seizure threshold 5
- Stimulants (amphetamines, methylphenidate) - one seizure reported with bupropion + sertraline + amphetamine combination in sleep-deprived patient 6
- Theophylline - lowers seizure threshold 5
- High-dose SSRIs - may lower threshold in combination with other factors 5
The Bupropion Controversy Resolved:
- Zero seizures reported in literature review of TMS patients on bupropion monotherapy 6
- One FDA-reported seizure involved bupropion + sertraline + amphetamine in a sleep-deprived patient (multiple risk factors) 6
- Bupropion should not be considered a contraindication to TMS 6
- The risk of TMS-related seizures (<1%) is comparable to most psychotropic medications 3
Medications Documented in TMS Studies:
Studies have safely combined TMS with: diazepam, trazodone, nicotine replacement, and zolpidem 4
Critical Safety Parameters
Stimulation Limits to Prevent Seizures:
Most TMS-related seizures occurred when practitioners exceeded published safety guidelines for stimulation parameters. 2, 5
- High-frequency rTMS (≥5 Hz) carries higher seizure risk than low-frequency 6
- Follow updated Rossi 2009 safety parameters for pulse frequency, intensity, and session duration 2, 5
- Most common protocols: 10 Hz (49% of studies), 20 Hz (24%), 1 Hz (12%) 4
- Typical pulse numbers: ≤2000 pulses per session in 82% of studies 4
Pre-Treatment Screening Essentials:
- Screen for sleep deprivation before EVERY session 6, 5
- Document all medications, especially combinations 6
- Assess for recent alcohol use 3
- Review neurological history (head trauma, seizures, structural lesions) 6, 5
- Verify absence of metallic implants 5
Seizure Risk Context
The overall risk of TMS-related seizures is less than 1%, and when they occur, they are typically self-limiting and managed with supportive care only. 3
- Seizures are extremely rare when guidelines are followed 2, 5
- Self-limiting in nature - no specific treatment usually required beyond supportive care 3
- TMS has been successfully continued even in patients who previously had a TMS-related seizure 3
- Benefits may outweigh risks in refractory depression given suicide risk 3
Team and Monitoring Requirements
Professionals performing TMS must undergo rigorous training to ensure quality technical execution and proper patient care. 1