Transcranial Magnetic Stimulation as a Treatment of Depression and Other Psychiatric and Neurologic Disorders
Transcranial magnetic stimulation (TMS) of the brain may be considered medically necessary for the treatment of Major Depression when one of the following criteria are met:
There is insufficient evidence to support TMS maintenance therapy. Therefore, TMS maintenance therapy is considered investigational.
Effective January 1, 2011, there are CPT category I codes for this procedure:
90867 Therapeutic repetitive transcranial magnetic stimulation treatment; planning
90868 delivery and management, per session.
90869 Therapeutic repetitive transcranial magnetic stimulation (TMS) treatment; subsequent motor threshold re-determination with delivery and management.
Transcranial magnetic stimulation (TMS) is a non-invasive method of delivering electrical stimulation to the brain. A magnetic field is delivered through the skull, where it induces electric currents that affect neuronal function. Repetitive TMS (rTMS) is being evaluated as a treatment of depression and other psychiatric/neurologic brain disorders.
Transcranial magnetic stimulation (TMS) was first introduced in 1985 as a new method of noninvasive stimulation of the brain. The technique involves placement of a small coil over the scalp; a rapidly alternating current is passed through the coil wire, producing a magnetic field that passes unimpeded through the scalp and bone, resulting in electrical stimulation of the cortex. TMS was initially used to investigate nerve conduction; for example, transcranial magnetic stimulation over the motor cortex will produce a contralateral muscular-evoked potential. The motor threshold, which is the minimum intensity of stimulation required to induce a motor response, is empirically determined for each individual by gradually increasing the intensity of stimulation. The stimulation site for treatment is usually 5 cm anterior to the motor stimulation site.
Interest in the use of transcranial magnetic stimulation as a treatment for depression was augmented by the development of a device that could deliver rapid, repetitive stimulation. Imaging studies had showed a decrease in activity of the left dorsolateral prefrontal cortex (DLPFC) in depressed patients, and early studies suggested that high frequency (e.g., 5–10 Hz) TMS of the left DLPFC had antidepressant effects. Low frequency (1–2 Hz) stimulation of the right DLPFC has also been investigated. The rationale for low frequency TMS is inhibition of right frontal cortical activity to correct the interhemispheric imbalance. A combination approach (bilateral stimulation) or deep stimulation with an H1 coil, are also being explored. In contrast to electroconvulsive therapy, transcranial magnetic stimulation does not require anesthesia and does not induce a convulsion.
rTMS is also being tested as a treatment for a variety of other disorders including alcohol dependence, Alzheimer’s disease, neuropathic pain, obsessive-compulsive disorder (OCD), post-partum depression, depression associated with Parkinson’s disease, stroke, posttraumatic stress disorder, panic disorder, epilepsy,dysphagia, Tourette’s syndrome, schizophrenia, migraine, spinal cord injury, fibromyalgia, and tinnitus. (See Related Policies.) In addition to the potential for altering interhemispheric imbalance, it has been proposed that high frequency rTMS may facilitate neuroplasticity.
Devices for transcranial stimulation have received clearance by the U.S. Food and Drug Administration (FDA) for diagnostic uses. One device, NeoPulse (Neuronetics, Atlanta, GA) received approval in Canada, Israel and the United States as a therapy for depression. Initially examined by the FDA under a traditional 510(k) application, the NeoPulse, now known as NeuroStar® TMS, received clearance for marketing as a “De Novo” device in 2008. NeuroStar® TMS is indicated for the treatment of patients with depression who have failed one 6-week course of antidepressant medication.
Note: An FDA advisory panel met in January 2007 to determine if the risk to benefit profile for the NeoPulse was comparable to the risk to benefit profile of predicate electroconvulsive therapy (ECT) devices. The panel was not asked for a recommendation regarding the regulatory determination of substantial equivalence for this 510(k) submission. Materials presented at the Neurological Devices Panel meeting are posted online at: www.fda.gov/ohrms/dockets/ac/07/briefing/2007-4273b1_00-index.htm. A summary of the meeting is available online at: http://www.fda.gov/cdrh/panel/summary/neuro-012607.html
Medical policies are systematically developed guidelines that serve as a resource for Company staff when determining coverage for specific medical procedures, drugs or devices. Coverage for medical services is subject to the limits and conditions of the member benefit plan. Members and their providers should consult the member benefit booklet or contact a customer services representative to determine whether there are any benefit limitations applicable to this service or supply.
State or federal mandates (e.g., FEP) may dictate that all devices, drugs, or biologics approved by the U.S. Food and Drug Administration (FDA) may not be considered investigational, and thus these devices may be assessed only on the basis of their medical necessity.
In October 2008, the NeuroStar® TMS received U.S. Food and Drug Administration (FDA) marketing clearance as a de novo device for therapy of patients with treatment-resistant depression (TRD) who have failed one 6-week course of antidepressant medication.
The Blue Cross and Blue Shield Technology Evaluation Center (TEC) published an assessment of repetitive TMS (rTMS) for depression in 2009. (1) The TEC Assessment concluded that the available evidence did not permit conclusions regarding the effect of TMS on health outcomes. Limitations of the evidence included:
TEC published an updated Assessment of TMS for depression in 2011. (2) Included were 6 recent meta-analyses, the largest of which evaluated 30 double-blind sham-controlled trials with a total of 1,383 patients. Recent clinical trials were also reviewed. The 2011 TEC Assessment reached the following conclusions:
Studies published prior to 2008 are included if the study design was a randomized sham-controlled double-blind trial that enrolled at least 40 subjects; refer to the 2008 meta-analysis by Schutter for a summary of study characteristics and stimulation parameters used in these trials. (3) The evidence review is divided by key differences in treatment protocols, specifically high-frequency left dorsolateral prefrontal cortex stimulation (DLPFC), low-frequency (1–2 Hz) stimulation of the right dorsolateral prefrontal cortex, or combined high-frequency and low-frequency stimulation.
Note that over the last decade, there has been a trend to increase the intensity, trains of pulses, total pulses per session, and number of sessions. (4) Unless otherwise indicated in the trials described below, stimulation was set at 100% to 120% of motor threshold, clinical response was defined as an improvement of 50% or more on the Hamilton Depression Rating Scale (HAM-D), and remission was considered to be a score of 7 or less on the HAM-D.
High frequency rTMS of the left DLPFC for Treatment-Resistant Depression (TRD)
Lam and colleagues conducted a meta-analysis of 24 randomized controlled trials comparing active versus sham repetitive TMS (rTMS) in patients with TRD, although there were varying definitions of TRD. (5) This analysis calculated a number needed to treat (NNT) of 6, with a clinical response in 25% of active rTMS and 9% of sham rTMS patients. Remission was reported for 17% of active rTMS and 6% of sham rTMS patients.
The largest study (23 study sites) included in the meta-analysis was a double blind multicenter trial with 325 TRD patients randomized to daily sessions of high frequency active or sham rTMS (Monday to Friday for 6 weeks) of the left dorsolateral prefrontal cortex (DLPFC). (6) Treatment-resistant depression was defined as failure of at least one adequate course of antidepressant treatment. Patients had failed an average of 1.6 treatments in the current episode, with approximately half of the study population failing to benefit from at least 2 treatments. Loss to follow-up was similar in the 2 groups, with 301 (92.6%) patients completing at least one post-baseline assessment and an additional 8% of patients from both groups dropping out before the 4-week assessment. Intent-to-treat (ITT) analysis showed a trend favoring the active rTMS group in the primary outcome measure (2 points on the Montgomery-Asberg Depression Rating Scale [MADRS]; p = 0.057) and a modest (2-point) but significant improvement over sham treatment on the HAM-D. The authors reported that after 6 weeks of treatment the subjects in the active rTMS group were more likely to have achieved remission than the sham controls (14% vs. 5% respectively), although this finding is limited by loss-to-follow-up.
In 2010, George et al. reported a randomized sham-controlled trial that involved 190 patients treated with left-prefrontal rTMS. (7) This was a multi-centered study involving patients with a moderate level of treatment resistance. The response rate using an ITT analysis was 14% for rTMS and 5% for sham (p=0.02). In this study, the site for stimulation was determined through pre-treatment magnetic resonance imaging (MRI). In a 3-week, open-label, follow-up phase of the study in which all patients received active therapy but remained masked to their original treatment arm, the remission rates rose to 30.2% in the originally active group and 29.6% in the original sham group.
Another randomized sham-controlled double-blind trial was conducted in 68 patients who had failed at least 2 courses of antidepressants. (8) Three patients in each group did not complete the 15 treatment sessions or were excluded due to a change in medication during treatment, resulting in 91% follow-up. Independent raters found a clinical response in 31% (11 of 35) of the active rTMS patients and 6% (2 of 33) of the sham group. The average change in HAM-D was 7.8 for the active group and 3.7 for the control group. The Beck Depression Inventory (BDI) decreased by 11.3 points in the active rTMS group and 4.8 points in controls. Remission was observed in 7 patients (20%) in the active rTMS group and 1 patient (3%) in the control group. Regarding effectiveness of blinding; 15% of subjects in each group guessed that they were receiving active TMS after the first session. After the 15th session, 58% of the rTMS group and 43% of the sham group guessed that they had received active TMS; responders were more likely than non-responders (85% vs. 42%) to think that they had received the active treatment. The 11 responders were treated with antidepressant medication and followed for 6-months. Of these, 1 was lost to follow-up, 5 (45%) relapsed, and 5 (45%) did not relapse.
Rossini and colleagues randomized 54 patients who had failed at least two adequate courses of antidepressants to sham control or active rTMS at 80% or 100% of motor threshold (MT) for 10 sessions over a 2-week period. (9) Double-blind evaluation found an intensity-dependent response with 6% (1 of 16) of the sham, 28% (5 of 18) of the 80% MT, and 61% (11 of 18) of the 100% MT groups showing improvement of 50% or more over a 5-week evaluation. All of the patients reported that they were unaware of the differences between sham and active stimulation.
In a 2008 report, Mogg et al. randomized 59 patients with major depression who had failed at least one course of pharmacotherapy for the index depressive episode. (10) In this study population, 78% of the patients had failed 2 treatment courses and 53% had failed 3. The sham coil, which was provided by Magstim, was visually identical to the real coil and made the same clicking sound, but did not deliver a magnetic field to scalp or cortex. Blinded assessments were measured 2 days after the 5th and final (tenth) sessions (97% follow-up), with additional assessments at 6 weeks (90% follow-up) and 4 months (83% follow-up). The mean group difference was estimated to be 0.3 points in HAM-D scores for the overall analysis. Interpretation of this finding is limited since 7 sham patients (23%) were given a course of real rTMS after the 6-week assessment and analyzed as part of the sham group in the ITT analysis. The study was powered to detect a difference of 3.5 points in the HAM-D between the active and sham groups, and the 2.9 point group difference observed at the end-of-treatment was not significant. A higher percentage of patients in the active rTMS group achieved remission criteria of 8 points or less on the HAM-D (25% vs. 10% control), and there was a trend for more patients to achieve clinical response in the active rTMS group (32% vs. 10%, p = 0.06). All of the 12 patients who met the criterion for clinical response (9 active and 3 sham) thought that they had received real rTMS, with more patients in the active group (70%) than the sham group (38%) guessing that they had received the real treatment. Interpretation of this finding is also limited, since the reason the subjects guessed that they had active treatment was not reported, and the subjects were not asked to guess before they began to show a clinical response.
A small double-blind randomized trial from 2009 suggests that specific targeting of Brodman areas 9 and 46 may enhance the anti-depressant response compared with the standard targeting procedure, i.e., measuring 5 cm anterior from the motor cortex. (11) Fifty-one patients who had failed at least two 6-week courses of antidepressant medication (average 5.7 failed courses) were randomized to a standard localization procedure or to structural magnetic resonance imaging (MRI)-aided localization for 3 weeks (with one-week extension if > 25% reduction on the MADRS). Six patients in the targeted group and 10 in the standard group withdrew due to lack of response. A single patient in the targeted group and 5 in the standard group withdrew for other reasons, resulting in 17 patients in the targeted group and 12 in the standard group continuing for the full 4 weeks of treatment. To adjust for the imbalance in discontinuation rates, a mixed model statistical analysis was used. There was a significant difference between the groups in the overall mixed model analysis, and planned comparisons showed significant improvement in MADRS scores for the targeted group at 4 weeks. Response criteria were met by 42% of the targeted group and 18% of the standard group. Remission criteria were met by 30% of the targeted group and 11% of the standard group. Although encouraging, additional trials with a larger number of subjects are needed to evaluate this procedure.
Several studies have compared the outcomes of rTMS with those from electroconvulsive therapy. In one study, 40 patients with nonpsychotic major depression were treated over the course of 1 month (20 total sessions) and evaluated with the HAM-D, in which a response was defined as a 50% decrease with a final score of less than or equal to 10. (12) There was no difference in response rate between the 2 groups; 12 of 20 responded in the electroconvulsive therapy group compared to 11 of 20 in the magnetic stimulation group. A United Kingdom National Institute for Health Research health technology assessment compared efficacy and cost-effectiveness of rTMS and electroconvulsive therapy. (13) Forty-six patients who had been referred for electroconvulsive therapy were randomly assigned to either electroconvulsive therapy (average of 6.3 sessions) or a 15-day course (5 treatments per week) of rTMS of the left DLPFC. Electroconvulsive therapy resulted in a 14-point improvement in the HAM-D and a 59% remission rate. Repetitive TMS was less effective than electroconvulsive therapy (5-point improvement in HAM-D and a 17% remission rate). Another study reported no significant difference between electroconvulsive therapy and rTMS in 42 patients with TRD; however, response rates for both groups were low. (14) The number of remissions (score of 7 or less on the HAM-D) totaled 3 (20%) for electroconvulsive therapy and 2 (10%) for rTMS.
Low frequency rTMS of the right DLPFC or Bilateral Stimulation for Treatment-Resistant Depression (TRD)
Fitzgerald et al. randomized 60 patients who had failed a minimum of at least 2 six-week courses of antidepressant medications into one of 3 groups; high frequency left rTMS, low frequency right rTMS, or sham stimulation over 10 sessions. (16) All patients who entered the study completed the double-blind randomized phase, which showed no difference between the two active treatments (left: 13.5% reduction; right: 15% reduction) and greater improvements in the MADRS scores compared to the sham group (0.76% reduction). Only 1 patient achieved 50% improvement during the initial 2 weeks. Then, only the subjects who showed at least 20% improvement at the end of the 10 sessions (15 active and 2 sham) continued treatment. Patients who did not respond by at least 20% were switched to a different active treatment. From week-2 to week-4 there was greater improvement in the low frequency right rTMS group compared with the high frequency left rTMS group (39% vs. 14% improvement in MADRS, respectively). Seven patients (18% of 40) showed a clinical response of greater than 50% by the end of the 4 weeks.
In a subsequent study Fitzgerald and colleagues randomized 50 patients with TRD to sequential bilateral active or sham rTMS. (17) After 2 weeks of treatment, 3 subjects had dropped out of the sham treatment group and there was a slight but non-significant improvement favoring the active group for the MADRS (26.2 vs. 30.9, respectively) and the BDI (18.3 vs. 21.6, respectively). At this time point, 60% of subjects receiving active rTMS and 50% of subjects receiving sham treatment guessed that they were in the active group. The clinical response was reported by subjects as the major reason for their guess, with 11 of 13 responders (9 active and 2 sham) guessing that they were in the active group. As in the earlier study, only the subjects who showed at least 20% improvement at the end of each week continued treatment. Treatment on week 3 was continued for 15 subjects in the active group and 7 subjects in the sham group. By week six, 11 subjects in the active rTMS remained in the study, with no control subjects remaining. Final ratings for the 11 subjects who continued to respond through week 6 were 8.9 on the MADRS and 9.2 on the BDI.
Another multicenter double blind trial randomized 130 patients with treatment-resistant depression to 5 sessions per week of either 1- or 2-Hz rTMS over the right DLPFC. (18) Sixty-eight patients (52%) completed 4 weeks of treatment; there was an approximate 30% improvement in depression scales, with no differences between the 1- or 2-Hz groups. Due to the potential for placebo effects for this type of intervention, the absence of a sham control group limits interpretation.
A small randomized, sham-controlled trial was published in 2010 that involved either right or left rTMS in 48 patients with TRD. (19) Overall reductions in the HAM-D-24 from baseline to 3 months were not significantly different between rTMS and sham treatment groups. In this small study, right cranial stimulation was significantly more effective than left cranial stimulation (sham or rTMS).
rTMS as an Adjunctive Treatment for Moderate to Severe Depression
Schutter conducted a meta-analysis of 30 double-blind randomized sham-controlled trials (1,164 patients) of high frequency rTMS over the left DLPFC in patients with major depression. (3) The pooled weighted mean effect size for treatment was calculated with Hedges’ g, a standardized mean difference that adjusts for sampling variance, to be 0.39 (95% confidence interval 0.25-0.54), which is considered moderate. For 27% of the population rTMS was used as a primary/adjunctive treatment; 3 trials were included that used rTMS as a primary/adjunctive treatment for depression and enrolled more than 40 subjects. (19-21) Repetitive TMS has also been examined in patients with clinical evidence of cerbrovascular disease and late-life depression. (22) A 2012 study examined the efficacy of ultra-high frequency (30Hz) rTMS over the left prefrontal cortex in moderate to severely depressed patients who were taking medication. (23) Sham treatment consisted of low frequency stimulation to the left prefrontal cortex. No benefit of rTMS was found to improve performance on the trail-making test, which covaried with improvement of psychomotor retardation.
Additional research on whether adjunctive rTMS can improve response to pharmacologic treatment as a first-line therapy is also needed.
Fitzgerald et al. reported a prospective open-label trial of clustered maintenance rTMS for patients with refractory depression. (24) All patients had received a second successful course of rTMS following relapse, and were then treated with monthly maintenance therapy consisting of 5 rTMS treatments over a 2.5-day period (Friday evening, Saturday and Sunday). Patients were treated with maintenance therapy of the same type that they had initially received (14 high frequency to the left dorsolateral prefrontal cortex, 12 low frequency to the right dorsolateral prefrontal cortex, and 9 bilateral). The primary outcome was the mean duration until clinical relapse, addition or change of antidepressant medication, or withdrawal from maintenance treatment to pursue other treatment options. Out of 35 patients, 25 (71%) relapsed at a mean of 10.2 months (range, 2 to 48 months), which was substantially shorter than the interval (< 3 months) for relapse from the initial treatment.
Janicak and colleagues reported on assessment of relapse during a multisite, open-label study. (25) In this study, patients who met criteria for partial response during either a sham–controlled or open-label phase of a prior study were tapered from rTMS and simultaneously started on maintenance antidepressant monotherapy. They were then followed for 24 weeks. Ten of 99 patients relapsed. Thirty-eight patients had symptom worsening, and 32 of these (84%) had symptomatic benefit with adjunctive rTMS.
A retrospective study that included maintenance rTMS was reported by Connolly et al. in 2012. (26) Out of the first 100 cases treated at their institution, 42 received maintenance rTMS. Most of the patients had failed more than 1 adequate antidepressant trial and were treated with high frequency rTMS over the dorsolateral prefrontal cortex. Low frequency rTMS to the right dorsolateral prefrontal cortex was given in patients with a family or personal history of seizures and in some patients who were also receiving high frequency rTMS. The response rate was 50.6% of the first 100 cases and the remission rate was 24.7%. Maintenance treatment (42 patients) was tapered gradually from 2 sessions per week for the first 3 weeks to monthly. At 6 months after the initial rTMS treatment, 26 of the 42 patients (62%) maintained their response.
Additional data are needed related to durability of effect and to maintenance phases.
Ahmed et al. randomized 45 patients with probable Alzheimer’s disease to 5 sessions of bi-lateral high-frequency rTMS, bi-lateral low-frequency rTMS, or sham TMS over the dorsolateral prefrontal cortex. (27) Thirty-two patients had mild to moderate dementia and 13 had severe dementia. There were no significant differences between groups at baseline. Measures of cortical excitability immediately after the last treatment session showed that treatment with high-frequency rTMS reduced the duration of transcallosal inhibition. At 3 months after treatment, the high-frequency rTMS group improved significantly more than the other 2 groups in standard rating scales, and subgroup analysis showed that this was due primarily to improvements in patients with mild/moderate dementia. Patients in the subgroup of mild to moderate dementia who were treated with high-frequency rTMS improved from 18.4 to 22.6 on the Mini Mental State Examination (MMSE), from 20.1 to 24.7 on the Instrumental Daily Living Activity (IADL) scale and from 5.9 to 2.6 on the Geriatric Depression Scale (GDS).
Rabey et al. reported an industry-sponsored randomized double-blind trial of rTMS with cognitive training (NeuroAD system) in15 patients with probable mild to moderate Alzheimer’s disease. (28) Patients received 5 sessions per week for 6 weeks over 6 different brain areas, followed by biweekly sessions for 3 months. Specific cognitive tasks were designed for the 6 targeted brain regions. These included syntax and grammar for Broca’s area, comprehension and categorization for Wernicke’s area, action naming, object naming and spatial memory tasks for the right and left dorsolateral prefrontal cortex, and spatial attention tasks for the right and left somatosensory association cortex. After 6 weeks of treatment there was an improvement in the average Alzheimer Disease Assessment Scale, cognitive subsection (ADAS-cog) score of 3.76 points in the rTMS group compared to 0.47 in the placebo group. After 4.5 months of treatment the ADAS-cog score in the rTMS group had improved by 3.52 points compared to a worsening of 0.38 in the placebo group. The Clinical Global Impression of Change improved significantly by an average of 3.57 after 6 weeks and 3.67 after 4.5 months compared to 4.25 and 4.29 in the placebo group.
In 2012, Weaver et al. reported a randomized sham-controlled crossover study of rTMS in 9 adolescents/young adults with attention-deficit/ hyperactivity disorder (ADHD). (29) rTMS was administered in 10 sessions over 2 weeks, with 1 week of no TMS between the active and sham phases. The clinical global impression and ADHD-IV scales improved in both conditions over the course of the study, with no significant differences between the active and sham phases.
In 2008, Walpoth et al. reported no evidence of efficacy of rTMS in a small trial (n=14) of patients with bulimia nervosa. (30)
rTMS for the treatment of dysphagia following stroke has been examined in small randomized controlled trials. One study randomized 26 patients to rTMS or sham over the affected esophageal motor area of the cortex. (31) Ten minutes of rTMS over 5 days reduced both dysphagia on the Dysphagic Outcome and Severity scale and disability measured by the Barthel Index. There was a trend for improved hand grip strength in the rTMS group. Blinded assessment showed that the effects were maintained at 1 month and 2 month follow-up. Another study randomized 30 patients with dysphagia following stroke or traumatic brain injury to high frequency rTMS, low frequency rTMS, or sham stimulation. (32) Active or sham rTMS was administered bilaterally over the anterolateral scalp over a period of 2 weeks. Swallowing scale scores improved in both the low-frequency and sham groups. Improvement in videofluoroscopic evaluation was greater in the low frequency rTMS group than the other 2 groups. Blinding of evaluators was not described.
Study in a larger number of subjects is needed to determine the efficacy of this treatment with greater certainty.
In 2012, Sun et al. reported a randomized double-blind controlled trial of low frequency rTMS to the epileptogenic zone for refractory partial epilepsy. (33) Sixty patients were randomized into 2 groups; one group received 2 weeks of rTMS at 90% of resting motor threshold and the other group received rTMS at 20% of resting motor threshold. Outcomes were measured for 8 weeks after the end of treatment. With intent-to-treat analysis, high intensity rTMS resulted in a significant decrease in seizures when compared to baseline (from 8.9 per week at baseline to 1.8 per week at follow-up) and when compared to low intensity rTMS (from 8.6 at baseline to 8.4 per week at follow-up). High intensity rTMS also decreased interictal discharges (from 75.1 to 33.6 per hour) and improved ratings on the Symptom Checklist-90. These initial results are promising, but require substantiation in additional trials.
A 2012 systematic review included 4 studies on transcranial direct current stimulation and 5 on rTMS for treatment of fibromyalgia pain. (34) Three of the 5 trials were considered to be high quality. Four of the 5 were double-blind randomized controlled trials; the 5th included study was a case series of 4 patients who were blinded to treatment. Quantitative meta-analysis was not conducted due to variability in brain site, stimulation frequency/intensity, total number of sessions, and follow-up intervals, but 4 of the 5 studies on rTMS reported significant decreases in pain. Greater durability of pain reduction was observed with stimulation of the primary motor cortex compared to the dorsolateral prefrontal cortex.
One of the studies included in the systematic review was a small 2011 trial that was conducted in the U.S. by Short et al. (35) Twenty patients with fibromyalgia, defined by the American College of Rheumatology criteria, were randomized to 10 sessions of left prefrontal rTMS or sham TMS along with their standard medications. At 2 weeks after treatment, there was a significant change from baseline in average visual analog scale (VAS) for pain in the rTMS group (from 5.60 to 4.41) but not in the sham-treated group (from 5.34 to 5.37). There was also a significant improvement in depression symptoms in the active group compared to baseline (from 21.8 to 14.10) but not in the sham group (from 17.6 to 16.4). There were no statistically significant differences between the groups in this small trial.
Additional study is needed to determine effective treatment parameters in a larger number of subjects and to evaluate durability of the effect.
Two small (n=18 and 30) randomized sham-controlled trials found no evidence of efficacy for treatment of obsessive compulsive disorder (OCD), although another small sham-controlled trial (n=21) reported promising results with bilateral stimulation of the supplementary motor area. (36-38)
In 2013, Mantovani et al. reported a randomized double-blind sham-controlled trial of low frequency rTMS to the right dorsolateral prefrontal cortex in 21 patients with panic disorder with comorbid major depression. (39) Response was defined as a 40% or greater decrease on the panic disorder severity scale (PDSS) and a 50% or greater decrease on the HAM-D. After 4 weeks of treatment, the response rate for panic was 50% with active rTMS and 8% with sham. There was no significant difference in the response rate for depressive symptoms (25% active rTMS vs. 8% for sham). After an additional 4 weeks of open-label treatment, the response rate was 67% for panic and 50% for depressive symptoms. Five of 12 responders returned for 6-month follow-up and showed sustained improvement.
A systematic review from 2009 included 10 randomized controlled trials with a total of 275 patients with Parkinson disease. (40) Seven of the studies were double-blind, one was not blinded and 2 of the studies did not specify whether the raters were blinded. In studies that used high frequency rTMS there was a significant improvement on the Unified Parkinson’s Disease Rating Scale (UPDRS) with a moderate effect size of -0.58. For low frequency rTMS the results were heterogeneous and did not significantly reduce the UPDRS. The analyzed studies varied in outcomes reported, rTMS protocol, patient selection criteria, demographics, stages of Parkinson disease and duration of follow-up, which ranged from immediate to 16 weeks after treatment.
In 2012, Benninger et al. reported a randomized double-blind sham-controlled trial of brief (6 sec) very high frequency (50 Hz) rTMS over the motor cortex in 26 patients with mild to moderate Parkinson disease. (41) Eight sessions of 50 Hz rTMS did not improve gait, bradykinesia, or global and motor scores on the UPDRS compared to the sham-treated group. Activities of daily living were significantly improved a day after the intervention, but the effect was no longer evident at 1 month after treatment. Functional status and self-reported well-being were not affected by the treatment. No adverse effects of the very high frequency stimulation were identified.
Another study from 2012 randomized 20 patients with Parkinson disease to 12 brief sessions (6 min) of high frequency (5-Hz) rTMS or sham rTMS over the leg area of the motor cortex followed by treadmill training. (42) Blinded evaluation showed a significant effect of rTMS combined with treadmill training on neurophysiological measures, and change in fast walking speed and the timed up and go task. Mean treadmill speed improved to a similar extent in the active and sham rTMS groups.
Additional study with a larger number of subjects and longer follow-up is needed to determine if rTMS improves motor symptoms in patients with Parkinson disease.
Myczkowski et al. conducted a double-blind sham-controlled study of 14 patients with postpartum depression randomized to 20 sessions of active or sham rTMS over the left dorsolateral prefrontal cortex. (43) A positive response to treatment was defined as a reduction of at least 30% in the HAM-D and Edinburgh Postnatal Depression Scale (EPDS). At 2 weeks after the end of treatment, the active rTMS group showed significant improvements in the HAM-D, Global Assessment Scale, Clinical Global Impression and Social Adjustment Scale. The difference in the EPDS (reduction of 39.4% vs. 6.2% for sham) did not reach statistical significance in this small study, and there were marginal cognitive and social improvements. In addition, results were presented as mean values, rather than by the proportion of patients who showed clinically meaningful improvement.
Posttraumatic Stress Disorder
The efficacy of rTMS for posttraumatic stress disorder (PTSD) has been examined in several small randomized controlled trials.
A 2004 study randomized 24 patients with PTSD to 10 sessions of low frequency (1 Hz), high frequency (10 Hz) or sham rTMS over the right dorsolateral prefrontal cortex. (44) Blinded assessment 2 weeks after the intervention found that high frequency rTMS improved the self-reported PTSD checklist (PCL) by 29.3%, the clinician evaluation on the Treatment Outcome PTSD scale by 39.0%, the HAM-D by 25.9%, and the Hamilton Anxiety Rating Scale by 44.1%. Scores for the sham and low-frequency group were not significantly improved.
In 2012, Watts et al reported a double-blind trial with 20 patients randomized to low frequency rTMS or sham over the right dorsolateral prefrontal cortex. (45) Blinded evaluation at the end of treatment showed clinically significant improvements in the Clinician Administered PTSD Scale (CAPS) and the PCL compared with sham. Depressive and anxiety symptoms also improved in the rTMS group. Six of the 10 rTMS patients showed a degradation of symptoms between the immediate post-treatment assessment and the 2-month post-treatment follow-up.
In another double-blind trial, 30 patients with PTSD were randomized to deep, high frequency rTMS after brief exposure to a script of the traumatic event, rTMS after a script of a non-traumatic event, or sham stimulation after a brief script of the traumatic event. (46) Patients received 3 treatment sessions per week for 4 weeks, and response was defined as a 50% or greater improvement in CAPS score. Intent-to-treat analysis showed a significant improvement in the total CAPS score in the exposure + stimulation group (24.3) compared to rTMS alone (7.9) or traumatic exposure with sham rTMS (9.1). The greatest improvement was in the intrusive component of the CAPS scale. Heart rate responses to the traumatic script were also reduced over the 4 weeks of treatment. The proportion of patients who showed a response to treatment was not reported and the durability of the response was not assessed.
Several small randomized controlled trials have reported improvement of PTSD with rTMS over the right dorsolateral cortex. Results of high frequency versus low frequency stimulation are conflicting, and durability of the response has not been assessed. Additional study is needed.
The largest area of TMS research outside of depressive disorders appears to be treatment of auditory hallucinations in schizophrenia resistant to pharmacotherapy. In 2011, TEC published an Assessment of TMS as an adjunct treatment for schizophrenia. (47) Five meta-analyses were reviewed, along with randomized controlled trials (RCTs) in which measurements were carried out beyond the treatment period. A meta-analysis of the effect of TMS on positive symptoms of schizophrenia (hallucinations, delusions, and disorganized speech and behavior) did not find a significant effect of TMS. Four meta-analyses that looked specifically at auditory hallucinations showed a significant effect of TMS. It was noted that outcomes were evaluated at the end of treatment, and the durability of the effect is unknown. The Assessment concluded that the available evidence is insufficient to demonstrate that TMS is effective in the treatment of schizophrenia.
A 2012 meta-analysis included 17 randomized double blind sham-controlled trials (n=337) of the effect of rTMS on auditory hallucinations. (48) When measured at the end of treatment, the mean effect size of rTMS directed at the left temporoparietal area was 0.40 (moderate) and the effect size of rTMS directed at all brain regions was 0.33 (small). For the 5 trials that examined outcomes of rTMS one month after treatment, the effect was no longer significant.
Blumberger et al. examined the efficacy of priming stimulation (6 Hz) prior to low frequency stimulation (1 Hz) of Heschl’s gyrus within the left temporoparietal cortex. (49) Fifty-four patients with medication resistant auditory hallucinations were randomized to receive 20 sessions of left-sided stimulation, priming, or sham rTMS. Response rates on the Psychotic Symptoms Rating Scale did not differ between the 3 treatment groups.
A small (n=18) double-blind randomized sham-controlled trial from 2012 found no significant effect of deep rTMS with an H1 coil on auditory hallucinations. (50)
The evidence on rTMS for the treatment of auditory hallucinations in schizophrenia consists of a number of small randomized controlled trials. Evidence to date shows small to moderate effects on hallucinations when measured at the end of treatment, but evidence suggests that the effect is not durable.
Hsu et al. reported a meta-analysis of the effect of rTMS on upper limb motor function in patients with stroke in 2012. (51) Eighteen randomized-controlled trials with a total of 392 patients were included in the meta-analysis. Most of the studies were double blind (n=11) or single blind (n=3). Eight studies applied low frequency (1 Hz) rTMS over the unaffected hemisphere, 5 applied high frequency (5 Hz) rTMS over the affected hemisphere, and 2 used both low- and high-frequency stimulation. Outcomes included kinematic motion analyses (5 trials), hand grip (2 trials), and the Wolf Motor Function Test (2 trials). Meta-analysis of results showed a moderate effect size (0.55) for rTMS on motor outcome, with a greater effect size of rTMS in patients with subcortical stroke (mean effect size, 0.73) compared to non-specified lesion sites (mean effect size, 0.45), and for studies applying low frequency rTMS (mean effect size, 0.69) compared to high frequency rTMS (effect size, 0.41). Effect size of 0.5 or greater was considered to be clinically meaningful.
In 2012, Seniow et al. reported a randomized double-blind sham-controlled pilot study of low frequency rTMS (1 Hz at 90% of resting motor threshold for 30 min) to the contralesional motor cortex combined with physiotherapy in patients with moderate upper extremity hemiparesis following stroke. (52) Power analysis indicated that a sample size of 129 patients would be required to detect changes in functional motor ability, but only 40 patients met eligibility criteria over the 4 years of the study. Blinded analysis showed no significant difference in hand function or level of neurological deficit between active or sham rTMS when measured either immediately after the 3-week intervention or at 3-month follow-up.
Evidence consists of a number of randomized controlled trials and a meta-analysis of the effect of rTMS on recovery from stroke. Results are conflicting, and efficacy may depend on the location of the stroke and frequency of the rTMS. Additional study is needed to determine whether rTMS facilitates standard physiotherapy in patients with stroke.
Other Psychiatric/Neurologic Disorders
For other psychiatric/neurologic conditions, the evidence is insufficient to determine whether rTMS leads to improved outcomes. The available clinical trials are small and report mixed results for a variety of conditions other than depression. There are no large, high-quality trials for any of these other conditions. Therefore, rTMS is considered investigational for other psychiatric/neurologic conditions.
Re-examination of the George et al. study (7) reveals the following additional information: This was an NIMH-sponsored, industry-independent trial. As such, it was the first major published study of rTMS that was not industry-sponsored and therefore free of potential industry bias. This was also the first major published study of rTMS with the sham treatment modified so that the experience of actual rTMS was duplicated, thereby creating a significantly more reliable sham effect than in the previous published trials. Although the response rate for rTMS subjects in Phase I was only 14.1%, the statistical effect size is significant and comparable to the best medication efficacy data. In addition, in the Phase II follow-up, although open-label, the response rate increased to 30%. The retention rate of 88% was higher than in most situations of actual clinical practice with antidepressant medication. The patient sample consisted of individuals who had either failed 3 or more research-quality antidepressant medication trials, or had tried and were intolerant to at least 3 antidepressant medications. In patients who have failed 2 medication trials, open-label studies (the STAR*D trials) have shown that remission rates with another medication or with augmentation are less than 20%, and in patients with 3 failed medication trials, remission rates with another medication trial are 10% to 20%. Thus, the 30% remission rate in Phase II of this trial compares favorably with continued medication trials, and demonstrates effectiveness for treatment-resistant depression that is exceeded only by electroconvulsive therapy (ECT), which remains the most effective treatment for treatment-resistant depression. This study indicates that rTMS is an effective antidepressant treatment for Major Depression in patients who do not respond to or cannot tolerate antidepressant medications.
A study by Ray et al. (53) that was also not industry-funded, in which none of the investigators had any ties to industry, and which also utilized realistic sham treatment, demonstrated remission in 75% of patients receiving actual rTMS as an add-on to antidepressant medication compared to 10% of patients who received sham rTMS. This study also included patients with psychotic depression, and in that population, 87.5% of patients receiving actual rTMS as an add-on to antidepressant medication achieved remission as compared to 7.7% of patients who received sham treatment. The study did lack rater blinding, which may have allowed for some degree of rater bias, but the effect size was substantial and would still be quite large even if rater bias could be accounted for.
Two more recent, naturalistic studies have demonstrated the effectiveness of TMS in real world practice settings without the constraints of research-based patient selection criteria. Carpenter et. Al. (54) studied the effectiveness of TMS with 339 consecutive patients at 42 different practice sites (academic and community). Patients had failed at least one antidepressant trial (average 2.5). The clinician-assessed response rate was 58% and remission rate was 37.1%. The patient-assessed response rate was 41.5%-56.4% and remission rate was 26.5%-28.7%. These rates are greater than those in earlier academic center studies. Although, as is typical of naturalistic studies, the study lacked sham treatment (placebo) and blinded rater assessment, it approximated real-world clinical practices to a much greater extent than prior studies.
Connolly et al. (55) conducted a retrospective chart review of 100 consecutive TMS patients at an academic medical center. Although done at an academic center, this study approximated real-world practice because patients were treated without applying research criteria. The patient population had failed an average of 3.4 adequate antidepressant trials in the current depressive episode. The clinician-measured response rate was 50.6% and the remission rate was 24.7%. This study and the Carpenter et al study, in spite of the absence of placebo controls and blinded rating, demonstrate real-world effectiveness of TMS in the treatment of Major Depression that has not responded to adequate trials of antidepressant medication.
Although questions still need to be answered about TMS, including the optimal length of treatment and the usefulness of maintenance treatment, the most recent studies demonstrate efficacy and real-world effectiveness of TMS in the treatment of unipolar Major Depression and psychotic depression (i.e. Major Depression with psychotic features). Antidepressant medication remains the biological treatment of first choice for Major Depression. ECT continues to be the most effective treatment for treatment-resistant depression, but the high incidence of functionally-impairing adverse cognitive effects renders ECT undesirable in many cases. In addition, there is a cohort of patients who have failed or cannot tolerate antidepressant medications and ECT. For those patients, with the possible exception of major chest surgery and its attendant potential complications (i.e. for a Vagus Nerve stimulator implant, for which the effectiveness data is weak), TMS is the only treatment option that remains, and that stands between possible relief of depression and continued indefinite suffering. That rationale, coupled with the results of the most recent studies, and with the knowledge that continued antidepressant medication trials after 3-4 trials have a high failure rate, leads to the conclusion that TMS is a reasonable and appropriate next intervention after 3 failed medication trials plus a failed ECT trial, or after 4 failed medication trials.
Practice Guidelines and Position Statements
The Canadian Network for Mood and Anxiety Treatments (CANMAT) updated their clinical guidelines on neurostimulation therapies for the management of major depressive disorder in adults. (56) The evidence reviewed supported ECT as a first-line treatment under specific circumstances; when used in patients who have failed to respond to one or more adequate antidepressant medication trials, ECT response rates have been estimated to be 50-60%. The guidelines considered rTMS to be a safe and well-tolerated treatment, with no evidence of cognitive impairment. Based on the 2008 meta-analysis by Lam et al. (5), response (25%) and remission (17%) rates were found to be greater than sham but lower than for other interventions for TRD, leading to a recommendation for rTMS as a second- line treatment. The guidelines indicated that there is a major gap in the evidence base regarding maintenance rTMS, as only one open-label case series was identified.
The Movement Disorder Society published an evidence-based review of treatments for the non-motor symptoms of Parkinson’s disease in 2011. (57) The review found insufficient evidence to make adequate conclusions on the efficacy rTMS for the treatment of depression in Parkinson’s disease.
Medicare National Coverage
There is no national coverage determination.
Therapeutic repetitive transcranial magnetic stimulation (TMS) treatment; initial, including cortical mapping, motor threshold determination, delivery and management
Therapeutic repetitive transcranial magnetic stimulation (TMS) treatment; subsequent delivery and management, per session
Therapeutic repetitive transcranial magnetic stimulation (TMS) treatment; subsequent motor threshold re-determination with delivery and management
Depressive disorder; not elsewhere classified
Major depressive disorder, single episode
Major depressive disorder, recurrent episode
Investigational for all relevant diagnoses
Schizophrenia code range
Major depressive disorder, recurrent, code range
Migraine code range
ICD-10-PCS codes are only used for inpatient services. There is no specific ICD-10-PCS code for this procedure.
Type of Service
Place of Service
BDI: Beck Depression Inventory;
DLFPC: Dorsolateral prefrontal cortex;
ECT: Electroconvulsive therapy;
HAM-D: Hamilton Depression Rating Scale;
MADRS: Montgomery-Asberg Depression Rating Scale;
MT: motor threshold;
rTMS: Repetitive transcranial magnetic stimulation;
TRD: Treatment-resistant depression.
Definitions (unless otherwise noted):
Clinical response: Improvement of 50% or more in the Hamilton Depression Rating Scale
Remission: Score of 7 or less on the Hamilton Depression Rating Scale
New policy. Policy replaces 2.01.50 which is deleted. Previously considered investigational for all indications, policy statement created to consider TMS medically necessary for treatment resistant major depression when certain criteria are met. Added code 296.2x.
Replace policy. Added code 296.3x. Added literature review on multiple conditions: rTMS maintenance therapy, Alzheimer’s, ADHS, Dysphagia, Epilepsy, Fibromyalgia, Panic Disorder, Parkinson Disease. Postpartum Depression, Posttraumatic Stress Disorder and Stroke.
Disclaimer: This medical policy is a guide in evaluating the medical necessity of a particular service or treatment. The Company adopts policies after careful review of published peer-reviewed scientific literature, national guidelines and local standards of practice. Since medical technology is constantly changing, the Company reserves the right to review and update policies as appropriate. Member contracts differ in their benefits. Always consult the member benefit booklet or contact a member service representative to determine coverage for a specific medical service or supply. CPT codes, descriptions and materials are copyrighted by the American Medical Association (AMA).