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Navigated Transcranial Magnetic Stimulation (nTMS)

Policy Number: MP-556

Latest Review Date: July 2019

Category: Medicine
Policy Grade: C

Description of Procedure or Service:

Navigated transcranial magnetic stimulation (nTMS) is a noninvasive imaging method for the evaluation of eloquent brain areas (e.g., controlling motor or language function). Navigated TMS is being evaluated as an alternative to other noninvasive cortical mapping techniques for presurgical identification of eloquent areas.

Management of Brain Tumors

Surgical management of brain tumors involves resecting the brain tumor and preserving essential brain function. “Mapping” of brain functions, such as body movement and language, is considered to be most accurately achieved with DCS, an intraoperative procedure that increases operating time and requires a wide surgical opening. Even if they are not completely accurate compared to DCS, preoperative techniques that map brain functions may aid in planning the extent of resection and the operative approach. Although DCS is still usually performed to confirm the brain locations associated with specific functions, preoperative mapping techniques may provide useful information that improves patient outcomes.

 

Noninvasive Mapping Techniques

The most commonly used tool for the noninvasive localization of brain functions is functional magnetic resonance imaging (fMRI). fMRI identifies regions of the brain where there are changes in localized cortical blood oxygenation, which correlates with the neuronal activity associated with a specific motor or speech task being performed as the image is obtained. The accuracy and precision of fMRI is dependent on the patient’s ability to perform the isolated motor task, such as moving the single assigned muscle without moving others. This may be difficult for patients in whom brain tumors have caused partial or complete paresis. The reliability of fMRI in mapping language areas has been questioned. Guissani et al (2010) reviewed several studies comparing fMRI and DCS of language areas and found large variability in sensitivity and specificity of fMRI. The discussion also points out a major conceptual point in how fMRI and DCS “map” language areas. fMRI findings reflect regional oxygenation changes which show that a particular region of the brain is involved in the capacity of interest, whereas DCS locates specific areas in which the activity of interest is disrupted. Regions of the brain involved in a certain activity may not necessarily be required for that activity and could theoretically be safely resected.

Magnetoencephalography (MEG) also is used to map brain activity. In this procedure, electromagnetic recorders are attached to the scalp. In contrast to electroencephalography, MEG records magnetic fields generated by electric currents in the brain, rather than the electric

currents themselves. Magnetic fields tend to be less distorted by the skull and scalp than electric currents, yielding improved spatial resolution. MEG is conducted in a magnetically shielded room to screen out environmental electric or magnetic noise that could interfere with the MEG recording.

Navigated transcranial magnetic stimulation (nTMS) is a noninvasive imaging method for the evaluation of eloquent brain areas. Transcranial magnetic pulses are delivered to the patient as a navigation system calculates the strength, location, and direction of the stimulating magnetic field. The locations of these pulses are registered to a magnetic resonance imaging (MRI) image of the patient’s brain. Surface electromyography (EMG) electrodes are attached to various limb muscles of the patient. Moving the magnetic stimulation source to various parts of the brain causes EMG electrodes to respond; indicating the part of the cortex involved in particular muscle movements. For evaluation of language areas, magnetic stimulation areas that disrupt specific speech tasks are thought to identify parts of the brain involved in speech function. nTMS can be considered a noninvasive alternative to DCS, in which electrodes are directly applied to the surface of the cortex during craniotomy. nTMS is being evaluated as an alternative to other noninvasive cortical mapping techniques, such as fMRI and MEG, for presurgical identification of cortical areas involved in motor and language functions. Navigated TMS, used for cortical language area mapping, is also being investigated in combination with diffusion tensor imaging tractography for subcortical white matter tract mapping.

Policy:

Navigated transcranial magnetic stimulation is considered not medically necessary for all purposes, including but not limited to the preoperative evaluation of patients being considered for brain surgery, and is considered investigational.

Key Points:

This policy was updated using references identified in the MEDLINE database through May 17, 2019.

Evidence reviews assess whether a medical test is clinically useful. In order to determine if a test is clinically useful, the test must provide information to make a clinical management decision that improves the net health outcome. The balance of benefits and harms is better when the test is used to manage the condition than when another test or no test is used to manage the condition.

The formulation of the clinical context and purpose of the test is the first step in assessing a medical test. The test must be technically reliable, clinically valid, and clinically useful for that purpose.

Preoperative Localization of Eloquent Areas of the Brain

Clinical Context and Test Purpose

The purpose of navigated transcranial magnetic stimulation (nTMS) in patients who have brain lesions is to aid in the localization of eloquent areas of the brain to reduce damage during surgery to verbal and motor functions.

The question addressed in this evidence review is whether there is evidence that nTMS improves health outcomes in patients who have brain lesions and are about to undergo surgery that has the potential to harm eloquent areas of the brain.

The following PICOTS were used to select literature to inform this review.

Patients

The relevant population of interest are individuals who have brain lesions and who are undergoing surgery that has the potential to harm eloquent areas of the brain.

Interventions

The intervention of interest is nTMS.

Comparators

There are several other tools used for the noninvasive localization of brain functions. They include functional magnetic resonance imaging (fMRI) and magnetoencephalography (MEG). Whether or not noninvasive pre-surgical tools are used, direct cortical stimulation (DCS) is usually performed during surgery to confirm the brain locations associated with specific functions.

Outcomes

The outcomes of interest are a surgical improvement in survival or in functional measures such as speaking and walking or in a reduction in morbidity.

Timing

Navigated TMS is performed during preoperative surgical planning.

Setting

Navigated TMS is done in a specialty setting (i.e., neurology).

Technically Reliable

Assessment of technical reliability focuses on specific tests and operators and requires a review of unpublished and often proprietary information. Review of specific tests, operators, and unpublished data are outside the scope of this evidence review, and alternative sources exist.

This evidence review focuses on the clinical validity and clinical utility.

Clinically Valid

A test must detect the presence or absence of a condition, the risk of developing a condition in the future, or treatment response (beneficial or adverse).

Most studies of nTMS are small case series of patients with brain tumors, cavernous angiomas, arteriovenous malformations, or other brain lesions; these are not ideal studies to ascertain diagnostic characteristics. There are also a number of small studies in healthy volunteers but these do not add substantially to the evidence base. Studies comparing nTMS to DCS, MEG, and/or fMRI and/or DCS as the reference standard are described next.

Distance Between nTMS and DCS Hotspots

Picht et al (2011) evaluated 17 patients with brain tumors with both nTMS and DCS. Both techniques were used to elicit “hotspots,” the point at which either nTMS or DCS produced the largest electromyographic response in the target muscles. Target muscles were selected based on the needs of each particular patient in regard to tumor location and clinical findings. The intraoperative DCS locations were chosen independently of nTMS, and the surgeon was not aware of the nTMS hotspots. There were 37 muscles in the 17 patients for which both nTMS and DCS data were available. The mean (SE) distance between the nTMS and DCS hotspots was

7.83 (1.18) mm for the abductor pollicis brevis muscle and 7.07 (0.88) mm for the tibialis anterior muscle. The 95% confidence interval for the mean distance was 5.31 to 10.36mm. When DCS was performed during surgery, there was large variation in the number of stimulation points, and the distance between nTMS and DCS was much smaller when a larger number of points were stimulated.

Forster et al (2011) performed a similar study in 11 patients. fMRI was also performed in these patients. The distance between corresponding nTMS and DCS hotspots was 10.49 (5.67) mm. The distance between the centroid of fMRI activation and DCS hotspots was 15.03 (7.59) mm. However, it is not clear whether there were hotspots with either device that cannot be elicited with the other. In at least two excluded patients, hotspots were elicited in which DCS but not by nTMS.

A 2012 study by Tarapore et al evaluated distance between nTMS and DCS hotspots. Among 24 patients who underwent nTMS, 18 of who also underwent DCS, 8 motor sites in 5 patients corresponded. The median distance between nTMS and DCS hotspots was 2.13 (0.29) mm. In the craniotomy field in which DCS mapping was performed, DCS did not find any new motor sites that TMS failed to identify. The study also evaluated magnetoencephalography (MEG); the median distance between MEG motor sites and DCS was 12.1 (8.2) mm.

Mangravati et al (2012) also evaluated the distance between nTMS and DCS hotspots in 7 patients. It is unclear how many hotspots are compared and how many potential comparisons were unavailable due to failure of either device to find a particular hotspot. It appeared that the mean distance between hotspots was based on the locations of hotspots for 3 different muscles. The overall mean difference between nTMS and DCS was 8.47mm, which was less than the mean difference between the fMRI centroid of activation and DCS hotspots of 12.9 (5.7) mm.

Krieg et al (2012) also evaluated nTMS in comparison to DCS in a study of 14 patients. However, the navigation device employed appears to be different than the FDA-approved device. Additionally, the comparison of nTMS to DCS uses a different methodology. Both nTMS and DCS were used to map out the whole volume of the motor cortex, and a mean difference between the borders of the edge of the mapped motor cortex was calculated. The mean distance between the 2 methods was 4.4 (3.4) mm.

Language Mapping

A 2013 study by Picht et al attempted to evaluate the accuracy of nTMS for identifying language areas. Twenty patients underwent evaluation of language areas over the whole left hemisphere, which was divided into 37 regions. DCS was necessarily performed only in areas accessible in the craniotomy site. Data for both methods were available in 160 regions in the 20 patients.

Using DCS as the reference standard, there were 46 true positives, 83 false positives, 26 true negatives, and 5 false negatives. Considering the analysis as 160 independent data points for each brain region, nTMS had a sensitivity of 90%, a specificity of 24%, positive predictive value of 36% and negative predictive value (NPV) of 84%. An analysis of regions considered to be in the classic Broca area showed a sensitivity of 100%, a specificity 13.0%, positive predictive value of 57%, and negative predictive value of 100%.

Tarapore et al (2013) also evaluated the use of nTMS and MEG to identify language areas (N=12). A total of 183 regions were evaluated with both nTMS and DCS. In these 183 regions, using DCS as the reference standard, there were 9 true positives, 4 false positives, 169 true negatives and 1 false negative. This translates to a sensitivity of 90%, specificity of 98%, and a positive predictive value of 69% and a NPV of 99%.

Section Summary: Clinically Valid

The studies assessing the distance between nTMS and DCS hotspots appear to show that stimulation sites eliciting responses from both techniques tended to be mapped within 1 cm of each other. This distance tends to be less than the distance between fMRI centers of activation and DCS hotspots. It is difficult to assess the clinical significance of these data for pre-surgical planning. The available studies of the diagnostic accuracy nTMS evaluating language areas have shown a sensitivity of 90% and variable specificity in 2 studies (range, 24%-98%). The PPVs were relatively low in both of the studies (range, 57%-69%). Even if nTMS were used to rule out areas in which language areas are unlikely, the sensitivity of 90% might result in some language areas not appropriately identified.

Clinically Useful

A test is clinically useful if the use of the results informs management decisions that improve the net health outcome of care. The net health outcome can be improved if patients receive correct therapy, or more effective therapy, or avoid unnecessary therapy, or avoid unnecessary testing.

Direct Evidence

Direct evidence of clinical utility is provided by studies that have compared health outcomes for patients managed with and without the test. Because these are intervention studies, the preferred evidence would be from randomized controlled trials (RCTs).

The ideal study to determine whether nTMS improves health outcomes in patients being considered for surgical resection of brain tumors would be an RCT comparing nTMS with strategies that do not use nTMS. There are challenges in the design and interpretation of such

studies. Given that results of diagnostic workups of brain tumor patients may determine which patients undergo surgery, the counseling given to patients, and the type of surgery performed, it would be difficult to compare outcomes of groups of patients with very qualitatively different outcomes. For example, it is difficult to compare the health outcome of a patient who ends up not being operated on, who conceivably has a shorter overall lifespan but a short period of very high quality of life, with a patient who undergoes operation but has some moderate postoperative disability, but a much longer lifespan.

No RCTs were identified. However, controlled observational studies are available. Several studies matched patients who underwent presurgical nTMS with similar historical controls who did undergo nTMS. Most recently in 2017, Hendrix et al reported on 20 consecutive patients with malignant brain tumors and lesions in language-eloquent areas who underwent preoperative nTMS and matched them to patients treated in the pre-nTMS era. Patients were matched on tumor location, tumor and edema volume, preoperative language deficits, and histopathology.

The primary efficacy outcome was not specified. Patients underwent clinical language assessments before surgery and after surgery at postoperative day 1 and at week 1, 6, and 12 after surgery. Language performance status was characterized as grade 0: no language deficit; grade 1: mild deficit; grade 2: medium deficit; and grade 3: severe deficit. The complication rate, gross resection rate, and residual tumor volume on MRI did not differ significantly between groups. The group that had pre-surgical nTMS had shorter surgery duration than patients treated pre-nTMS (mean, 104 minutes and 135 minutes, respectively, p=0.039) and a shorter inpatient stay (mean, 9.9 days vs 15 days, p=0.001). Language deficits did not differ between groups preoperatively, or at postoperative day 1, week 1, or week 12. For example, at week 12, 15 patients in the nTMS group and 14 patients in the pre-TMS group had a grade 0 deficit (p=0.551). There was a statistically significant difference at week 6 (p=0.048); the p-value was not adjusted for multiple comparisons (i.e., assessment at multiple time points). Groups may have differed in other ways that affected outcomes and procedures may have changed over time in ways that affected surgical duration, complication rates, and inpatient stays.

Krieg et al (2014) enrolled 100 consecutive patients who underwent nTMS preoperative mapping and identified 100 historical controls who were matched for tumor location, preoperative paresis, and histology.22 Most patients had glioblastoma (37%), brain metastasis (24%), or astrocytoma (29%). Data analysis was performed blinded to group assignment. The primary efficacy outcome was not specified. Median follow-up was 7.1 months (range, 0.2-27.2 months) in the nTMS group and 6.2 months (range, 0.1-79.4 months) in controls. Incidence of residual tumor by postoperative MRI was less in the nTMS group compared with controls (22% vs 42%; odds ratio [OR], 0.38; 95% CI, 0.21 to 0.71). Incidence of new surgery-related transient or permanent paresis did not differ between groups. However, “when also including neurological improvement [undefined] in the analysis,” more patients in the nTMS group improved (12% nTMS vs 1% controls), and similar proportions of patients worsened (13% nTMS vs 18% controls) or remained unchanged (75% nTMS vs 81% controls; Mann-Whitney-Wilcoxon test, p=0.006).

Limitations of this study include the use of historical control, uncertain outcome assessments (“neurological improvement” not defined), and uncertain validity of statistical analyses since the primary outcome was not specified and there was no correction for multiple testing).

A second study by Krieg et al (2015) had some overlap in enrolled patients, was published by Krieg et al in 2015. This study prospectively enrolled 70 patients who underwent nTMS and matched them with a historical control group of 70 patients who did not have preoperative nTMS. All patients had motor eloquently located supratentorial high-grade gliomas (HGG) and they all underwent craniotomy in the single department by the same group of surgeons. As in the 2014 study by Krieg et al, patients were matched by tumor location, preoperative paresis and histology, and the primary outcome was not specified. Outcome assessment was blinded.

Craniotomy size was 25.3 cm² (SD: 9.7cm) in the nTMS group and 30.8 cm² (SD: 13.2) in the non-nTMS group; the difference in size was statistically significant, p=0.006. There was not a statistically significant difference between groups in the rate of surgery-related paresis, rate of surgery-related complications on MRI or the degree of motor impairment during follow-up.

Median overall survival was 15.7 months (SD: 10.9) in the nTMS group and 11.9 months (SD: 10.3) in the non-nTMS group which was not significantly different between groups (p=0.131). Mean survival at 3, 6 and, 9 months was significantly higher in the nTMS group compared with the non-nTMS group and mean survival at 12 months did not differ significantly between groups.

Frey et al (2014) enrolled 250 consecutive patients who underwent nTMS preoperative mapping and identified 115 similar historical controls who met the same eligibility criteria. Fifty-one percent of the nTMS group and 48% of controls had WHO Grade II to IV gliomas; remaining patients had brain metastases from other primary cancers or other lesions. Intraoperative motor cortical stimulation to confirm nTMS findings was performed in 66% of the nTMS group.

British Medical Research Council and Karnofsky scales were used to assess muscle strength and performance status, respectively. Outcomes were assessed at postoperative day seven and then at three-month intervals. At three month follow-up, 6.1% of the nTMS group and 8.5% of controls had new postoperative motor deficits (p=NS); changes in performance status postoperatively also were similar between groups. Other outcomes were reported for patients with glioma only (128 nTMS patients, 55 controls). Based on postoperative MRI, gross total resection was achieved in 59% of nTMS patients and in 42% of controls (2 test, p<0.05). At mean followup of 22 months (range, 6-62) in the nTMS group and 25 months (range, 9-57) in controls, mean PFS was similar between groups (mean PFS, 15.5 months [range, 3-51] nTMS vs 12.4 months [range, 3-38] controls; statistical test for survival outcomes not specified, p=NS). In the subgroup of patients with low grade (Grade II) glioma (38 nTMS patients, 18 controls), mean PFS was longer in the nTMS group (mean PFS, 22.4 months [range, 11-50] nTMS vs 15.4 months [range, 6-42] controls; p<0.05), and new postoperative motor deficits were similar (7.5% vs 9.5%, respectively; 2 test, p=NS). Overall survival did not differ statistically between treatment groups.

One nonrandomized study used concurrent controls, but did not randomize patients to treatment group. Sollman et al (2015) matched 25 prospectively enrolled patients who underwent preoperative nTMS but whose results were not available to the surgeon during the operation (group 1) to 25 patients who underwent preoperative nTMS and results were available to the surgeon (group 2). All patients had language eloquently located brain lesions within the left hemisphere. Primary outcomes were not specified. Three months after surgery, 21 patients in group 1 had no or mild language impairment and 4 patients had moderate to severe language deficits.

In group 2, 23 patients had no or mild language impairment and 2 patients had moderate

to severe deficits. The difference between groups in post-operative language deficits was statistically significant (p=0.0153). Other outcomes, including duration of surgery, post-

operative scores on the Karnofsky performance status scale, percent residual tumor, and peri- and postoperative complication rates did not differ significantly between groups.

Picht et al (2012) assessed whether a change in management occurred as a result of knowledge of nTMS findings. In this study, surgeons first made a plan based on all known information without nTMS findings. After being informed of nTMS findings, the surgical plan was reformulated if necessary. Among 73 patients with brain tumors in or near the motor cortex, nTMS was judged to have changed the surgical indication in 2.7%, changed the planned extent of resection in 8.2%, modified the approach in 16.4%, added awareness of high-risk areas in 27.4%, added knowledge not used in 23.3%, and only confirmed the expected anatomy in 21.9%. The first 3 surgical categories, judged to have been altered because of nTMS findings, were summed to determine “objective benefit” of 27.4%.

Chain of Evidence

Indirect evidence on clinical utility rests on clinical validity. If the evidence is insufficient to demonstrate test performance, no inferences can be made about clinical utility. Current evidence on clinical validity does not permit construction of a chain of evidence to support the use of nTMS for presurgical mapping of eloquent areas of the brain.

Section Summary: Clinically Useful

No randomized controlled trials comparing health outcomes in patients who did and did not have pre-surgical nTMS before brain surgery. However, there is direct evidence from several nonrandomized comparative studies of patients undergoing nTMS, mainly compared with historical controls. Findings were mixed; outcomes were not consistently better in patients who underwent pre-surgical nTMS. Complication rates did not differ significantly between groups. In two of three studies, residual tumor volume did not differ between groups. Two studies reported survival rates. In both of these, overall survival did not differ significantly between groups. One of the studies found significantly higher mean survival rates in the nTMS group at 3, 6, and 9 months post-surgery, but not 12 months. One of two studies reporting postoperative language deficits found significantly fewer deficits in the group that received presurgical nTMS. Limitations of all studies discussed in this section include the single-center setting (because nTMS is an operator-dependent technology, applicability may be limited), lack of randomization and/or use of historical controls (surgeon technique and practice likely improved over time), selective outcome reporting (survival outcomes in glioma patients only), and uncertain validity of statistical analyses (primary outcome not identified and no correction for multiple testing).

Additionally, studies either matched patients to controls on a few variables or used controls who met similar eligibility criteria. These techniques may not adequately control for differences in patient groups that may affect outcomes.

Summary of Evidence

For individuals who have brain lesion(s) undergoing preoperative evaluation for localization of eloquent areas of the brain who receive nTMS, the evidence includes controlled observational

studies and case series. Relevant outcomes are overall survival, test accuracy, morbid events, and

functional outcomes. Several small studies have evaluated the distance between nTMS hotspots

and direct cortical stimulation hotspots for the same muscle. Although the average distance in

most studies is 10 mm or less, this does not take into account the error margin in this average

distance or whether hotspots are missed. It is difficult to verify nTMS hotspots fully because only exposed cortical areas can be verified with direct cortical stimulation. Limited studies of nTMS evaluating language areas have shown high false-positive rates (low specificity) and sensitivity that may be insufficient for clinical use. Several controlled observational studies have compared outcomes in patients undergoing nTMS with those (generally pre-TMS historical controls) who did not undergo nTMS. Findings of the studies were mixed; outcomes were not consistently better in patients who underwent presurgical nTMS. For example, overall survival did not differ significantly between groups in two studies and one reporting postoperative language deficits found significantly fewer deficits in the group that had presurgical nTMS. The controlled observational studies had various methodologic limitations and, being nonrandomized, might not have adequately controlled for differences in patient groups, which could have biased outcomes. The evidence is insufficient to determine the effects of the technology on health outcomes.

Practice Guidelines and Position Statements

No guidelines or statements were identified.

U.S. Preventive Services Task Force Recommendations

Not applicable.

Key Words:

Navigated transcranial magnetic stimulation, nTMS, Nexstim®, Nexstim NBS System 4, NexSpeech®

Approved by Governing Bodies:

In 2009, the eXimia Navigated Brain Stimulation System (Nexstim) was cleared for marketing by the U.S. Food and Drug Administration through the 510(k) process for noninvasive mapping of the primary motor cortex of the brain to its cortical gyrus for preprocedural planning.

Similarly, the Nexstim NBS System 4 and NBS System 4 with NexSpeech® received FDA 510(k) clearance in May 2012 for noninvasive mapping of the primary motor cortex and for localization of cortical areas that do not contain speech function, for the purposes of preprocedural planning.

Benefit Application:

Coverage is subject to member’s specific benefits. Group specific policy will supersede this policy when applicable.

ITS: Home Policy provisions apply.

FEP: Special benefit consideration may apply. Refer to member’s benefit plan. FEP does not consider investigational if FDA approved and will be reviewed for medical necessity.

Current Coding:

CPT Codes:

As of 01/01/2018, there is no specific CPT code for this procedure. Use the following CPT code:

64999 Unlisted procedure, nervous system

Previous Coding:

0310T Motor function mapping using noninvasive navigated transcranial magnetic stimulation (nTMS) for therapeutic treatment planning, upper and lower extremity (Deleted 12/31/2017)

References:

      1. Conti A, Raffa G, Granata F, et al. Navigated Transcranial Magnetic Stimulation for "Somatotopic" Tractography of the Corticospinal Tract. Neurosurgery. Dec 2014; 10 Suppl 4:542-554.

      2. Forster MT, Hattingen E, Senft C et al. Navigated transcranial magnetic stimulation and functional magnetic resonance imaging: advanced adjuncts in preoperative planning for central region tumors. Neurosurgery 2011; 68(5):1317-24; discussion 24-5.

      3. Forster MT, Limbart M, Seifert V et al. Test-Retest-Reliability of Navigated Transcranial Magnetic Stimulation of the Motor Cortex. Neurosurgery 2013.

      4. Frey D, Schilt S, Strack V, et al. Navigated transcranial magnetic stimulation improves the treatment outcome in patients with brain tumors in motor eloquent locations. Neuro Oncol. Oct 2014; 16(10):1365-1372.

      5. Giussani C, Roux FE, Ojemann J et al. Is preoperative functional magnetic resonance imaging reliable for language areas mapping in brain tumor surgery? Review of language functional magnetic resonance imaging and direct cortical stimulation correlation studies. Neurosurgery 2010; 66(1):113-20.

      6. Hendrix P, Senger S, Simgen A, et al. Preoperative rTMS language mapping in speech- eloquent brain lesions resected under general anesthesia: a pair-matched cohort study. World Neurosurg. Apr 2017; 100:425-433.

      7. Jensen RL. Navigated transcranial magnetic stimulation: another tool for preoperative planning for patients with motor-eloquent brain tumors. Neuro Oncol. Oct 2014; 16(10):1299-1300.

      8. Kato N, Schilt S, Schneider H, et al. Functional brain mapping of patients with arteriovenous malformations using navigated transcranial magnetic stimulation: first experience in ten patients. Acta Neurochir (Wien). May 2014; 156(5):885-895.

      9. Krieg SM, Sabih J, Bulubasova L, et al. Preoperative motor mapping by navigated transcranial magnetic brain stimulation improves outcome for motor eloquent lesions. Neuro Oncol. Sep 2014; 16(9):1274-1282.

      10. Krieg SM, Shiban E, Buchmann N et al. Utility of presurgical navigated transcranial magnetic brain stimulation for the resection of tumors in eloquent motor areas. J Neurosurg 2012; 116(5):994-1001.

      11. Krieg SM, Sollmann N, Hauck T, et al. Repeated mapping of cortical language sites by preoperative navigated transcranial magnetic stimulation compared to repeated intraoperative DCS mapping in awake craniotomy. BMC Neurosci. 2014; 15:20.

      12. Krieg SM, Sollmann N, Obermueller T, et al. Changing the clinical course of glioma patients by preoperative motor mapping with navigated transcranial magnetic brain stimulation. BMC Cancer. 2015; 15:231.

      13. Mangraviti A, Casali C, Cordella R et al. Practical assessment of preoperative functional mapping techniques: navigated transcranial magnetic stimulation and functional magnetic resonance imaging. Neurol Sci 2013; 34(9):1551-1557.

      14. Nexstim. Healthcare providers: clinical evidence. www.nexstim.com/healthcare- providers/navigated-brain stimulation/clinical-evidence/.

      15. Opitz A, Zafar N, Bockermann V, et al. Validating computationally predicted TMS stimulation areas using direct electrical stimulation in patients with brain tumors near precentral regions. Neuroimage Clin. 2014; 4:500-507.

      16. Paiva WS, Fonoff ET, Marcolin MA, et al. Navigated transcranial magnetic stimulation in preoperative planning for the treatment of motor area cavernous angiomas. Neuropsychiatr Dis Treat. 2013; 9:1885-1888.

      17. Picht T. Current and potential utility of transcranial magnetic stimulation in the diagnostics before brain tumor surgery. CNS Oncol. Jul 2014; 3(4):299-310.

      18. Picht T, Krieg SM, Sollmann N et al. A comparison of language mapping by preoperative navigated transcranial magnetic stimulation and direct cortical stimulation during awake surgery. Neurosurgery 2013; 72(5):808-19.

      19. Picht T, Schmidt S, Brandt S, et al. Preoperative functional mapping for rolandic brain tumor surgery: comparison of navigated transcranial magnetic stimulation to direct cortical stimulation. Neurosurgery. Sep 2011;69(3):581-588; discussion 588.

      20. Picht T, Schulz J, Hanna M et al. Assessment of the influence of navigated transcranial magnetic stimulation on surgical planning for tumors in or near the motor cortex. Neurosurgery 2012; 70(5):1248-56; discussion 1256-1247.

      21. Rizzo V, Terranova C, Conti A, et al. Preoperative functional mapping for rolandic brain tumor surgery. Neurosci Lett. Sep 16 2014; 583C:136-141.

      22. Schmidt S, Bathe-Peters R, Fleischmann R, et al. Nonphysiological factors in navigated TMS studies; Confounding covariates and valid intracortical estimates. Hum Brain Mapp. Aug 29 2014.

      23. Sollmann N, Hauck T, Hapfelmeier A, et al. Intra- and interobserver variability of language mapping by navigated transcranial magnetic brain stimulation. BMC Neurosci. 2013; 14:150.

      24. Sollmann N, Ille S, Boeckh-Behrens T, et al. Mapping of cortical language function by functional magnetic resonance imaging and repetitive navigated transcranial magnetic stimulation in 40 healthy subjects. Acta Neurochir (Wien). May 2 2016.

      25. Sollmann N, Ille S, Hauck T, et al. The impact of preoperative language mapping by repetitive navigated transcranial magnetic stimulation on the clinical course of brain tumor patients. BMC Cancer. 2015; 15:261.

      26. Sollmann N, Tanigawa N, Tussis L, et al. Cortical regions involved in semantic processing investigated by repetitive navigated transcranial magnetic stimulation and object naming. Neuropsychologia. Apr 2015; 70:185-195.

      27. Tarapore PE, Findlay AM, Honma SM et al. Language mapping with navigated repetitive TMS: Proof of technique and validation. Neuroimage 2013; 82:260-72.

      28. Tarapore PE, Picht T, Bulubas L, et al. Safety and tolerability of navigated TMS for preoperative mapping in neurosurgical patients. Clin Neurophysiol. Mar 2016; 127(3):1895-1900.

      29. Tarapore PE, Tate MC, Findlay AM et al. Preoperative multimodal motor mapping: a comparison of magnetoencephalography imaging, navigated transcranial magnetic stimulation, and direct cortical stimulation. J Neurosurg 2012; 117(2):354-62.

      30. Weiss C, Nettekoven C, Rehme AK et al. Mapping the hand, foot, and face representations in the primary motor cortex-- retest reliability of neuronavigated TMS versus functional MRI. Neuroimage 2013; 66:531-542.

Policy History:

Medical Policy Panel, December 2013

Medical Policy Group, December 2013 (3): New policy; does not meet medical criteria for coverage and therefore considered investigational

Medical Policy Administration Committee, February 2014 Available for comment February 5 through March 21, 2014 Medical Policy Panel, December 2014

Medical Policy Group, February 2015 (6): Updated Key Points, Key Words, Approved by Governing Bodies and References; no change in policy statement.

Medical Policy Panel, June 2016

Medical Policy Group, July 2016 (6): Updated Description of Procedure, Key Points, Key Words, Summary of Evidence, Approved by Governing Bodies and References; no change in policy statement.

Medical Policy Panel June 2017

Medical Policy Group, June 2017 (6): Updates to Description, Key Points and References. No change to policy statement.

Medical Policy Group, December 2017: Annual Coding Update 2018. Created Previous Coding section and moved deleted code 0310T to this section. Added existing CPT code 64999 to current coding.

Medical Policy Panel, June 2018

Medical Policy Group, June 2018 (6): Updates to Key Points.

Medical Policy Group, December 2018 (6): Edit to policy statement verbiage. No change to policy intent.

Medical Policy Panel, June 2019

Medical Policy Group, July, 2019 (3): 2019 Updates to Key Points and References. No changes to policy statement or intent.

 

This medical policy is not an authorization, certification, explanation of benefits, or a contract. Eligibility and benefits are determined on a case-by-case basis according to the terms of the member’s plan in effect as of the date services are rendered. All medical policies are based on (i) research of current medical literature and (ii) review of common medical practices in the treatment and diagnosis of disease as of the date hereof. Physicians and other providers are solely responsible for all aspects of medical care and treatment, including the type, quality, and levels of care and treatment.

This policy is intended to be used for adjudication of claims (including pre-admission certification, pre-determinations, and pre-procedure review) in Blue Cross and Blue Shield’s administration of plan contracts.

The plan does not approve or deny procedures, services, testing, or equipment for our members. Our decisions concern coverage only. The decision of whether or not to have a certain test, treatment or procedure is one made between the physician and his/her patient. The plan administers benefits based on the member’s contract and corporate medical policies. Physicians should always exercise their best medical judgment in providing the care they feel is most appropriate for their patients. Needed care should not be delayed or refused because of a coverage determination.

As a general rule, benefits are payable under health plans only in cases of medical necessity and only if services or supplies are not investigational, provided the customer group contracts have such coverage.

The following Association Technology Evaluation Criteria must be met for a service/supply to be considered for coverage:

1. The technology must have final approval from the appropriate government regulatory bodies;

2. The scientific evidence must permit conclusions concerning the effect of the technology on health outcomes;

3. The technology must improve the net health outcome;

4. The technology must be as beneficial as any established alternatives;

5. The improvement must be attainable outside the investigational setting.

Medical Necessity means that health care services (e.g., procedures, treatments, supplies, devices, equipment, facilities or drugs) that a physician, exercising prudent clinical judgment, would provide to a patient for the purpose of preventing, evaluating, diagnosing or treating an illness, injury or disease or its symptoms, and that are:

1. In accordance with generally accepted standards of medical practice; and

2. Clinically appropriate in terms of type, frequency, extent, site and duration and considered effective for the patient’s illness, injury or disease; and

3. Not primarily for the convenience of the patient, physician or other health care provider; and

4. Not more costly than an alternative service or sequence of services at least as likely to produce equivalent therapeutic or diagnostic results as to the diagnosis or treatment of that patient’s illness, injury or disease.