Repetitive Transcranial Magnetic Repetitive Transcranial Magnetic Stimulation (rTMS)Stimulation (rTMS)

Tung-Ping Su, MDTung-Ping Su, MDDepartment of PsychiatryDepartment of Psychiatry

Taipei-Veterans General HospitalTaipei-Veterans General Hospital

National Yang-Ming UniversityNational Yang-Ming UniversityDec. 09, 2009 for IBSDec. 09, 2009 for IBS

History of NeuromodulationHistory of Neuromodulation

• ECT: electroconvulsive therapyECT: electroconvulsive therapy

• rTMS: repetitive transcranial rTMS: repetitive transcranial magnetic stimulationmagnetic stimulation

• VNS: vagus nerve stimulationVNS: vagus nerve stimulation

• DBS: deep brain stimulationDBS: deep brain stimulation

• MST: magnetic seizure therapyMST: magnetic seizure therapy

Electro-chemical communicationElectro-chemical communication

Electrical brain:

Excitatory (glutamate) and Inhibitory (GABA)neurons

Introduction to TMSIntroduction to TMS(Transcranial Magnetic (Transcranial Magnetic

Stimulation)Stimulation)

First Patent of TMS First Patent of TMS

for Depression--1902for Depression--1902

• The 1902 patent was issued The 1902 patent was issued to Pollocsek and Beer for an to Pollocsek and Beer for an electromagnetic device to electromagnetic device to treat depression and treat depression and neuroses.neuroses.

• Source: Library of Mark S. GeorgeSource: Library of Mark S. George

Early TMS Early TMS

• Sylvanius Sylvanius P.Thompson and his P.Thompson and his apparatus to produce apparatus to produce phosphenes using phosphenes using magnetic stimulationmagnetic stimulation

Modern TMSModern TMS

• A.T barker with his A.T barker with his TMS machine in TMS machine in 1985, which set the 1985, which set the stage for much of stage for much of today’s work with today’s work with TMSTMS

TMS HistoryTMS History

• 19951995 – First therapeutic cases reported in – First therapeutic cases reported in depression depression (Mark George et al, Neuroreport)(Mark George et al, Neuroreport)

Rapid increase in publications Rapid increase in publications concerning rTMSconcerning rTMS

• 1985: 11985: 1• 1987: 71987: 7

• 1989: 211989: 21• 1991: 971991: 97• 1993: 871993: 87

• 1995: 1341995: 134• 1997: 1921997: 192

Brain Stimulation LaboratoryBrain Stimulation LaboratorySpecialty Division, MUSC Psychiatry Dept.Specialty Division, MUSC Psychiatry Dept.

• • Brain Behavior ResearchBrain Behavior Research• • Translation to TherapiesTranslation to Therapies• • Interface with CAIRInterface with CAIR

Started in 1995,Assembled grant by grant

Transcranial Magnetic Stimulation (TMS)

Time-Varying Electrical Current in a Coil Produces

Focal 2 Tesla Magnetic FieldPasses Unimpeded ThroughSkull

Induces Current in Neurons

Behavioral Change

TMS is TMS is ‘Electrodeless’ Electrical Stimulation‘Electrodeless’ Electrical Stimulation

1) Electrical Energy in CoilInduces2) Magnetic Field (right handRule, Maxwell’s Equations)3) Passes unimpeded through theSkull4) Induces an electrical current inThe brainFrom TMS Review in Science, June 18, 2001

Understanding TMS Effects on NeuronsUnderstanding TMS Effects on Neurons

Critical Variables Include:• fiber orientation• intensity (submotor likely more inhibitory interneurons)• frequency• region• Distance into cortex

Using Phase Maps to Determine The Using Phase Maps to Determine The Exact Magnetic FieldExact Magnetic Field

Structural Scan with TMS Coil Phase Map of Exact Magnetic Field

Approximate Depth Limit of Direct Approximate Depth Limit of Direct Stimulation with Current TMS CoilsStimulation with Current TMS CoilsApproximate Depth Limit of Direct Approximate Depth Limit of Direct Stimulation with Current TMS CoilsStimulation with Current TMS Coils

TMS as a Brain Circuit ProbeTMS as a Brain Circuit Probe• ProsPros

– Relatively non-invasive– Good spatial and temporal resolution

• ConsCons– Unclear knowledge of effects on neurons (local

or secondary), especially as a function of• Frequency,• Duration• Brain region• Intensity

Hughlings Jackson - “Is TMS irritative (augment) or ablative?”

Applications of TMSApplications of TMS• Anticonvulsant(<1 HZ) or proconvulsant (fast)

• Mapping the cortex of the brain

• Probing neural networks by stimulation or inhibition at different places and times

• Measuring cortical excitability in health and in disease, and in response to drugs

• Modulating brain function to study the pathophysiology of a variety of neuropsychiatric conditions, and possibly treat them

• Sadness Induction in Healthy Adults, O15 PET, Sadness Induction in Healthy Adults, O15 PET, (George et al, Am J Psych, (George et al, Am J Psych, 1995)1995)

– Historical Recollection, Viewing Faces– Bilateral Anterior Paralimbic Activation

• Unclear Unclear – What’s causal and true to the emotion, – what’s due to the method, and – what’s epiphenomenal?

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Percent Improvement in Depression Over Time by Group

Week 1 Week 2 (End)

Placebo Fast TMS Slow TMS

Figure 1

Placebo Fast TMS Slow TMS

George et al, 2000 Bio Psych

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TMS Antidepressant Effect Size and Speed of Response:Blinded Studies to Date

%drop Hamd

Pascual-Leone, 1996

Klein, 1998

George, 1997

Loo, 1998

Berman,1998

Nahas, George, 1998

Summary of 5 Published RCTSummary of 5 Published RCTTMS Antidepressant TrialsTMS Antidepressant Trials

n=86 active, 83 placebo, 2 Weeks, Prefrontaln=86 active, 83 placebo, 2 Weeks, Prefrontal

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REMITTERS & RESPONDERS

Mean MADRS scores obtained at end of each week over a period of 4 weeks

12.1713.87

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We need to treatFor more than 2 weeks

Possible mechanism of action of Possible mechanism of action of TMSTMS

• Step 1: Creation of a transmembrane Step 1: Creation of a transmembrane potentialpotential

• Step 2: Spatial derivative of the electric filed Step 2: Spatial derivative of the electric filed along the nervealong the nerve

• Step 3: Electric field distribution and Step 3: Electric field distribution and transmembrane potentialtransmembrane potential

Observable effects of TMSObservable effects of TMS

• Magnetic field of TMS coilMagnetic field of TMS coil

• Electric field induced by TMS coilElectric field induced by TMS coil

• Local response to TMS stimulationLocal response to TMS stimulation

TMS as TherapyTMS as Therapy

• Clear and convincing data for depressionClear and convincing data for depression– Approved in Canada, Israel– US FDA approved in 2008

• Need much more work on use Need much more work on use parameters, mechanisms of action, parameters, mechanisms of action, maintenancemaintenance

How does TMS treat depression?How does TMS treat depression?

• HormonalHormonal - hits HPA circuit, resets - hits HPA circuit, resets thryoid, CRH, cortisolthryoid, CRH, cortisol

• Cortical Governing - Cortical Governing - rebalances rebalances relationship between relationship between cortex and limbiccortex and limbic

• AnticonvulsantAnticonvulsant - mimics brain’s - mimics brain’s antiseizure surveillance mechanism with antiseizure surveillance mechanism with local transmitter changes (gaba) local transmitter changes (gaba)

Prefrontal TMS Effects on Prefrontal TMS Effects on Blood FlowBlood Flow

TMS in other mental disordersTMS in other mental disorders

• ManiaMania

• CatatoniaCatatonia

• SchizophreniaSchizophrenia

• Obsessive-compulsive disorderObsessive-compulsive disorder

• PTSDPTSD

• Panic disorderPanic disorder

TMS - ConclusionsTMS - Conclusions

• Pros - Great potentialPros - Great potential– Non-invasive– Potential for pushing and pulling circuits

• Therapeutics - Therapeutics - – Still Experimental– Repeated stimulation over 2-3 weeks treats depression

• Problems - Problems - basic effectsbasic effects on neuronal function are on neuronal function are largely unknownlargely unknown– Intensity, frequency, location, trains, dose– Currently limited to cortex

Safety Concerns of Safety Concerns of Transcranial Magnetic StimulationTranscranial Magnetic Stimulation

rTMS Parameters Important for safetyrTMS Parameters Important for safety

• Intensity (strength of voltage; %MT)Intensity (strength of voltage; %MT)

• versusversus

• Frequency (how fast; Hz)Frequency (how fast; Hz)

• versus versus

• Train duration (how long; sec)Train duration (how long; sec)

• versus versus

• Intertrain interval (spacing)Intertrain interval (spacing)

• versus versus

Current rTMS safety guidelines Current rTMS safety guidelines ::

maximum safe duration (seconds) for single trains of rTMS based on the National maximum safe duration (seconds) for single trains of rTMS based on the National

Institute of Neurological Disorders and Stroke experience(NINDS)Institute of Neurological Disorders and Stroke experience(NINDS)

Conclusions: side effectsConclusions: side effects

• Both Single-pulse TMS / rTMSBoth Single-pulse TMS / rTMS can cause can cause• Headache:Headache:

local discomfortlocal discomfort

muscle tension headachemuscle tension headache• Temporary Temporary increase in auditory thresholdincrease in auditory threshold without without

earplugsearplugs• Heating of metallic objectsHeating of metallic objects within head,on scalp within head,on scalp• Malfunction Malfunction of very close electronic/magnetic devicesof very close electronic/magnetic devices

Effect of Repetitive Transcranial Magnetic Effect of Repetitive Transcranial Magnetic Stimulation (rTMS)Stimulation (rTMS)

on Mood and Cognition on Mood and Cognition

Tung-Ping Su, MDTung-Ping Su, MD

Department of PsychiatryDepartment of Psychiatry

Taipei-Veterans General HospitalTaipei-Veterans General Hospital

April, 23, 2002April, 23, 2002

The five major regions of dysfunction in depressed brains

and Nu. Accumbens are underactivity and HPA axis: overactivity

Frontal-subcortical circuit

governance

• Lt frontal: positive emotion

• Rt frontal: negative emotion

Acute depression (transient sadness)Lt PFC activity increase

Chronic depressionLt PFC activity decrease

• Similar to seizure:

Cingulate:Attention& mood

Amygdala:Emotional recognition of facesLt Amygdala activated during sadness

• Personality change

• ResultsResults

Hamilton Depressive Rating Scale

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Add-on rTMS for medication-resistant Add-on rTMS for medication-resistant depression:depression:

a randomized, double-blind, sham-a randomized, double-blind, sham-controlled trial in Chinese patientscontrolled trial in Chinese patients

Tung-Ping Su, Chih-Chia HuangTung-Ping Su, Chih-Chia Huang

J of Clinical Psychiatry 2005:66:930-937J of Clinical Psychiatry 2005:66:930-937

Effect of Age, Gender, Menopausal Status, and Ovarian Hormonal Level

on rTMS in Treatment-Resistant Depression

Chih-Chia Huanga, I-Hua Weid, Yuan-Hwa Choua, Tung-Ping Su

Psychoneuroendocrinology, 2007

post-menopausal women

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N=47

Responder: 23

Non-responder: 24

N=17

Responder: 12

Non-responder: 5

N=14

Responder: 0

Non-responder: 14

N=16

Responder: 11

Non-responder: 5

N=31

Responder: 12

Non-responder: 19

Pearson’s correlation test

r = -0.276

P = 0.061

Pearson’s correlation test

r = -0.322

P = 0.207

Pearson’s correlation test

r = 0.35

P = 0.184

Pearson’s correlation test

r = 0.117

P = 0.691

Pearson’s correlation test

r = -0.646

P < 0.001

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Fig. 1 Relationship of reduction of percent HAM-D Score with Age in the Whole Group of Depressed Patients, between Genders, and Premenopausal and Postmenopausal Females

all subjects

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Fig. 2 Percentage HAM-D reduction vs. E2/P ratio

N=16

r = -0.11

P = 0.968

N=17

r = 0.563

P = 0.019

N=14

r = 0.158

P = 0.590

N=31

r = 0.527

P = 0.002

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Table 3 Stepwise Multiple Linear Regression Analysis of Factors Correlated to Percentage HAM-D Reduction After rTMS in Female Patients

Variables

Percentage HAM-D reduction

β t P Adjusted r2

Menopausal status(pre=1; post = 0)

0.728 6.334 <0.001 0.525

P -0.266 -2.350 0.026 0.630

E2/P ratio 0.257 2.248 0.033 0.677

LOCF was applied.E2, estradiol; P, progesterone; pre, premenopausal status; post, postmenopausal status.

Prediction of antidepressant efficacy of a 2-week add-on trial rTMS

in Medication-Resistant Depression: a 18F-FDG PET study

Tung-Ping Su, MDDepartment of Psychiatry

National Yang-Ming UniversityTaipei Veterans General Hospital

2nd WCAP, Taipei, Nov. 9, 2009

Introduction

• Impaired reciprocal function relationship of limbic amygdala &

hippocampus - cortical dorsolateral, medical and ventral prefrontal circuit—thought to correlate with emotional dysregulation and depression– Inconsistent results from imaging studies (PET or SPECT) in exact

location and direction of regional cerebral metabolism in depression, suggesting possible roles of using pre-Tx regional metabolic activities in various parts of the brain to predict tx response from antidepressants (Mayberg 2000, Little 2005,Milak, 2009)

– Medication-resistant depression (MRD) is a unique model for study as if underlying pathophysiology is different from pharmaco-responsive major depression (MDD).

Hypotheses and Aims

• Responders are different from non-responders in resting brain metabolism– Differences may account for core antidepressant mechanism of

rTMS

• Pre-rTMS regional brain glucose uptake in DLPFC, ACC, hippocampus and brainstem may – Predict rTMS effectiveness in medicated MRD patients.

• Is underlying pathophysiology of MRD different from other depressives ?– Compare with previous hypothesis of depression

Methods• Criteria for MRD (N=20)

– MDD dx through MINI and history taking– MRD dx, a hx of failing to respond to at least 2 different antidepressant trials and

with severity of scores >=18 of Hamilton Depression Rating Scale (HRDS-17)– No alcohol or substance abuse history, no major medical and neurological

disorders, no comorbidity of schizophrenia, bipolar disorder, OCD, PTSD or cluster–B personality d/o

• A 2-week of daily rTMS administration with continuation of the current antidepressant medications

• Responders (HDRS-17 score >= 50% reduction) vs. non-responders• PET and MRI procedures

– Healthy control subjects (N=20)

Setting for Repetitive transcranial stimulation, r-TMSm using Brainsight(MRI DLPFC localization)

Study designStudy design

ResultsResults

Treatment-Resistant MDD (20) vs. NC (20) Treatment-Resistant MDD (20) vs. NC (20)

NC < MDDNC > MDD

•Global variance across scans: removed by analysis of covariance (ANCOVA)•Btw-gp comparison: ANCOVA, Controlling for age and gender•Cluster level, corrected p <0.001

Treatment-Resistant MDD (20) vs. NC (20) Treatment-Resistant MDD (20) vs. NC (20) A cortico-limbal dysregulationA cortico-limbal dysregulation

• MDDMDDBil DLPFCBil DLPFCBil OFCBil OFCBil Med. PFC Bil Med. PFC Bil Ant. Insula - IFABil Ant. Insula - IFAAnterior CingulumAnterior CingulumMiddle CingulumMiddle Cingulum

Bil AmygdalaBil AmygdalaBil Putamen/GP Bil Putamen/GP Bil InsulaBil InsulaHippo/ParahipHippo/ParahipRaphe nu. Raphe nu. CerebellumCerebellum

Responder(13) Responder(13) vs.vs. Non-Responder(7)Non-Responder(7)• RespondersResponders

Bil DLPFC (BA 9)Bil DLPFC (BA 9)

Bil OFCBil OFC

Bil Med. PFC (BA 6d)Bil Med. PFC (BA 6d)

Anterior CingulumAnterior Cingulum

Middle CingulumMiddle Cingulum

Bil Uncus/FusiformBil Uncus/Fusiform

Bil Srtiatum Bil Srtiatum

Bil InsulaBil Insula

Hippo/ParahipHippo/Parahip

Raphe nu. Raphe nu.

Cerebellum Cerebellum

•voxel level, k=300, uncontrolled p <0.05

Less hypoactive in ACC, bilateral medial prefrontal Less hypoactive in ACC, bilateral medial prefrontal gyrusgyrus

Responder > N-R

•Global variance across scans: removed by analysis of covariance (ANCOVA)•Btw-gp comparison: ANCOVA, Controlling for age and gender•Using NC vs. MDD mask•Cluster level, k=2000,uncorrected p <0.05

Less hyperactive in Less hyperactive in left hippocampus and fusiform gyrusleft hippocampus and fusiform gyrus

Responder < N-R

•Global variance across scans: removed by analysis of covariance (ANCOVA)•Btw-gp comparison: ANCOVA, Controlling for age and gender•Using MDD vs NC mask•Cluster level, k=1000,uncorrected p <0.10

Pre-tx areas predicting treatment responses Pre-tx areas predicting treatment responses (≥50% decreases in HDRS)(≥50% decreases in HDRS)

•Higher pre-tx metabolism in ACC •Cluster level, k=1000, uncorrected, p = 0.089 (trend-significance)

•Lower pre-tx metabolism in Left fusiform/hippo/parahippocamcal gyri •Cluster level, k=1000, uncorrected, p = 0.004

ACC Left fusiform/hippocamcal gyri

(Paper in submission, 2009)

SummarySummary• Medicated M-R MDD patients vs. normal subjectsMedicated M-R MDD patients vs. normal subjects

– Lower metabolism in both L and R DLPFC

– Also in the status of limbic-cortical dysregulation

• Patients who responded well to rTMS Patients who responded well to rTMS – Not that severe in limbic-corticol dysregulation

– Higher pre-tx ACC and lower left Hippocampal/Fusiform activities could predict rTMS responses

• rTMS mechanism: stimulate L DLPFCrTMS mechanism: stimulate L DLPFC– By reverse metabolism of L DLPFC activities only ?

– Might have an effect of normalizing limbal-cortical dysregulation

Responder Non-Responder

ResponderTMS治療前和 Normal做比較

Normal>MDD_Responder Normal<MDD_Responder

ResponderTMS治療後和 Normal做比較

Normal>MDD_Responder Normal<MDD_Responder

Remark:1. TMS 治療後， Responder 和 Normal 在大腦前方的活性差異消失。2. Responder 和 Non-responder 在 TMS 治療前，差異度最大的地方是在大腦前區的活性 ( 和Normal 比較 ) 。

Non-responderTMS治療前和 Normal做比較

Normal>Non-responder Normal<Non-responder

Non-responderTMS治療後和 Normal做比較

Normal>Non-responder Normal<Non-responder

Remark:1. Non-Responder 在 TMS 治療後，和 Normal 比較的 pattern 更接近 Responder 。 (??)

Non-responder (Paired t test)TMS 治療前 >TMS 治療後 TMS 治療前 <TMS 治療後

Remark: Non-responder 在 TMS 治療前後， cortex 活性差異不大。

Important PointsImportant Points

There is an explosion of new techniques for There is an explosion of new techniques for stimulating the brain stimulating the brain (TMS, MST, VNS (TMS, MST, VNS and DBS)and DBS)

These new tools will drastically change These new tools will drastically change neuropsychiatry researchneuropsychiatry research and therapies and therapies in the in the next 20 yearsnext 20 years

OutlineOutline• ECTECT• MSTMST• TMSTMS• VNSVNS• DBSDBS• ConclusionsConclusions

AscendingVagal projections

Vagus nerveAfferentconnections

Effects of vagus Nerve stimulation on the brain

Thank you for your attentionThank you for your attention