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Biological/psychological effects of being scanned with an MR scanner R. Kortekaas MR Methodology Journal Club 10AM, Friday, 29-08-08 3211-032 (ADL1)

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Presentation on theme: "Biological/psychological effects of being scanned with an MR scanner R. Kortekaas MR Methodology Journal Club 10AM, Friday, 29-08-08 3211-032 (ADL1)"— Presentation transcript:

1 Biological/psychological effects of being scanned with an MR scanner R. Kortekaas MR Methodology Journal Club 10AM, Friday, (ADL1)

2 boredom, fatigue, anxiety, claustrophobia....? NO! magnetism or RF mediated effects on the body!

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5 Intro: Anecdotal reports suggested mood improvement in bipolar disorder immediately after EPMRSI Aim: evaluate mood improvement associated EPMRSI

6 Methods: 3 treatment groups: BD active (n=30), BD sham (n=10), HC active (n=14) subjects were blinded to the hypothesis (EPMRSI causes mood change) Brief Affect Scale, Hamilton Depression Rating Scale, Young Mania Rating Scale (by same research assistant) rater was not blinded to the treatment conditions

7 Methods: 1.5 T Signa scanner (5.8 EchoSpeed version, GE) 4 EPMRSI scans / patient / visit (totaling 20.5 minutes) (sequence in ref #10) EP-MRSI fields are <= 6 1 kHz. sham EPMRSI: 15-minute three- dimensional spoiled gradient echo scan conventional double-echo spin-echo T2 T1 anatomic scan echo-planar T2 acquisition total: about 1 hour

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10 Results: verum vs placebo in BD Z=2.63, p=0.009

11 Discussion: effects likely due to time-varying gradient magnetic fields of EPMRSI: the readout gradient not due to B static

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13 Intro: paper by Rohan Aim: evaluate effects in behavioural tasks in rats

14 Methods: rats received LFMS (three 20-min sessions at 1.5 G/cm and.75 V/m) before behavioral testing immobility in the forced swim test activity within an open field fear conditioning

15 114 male rats head gradient coil: a development prototype(Advanced NMR Systems, Woburn, Massachusetts) comprising a cylinder (diameter, cm; length, cm; thickness, 1.59 cm) with three embedded magnetic coils

16 control of the waveform by LabVIEW switching amplifier (MTS Automation, Horsham, Pennsylvania) magnetic field gradient strength for this experiment was 1.5 G/cm 2A), and the electric field strength at the coil center was.75 V/m right-to-left electric field was delivered in ms square 1 kHz pulse polarity alternated With gradient design and analysis software, electric field distributions for the LFMS gradient coils were calculated with a Biot-Savart style integration of simulated coil design files containing three-dimensional wire information with a.5-cm linear resolution.

17 Results: magnetic stimulation reduced immobility in the forced swimming task –an antidepressant-like effect –qualitatively similar to that of standard antidepressants magnetic stimulation did not alter: –locomotor activity –fear conditioning

18 Discussion: Low-field magnetic stimulation has antidepressant-like effects in rats electromagnetic fields affect the brain novel approaches to therapy for psychiatric disorders MRI scans are less inert than previously thought

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20 Intro: EPMRSI may show antidepressant effects Aim: What about T1 and EPI-DWI?

21 Methods: modified forced swimming test in mice immobility, swimming and climbing times four groups (n=21): T1 EPI-DWI sham controls 84 fixative chambers

22 Results: T1 and EPI-DWI: reduction in immobility time (p < 0.017) EPI-DWI: climbing time longer T1: swimming time longer sham and control were equal

23 Discussion: antidepressant profiles of both T1 and EPI-DWI Even 'mundane' protocols like T1 may have biological effects!

24 3 papers’ summary filing cabinet effect? Rohan: 6 1 kHz is effective observer effect: the act of observing will influence the phenomenon being observed

25 An emerging concept Resonance Photic driving

26 “  TMS project ” arbitrary waveshapes and frequency content up to 6 G (0.6 mT) (like EPMRSI) one channel for 19 electromagnets clinical trial ongoing, analgesic effects individual switching being implemented four independent channels being implemented find evidence for EEG entrainment with  TMS

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32 32 Bioelectriciteit De Viribus - Electricitatis in Motu Musculari Luigi Galvani

33 33 stroom in de hersenen

34 34 inzoomen op zenuwcel

35 35 met dank aan:

36 36 Actie potentiaal

37 37 Synaptische potentiaal resting potential? 10 4 contacts EPSP / IPSP

38 38 Wet van Ampere I → B “rechterhandregel” Principe TMS

39 39 Wet van Faraday ΔB → I Principe TMS hinson/images/0008n093.jpg

40 40 Combinatie van de wetten van Ampere en Faraday: ΔI → ΔI Stroom over afstand ‘versturen’

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42 42 Principe TMS Combinatie van de wetten van Ampere en Faraday: ΔI → ΔI demo: stimulatie van sensorische en motorische zenuwen in de hand en pols

43 43 Mechanisme voltages in hersenen anders stromen beweging van ionen verandering van synaptische potentialen verandering van actiepotentialen

44 behandeling –depressie –migraine –oorsuizen (tinnitus) –psychose (schizofrenie) –verslaving: roken onderzoek: wat doet een hersengebied? –demo: motorcortex Maar waarom eigenlijk?


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