Electrical brain activity following magnetic stimulation as recorded with high-resolution QEEG
Presented in the 8th World Congress of Psychiatry in Vienna in July 2th, 2005.
(A symposium called ‘Brain Stimulation Techniques in Psychiatry and Electrophysiology’. Chair: Bilgen Taneli, Co-chair: Mark George, Other speakers: David Avery, Nevzat Tarhan).
Published in The World Journal of Biological Psychiatry, Volume 5-3 (Supplement 1), 2005-July.
www.wfsbp-vienna2005.com
Prof. Dr. Nevzat Tarhan'ın Viyana 8. Dünya Psikiyatri Kongresi Sunumu (PPS Formatında indirmek için tıklayınız.)
Electrical brain activity following magnetic stimulation as recorded with high-resolution QEEG
Prof. Dr. Nevzat Tarhan
rTMS
- First TMS capable of delivering a pulse every three seconds (as diagnostic aids for neurologists.)
- New machines which can give up to 50 stimuli per second (rTMS)
- A non-invasive technique, free of serious side effects, easily modifying activity of specific brain areas
How does rTMS work for brain electrical activity?
- rTMS gives short pulses of magnetic energy to Limbic system structures
- Small electric charges can cause the neurons to fire or to become active
Ilmoniemi et.al.(1997) were able to measure with QEEG just seconds after electromagnetic pulse
- Nashaat et.al (2001),
- Nikulin et.al (2003),
- Kommsi et.al (2004) have used ongoing rTMS and QEEG Monitoring
Brain electrical activity changes with rTMS
- lAcute rTMS induces changes in regional activity throughout the brain
- Stimulation intensity is important
- Low frequency has a tendency to decrease
- High frequency has a tendency to increase
Resynchronization effects
- lNormal brain function requires synchronized activity of interconnected brain areas
- rTMS may help ‘reset’ the normal synchrony between brain regions
(Garcia-Toro et.al. 2001, Avery 2004)
GABA and QEEG
- lGABA increases functional connectivity on QEEG (Benzodiazepine effect)
- GABA decreases with stress
- GABA decreases in plasma and in brain (MRS) of depressed patients
- ECT increases GABA level in depressed patients.
- rTMS: increase ?
State marker improves after treatment
- Trait marker doesn’t improve after treatment
‘State markers’ of QEEG being:
- lRatio of Alpha waves
- Ratio of Delta waves
- Hemispheric asymmetry
- Alpha/Delta ratio of the frontal area
Acute drug effect in QEEG
- lTricyclic Antidepressant drugs: Alpha, Theta, Delta
- Antipsychotic drugs :Theta and Delta waves
- Antianxiety drugs :beta
- Cognitive activator drugs : Alpha
- SSRI drugs: Alpha (Itil 1989)
- •Delta waves: good response,
- Alpha and Beta waves: good response,
- Unchanged QEEG: bad response. (Kendler)
According to HAM ScoresHAM Scores and QEEG after 10 sessions of rTMS “An interpretation”
- lAll patients showed 30-50% treatment response
- In Alpha increases group, HAM improvement was greater
- In no changes group, HAM improvement was minimal
- More verification, and MEG studies, are necessary
Pregnancy and rTMS (Case Study I)
- lOne case (I.D., 32 years)
- She had serious non-psychotic Chronic Major Depression.
- She used antiepileptic and antidepressant drugs.
- She became pregnant during treatment.
- She wanted to continue the pregnancy.
Pregnancy and rTMS (Case Study II)
- lFirstly, we stopped her using the antidepressant drugs
- We applied 40 sessions of rTMS to her.
- Every session was 25 Hz. and 1000 pulses.
- Now, she has a healthy baby.
- After birth, rTMS was continued.
Frequency of seizures
- lWe applied rTMS at approximately 15,000 sessions in two years
- In every session, rTMS was applied at 25 Hz
- In most cases, 1000 pulses were applied in every session
- Grandmal seizures were observed only in 3 cases.(3 /15,000)
- 25 Hz, 1 Pulses, 50% Power
- 25 Hz, 1 Pulses, 100% Power
- 25 Hz, 3 Pulses, 100% Power
- 5 Hz, 10 Pulses, 50% Power, Duration 1.8 sec
- 5 Hz, 10 Pulses, 75% Power, Duration 1.8 sec
- 5 Hz, 10 Pulses, 100% Power, Duration 1.8 sec
- 25 Hz, 50 Pulses, 50% Power, Duration 1.9 sec
- 25 Hz, 50 Pulses, 75% Power, Duration 1.9 sec
- 25 Hz, 50 Pulses, 100% Power, Duration 1.9 sec
Scientific Inspiration
- One day, in 1990 at a London Hospital in an elevator, a passenger was giggling. A magnetic stimulation had been applied to his head. It was a neuro-diagnostic motor test, for thumb jerk
- Dr. Mark George observed and was astonished by this situation. He suspected that magnetic fields could move much more than the thumb.
- The story of magnetic therapy in psychiatry started like this.
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