Overview of transcranial direct current stimulation

1. tDCSの臨床研究
Clinical application of tDCS
Yuma Yokoi, MD
2015

2. 2
Conflict Of Interest

3. 3
tDCS stands for
transcranial direct current stimulation
経頭蓋 直流電気 刺激

4. 4
Direct current
Anode
陽極
Cathode
陰極
Current
電流
Battery
電池

5. 5
h/o tDCS
18th/19th century: Galvanism
20th century: prosperity of ECT and disregard of tDCS

6. 6
Current tDCS
(a)Stimulator
(b)Anode electrode
(c)Cathode electrode
(d)Strap
(e)Rubber band
(Yokoi [in press])

7. 7
tDCS devices
(Guleyupoglu 2013)

8. • Current intensity 電流量 ( 0.5 to 2 mA )
• Duration 刺激時間 ( 5 to 40 min )
• Frequency 刺激頻度 (3~5/week, 1~2/day)
• Size of electrodes 電極サイズ ( 3 to 100
cm2)
→ Current density 電流密度 ( A / m2 )
Total charge 総電流量 ( Coulombs )
8
dose of tDCS

9. • High-definition tDCS
– Many electrodes
• tACS (transcranial
alternating current
stimulation)
• tRNS (transcranial
random noise
stimulation)
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variants of tDCS
(Guleyupoglu 2013)

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Mechanism of Action (Filmer 2014)

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Mechanism of Action (Filmer 2014)
(Purpura 1965)
motor evoked potentials (MEPs)

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Mechanism of Action (Santarnecchi 2014)

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Mechanism of Action (Filmer 2014)
Anodal stimulation inhibits
GABA
(Mondino 2014, Stagg 2011)
Long-term potentiation
(LDP)-like
長期増強

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Mechanism of Action (Filmer 2014)
Cathodal stimulation inhibits
glutamate
(Stagg 2011)
Long-term depression
(LDP)-like
長期抑制

15. • DLPFC (Dorsolateral prefrontal cortex)
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Rationale for treating depression
( Kim 2014 )

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Mechanism of action is complex
◯ Electricity  Nonfocal (Russel 2013)
• Anatomical factors  up to 50%
– Geometory of sulci and gyri (Miranda 2013)
– Thickness of cerebrospinal fluid (CSF) and skull
(Opitz 2015)
– Cathodal stimulation? (Filmer 2013)
◯ Neurotransmitter  GABA, glutamate,
catecholamine, acetylcholine and serotonin (Stagg
2011, Medeiros 2012, Mondino 2014)

17. 17
Mechanism of action is complex
( Kuo 2013 )

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Safety
( Tortella 2015 )
かゆみ
ひりひり
頭痛
焼ける感じ
不快感

19. 19
Meta-analysis of tDCS for depression
(Shiozawa 2014)

20. ADAPT研究
Ameliorating Depression in Alzheimer’s disease Patients by
Transcranial direct current stimulation
A randomized, double-blind, sham-controlled trial
アルツハイマー病のうつに対して経頭蓋直
流電気刺激を行うRCT
ClinicalTrials.gov Identifier: NCT02351388
UMIN ID:UMIN000014561
科研費番号:26860958
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ADAPT研究

21. Participants
アルツハイマー病患者
MINH基準でのdAD診断
Intervention/Control
tDCS 週5日×3週
実刺激 or 偽刺激
二重盲検RCT
Outcome
安全性・忍容性
CSDD(コーネル認知症
抑うつ尺度)のBLからの
変化 など
Sample size
実刺激10+偽刺激10
Phase 1/2
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アウトライン