treatment of auditory verbal hallucinations in schizophrenia using tdcs
TRANSCRIPT
Treatment of auditory verbal hallucinations in schizophrenia using tDCS Charlotte Chaze1, Vince P. Clark1,2, Jessica Turner1,3, Rose Bigelow2, Jason Long2, Vince Calhoun1,2, Robert Thoma2
1Medical Image Analysis Lab, The Mind Research Network, Albuquerque, United States 2Departments of Psychology & Psychiatry, University of New Mexico, Albuquerque, United States 3Department of Psychology, Georgia State University, Atlanta, United States
References:
Brunelin, J. et al. Examining transcranial direct-current stimulation (tDCS) as a treatment for hallucinations
in schizophrenia. Am. J. Psychiatry 2012; 169:719-24.
Drake, R. et al. The Psychotic Symptom Rating Scales (PSYRATS): their usefulness and properties in
first episode psychosis. Schiz. Research 2007; 89:119-122.
Results
Figure 1. Response to real voices before & after tDCS treatment
• There is a decrease in activation in the auditory cortex when listening to real voices
post-treatment
Question
Can transcranial direct current stimulation (tDCS) lessen the severity
of auditory verbal hallucinations (AVH) in schizophrenia by
modulating neural activation in pertinent brain regions?
Background
• Brunelin et al (2012) reported reduction in the severity of AVH in a tDCS
treatment trial
• We use fMRI to measure neural activation before and after treatment
Methods
• Volunteers with schizophrenia underwent a 5-day tDCS treatment program:
• AVH-on and AVH-off were tracked during fMRI scanning using a button-press
paradigm
• Volunteers also completed tasks that involved listening to stories and imagining
scenarios during fMRI scanning
Figure 2. Core PSYRATS Variables: Mean AVH Frequency & Duration Scores
Figure 3. Mean PANSS Scores
• A decrease in PSYRATS and PANSS scores with tDCS treatment is associated with
decreased activation in auditory cortex during a listening task
• A decrease in PSYRATS and PANSS scores are indicative of:
• A decrease in the severity of AVH
• A reduction in positive and negative symptoms of schizophrenia
Conclusions & Applications
• The first 3 participants experienced a decrease in frequency and duration of AVH
following treatment with tDCS
• Atypical function of auditory cortex is associated with the presence and severity of
AVH
• tDCS neurostimulation may be used to affect schizophrenia AVH
Right index finger:
AVH/”voices” on Left index finger:
AVH/”voices” off
Images from:
en.wikipedia.org/wiki/Wernicke's_area, neuroconn.de/dc-stimulator-2 , pixshark.com/duracell-battery-9v.htm,
boundless.com/biology/textbooks/boundless-biology-textbook/the-nervous-system-35/how-neurons-communicate-
200/
http://neurosciencenews.com/fmri-brain-differences-drug-use-889/mri-scan-normal-brain-sagital-view
Future
• Add sham trials
• Analyze listening task for controls
-70
-55
Resting potential
Excitation threshold
Mg+ Ca2+
Na+
-70
-55
e- e-
e-
Cathode
Wernicke’s area:
Language production
Anode
Broca’s area:
Language comprehension
tDCS
e-
Mg+
Ca2+
Na+
Anode: Makes neurons fire more easily Cathode: Makes it more difficult for neurons to fire PSYRATS
PANSS
PSYRATS
PANSS
Day 1
tDCS
Day 2 Day 3 Day 4 Day 5
tDCS tDCS tDCS
tDCS
PSYRATS
PANSS
Neural networks underlying auditory verbal hallucinations in schizophrenia Charlotte Chaze1, Robert Thoma1,2, Rose Bigelow2, Vince P. Clark1,2, Juan Bustillo2, Vince Calhoun1,2, Jessica Turner1,3
1Medical Image Analysis Lab, The Mind Research Network, Albuquerque, United States 2Departments of Psychology & Psychiatry, University of New Mexico, Albuquerque, United States 3Department of Psychology, Georgia State University, Atlanta, United States
Question
How are regions involved in auditory verbal hallucinations
(AVH) linked together into networks in the brain?
Background
• Auditory verbal hallucinations are heard, not imagined (Figure 1)
• fMRI studies have identified regions active during auditory verbal
hallucinations (AVH) in schizophrenia
• Little is known about how these regions may be linked together into
networks
Methods
• Volunteers with schizophrenia were scanned in a 3-Tesla Siemens Trio
MRI
• Volunteers pressed buttons to indicate when they were experiencing
AVH (“hearing voices”)
• A minimum of 3 5-minute scans were collected for each volunteer
• Scan data was analyzed using both the general linear model and
independent component analysis
Figure 4. Brain activations during AVH (GLM + ICA)
• Temporal lobe (red): auditory processing and language recognition
• Inferior frontal gyrus (violet): language comprehension and production
• Basal ganglia (green): movement and motivation
• Insula (blue): self awareness, emotions
Discussion
• Activations in presumed auditory/linguistic processing networks show
a strong relationship to AVH
• Multiple networks are activated during AVH
Conclusions
• Each method of analysis has complimentary strengths and
weaknesses
• When combined, the GLM and ICA identify multiple neural networks
underlying the generation of AVH
• Most overlap is on the auditory cortex and temporal
lobes (language regions of the brain)
Applications
• Treatment of schizophrenia using precise techniques focused on
networks implicated in AVH
Right index finger:
AVH/”voices” on
Left index finger:
AVH/”voices” off
Figure 1. Actual hearing vs. “inner speech”
Results
Figure 2. Brain activations during AVH: GLM results
• Activation in auditory cortex and temporal lobes
Figure 3. Brain activations during AVH : ICA results
• Activations in areas previously implicated in AVH
Actual hearing Imagined repeating a sentence
References:
Brunelin, J. et al. Examining transcranial direct-current stimulation (tDCS) as a treatment for hallucinations in schizophrenia. Am. J. Psychiatry 2012; 169:719-24.
Drake, R. et al. The Psychotic Symptom Rating Scales (PSYRATS): their usefulness and properties in first episode psychosis. Schiz. Research 2007; 89:119-122.
PSYRATS
PANSS MRI
MRI
PSYRATS
PANSS
Day 1
tDCS
Day 2 Day 3 Day 4 Day 5
tDCS tDCS tDCS
tDCS