a case study on auditory verbal hallucinations
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Case study on Auditory Verbal HallucinationsTRANSCRIPT
Mark Gronowski
A Case Study on Auditory Verbal Hallucina5ons
Monday, 29 April, 13
Auditory Verbal Hallucina5ons (AVH)
• One of the most characteris4c symptoms of Schizophrenia
• But, why do they occur?
• Two hypotheses exist:• Misinterpreted inner
speech• Abnormal ac4va4on of the
auditory cortex
Monday, 29 April, 13
Hypothesis 1: Misinterpreted Inner Speech
• AVH occurrences with perioral movements • Perioral ac4vity is generally associated with
inner speech • Inner Speech genera4on ac4vates Broca’s area• Misrecogni4on of inner speech also associated with leK Middle Temporal Gyrus (MTG)
Monday, 29 April, 13
Hypothesis 2: Abnormal ac5va5on of the auditory cortex
• AVHs also linked to abnormal ac4va4on of the primary auditory cortex (PAC)• May cause experience of a perceived real
sound leading to misinterpreta4on of its source as external
•
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Case Study: Pa5ent DT
• Female with Paranoid Schizophrenia• Experienced con4nuos AVHs
• Single voice commen4ng on her behaviour• Ordered her to accomplish some acts• Some4mes heard mul4ple voices talking to each other
• Trained to report the onset and end of her AVHs• Hallucina4ons inhibited by loud external speech
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Case Study: Control Subject
• Matched Control Subject• Both right-‐handed females• Matched in age (36 years) • Same level of educa4on (high school)
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fMRI Tes5ng• fMRI (Func4onal Magne4c Resonance Imaging) • Measure of Blood Oxygena4on
Level Dependent (BOLD) change
• Experimental Condi4on• Listen to noise generated by the fMRI scanner
• Control Condi4on• Listen to recorded speech through headphones
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Results: Control Subject• BOLD signal response to External Speech (Control):
• LeK/Right Middle and Superior Temporal Gyri• LeK Inferior Temporal Gyrus
fMRI of auditory verbal hallucinations
Vol. 27, No. 2, 2002 Journal of Psychiatry & Neuroscience 113
Fig 1A: In the normal control subject, coronal statistical map showing bilateral blood oxygenation level dependent(BOLD) signal increases in auditory cortex while subject was listening to external speech (subtraction of brain activityassociated with listening to the noise produced by the functional magnetic resonance imaging [fMRI] machine fromthat associated with listening to an external speech and the noise of the fMRI machine).B: Absence of activation in the auditory cortex and in the inferior frontal lobe when the brain activity associated withlistening to external speech and the noise produced by fMRI machine was subtracted from that associated with listen-ing to the fMRI machine alone.C–F: In patient DT, the subtraction of brain activity associated with listening to external speech and fMRI machinenoise from that associated with experiencing auditory verbal hallucinations (AVHs) and fMRI machine noise revealed asignificant activation of the left superior temporal gyrus (primary auditory cortex, Brodmann’s area 41) (C) and theright middle temporal gyrus (auditory association cortex, Brodmann’s area 21) (E). The time courses of the BOLDsignal increases for coronal statistical maps depicted in C and E are presented in D and F, respectively.G: When the brain activity associated with experiencing an AVH and listening to the noise of the fMRI machine wassubtracted from that associated with listening to external speech and the fMRI machine, there were BOLD signalincreases seen in the areas of interest.
• fMRI noise (Experimental) response:• No significant ac4va4on seen in the temporal lobes
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Left Hemisphere Right Hemisphere
External Speech / Control
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Results: Pa5ent DT
• BOLD signal response to fMRI noise (Experimental):• LeK Superior Temporal Gyrus (Auditory Cortex)• Right Middle Temporal Gyrus (Auditory Associa4on Cortex)
• No significant ac4va4on in Broca’s area
fMRI of auditory verbal hallucinations
Vol. 27, No. 2, 2002 Journal of Psychiatry & Neuroscience 113
Fig 1A: In the normal control subject, coronal statistical map showing bilateral blood oxygenation level dependent(BOLD) signal increases in auditory cortex while subject was listening to external speech (subtraction of brain activityassociated with listening to the noise produced by the functional magnetic resonance imaging [fMRI] machine fromthat associated with listening to an external speech and the noise of the fMRI machine).B: Absence of activation in the auditory cortex and in the inferior frontal lobe when the brain activity associated withlistening to external speech and the noise produced by fMRI machine was subtracted from that associated with listen-ing to the fMRI machine alone.C–F: In patient DT, the subtraction of brain activity associated with listening to external speech and fMRI machinenoise from that associated with experiencing auditory verbal hallucinations (AVHs) and fMRI machine noise revealed asignificant activation of the left superior temporal gyrus (primary auditory cortex, Brodmann’s area 41) (C) and theright middle temporal gyrus (auditory association cortex, Brodmann’s area 21) (E). The time courses of the BOLDsignal increases for coronal statistical maps depicted in C and E are presented in D and F, respectively.G: When the brain activity associated with experiencing an AVH and listening to the noise of the fMRI machine wassubtracted from that associated with listening to external speech and the fMRI machine, there were BOLD signalincreases seen in the areas of interest.
fMRI of auditory verbal hallucinations
Vol. 27, No. 2, 2002 Journal of Psychiatry & Neuroscience 113
Fig 1A: In the normal control subject, coronal statistical map showing bilateral blood oxygenation level dependent(BOLD) signal increases in auditory cortex while subject was listening to external speech (subtraction of brain activityassociated with listening to the noise produced by the functional magnetic resonance imaging [fMRI] machine fromthat associated with listening to an external speech and the noise of the fMRI machine).B: Absence of activation in the auditory cortex and in the inferior frontal lobe when the brain activity associated withlistening to external speech and the noise produced by fMRI machine was subtracted from that associated with listen-ing to the fMRI machine alone.C–F: In patient DT, the subtraction of brain activity associated with listening to external speech and fMRI machinenoise from that associated with experiencing auditory verbal hallucinations (AVHs) and fMRI machine noise revealed asignificant activation of the left superior temporal gyrus (primary auditory cortex, Brodmann’s area 41) (C) and theright middle temporal gyrus (auditory association cortex, Brodmann’s area 21) (E). The time courses of the BOLDsignal increases for coronal statistical maps depicted in C and E are presented in D and F, respectively.G: When the brain activity associated with experiencing an AVH and listening to the noise of the fMRI machine wassubtracted from that associated with listening to external speech and the fMRI machine, there were BOLD signalincreases seen in the areas of interest.
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Primary Auditory Cortex
Auditory Association Cortex
Left Hemisphere Right Hemisphere
AVH Response / DT
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Analysis• Increased metabolic ac4vity in PAC
• Consistent with abnormal ac4va4on of PAC
• Defec4ve leK MTG could permit access of internal speech to the PAC• Consistent with misinterpreta4on of inner speech• Lack of ac4va4on of Broca’s area inconsistent with hypothesis predic4on
• Type II error?
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Contribu5ons• Areas ac4vated by normal speech in healthy individuals are also ac4vated by the experience of AVHs
• Hypotheses not mutually exclusive• Defec4ve internal monitoring in the leK hemisphere may be associated with abnormal ac4va4on of the auditory cortex
Monday, 29 April, 13