Transcript Prefrontal gray matter volume - National Center for State

Use and admissibility of
positron emission tomography
(PET) scanning in head injury
Monte S. Buchsbaum, M.D.
Professor of Psychiatry
Director, Neuroscience PET
Laboratory
New York
Anatomy and function
PET fluorodeoxyglucose
• Uptake of artificial radiolabeled
sugar (FDG) over 30 minutes
• Subject does task during uptake
• FDG metabolically trapped in brain
• Move to scanner after uptake to
image brain activity during task
After uptake, subject lies in
scanner
PET shows abnormalities in:
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Head injury
Schizophrenia
Alzheimer’s disease
Stroke
Chronic methamphetamine abuse
Visualizing brain injury
• Computerized tomography (CT)
• Magnetic resonance imaging (MRI)
• Single photon emission computed
tomography (SPECT)
• Electroencephalographic mapping
• Positron emission tomography (PET)
Head injury by dropping at
delivery
Head injury after birth
Statistical probability map
Statistical probability map
Normal group mean=1.20
standard deviation .10
lower limit of normal=1.00
Patient value=0.90
Frontal lobe damage
• lack of insight
• disinhibition
• loss of mental models of social
rules
Automobile head injury
Frontal lobe
Closed head injury imaging
• “The most promising aspects of the
application of nuclear medicine techniques
…relate to the demonstration of neuronal
dysfunction in regions that look structurally
intact on CT or MRI”
• Oder et al.
Newberg AB, Alavi A.
Division of Nuclear Medicine, Philadelphia, PA 19104, USA.
Neuroimaging techniques provide some of the most important
diagnostic, prognostic, and pathophysiological information in the
management of brain injury. Anatomical imaging modalities can
help assess intracranial hemorrhage, fractures, and other structural
lesions. Functional imaging has been shown to be helpful in
assessing the areas of the brain affected by the trauma as well as
determining long term prognosis and rehabilitation potential. This
article will review the current uses of neuroimaging techniques in
head trauma and delineate future applications.
Semin Nucl Med. 2003 Apr;33(2):136-47
Van Heertum et al.
• In evaluating acute head injury, CT and MR are the
primary diagnostic tools. They play a critical role in
detecting intracranial lesions that may require
neurosurgical intervention. It should be noted, however,
that SPECT and PET brain imaging have been found
to be better than CT or MRI as prognostic indicators
and thus may play a valuable role in the critical care
management of these patients. In general, patients with
larger and or more numerous lesions encountered on
SPECT or PET relative to CT or MRI tend to have a
poorer prognosis and conversely an initial negative
Seminars in Nuclear Medicine 34:300 2004
Closed head injury
• “The PET scans in each study demonstrated
cerebral pathology not visualized by CT and
in some cases, not visualized by MRI,
either.
Boller et al. Annals New York Academy of Sciences,
769:23, 1995
Skull fracture, orbital surface
Encephalomalacia
on MRI
Typical adult and patient
ab
PET and statistical analysis
PET and MRI
MRI
PET
statistics
Closed head injury
• “The PET scans in each study demonstrated
cerebral pathology not visualized by CT and
in some cases, not visualized by MRI,
either.
Boller et al. Annals New York Academy of Sciences,
769:23, 1995
Subtraction of right from left in
severe hemispheric injury
Left minus
Right 2 sd low
Left minus right of patient minus mean normal score/normal sd
Statistical survey of brain
Basal ganglia and temporal lobe
Basal ganglia
Temporal
lobe
Mitigative evidence
• Brain change associated with mental
illness
• brain damage to executive functions
• brain damage to areas involved in
impulse control
• brain diseases diminishing capacity for
cognitive function
Head injury in a violent offender
Multiple regions of decreased
function
Two head injuries before crime
Patient AB
Competency
Gigante statistical contrast
Patient and areas
in lowest 5% of elderly
33 patients with AD
statistically contrasted with
33 normal elderly
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Scientific basis of PET
• More than 5000 scientific articles in
reviewed journals
• 18-F deoxyglucose widely accepted as valid
and reliable assessment of metabolic rate
• Quantitative analysis on pixel-by-pixel
basis widely used in hundreds of research
studies
PET has wide scientific base
Research tools may
receive more detailed
scientific scrutiny
than
clinical tools
Scientific basis of PET
• Insurance coverage is not a measure of
scientific acceptability
• 18-F deoxyglucose widely accepted in the
scientific community for assessment of
metabolic rate and regional brain function
• Insurance pays for Alzheimer’s disease vs.
Picks disease since it changes treatment,
not confirms untreatable diagnosis
Scientific basis of PET
• 18-F deoxyglucose widely accepted for
assessment of metabolic rate and
regional brain function
• DNA testing is widely accepted as
forensic evidence but is not paid for by
insurance because it doesn’t affect
patient care
Diagnosis and lab measures
• Diagnosis requires history, physical
examination and laboratory tests
• Few diagnoses are made on the basis
of a single laboratory test
• PET helps corroborate history and
physical examination
Diagnosis and lab measures
• Validation based on scientific principle
• Watch for “too few scientific articles
on PET scans in this disease in this
type of patient at this age…”
• PET helps corroborate history and
physical examination
Exclusion of evidence
• More often rejected on non-disclosure than
scientific merit
• Disclose displays, especially normal images
• Specify what material was used to arrive at
opinion of experts to avoid unreasonable
requests for information and data
“just for research”
• Research published in peer-reviewed
journals
• Research requires statistical confirmation
• Clinical usage may not always be supported
by rigorous research
• Insurance may be paid for tests not
supported by research
Admissibility in New York
R 4532-a. X-rays, magnetic resonance images,
computed axial tomograms, positron emission tomographs,
electromyograms, sonograms and fetal heart rate monitor
strips in personal injury actions
Admissible if photographically identified,
disclosed 10 days before the date of trial
Amended CPLR 4532, May 23, 1986
Kelly/Frye Rule
People v. Kelly (1976) 17 Cal.3d 24
• The scientific method must have been
shown to be reliable
• The witness utilizing the new procedure
must be qualified as an expert in the field
• It must be shown that correct scientific
procedures were used in the application of
the new procedure (summary by Terri Towery Feb 18,
Monterey Capital Case Conference)
Diminished frontal lobe function
We found these two in the group of
normals
Two standard deviations means just that…
below 5% of the population
Diffusion tensor imaging
White
matter of
Corpus
callosum
Monte S. Buchsbaum, M.D.
Mount Sinai School of Medicine
212-241-5294
[email protected]
Temporal lobe change
Pt. JH
Parietal lobe metabolic decrease
Nat Neurosci 1999 Nov;2(11):1032-7
Impairment of social and moral behavior related to early
damage in human prefrontal cortex.
Anderson SW, Bechara A, Damasio H, Tranel D, Damasio AR
The long-term consequences of early prefrontal cortex
lesions occurring before 16 months were investigated in
two adults. The two early-onset patients had severely
impaired social behavior despite normal basic cognitive
abilities, and showed insensitivity to future consequences
of decisions. Unlike adult-onset patients, however, the
two patients had defective social and moral reasoning,
suggesting that the acquisition of complex social
conventions and moral rules had been impaired.
A man infected with cholera is not allowed to
mix freely with the population, but we do not
think him wicked. We may similarly be
obliged to interfere with the freedom of a
murderer, but we should not have a feeling of
moral reprobation in the one case more than in
the other.
Bertrand Russell
Aging change
Performance on CPT task during
FDG uptake
• Murderers
• Controls
3.6 SD= 0.71
3.5 SD =0.77
Neurology 1998 Jul;51(1):142-8
Clinicometabolic dissociation of cognitive
functions and social behavior in frontal lobe lesions.
Sarazin M, Pillon B, Giannakopoulos P, Rancurel G, Samson Y, Dubois B
Case studies suggest a dissociation between cognitive functions
that have been impaired after damage to the dorsolateral
prefrontal cortex and social skills disturbed when the
ventromedial prefrontal areas are affected.
Because this dissociation had not been confirmed in a clinical setting,
clinicometabolic PET correlations were sought in 13 patients with various
lesions of the prefrontal cortex.
: Executive-function test performance was significantly correlated with activity
in the dorsolateral prefrontal cortex) and anterior cingulate cortex. Behavioral
scores were significantly correlated with activity in the frontopolar and
orbitofrontal cortex.