Chronic smoking affects nerve cells
and alters the chemical makeup of the
brain, according to research
presented at the annual meeting of
the Radiological Society of North
America (RSNA) .
"This is the first imaging study to
focus on the relationship between
brain metabolites and nicotine
dependence ," said Okan G-r, M.D. ,
from the Department of Radiology at
the University of Bonn in Germany.
Dr. G-r and colleagues used proton
magnetic resonance spectroscopy
(MRS) to study 21 men and 22
women, age 21 to 59, in a smoking
cessation program two weeks after
quitting and again six months later.
Patients were encouraged to use
nicotine patches during the initial six
weeks of smoking cessation; however,
only 36 of the patients complied.
Proton MRS is able to measure brain
metabolism at the cellular level and
can provide detailed chemical data
about the brain's metabolites, which
are involved in many physical and
chemical processes within the body.
The researchers compared the data
collected from the smokers to proton
MRS data collected from 35 age- and
gender-matched healthy controls.
The results showed that the nicotine-
dependent patients had significantly
decreased concentrations of the
amino acid N- acetylaspartate (NAA) in
the anterior cingulate cortex (ACC),
the part of the brain that processes
pleasure and pain. The decreased
NAA levels were evident regardless of
whether or not the patient used a
nicotine patch and correlated directly
with the patient's smoking history: the
greater the number of pack years
(one pack per day for one year equals
one pack year), the lower the NAA
level.
"The ACC is involved in mediating
conditioned reinforcement, craving
and relapsing behavior in addiction,"
said study co-author Christian G. Sch-
tz, M.D., M.P.H ., from the Department
of Psychiatry at the University of Bonn.
"Lower NAA levels have been
implicated as indicators of neuronal
or axonal dysfunction."
Reduced NAA levels have been
reported for a number of psychiatric
and mood disorders, including
schizophrenia , dementia and bipolar
disorder , as well as in cases of
substance abuse, particularly alcohol
dependence.
Choline concentrations in the ACC
were slightly lower in the smokers
compared with the nonsmokers, and
lower still in the female smokers
compared with the male smokers.
Choline is significantly involved in cell
membrane metabolism, which is
essential for cardiac and brain
function. Reduced choline levels can
be a precursor to the breakdown of
cell membranes.
Concentration of total creatine (tCr)
levels in the frontal lobes was typically
higher in the smokers who did not
use patches compared to those who
did. The metabolite tCr plays an
important role in supplying energy to
the muscle cells. Higher tCr levels
have been associated with stimulant
use. Furthermore, the researchers
found that high tCr levels predicted a
higher likelihood of relapse.
Upon follow-up after six months, the
researchers found that most
metabolite concentrations, including
that of NAA, had normalized in the 25
ex-smokers who did not relapse.
"These findings further emphasize the
importance of quitting smoking," Dr.
G-r said. "The degree of reduction of
NAA in the ACC depends on the
amount of tobacco consumed over
time, but it appears to normalize after
smoking cessation."
###
Co-authors are Hans H. Schild, M.D.,
Wolfgang Block, Ph.D. , Frank Tr-ber,
Ph.D ., and Wolfgang Maier, M.D.
RSNA is an association of more than
40,000 radiologists, radiation
oncologists, medical physicists and
related scientists committed to
promoting excellence in radiology
through education and by fostering
research, with the ultimate goal of
improving patient care. The Society is
based in Oak Brook, Ill.
The data in these releases may differ
from those in the printed abstract and
those actually presented at the
meeting, as researchers continue to
update their data right up until the
meeting.
Contact: Maureen Morley
Radiological Society of North America
and alters the chemical makeup of the
brain, according to research
presented at the annual meeting of
the Radiological Society of North
America (RSNA) .
"This is the first imaging study to
focus on the relationship between
brain metabolites and nicotine
dependence ," said Okan G-r, M.D. ,
from the Department of Radiology at
the University of Bonn in Germany.
Dr. G-r and colleagues used proton
magnetic resonance spectroscopy
(MRS) to study 21 men and 22
women, age 21 to 59, in a smoking
cessation program two weeks after
quitting and again six months later.
Patients were encouraged to use
nicotine patches during the initial six
weeks of smoking cessation; however,
only 36 of the patients complied.
Proton MRS is able to measure brain
metabolism at the cellular level and
can provide detailed chemical data
about the brain's metabolites, which
are involved in many physical and
chemical processes within the body.
The researchers compared the data
collected from the smokers to proton
MRS data collected from 35 age- and
gender-matched healthy controls.
The results showed that the nicotine-
dependent patients had significantly
decreased concentrations of the
amino acid N- acetylaspartate (NAA) in
the anterior cingulate cortex (ACC),
the part of the brain that processes
pleasure and pain. The decreased
NAA levels were evident regardless of
whether or not the patient used a
nicotine patch and correlated directly
with the patient's smoking history: the
greater the number of pack years
(one pack per day for one year equals
one pack year), the lower the NAA
level.
"The ACC is involved in mediating
conditioned reinforcement, craving
and relapsing behavior in addiction,"
said study co-author Christian G. Sch-
tz, M.D., M.P.H ., from the Department
of Psychiatry at the University of Bonn.
"Lower NAA levels have been
implicated as indicators of neuronal
or axonal dysfunction."
Reduced NAA levels have been
reported for a number of psychiatric
and mood disorders, including
schizophrenia , dementia and bipolar
disorder , as well as in cases of
substance abuse, particularly alcohol
dependence.
Choline concentrations in the ACC
were slightly lower in the smokers
compared with the nonsmokers, and
lower still in the female smokers
compared with the male smokers.
Choline is significantly involved in cell
membrane metabolism, which is
essential for cardiac and brain
function. Reduced choline levels can
be a precursor to the breakdown of
cell membranes.
Concentration of total creatine (tCr)
levels in the frontal lobes was typically
higher in the smokers who did not
use patches compared to those who
did. The metabolite tCr plays an
important role in supplying energy to
the muscle cells. Higher tCr levels
have been associated with stimulant
use. Furthermore, the researchers
found that high tCr levels predicted a
higher likelihood of relapse.
Upon follow-up after six months, the
researchers found that most
metabolite concentrations, including
that of NAA, had normalized in the 25
ex-smokers who did not relapse.
"These findings further emphasize the
importance of quitting smoking," Dr.
G-r said. "The degree of reduction of
NAA in the ACC depends on the
amount of tobacco consumed over
time, but it appears to normalize after
smoking cessation."
###
Co-authors are Hans H. Schild, M.D.,
Wolfgang Block, Ph.D. , Frank Tr-ber,
Ph.D ., and Wolfgang Maier, M.D.
RSNA is an association of more than
40,000 radiologists, radiation
oncologists, medical physicists and
related scientists committed to
promoting excellence in radiology
through education and by fostering
research, with the ultimate goal of
improving patient care. The Society is
based in Oak Brook, Ill.
The data in these releases may differ
from those in the printed abstract and
those actually presented at the
meeting, as researchers continue to
update their data right up until the
meeting.
Contact: Maureen Morley
Radiological Society of North America
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