1340h
AN: B33C-1440
TI:
Preliminary non-invasive measurement of magnetic susceptibility of the
frontal lobe: a possible antecedent marker for Alzheimer's disease.
AU: * Kletetschka, G
EM: kletetschka@nasa.gov
AF: Catholic University of America,
Department of Physics, Washington, DC 20064, United
States
AU: * Kletetschka, G
EM: kletetschka@nasa.gov
AF: GSFC/NASA, Code 691, Greenbelt, MD 20771,
United States
AU: * Kletetschka, G
EM: kletetschka@nasa.gov
AF: Acad Sci Czech Republic, Institute of
Geology, Prague, 16000, Czech Republic
AU: Mikula, V
EM: mikula.vilem@ssedmail.gsfc.nasa.gov
AF: Catholic University of America,
Department of Physics, Washington, DC 20064, United
States
AU: Mikula, V
EM: mikula.vilem@ssedmail.gsfc.nasa.gov
AF: GSFC/NASA, Code 691, Greenbelt, MD 20771,
United States
AU: Mikula, V
EM: mikula.vilem@ssedmail.gsfc.nasa.gov
AF: Charles University, Faculty of Science,
Prague, 12843, Czech Republic
AU: Adachi, T
EM: tomoko.adachi@ssedmail.gsfc.nasa.gov
AF: Catholic University of America,
Department of Physics, Washington, DC 20064, United
States
AU: Adachi, T
EM: tomoko.adachi@ssedmail.gsfc.nasa.gov
AF: GSFC/NASA, Code 691, Greenbelt, MD 20771,
United States
AU: Fuller, M
EM: mfuller@soest.hawaii.edu
AF: University of Hawaii'i at Manoa, HIGP,
Honolulu, HI 96822, United States
AB:
It is generally recognized that the amount of iron in the brain
increases with age. Magnetic work on post mortem
tissue from Alzheimer's patients has indicated the presence of
magnetite and there seems to be a direct relation
between magnetite and Alzheimer's disease. We measured the magnetic
susceptibility of the frontal lobe of
subjects using a sensitive susceptibility meter SM30 placed against the
forehead. This is a very simple and
speedy observation normally made by geologists to investigate rock
outcrops. Preliminary measurements were
performed on 53 persons, whose ages ranged from 3 to 92 and included
several Alzheimer's patients. The
magnetic susceptibiIity is negative, reflecting the dominant
diamagnetism of brain tissue. The positive
susceptibility of ferrimagnetic material present therefore reduces this
negative number. Interestingly the magnetic susceptibility of 3 of the
Alzheimer patients was among the 5 lowest negative susceptibilities
measured. The
mean value of magnetic susceptibility of the population is close to
-6e-6 SI units. Alzheimer patients show slightly
higher values, closer to -5e-6 SI units. The susceptibilities of the
Alzheimer's patients can be distinguished at one standard deviation
from the whole population tested. The mean susceptibility of the
Alzheimer's patients is also
greater than the mean value from patients of the same age group, but it
cannot be distinguished at one standard
deviation. We speculate that the source of the positive susceptibility
contribution may be magnetite. We suggest
that extensions of this observation may serve as an antecedent marker
of the onset of Alzheimer's disease.
DE: 0416 Biogeophysics
DE: 0419 Biomineralization
DE: 1512 Environmental magnetism
DE: 1540 Rock and mineral magnetism
DE: 1594 Instruments and techniques
SC: Biogeosciences [B]
MN: 2007 Fall Meeting