HR: 1340h
AN: B33C-1440    [Abstracts]
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