Alzheimer’s disease (AD) is a major neurodegenerative
disorder that affects millions of people worldwide. New and accurate techniques
for early diagnosis are critical. Pravat K. Mandal, PhD, and his colleagues
have developed a completely non-invasive brain imaging technique to measure
specific brain chemical changes. This provides a signature of the early stages
of AD from the hippocampal region of the brain. Their work is reported in the Journal
of Alzheimer’s Disease.
“Alzheimer’s disease has become a silent tsunami in the
aging population,” says Dr. Mandal, who is associated with the National Brain
Research Center,
Gurgaon, India, and Johns Hopkins University
School of Medicine. “This discovery of a diagnostic technique that
requires no blood work or radiation, and that can be conducted in less than
fifteen minutes, may offer hope to Alzheimer’s disease patients and their
families.”
Dr. Mandal and his co-investigators studied the brains of
normal controls, AD patients, and patients with mild cognitive impairment (MCI)
using multi-voxel 31P magnetic resonance spectroscopy (MRS) imaging, along with
an advanced analytical tool, to assess brain chemistry in the hippocampal
regions. They observed during the course of their study that the left
hippocampus becomes alkaline in AD patients, which is in contrast to the normal
aging process in which the brain tends to be more acidic.
Dr. Mandal and his colleagues also identified four brain
chemicals that change significantly in pre-Alzheimer and Alzheimer disease patients
compared to normal subjects. They are phosphomonoester (PME), the building
block of neuronal membrane; phosphodiester (PDE), the membrane degradation
product; phosphocreatine (PCr), stored energy for -ATP), the source ofgbrain
functioning; and adenosine triphosphate ( brain energy. The level of PME is
significantly decreased in the left hippocampal areas of these patients, and
the levels of PDE, PCr, and -ATP are increased.g
“In the left hippocampus the increase in pH to the
alkaline range, -ATPgalong
with statistically significant increases in PDE, PCr, and and decreases in PDE, serve as a promising new
biomarker for AD,” notes Dr. Mandal. He and his colleagues plan to conduct
longitudinal studies with Alzheimer and Parkinson patients with larger sample
sizes to investigate specificity of their test. “It is our hope that such
clinical research, using state-of-the-art technology, may give new hope to
cognitively impaired patients for an earlier and more predictable AD diagnosis.”
