Value of magnetic resonance spectroscopy in geriatric patients with cognitive impairment

Background Mild cognitive impairment is a transitional stage prior to dementia, and it is reported in depressed patients. Early diagnosis could predict the reversible etiologies and prevent further deterioration. Proton magnetic resonance spectroscopy has been used for early diagnosis and differential diagnosis of cognitive impairment. Objective We aimed to study the difference of hippocampal and frontal white matter metabolites between patients with Alzheimer's disease, mild cognitive impairment, and cognitive impairment associated with depression, and if those metabolites can differentiate between them. Subjects and methods Geriatric patients with cognitive impairment were recruited from neurology and psychiatry clinics. All subjects underwent comprehensive medical evaluations, neuropsychological testing, laboratory tests as well as brain MRI and H-1-MRS studies. Results The present study included 85 subjects. Patients with MCI and AD had lower hippocampal NAA and NAA/Cr ratio than patients with depression and normal controls, while, frontal NAA and NAA/Cr ratio were lower in all patient's subgroups compared to normal control. Conclusion Hippocampal NAA and NAA/Cr ratio might help to differentiate between MCI and cognitive impairment associated with depression.