Basal Serum Cortisol Levels, Depression and Medial Temporal Lobe Atrophy in Patients With Mild Cognitive Impairment and Alzheimer’s Disease - Basal Serum Cortisol Levels, Depression and Medial Temporal Lobe Atrophy in Patients With Mild Cognitive Impairment and Alzheimer’s Disease - Open Access Pub

DOI10.14302/issn.2476-1710.jdt-15-719 Alteration of the hypothalamic-pituitary-adrenal (HPA) axis has been observed in patients with Alzheimer’s disease (AD) 1-5. Changes in Cortisol levels in patients with AD prompted the hypothesis that stress and glucocorticoids are involved in the development or maintenance of AD6. Glucocorticoids might also influence amyloid beta levels and their deposition in patients with AD6. A small study (n=9) conducted almost a decade ago demonstrated that serum cortisol is mildly elevated in AD and could be related to disease progression7, 8. The association between apolipoprotein E Epsilon 4 (APOE ？4) and serum cortisol also suggests that the two common pathophysiological links i.e. amyloid beta and APOE ？4 areinterrelated9. Prior studies have demonstrated that Medial Temporal Lobe (MTL) could be affected by AD/MCI. The importance of Medial Temporal Lobe Atrophy (MTLA) with respect to cognitive decline is further established by hippocampus’s role in memory formation10, 11 Chronically elevated cortisol levels have been associated with increased blood pressure and cerebral atrophy 10but its relationship with cognition seems to be a complex one. In one study of older adults (n=27), significant correlation between the HPA axis hyperactivity and frontal lobe atrophy10was observed. MTLA is more common in patients with AD/MCI with comorbid depression compared to those without2. There is an elevation of serum cortisol in some patients with AD and in major depression as well9. Hippocampal area, the major component of the medial temporal lobe is sensitive to the toxic effects of glucocorticoids and undergoes atrophy under the influence of its chronic elevation. Therefore, the relationship between MTLA, serum cortisol and depression seems plausible. In the present study, an attempt was made to see if a correlation exists between basal Serum Cortisol, Depression and Medial Temporal Lobe Atrophy Visual Rating Scores in patients with AD/MCI. Screening We screened 60 patients with complaints of subjective memory impairment presenting to the Department of Neurology at a tertiary care centre starting from July 2012 to July 2015 and enrolled 28 of them into the study. These patients met the diagnostic Criteria for diagnosis of Dementia of Probable Alzheimer’s disease ((National Institute of Neurological and Communicative Disorders and Stroke, Alzheimer’s disease related Disease Association criteria (NINCDS-ARDA)). For the diagnosis of MCI, Clinical Dementia Rating Scale (CDR Score=0.5) was used. Dementias other than AD were excluded from the