title: Pineal calcification in Alzheimer's disease: an in vivo study using computed tomography.
abstract: Melatonin has been postulated to have diverse properties, acting as an antioxidant, a neuroprotector, or a stabilizer within the circadian timing system, and is thus thought to be involved in the aging process and Alzheimer's disease (AD). We used computed tomography to determine the degree of pineal calcification (DOC), an intra-individual melatonin deficit marker, as well as the size of uncalcified pineal tissue, in 279 consecutive memory clinic outpatients (AD: 155; other dementia: 25; mild cognitive impairment: 33; depression: 66) and 37 age-matched controls. The size of uncalcified pineal tissue in patients with AD (mean 0.15 cm(2) [S.D. 0.24]) was significantly smaller than in patients with other types of dementia (0.26 [0.34]; P=0.038), with depression (0.28 [0.34]; P=0.005), or in controls (0.25 [0.31]; P=0.027). Additionally, the DOC in patients with AD (mean 76.2% [S.D. 26.6]) was significantly higher than in patients with other types of dementia (63.7 [34.7]; P=0.042), with depression (60.5 [33.8]; P=0.001), or in controls (64.5 [30.6]; P=0.021). These two findings may reflect two different aspects of melatonin in AD. On the one hand, the absolute amount of melatonin excretion capability, as indicated by uncalcified pineal volume, refers to the antioxidant properties of melatonin. On the other hand, the relative reduction in melatonin production capability in the individual, as indicated by DOC, refers to the circadian properties of melatonin.
authors.affiliation: Department of Psychiatry and Psychotherapy, Charité Campus Mitte, Charité-Universitätsmedizin Berlin, Turmstrasse 21, D-10559 Berlin, Germany. richard.mahlberg@charite.de
authors.forename: Richard
authors.initials: R
authors.lastname: Mahlberg
authors.forename: Sebastian
authors.initials: S
authors.lastname: Walther
authors.forename: Peter
authors.initials: P
authors.lastname: Kalus
authors.forename: Georg
authors.initials: G
authors.lastname: Bohner
authors.forename: Sven
authors.initials: S
authors.lastname: Haedel
authors.forename: Friedel M
authors.initials: FM
authors.lastname: Reischies
authors.forename: Klaus-Peter
authors.initials: KP
authors.lastname: Kühl
authors.forename: Rainer
authors.initials: R
authors.lastname: Hellweg
authors.forename: Dieter
authors.initials: D
authors.lastname: Kunz
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000473:pathology*; D002114:Calcinosis / Q000209:etiology*; D005260:Female; D006801:Humans; D008297:Male; D010870:Pineal Gland / Q000473:pathology*; D014057:Tomography, X-Ray Computed