title: Reduced olfactory bulb and tract volume in early Alzheimer's disease--a MRI study.
abstract: Olfactory dysfunction has been reported to occur already in the early stages of Alzheimer's disease (AD) and to increase with disease severity. In neuropathological research, the deposition of neurofibrillary tangles and neuritic plaques in the olfactory bulb and tract (OBT) of AD patients has been consistently demonstrated. We used high-resolution magnetic resonance imaging (MRI) to determine the volume of the OBT in 21 patients with early AD and in 21 healthy comparison subjects. The OBT was manually traced on consecutive coronal slices. When compared to healthy controls, right, left and mean OBT volumes were significantly reduced in patients with AD (p<0.01). In AD patients, the mean OBT volume was significantly correlated with global cognitive performance as determined by the mini-mental state examination (r=0.605; p=0.004). Manual tracing on MRI images revealed OBT atrophy to be present early in the course of AD. Since the respective findings were associated with cognitive impairment, they may contribute to early recognition and diagnosis of the disease.
authors: Section of Geriatric Psychiatry, University of Heidelberg, Vossstr. 4, 69115 Heidelberg, Germany. philipp thomann@med.uni-heidelberg.de
authors: Philipp A
authors: PA
authors: Thomann
authors: Vasco
authors: V
authors: Dos Santos
authors: Pablo
authors: P
authors: Toro
authors: Peter
authors: P
authors: Schönknecht
authors: Marco
authors: M
authors: Essig
authors: Johannes
authors: J
authors: Schröder
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000473:pathology* / Q000503:physiopathology; D001284:Atrophy / Q000209:etiology / Q000473:pathology / Q000503:physiopathology; D015415:Biomarkers; D001931:Brain Mapping; D018450:Disease Progression; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D009830:Olfactory Bulb / Q000473:pathology* / Q000503:physiopathology; D009833:Olfactory Pathways / Q000473:pathology* / Q000503:physiopathology; D011237:Predictive Value of Tests; D011379:Prognosis
chemical_list: D015415:Biomarkers