A SINGLE-PHOTON EMISSION COMPUTED TOMOGRAPHIC STUDY OF ANOSOGNOSIA INALZHEIMERS-DISEASE

Objective: To examine the presence of specific regional cerebral blood flow correlates of anosognosia in patients with probable Alzheimer's disease. Design: Case series, group comparisons. Setting: Ambulatory c are referral center. Patients: Twelve patients with probable Alzheimer 's disease and anosognosia and 12 patients with probable Alzheimer's d isease without anosognosia who were matched for age, duration of illne ss, and cognitive impairments. Main Outcome Measures: Single-photon em ission computed tomographic scan studies with technetium Tc 99m hexame thylpropylene-amine oxime and regional cerebral blood flow measurement s. Results: Patients with Alzheimer's disease and anosognosia showed s ignificant blood flow deficits in the frontal inferior and superior (d orsal) areas of the right hemisphere. On the other hand, no significan t between-group differences were found in depression scores and neurop sychological tasks that assessed verbal and visual memory, verbal comp rehension, naming, verbal fluency, auditory attention, abstract reason ing, and set-shifting abilities. Conclusions: Our study demonstrates t hat anosognosia may not be related to deficits in specific cognitive d omains, but it may result from dysfunction of the right frontal lobe.