Temporal lobe-oriented CT scanning and dementia in Down's syndrome

Background Although individuals with Down's syndrome (DS) are uniquely at r isk of developing Alzheimer's disease, the diagnosis of dementia in DS is p roblematic because of the difficulty in detecting cognitive decline in indi viduals with pre-existing learning disability. Aim To determine if dementia in DS is associated with Medial Temporal Lobe (MTL) atrophy as measured by temporal lobe-oriented CT scanning. Method Ten individuals with DS who were experiencing functional decline had CT scans with temporal lobe-oriented views. All individuals were assessed for the presence of dementia according to modified DSM-LIIR criteria. The m inimal thickness of the MTL, corrected for age-related atrophy was measured using a computer calipers at the level of the mid-brainstem by a radiologi st blind to the dementia diagnosis. Results All six individuals who met modified DSM-IIIR criteria for dementia showed significant MTL atrophy. Conclusions The utility of temporal lobe-oriented CT scanning as an adjunct to the diagnosis of dementia in DS appears promising and warrants further study. Copyright (C) 2001 John Wiley & Sons, Ltd.