CT Criteria in Vascular Dementia: A Study in Thai Population

Abstract

Objective: To evaluate CT criteria for diagnosis of vascular dementia (VaD) in Thai population.
Methods: Cranial CT was performed in the elderly from an urban community in the west of Bangkok. The evaluation of infarction (number, location and volume of infarction), white matter low attenuation, and atrophy were performed by neuroradiologists; and, the final diagnoses of dementia were done by neurologists.
Results: Ninety-one patients were recruited into the study with their mean age of 70.16 years old (range = 53-90). Twentyseven patients were males and 64 were females. The final diagnoses were, namely: normal cognition (10=11%), vascular dementia (30=33%), Alzheimerus disease (AD) (41=45.1%), and mixed VaD and AD (10=11%). On CT, most patients had infarction of less than two lesions and the volume of infarction was less than 25 ml. Two (2.2%) patients who were diagnosed as AD and one who was diagnosed as normal had lesions more than one lesion; whereas 11 (12.1%) patients who were diagnosed as VaD had more than one lesion. No patients who were diagnosed with AD or those who were normal had infarction volume more than 25 ml, except two patients who were diagnosed with VaD had infarction volume more than 25 ml. Most patients who had white matter scale more than 2 were VaD (52%). No significant difference between atrophy and dementia was found. With the CT grading criteria of 0 for non-VaD and combined 1, 2 and 3 for VaD, the sensitivity, specificity and accuracy for diagnosis of VaD were 96%, 64.7%, and 76.5%, respectively.
Conclusion: Modified CT criteria for VaD established by reducing volume of infarction regardless of the atrophy are helpful to identify VaD patients with improved diagnostic performance.