Assessment of regional cerebral blood flow by ct perfusion in patients of Alzheimer’s disease

Abstract

Background: Alzheimer’s disease is a neurodegenerative disorder and is characterized by progressive cognitive decline which starts with an impairment in the ability to recollect recent memories, but eventually affects all the intellectual functions and finally leads to a total dependence for basic functions of daily life culminating into premature death. Dementia can be defined as a clinical syndrome characterized by a cluster of symptoms and signs manifested by difficulties in memory, disturbances in language and other cognitive functions, changes in behavior, and impairments in activities of daily living. Alzheimer is an age-associated degenerative disorder. The burden of Alzheimer’s disease and that of dementia per se is dependent on age. With increasing life expectancy, the proportion of elderly is increasing and so is the number of patients with Alzheimer’s disease associated dementia. Material and Method: This cross-sectional study was carried out for duration of 18 months at Department of Radiodiagnosis, Era s Lucknow Medical College, Lucknow with an aim to study the parameters viz. cerebral blood flow and cerebral blood volume and to correlate the finding of CT perfusion with the clinical score of dementia. The Patients attending adult psychiatry OPD diagnosed as a case of Alzheimer s as per DSM 4 criteria by fulfilling the inclusion criteria and giving informed consent were taken up for study. They were also evaluated for socio-demographic details and illness related variables. After obtaining an informed consent, demographic information, duration and nature of complaints was noted. All the patients were then subjected to CT Perfusion evaluation. Dementia severity was assessed using Clinical Dementia Rating Scale (CDRS).Result: Age of patients ranged from 60 to 75 years with a mean of 66±4.03 years. Majority of cases were aged between 60 and 69 years (77.5%). There were only 9 patients aged >70 years (22.5%).Forgetfulness (40%), difficulty in thinking (27.5%) and mental confusion (27.5%) were the three most common presenting complaints followed by loneliness (22.5%), agitation (17.5%), depression and mental decline (15% each). Inability to recognize (10%) and hallucinations (7.5%) were among the least common presenting complaints. According to clinical dementia score, a total of 16 (40%) patients were categorized as mild dementia, 20 (50%) as moderate dementia and 4 (10%) as severe dementia respectively. Mean regional cerebral blood flow values for right frontal, left frontal, left temporal, right occipital, right lenticular nucleus and left lenticular nucleus were 39.46±3.82, 39.33±3.87, 45.59±4.66, 45.51±5.02, 45.59±4.76, 45.65±4.49, 42.57±4.23 and 42.87±4.81 ml/100 g/min respectively. Mean global CBF was calculated as 43.32±4.29 ml/100 g/min. Mean regional cerebral blood volume values for right frontal, left frontal, left temporal, right occipital, right lenticular nucleus and left lenticular nucleus were 2.56±0.49, 2.62±0.54, 2.97±0.50, 3.03±0.56, 2.95±0.48, 2.92±0.52, 3.13±0.55 and 3.13±0.55 ml/100 g respectively. Mean global CBF was calculated as 2.91±0.49 ml/100 g/min.Conclusion: A total of 40 patients of Alzheimer’s disease aged 60 to 75 years (Mean age 66±4.03 years; 65% males) were enrolled and subjected to clinical and CT evaluation. According to clinical dementia score, a total of 16 (40%) patients were categorized as mild dementia, 20 (50%) as moderate dementia and 4 (10%) as severe dementia respectively. Mean cerebral blood flow (CBF) ranged from 39.33±3.87 ml/100 g/min (Left frontal region) to 45.65±4.49 ml/100 g/min (Left occipital region) among different brain regions. Mean global CBF was 43.32±4.29 ml/100 g/min.