Correlation between pulsatility index (pi) in transcranial doppler (tcd) and cognitive profile of patients with alzheimer’s dementia and vascular dementia
No Thumbnail Available
Files
Date
2019-12
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
SCTIMST
Abstract
The World Health Organization (WHO) predicts that by 2025, about 3/4th of the
estimated 1.2 billion people aged >60 years will reside in developing countries1
. 4.6
million new cases of dementia are added every year, and the highest rate of growth is
expected in South Asian countries including India. Education attainment is known to
protect against dementia. Diet and lifestyle can also influence risk of dementia, and
studies suggest that disorders affecting the vascular system, such as hypertension,
diabetes mellitus and obesity, increase the risk for dementia, including Alzheimer's
disease (AD).
There is increasing evidence linking cerebral hypoperfusion and neurodegeneration,
specifically in Alzheimer’s disease (AD) and vascular dementia (VaD)2
. In the
Rotterdam study3
, cerebral hypoperfusion was demonstrated to be a risk or an
aggravating factor in dementia. Hypoperfusion because of microangiopathy,
macroangiopathy or cardiac dysfunction can promote or accelerate
neurodegeneration, blood-brain barrier disruption and neuroinflammation.4
Diagnostic
tools that can provide real-time functional assessment of the cerebrovascular tree can
have a significant impact on our understanding of the vascular contribution to
neurodegeneration at different stages of cognitive decline.
Ultrasound can evaluate the cerebrovascular tree for pathological structure and
functional changes contributing to cerebral hypoperfusion. Studies have shown an
association between leukoaraiosis and transcranial doppler (TCD) pulsatility index
(PI) in several kinds of patients.5
Despite increasing evidence supporting the utility of
these methods in detection of microvascular pathology, cerebral hypoperfusion, neurovascular unit dysfunction and disease progression, non-availability for routine
use and incomplete standardisation limit their use in daily routine.
Studies have evaluated the utility of Middle cerebral artery-Pulsatility index (MCA
PI) to differentiate between AD and VaD and have found conflicting results.6
PI has
been correlated with severity of cognitive decline in few studies. Studies have also
evaluated correlation of PI with decline in cognition. However, correlation of PI with
detailed cognitive profile has not been evaluated.
In this background, we planned our study to assess whether MCA PI can be used to
differentiate between patients with AD and VaD. Also, we propose that increase in PI
correlates with severity of cognitive deficit in patients with dementia.