title: Factors Determining Cognitive Dysfunction in Cerebral Small Vessel Disease.
abstract: BACKGROUND
  Vascular dementia consists of cognitive and functional impairment due to cerebrovascular brain injury. With reference to small vessel disease (SVD), even though the radiological evidence of SVD is present in a large number of persons above the age of 80 years, less than one-third of the people progress to dementia. Hence, if those factors are identified, we may be able to formulate strategies to protect that percentage of patients who progress to dementia. In this study, we have analyzed some genetic and nongenetic factors in patients with and without a cognitive impairment in the presence of radiological SVD.
  
  
  METHODS
  Two hundred and ten patients who satisfied the criteria for the study were included. All medical comorbidities, demographic factors, substance abuse, etc., were documented and neuropsychological evaluation done. In addition, the genetic testing was done for the polymorphisms of TT, TC, and CC alleles of CYP11B2 based on the literature evidence of the association of CYP11B2 polymorphism and hypertension.
  
  
  RESULTS
  This prospective hospital-based study revealed a significant relationship among hypertension, hyperhomocysteinemia, and severity of white matter changes but other comorbidities did not correlate. No significant correlation was seen between cognitive dysfunction and severity of white matter changes or genotypes TT, TC, and CC. However, TC genotype was more common in male hypertensives. Even though hypertension and hyperhomocysteinemia were associated with leukoaraiosis, none of the factors studied trigger conversion of these radiological changes to clinical cognitive impairment.
  
  
  CONCLUSIONS
  Severity of cerebral white matter changes seems to correlate with hypertension and hyperhomocysteinemia, however, none of the co-morbidities studied including the three polymorphisms of CYP11B2, that is, TT, TC, and CC seem to determine the conversion of leukoaraiosis to dementia.
authors.affiliation: Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, Karnataka, India.
authors.forename: Vinod
authors.initials: V
authors.lastname: Varghese
authors.affiliation: Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, Karnataka, India.
authors.forename: Sadanandavalli Retnaswami
authors.initials: SR
authors.lastname: Chandra
authors.affiliation: Department of Neurochemistry, National Institute of Mental Health and Neurosciences, Bengaluru, Karnataka, India.
authors.forename: Rita
authors.initials: R
authors.lastname: Christopher
authors.affiliation: Department of Clinical Psychology, National Institute of Mental Health and Neurosciences, Bengaluru, Karnataka, India.
authors.forename: Jamuna
authors.initials: J
authors.lastname: Rajeswaran
authors.affiliation: Department of NIIR, National Institute of Mental Health and Neurosciences, Bengaluru, Karnataka, India.
authors.forename: Chandrajit
authors.initials: C
authors.lastname: Prasad
authors.affiliation: Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, Karnataka, India.
authors.forename: Ramakrishnan
authors.initials: R
authors.lastname: Subasree
authors.affiliation: Department of Clinical Neurosciences, National Institute of Mental Health and Neurosciences, Bengaluru, Karnataka, India.
authors.forename: Thomas Gregor
authors.initials: TG
authors.lastname: Issac
keywords: CYP11B2 gene polymorphism; Cognitive impairment; leukoaraiosis