© 2017, GENASSISTTM Inc.              

By Keith S. Wexler, MBA, Maternal Fetal Medicine, Prenatal Diagnosis and Biotech/Life Sciences Consultant, GENASSIST, Inc.

Paul Wexler, M.D., F.A.C.O.G., Medical Director, GENASSIST, Inc.

Clinical Professor, Department of OB/GYN, University of Colorado Health Sciences Center

Clinical Professor, Division of Genetics/Dept. of Pediatrics, Univ. of Colorado/The Children’s Hospital


Dementia: A chronic or persistent disorder of the mental processes caused by brain disease or injury or marked by memory disorder, personality change or impaired reasoning.

  • Cortex: The outer layer of the cerebral cortex composed of folded gray matter
  • Subcortex: Tissue lying immediately below the cortex
  • Subcortical Dementia: Vascular Dementia


  • Approximately 1 in 14 after 65 years of age
  • Approximately 1 in 8 after 80 years of age

Vascular Dementia: Also called Multi-Infarct Dementia (MID) or Vascular Cognitive Impairment (VCI). Many years ago was referred to as “organic brain disease”.

Transient Ischemic Attacks (TIA’s) – often occur over a prolonged period of time. Small strokes may be overlooked until multiple areas of the brain are involved and memory loss, confusion and more comprehensive symptoms and signs of dementia become manifest.

Transient Ischemic Attack (TIA’s) is usually caused by a clot but the vascular occlusion is usually transient and results in no significant brain injury. It is also called a “mini stroke” or “warning stroke” and may precede a true stroke.

A stroke is an interruption in the blood supply to a portion of the brain leading to the death of brain cells. It can be due to the occlusion of blood supply to a portion of the brain or hemorrhage in an area of the brain resulting in damage and death of brain cells.

Organic Brain Disease is a general term that refers to decreased mental functioning due to a disease rather than a psychiatric problem. Diseases which damage the brain such as certain biochemical disorders, vascular problems, trauma or progressive neurodegenerative diseases such as Alzheimer’s or Huntington’s Disease can all cause Organic Brain Disease.

Predisposing Factors for Vascular Dementia: 

  • Hypertension
  • High cholesterol
  • Diabetes

CADASIL (Cerebral Autosomal Dominant Arteropathy with Subcortical Infarcts and Leukoencephalopathy) – The condition affects small blood vessels particularly in the brain. The condition can lead to multiple strokes. It can occur anytime but usually is in the middle adulthood. Can affect memory, reasoning, intellectual function, mood and personality. Although usually inherited in an autosomal dominant manner. Rare sporadic cases have been described.

Mutation in the Notch 3 Gene – chromosome 19p13.2-13.1 affects the survival and function of vascular smooth muscle cells and is implicated in CADASIL.