Investigators released the cause of death for Gene Hackman and his wife Betsy Arakawa on Friday.The New Mexico Office of the Medical Investigator says Hackman died from a cardiovascular disease with Alzheimer's being a contributing factor. What is Alzheimer's disease?Sister station KOAT and University of New Mexico health expert Dr. Abinash Achrekar explained what the disease is."Alzheimer's disease is a brain disorder that slowly destroys memory and thinking skills and, eventually, the ability to carry out the simplest tasks," Achrekar said. "It is the most common cause of dementia among older adults."Diagnoses of the memory-loss disease normally happens after the age of 60."Late-onset type symptoms first appear in their mid-60s," Achrekar said. "Early onset Alzheimer's occurs between a person's 30s and mid-60s and is very rare. "The main features of Alzheimer's disease include plaques and tangles in the brain. Another feature is the loss of connections between nerve cells (neurons) in the brain."How do medical professionals diagnose the disease?"Doctors use medical history, mental status tests, physical and neurological exams, diagnostic tests and brain imaging," Achrekar said. "But we know toxic aggregates, called oligomers, can start to form more than a decade before symptoms appear and before other known disease markers form."Achrekar explains how the knowledge and detection of oligomers can assist in the long-term health care treatment of Alzheimer's disease."The ability to detect these oligomers would allow doctors to intervene before irreparable brain damage occurs possible," Achrekar said.Achrekar also said researchers are working to create a blood test that can detect the disease. This test could hypothetically detect Alzheimer's disease long before any late-onset symptoms occur.