What We Know About Alzheimer's Disease

Earlier Detection, Clinical Trials Offer Hope

While the terms Alzheimer’s disease and dementia are often used interchangeably, the two conditions are not the same. Whereas dementia presents with memory loss, behavioral changes, language difficulties or disorientation which affects a person’s ability to function in daily life, Alzheimer’s disease refers to a specific brain pathology, explains Ian Grant, MD, assistant professor of neurology and director of clinical trial operations at the Mesulam Center for Cognitive Neurology and Alzheimer’s Disease at Northwestern University Feinberg School of Medicine.

“The presence of two abnormal proteins in the brain — amyloid and tau proteins — signal Alzheimer’s disease,” Dr. Grant says. “And where those proteins appear in the brain determines the patient’s symptoms.”

These abnormal proteins may accumulate in the brain up to 15 years before symptoms develop, he says, and the first indication of the disease is usually short-term memory loss. Fortunately, physicians now have access to technologies that make it easier to diagnose Alzheimer’s disease at an earlier stage. For example, one type of positron emission tomography (PET) scan literally “lights up” amyloid proteins in the brain, while a different PET scan can show abnormal function in parts of the brain, Dr. Grant says. He adds that the most definitive current test for the disease is a lumbar puncture that analyzes a patient’s cerebrospinal fluid for the presence of amyloid and tau proteins.

Alzheimer’s disease tends to be associated with the elderly, but it can strike younger people, too. “An Alzheimer’s diagnosis before age 65 is considered ‘early-onset,’ and those who develop it may have more advanced brain pathology, so the disease may progress more quickly,” Dr. Grant says.

Hope for Those With Alzheimer’s

Although it is difficult to receive an Alzheimer’s disease diagnosis, patients today have more reasons for hope than ever before. Several medications are available to slow down the progression of disease symptoms, and an Alzheimer’s diagnosis does not mean an immediate loss of independence.

“I always tell my patients that while there are no therapies to reverse or stop Alzheimer’s disease — it is a progressive neurodegenerative disease — its earliest symptoms don’t yet interfere with daily living,” Dr. Grant says. “What’s most important to convey is that we don’t want to take away individuals’ independence; we just want to make sure they have safety nets in place ahead of time.”

Dr. Grant notes that scores of clinical trials are underway across the country, and he frequently offers his patients the option to participate in the numerous trials in progress at the Mesulam Center. As an example, one of the trials he supervises, the “A4” trial, is targeting amyloid proteins in the brains of people who don’t yet have any symptoms, to see if removing them prevents or delays the onset of the disease.

“We still don’t fully understand why Alzheimer’s disease happens at all, but we’ve learned that people who are physically active do better, as well as those who eat a healthy diet such as a Mediterranean diet,” says Dr. Grant. “It’s also important to stay socially and mentally active — playing games that engage the mind, and having social and cultural activities and creative pursuits.”