What’s the Difference Between Alzheimer’s Disease and Dementia?

Difference Between Alzheimer’s Disease and Dementia


Alzheimer’s disease and dementia are often confused for one another and frequently used interchangeably. However, it’s important to understand the distinction.

The most significant difference is that the term dementia does not refer to a specific disease. Instead, it is an overall term or “umbrella” term used to describe a decline in cognitive function that always includes memory impairment and impairment in the ability of the individual to function in their usual social and occupational activities.

Alzheimer’s disease, on the other hand, is a degenerative brain disease which, when it progresses, will ultimately cause dementia. With an estimated 5.7 million Americans living with Alzheimer’s, it is the most common form of dementia. But, not everyone with dementia has Alzheimer’s disease.

Other types of dementia include:

  • Parkinson’s Disease Dementia
  • Creutzfeldt-Jakob Disease
  • Frontotemporal Dementia
  • Normal Pressure Hydrocephalus
  • Vascular Dementia
  • Lewy Body Dementia
  • Huntington’s Disease
  • Posterior Cortical Atrophy
  • Mixed Dementia (a combination of the some of the above)

What are the symptoms?

The hallmark of any dementia is a loss of the ability to remember, though the type of memory difficulty varies from one type of dementia to another.

For example, patients with Alzheimer’s disease are able to recall events from his or her distant past but cannot recall what happened just a few minutes or hours ago. This is called short term memory impairment. In Alzheimer’s disease, it’s caused by difficulty in creating new memories–a process called encoding. Picture a tape recorder which is no longer recording sound. You cannot play anything back, because there is nothing recorded to play.

This may be distinguished from the problem that may be encountered in Parkinson’s Disease for example, where the memories are encoded, but the patient has difficulty accessing them. We sometimes call this “forgetting to remember”. This type of memory impairment frequently improves with cueing, whereas a cue will not help someone with Alzheimer’s Disease, because the memory was never formed to begin with and therefore no amount of cueing will allow something that isn’t there to be retrieved.

Other cues that someone might not have Alzheimer’s disease include a step-wise progression of decline. Alzheimer’s patients tend to gradually decline in their cognitive skills, and while they may seem to suffer more severe setbacks in times of illness when they look worse, in general, the progression tends to be smooth.

A more step-wise decline may suggest multiple strokes leading to “vascular dementia,” particularly in someone who has appropriate risk factors such as high blood pressure and/or diabetes, or prior known strokes or heart disease.

Someone who early on in the course of their dementia shows signs of balance or walking difficulty, depression and/or delusions, confusion, and perhaps rigidity, may have Lewy Body disease. While only recently recognized as common, this is likely an underdiagnosed condition. Some famous individuals who have been diagnosed with this were Robin Williams and Casey Kasem.

When to Seek Help

If you or someone you love displays any of the symptoms above, schedule an appointment with your doctor today. Unfortunately, there is no single test to diagnose Alzheimer’s disease. Physicians can almost always determine if a person has dementia, but determining the exact cause is often more difficult.

By evaluating your medical history and performing a physical and neurological exam, your doctor can help determine if the symptoms you are experiencing are truly due to dementia, Alzheimer’s or some other condition. These exams may include diagnostic tests, mental status tests and brain imaging.

The most important thing is to seek help promptly. Early diagnosis can have many benefits including:

  • Greater access to treatment options
  • Opportunity to participate in clinical trials
  • The chance to prioritize your health through lifestyle changes
  • Opportunity to maximize your time with family and friends
  • Better ability to plan for the future such as documenting your legal, financial and end-of-life decisions.
  • Time to plan for and address potential safety issues that may occur such as driving or wandering

With five locations in the Bronx and surrounding areas, the team at Regional Neurosurgical Associates is dedicated to providing state-of-the-art individualized care for a variety of neurological conditions including dementia. To schedule an appointment, call (718) 515-4347.