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Geisinger becomes the first member of Risant Health

Explore these and other terms for — and types of — cognitive impairment.

Alzheimer’s and dementia. These two terms are often used interchangeably. They both describe severe memory loss and cognitive decline. But they’re not the same. So, what's the difference between them?

Why knowing the difference matters

These two illnesses are similar, but dementia isn’t a disease. Rather, it’s an umbrella term for a variety of symptoms that can include: 

  • Memory loss
  • Challenges with language 
  • Poor decision making
  • Mood and/or behavioral changes

Dementia means one or more cognitive areas has declined enough to interfere with a person’s day-to-day life.

Alzheimer’s disease is the most common type of dementia, accounting for 50 to 70 percent of dementia cases. 

“Alzheimer’s disease is a cause of dementia, but not all dementias are caused by Alzheimer’s,” explains Maya Lichtenstein, MD, a behavioral neurologist at Geisinger’s Memory and Cognition Program. “There are many different causes of dementia, each with different though overlapping symptoms and treatment plans.”

What is dementia?

Dementia refers to a group of symptoms. Someone with dementia may have difficulty with two or more of the following tasks:

  • Memory
  • Speech/language
  • Judgment\
  • Planning/organizing

Early signs of dementia are usually mild and begin with simple forgetfulness. This can often be overlooked as “normal aging.” 

As dementia progresses, a person may:

  • Become more confused and forgetful
  • Have difficulty managing their daily affairs, like appointments or medications
  • Have more difficulty caring for themselves, like bathing or dressing

What is Alzheimer’s?

Alzheimer’s disease is a specific condition that causes dementia. It typically starts with short-term memory loss and progresses to involve other areas of thinking, including language. It also leads to increased difficulty completing daily tasks. 

“Receiving a diagnosis of dementia — whether it’s Alzheimer’s or another cause of dementia — can be difficult for patients and families," Dr. Lichtenstein says. "But new treatments are helping people manage their symptoms and live healthier lives."

Types of dementia

After Alzheimer’s disease, the most common types of dementia include:

Vascular dementia

This condition is caused by a lack of blood flow to the brain. It’s related to one or more strokes or chronic hardening of the arteries. People with vascular dementia may have:

  • Problems completing tasks
  • Trouble concentrating
  • Trouble managing their emotions
  • Gait changes

Lewy body dementia/Parkinson’s disease with dementia

Parkinson’s disease and Lewy body disease are caused by the same disease process. But first symptoms and how they progress can be different.

These forms of dementia can cause: 

  • Trouble paying attention, planning and organizing
  • Visual disturbances
  • Lightheadedness
  • Difficulty walking and slow movement

Some rare types of dementia can have symptoms that cause “parkinsonism” — gait and movement changes that look like Parkinson’s but aren’t Parkinson’s disease. This can include diseases like corticobasal degeneration or supranuclear palsy. 

Mixed dementia

Many people have dementia that’s caused by more than one underlying disease. The symptoms depend on which diseases are present.

Normal pressure hydrocephalus (NPH)

This condition is caused by excess fluid in the brain’s ventricles. Symptoms include balance and memory issues, as well as incontinence.

Frontotemporal dementia 

This used to be known as Pick’s disease. This type of dementia sometimes runs in families and can affect those as young as 45. Symptoms can include behavioral and personality changes or speech and language problems.

Creutzfeldt-Jakob disease (CJD) 

This is the rarest form of dementia. Only one in one million people are diagnosed each year. Symptoms often progress quickly. They can include: 

  • Agitation
  • Memory loss
  • Confusion
  • Involuntary movements

Wernicke-Korsakoff syndrome (WKS)

Also referred to as Wernicke’s encephalopathy, WKS affects a person’s ability to retain and process new information. It’s caused by vitamin B1 deficiency, which may be brought on by alcohol misuse or extreme nutritional deficiency. 

Normal aging or something more?

“As we age, episodes of forgetfulness are normal. It’s when they become more frequent or more serious or start to affect daily function that we should begin to worry,” says Dr. Lichtenstein.

If you or a loved one are dealing with symptoms, start by having a conversation with a healthcare provider. They can help make a diagnosis and create a treatment plan help you live your best life.

Next steps:

Learn about dementia and Alzheimer’s care at Geisinger 
What’s behind your brain fog? 
When to be concerned about forgetfulness 

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