When someone tells you they’re having trouble remembering where they put their keys, that’s probably just normal aging. But when they forget what keys are for altogether, that’s when doctors start thinking about dementia. It’s a distinction that matters deeply to millions of families navigating one of medicine’s most challenging conditions.

While reviewing some of my previous articles, I realized that while I have discussed conditions that mimic dementia, I haven’t discussed dementia itself.  This discussion has quite a bit of technical jargon, but it’s unavoidable.

Dementia isn’t a specific disease—it’s an umbrella term describing a decline in mental ability that interferes with daily life. Think of it like how “cancer” describes many different diseases. About 50 percent of people age 85 and older have some form of dementia, making it one of the most pressing health challenges of our aging population.

The Major Players: Types of Dementia

Alzheimer’s Disease stands as the heavyweight champion of dementia causes, accounting for an estimated 50 to 70 percent of all cases. What’s happening in the brain is both complicated and tragic. Beta-amyloid and phosphorylated tau proteins accumulate and spread through distributed neural networks in the brain, causing progressive metabolic abnormalities, neuronal injury, and cellular death all of which disrupt functional connectivity. The hallmark symptoms include problems with short-term memory: paying bills, preparing meals, remembering appointments, or getting lost in familiar areas. Your grandmother might remember vivid details from her childhood but can’t recall what she ate for breakfast or even recognize you.

Vascular Dementia comes in second place, accounting for about 5 to 15 percent of cases. Typical symptoms include slowed thinking, trouble with organization, difficulty planning or following instructions, and in the later phases, gait problems and urinary difficulties.  It results from strokes or other problems with blood flow to the brain.  On occasion it may be the result of a series of subclinical strokes with the victim being unaware of the individual events.  Symptoms gradually become worse as blood vessels get damaged. Imagine the brain like a city—when the roads get blocked, supplies can’t get through, and neighborhoods start to fail.

Lewy Body Dementia Involves the deposit of abnormal alpha-synuclein proteins called Lewy bodies.  It presents a particularly unsettling picture. Many people with this type of dementia experience daytime sleepiness, confusion, fluctuating cognition, staring spells, sleep disturbances, visual hallucinations, or movement problems. The visual hallucinations are generally vivid images of people or animals and often occur when someone is about to fall asleep or wake up.

Frontotemporal Dementia often hits younger people. It is caused by abnormalities in the proteins FUS and TDP-43. Most cases are diagnosed in people aged 45 to 65. Rather than starting with memory loss, early symptoms may include personality changes like reduced sensitivity to others’ feelings, lack of social awareness, making inappropriate jokes, language problems, obsessive behavior, or sudden outbursts of anger. It’s heartbreaking when someone’s personality fundamentally changes before your eyes.

LATE is a newly recognized form of dementia (Limbic-predominant Age-related TDP-43 Encephalopathy), which causes symptoms similar to Alzheimer’s but has different underlying causes involving abnormal clusters of TDP-43 protein. Research suggests that almost 40 percent of people whose age at death was 88 years or greater may have had LATE of varying degrees.

Less Common Forms:  Parkinson’s disease dementia (movement disorder first, dementia later).Normal Pressure Hydrocephalus (NPH)—one of the few reversible types.  Chronic traumatic encephalopathy (CTE)—linked to repeated head injuries.HIV-associated dementia—less common with modern treatment.  Severe vitamin deficiencies (e.g., B1 or B12)—reversible if caught early.

Figuring Out What’s Wrong: The Diagnostic Process

Making a dementia diagnosis isn’t like getting a strep test or an Xray—there’s no single definitive test. Physicians use diagnostic tools combined with medical history and other information, including neurological exams, cognitive and functional assessments, brain imaging like MRI or CT, and cerebrospinal fluid or blood tests.

The process starts with your doctor asking detailed questions about your symptoms and medical history. Typical questions include asking about whether dementia runs in the family, how and when symptoms began, changes in behavior and personality, and if the person is taking certain medications that might cause or worsen symptoms.  There are various cognitive tests—like the infamous clock face drawing—that physicians can use to assess the likelihood of dementia.

Brain imaging can play a crucial role for some patients. Structural imaging with MRI or CT is primarily used to rule out other conditions that may cause symptoms similar to dementia but that require different treatment.  They can reveal tumors, evidence of strokes, damage from head trauma, or fluid buildup in the brain. Common MRI findings include brain atrophy, particularly shrinkage of the hippocampus which supports learning and memory and the cortex which supports perception, thought and voluntary action.  Other findings may include white matter changes that affect communication between brain regions.  Lesions from small strokes may be identified.

More sophisticated imaging like PET scans can detect specific proteins associated with Alzheimer’s. Recent advances in molecular imaging allow for visualization of amyloid and tau deposits in a living human brain, bringing us closer to an in vivo (while alive) definitive diagnosis.  This is significant because historically Alzheimer’s could only be definitively diagnosed at autopsy.

Treatment Options: Managing the Unmanageable

Here’s where I need to be honest: there’s no cure for dementia. But that doesn’t mean we’re helpless. Several medications can help manage symptoms and potentially slow progression.

For Alzheimer’s specifically, the FDA has approved two categories of drugs. These include drugs that change disease progression in people living with early Alzheimer’s disease, and drugs that may temporarily mitigate some symptoms. The newer disease-modifying drugs include donanemab and lecanemab.  They are anti-amyloid antibody intravenous infusion therapies that have demonstrated that removing beta-amyloid from the brain reduces cognitive and functional decline in people living with early Alzheimer’s.

More traditional treatments focus on symptom management. Medications such as galantamine, rivastigmine, and donepezil improve communication between nerve cells. Cholinesterase inhibitors work by preventing the breakdown of acetylcholine, a neurotransmitter, which may stabilize dementia symptoms.

Beyond medications, lifestyle modifications matter. Lifestyle changes including eating a balanced diet full of fruits and vegetables may help slow progression. Maintaining a routine to avoid confusion, including regular exercise and sleep, all help keep people with dementia as functional as possible for as long as possible.  Staying mentally active and socially connected can help slow the onset and progression of dementia.

What to Expect: The Prognosis

This is the hardest part to talk about.  The life expectancy of dementia patients varies enormously. Most people older than 65 with Alzheimer’s die within four to eight years of being diagnosed, but some people live for decades, especially if they were diagnosed before turning 65.

Life expectancy depends on a huge range of factors including the type of dementia diagnosed, overall health, and the age of diagnosis. Vascular dementia typically has a shorter life expectancy than Alzheimer’s disease due to underlying cardiovascular problems.

Progression happens in stages. Early symptoms include finding it hard to carry out familiar daily tasks, struggling to follow conversations or find the right word, and getting confused with familiar places. Signs of late-stage dementia include speaking in single words or repeated phrases that don’t make sense, not being able to understand what people are saying, or following things that are happening around them.

Those living with advanced dementia are especially prone to infection, constipation, skin ulcers and blood clots, which can put their life in danger if treatment is delayed.  Dehydration and malnutrition are serious risks for those without a strong support network as they often forget to eat or drink.  They are also more likely to be injured in falls and other accidents.

Ultimately, as you lose more brain function, activities vital to life begin to be affected, including breathing, swallowing, digestion, heart rate and sleep. Most people don’t die directly from dementia but from complications like pneumonia or falls.

A Note on Hope

Reading about dementia can feel depressing, but there’s reason for cautious optimism. While individual prognosis varies significantly and can’t be predicted with precision, early detection of symptoms and an early diagnosis can help with planning ahead to manage the disease.  Scientists continue researching new treatments, particularly regarding new biomarkers and disease modifying drugs.  Life expectancy estimates are improving all the time as many people are diagnosed earlier and receive better treatment and care. 

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Sources

  1. National Institute on Aging – What Is Dementia? Symptoms, Types, and Diagnosis https://www.nia.nih.gov/health/alzheimers-and-dementia/what-dementia-symptoms-types-and-diagnosis
  2. NHS – Symptoms of Dementia https://www.nhs.uk/conditions/dementia/symptoms-and-diagnosis/symptoms/
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  12. Alzheimer’s Association – Medications for Memory, Cognition & Dementia-Related Behaviors https://www.alz.org/alzheimers-dementia/treatments/medications-for-memory
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  14. DRI Health Group – Can MRI Diagnose Dementia? https://drihealthgroup.com/health-tips/can-mri-diagnose-dementia