What is Dementia?

Dementia is the loss of cognitive functioning to the extent that it interferes with a person’s daily life and activities. Dementia ranges in severity from the mildest stage, when it is just beginning to affect a person’s functioning, to the most severe stage, when the person is completely dependent on others for basic activities of daily living.

Functions affected include memory, language skills, visual perception, problem solving, self-management, and the ability to focus and pay attention. In some cases, people with dementia are no longer able to control their emotions, and their personalities may change.

Symptoms of dementia result when once-healthy neurons (nerve cells) in the brain stop working, lose connections with other brain cells, and die – a process called neurodegeneration. Unlike dementia, age-related memory loss isn’t disabling. While dementia is more common with advanced age, it is not a normal part of aging. Many people live into their 90’s and beyond without any signs of dementia.[1]

How Serious a Problem is Dementia?

Every three seconds someone is diagnosed with dementia. Four U.S. Surgeons General declared dementia a global health crisis[2] and cautioned that we are ill-prepared to manage its impact. There is no cure yet for any of the leading forms of progressive dementia. By current estimates, 50 million people have dementia worldwide, and this number is expected to reach 139 million by 2050.[3] In the U.S., the total cost of dementia is estimated at $355 billion in 2021, projected to exceed $1.1 trillion by 2050. This includes medical and social care costs and the cost of informal care. People are living longer, often with complex health challenges. Many are living alone. Those with dementia who can no longer live independently and lack access to in-home care must leave their homes to be cared for in memory care facilities or nursing homes.

What is Lewy Body Dementia?

Lewy body dementia (LBD) is an umbrella term related to two conditions known as dementia with Lewy bodies (DLB) and Parkinson’s disease dementia (PDD). Researchers and physicians often use what’s known as the 1-year rule[4] for diagnosis: if cognitive symptoms are noted at the same time as or within one year of specific motor symptoms (slowness, muscle stiffness, tremor, balance issues), the diagnosis is dementia with Lewy bodies. If these motor symptoms appear first, with cognitive symptoms developing much later, the diagnosis is Parkinson’s disease dementia.

Lewy body dementia typically progresses over five to nine years from the time of diagnosis, but can vary on either side of this range. Currently there is no treatment to slow, halt, or cure Lewy body dementia.

What Causes Lewy Body Dementia?

Based on current science, Lewy body dementia involves alpha-synuclein, a naturally-occurring protein essential to brain and nervous system function.

When alpha-synuclein forms abnormal clumps, or “Lewy bodies,” it damages neurons and neurotransmitters (chemical messengers) in the brain.[5] One of these messengers, acetylcholine, is important for learning and memory. Another, dopamine, is important in thinking, behavior, movement, motivation, sleep, and mood.

Lewy bodies were named in recognition of the work of Dr. Friedrich H. Lewy, a German neurologist, published in 1912-13; and later credited to him by Dr. Konstantin Tretiakoff in 1919. Dr. Lewy founded the Berlin Neurological Institute in 1932 and might have continued his original line of research there, but he fled Germany a year later to escape Nazi persecution of the Jews. He immigrated to America where he taught at the University of Pennsylvania School of Medicine and served as Consultant to the Surgeon General of the U.S. Army.

Today, researchers are working to identify what causes Lewy bodies to form in the first place. They are also exploring genetic, environmental, and other factors that may be linked to Lewy body formation and the progression of this fatal disease.

What Parts of the Brain are Affected in LBD?

Lewy body dementia may affect multiple brain regions, including:[6]

  • Cerebral cortex (thinking, processing information, language, and visual/spatial perception)
  • Limbic cortex (emotions and behavior)
  • Hippocampus (formation of new memories)
  • Midbrain (movement)
  • Brain stem (sleep and alertness)
  • Brain regions that control sensory perceptions (e.g. olfactory)

What Symptoms are Associated with LBD?

  • Trouble with executive function: thinking, judgement and decision-making
  • Visuo-spatial deficits
  • Memory loss (inability to form short term memories)
  • Difficulty with language, word-finding, making or following conversations
  • Visual hallucinations, delirium, and delusions
  • Fluctuating cognition, periods of confusion, lack of focus or attention
  • Parkinsonism (slowness, muscle stiffness, tremor, balance issues)
  • REM sleep behavior disorder
  • The “three A’s” – Anxiety, Agitation, Aggression
  • Depression
  • Autonomous dysfunction
  • Sensory loss
  • Severe sensitivity to certain drugs (anti-psychotics, opioids)

Testing and Diagnosis

Along with medical history and cognitive assessment, sleep studies, brain imaging and biofluid testing can support a differential diagnosis; but currently, a definitive diagnosis of Lewy body dementia can only be reached post-mortem with a brain autopsy. Physicians utilize a variety of tools and tests to form an LBD diagnosis.

  • Evaluation and Physical Exam
  • Neurological Exam for Parkinsonism
  • Cognitive Screening (MoCA/MMSE/Mini-Cog)
  • Neuropsychological Testing
  • Functional Activities of Daily Living/ADLs, IADLs
  • Bloodwork, Cerebrospinal fluid (CSF) testing
  • Sleep Study
  • Structural Brain Imaging-MRI Brain/CT Head
  • Functional Brain Imaging-PET Scan, EEG

There are challenges to diagnosis. First, scientists don’t yet fully know the root cause(s) of Lewy body dementia and other neurodegenerative diseases (e.g., what causes various proteins to clump or misfold in different regions of the brain). Second, different dementias share some symptoms in common, and some people have mixed dementia. And third, many physicians and nurses have not yet been trained to identify or treat LBD. Because it is less well known, Lewy body dementia may go undiagnosed or be misdiagnosed as Alzheimer’s or a psychiatric disorder with some symptoms in common.

LBD Research

A key goal of research is to identify novel markers for Lewy body dementia. Biomakers will advance development of diagnostic solutions such as blood or urine tests. Ideally, these solutions will also be less invasive, more accessible and more affordable for patients. At Stanford, the Sue Berghoff LBD Research Fellowship is funding collaborative research to identify novel Lewy body dementia biomakers, integrating research findings from biologics, imaging and sleep data.

Palliative Care and LBD

Palliative care is specialized medical care for people living with a serious illness or disease.[7] It goes beyond a patient’s prognosis and addresses their wishes, goals, fears and needs holistically, in order to:

  • provide comfort and relief from symptoms and stress of an illness;
  • improve quality of life for both patients and family/caregivers; and
  • improve health care resource utilization and reduce avoidable spending.

This is important for people with Lewy body dementia and other dementias with progressive decline in function and no cure yet in sight.

Working with the primary care physician, the palliative care team can support complex dementia care needs by delivering the following benefits:

  • time to devote to intensive family meetings and patient/family counseling;
  • skilled communication about what to expect in the future in order to ensure that care is matched to the goals and priorities of the patient and the family;
  • expert management of complex physical and emotional symptoms, including complex pain, depression, anxiety, fatigue, shortness of breath, constipation, nausea, loss of appetite, and difficulty sleeping; and
  • coordination and communication of care plans among all providers and across all settings.

Palliative care has value at any age and at any stage in a serious illness or disease, and it can be provided alongside medical treatment.

Dementia Risk Factors[8]

  • Age
  • Genetics/family history
  • Cardiovascular disease
  • Diabetes
  • Smoking and excessive alcohol use
  • Sleep disturbances
  • Poor nutrition, vitamin deficiencies
  • Head trauma
  • Depression

Lifestyle Choices for Brain Health

Studies show that adopting a “brain healthy” lifestyle, sooner rather than later, is the best way to help reduce or delay risk of dementia later in life.[9] [10]

  • Good Nutrition (e.g. The MIND Diet)
  • Regular exercise
  • Adequate and good quality sleep
  • Education, lifelong learning
  • Social connection and caring relationships (people and pets)
  • Avoidance of smoking and excessive alcohol intake
  • Seeking help for depression


All text, graphics, images, and other material contained on The Sue’s Story Project website are for informational purposes only. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of your doctor or other qualified health professional with any questions you may have regarding your health or a medical condition.