Lewy Body Dementia (LBD)

Lewy Body Dementia (LBD) is the most common of the four atypical parkinsonism disorders and exists in two forms: Dementia with Lewy Bodies and Parkinson’s Disease Dementia.  LBD is also classified as a non-Alzheimer’s dementia. It is not a rare disorder.

LBD Symptoms

Lewy Body Dementia (LBD) is an umbrella term that refers to two diagnoses:

  • Dementia with Lewy Bodies (DLB)
  • Parkinson’s Disease Dementia (PDD)

The terms DLB and PDD are of primary interest to researchers and less to families and clinicians. Whether someone is diagnosed with DLB or PDD is largely determined by the arbitrary “one-year rule”: if the onset of dementia or psychiatric symptoms is within one-year of parkinsonism, the disorder is called DLB, and if parkinsonism continues for more than one year before the onset of dementia, the disorder is called PDD. Unfortunately, the one-year rule ignores the possibility that parkinsonism may never be part of DLB.

Though the diagnostic criteria for DLB and PDD differ, the associated symptoms are largely the same:

  • Dementia: Everyone with LBD must have progressive dementia. Find our definition of dementia here.
  • Fluctuating Cognition: This refers to variability–on the basis of a minute, hour, or day–of attention and alertness. Unfortunately there is no consensus in the medical community how fluctuating cognition is objectively measured. This is part of the diagnostic criteria for DLB, but not PDD.
  • Visual Hallucinations: In DLB, usually hallucinations are complex and recur. Note that hallucinations are different from delusions, which can also occur in LBD. A hallucination is where an individual sees something that is not there – often children or animals. A delusion is where there is an entire story and emotional response to something that isn’t real such as thinking the house is on fire, thinking a family member is an “imposter,” or believing a spouse is unfaithful.
  • Parkinsonism: This term includes rigidity, bradykinesia (slow movements), tremor, and postural instability. If someone has a Parkinson’s Disease diagnosis, by definition the person has parkinsonism.  Find our definition of parkinsonism here.
  • Rapid Eye Movement (REM) sleep behavior disorder (RBD).  This is sometimes called “dream enactment behavior” because dreams are acted out.

Other important symptoms that are suggestive of LBD include:

  • Extreme sensitivity to antipsychotic medication (also called neuroleptics)
  • Low dopamine transporter (DaT) uptake in the basal ganglia as demonstrated by SPECT or PET scans

Note: these symptoms are for what we might refer to as “pure” LBD.  In most brain bank studies, those with Lewy Body Dementia also have Alzheimer’s pathology, vascular pathology, or other co-occurring pathologies.

What about memory problems? Note that many people with DLB receive a high score on the Mini-Mental Status Exam (MMSE) so that test is often not relevant in DLB. Those with PDD may have more memory impairment than those with DLB. It could be that if memory problems are present, Alzheimer’s pathology is to blame.

LBD Treatment

Pharmacological treatment of LBD is complex given how sensitive many people are to all kinds of medications.

Generally those with LBD are prescribed Alzheimer’s medications as a first-line treatment for dementia and hallucinations. Current Alzheimer’s medications include donepezil, rivastigmine, galantamine, memantine, and memantine/donepezil (combination). Rivastigmine is the only FDA-approved medication for treating dementia in Parkinson’s Disease.

There can be a tricky balancing act with Parkinson’s medications as a treatment for parkinsonism symptoms. Parkinson’s medications can cause hallucinations and delusions, yet many with LBD are extremely rigid without PD medications.

If hallucinations are frightening or if there are delusions, often atypical antipsychotics are prescribed. Many LBD specialists prefer clozapine or quetiapine. Note that there is an FDA black-box warning on all antipsychotic medications for those with dementia. That said, many in our local support group find these medications to be life-savers. In May 2016, the FDA approved a new medication for psychosis (hallucinations and delusions) in PDD.

LBD experts warn against taking anticholinergic medications (such as many bladder/incontinence medications) and typical antipsychotics (such as haloperidol). Also, given the risks of falls, experts encourage caution for all medications, especially those that can cause sedation (i.e. other-the-counter cold or allergy medications, sleep aids, cough syrups). We always recommend that you consult your physician prior to administering any medication other than what has been prescribed.

Go-To Organizations for LBD Education

A handful of organizations consistently deliver quality information about LBD. Click the link for each organization to review their web sites:

Organization Name Country Focus Web Address
Lewy Body Dementia Association USA Information, awareness
Lewy Body Dementia Resource Center USA Helpline, Support
Alzheimer’s Association USA Research, information


LBD Top Resources

Brain Support Network continually reviews most of the resources available on LBD. In our opinion, these web pages, documents, and videos are the most helpful resources for families:

Alzheimer’s Association Overview of Dementia with Lewy Bodies

This webpage provides a straightforward explanation of DLB symptoms, diagnosis, causes, and treatments.  It includes a list of key differences between Alzheimer’s and DLB.

> alz.org/dementia/dementia-with-lewy-bodies-symptoms.asp

Facing Lewy Body Dementia Together (includes a Medical Alert Card)

This publication of the Lewy Body Dementia Association is for newly diagnosed.  It used to be titled “An Introduction to Lewy Body Dementia.”  It includes a Medical Alert Card.

> lbda.org/wp-content/uploads/2020/09/facing_lewy_body_dementia_together_brochure.pdf

Caregiving Brief – Behavioral Changes in LBD

In 2013, the Lewy Body Dementia Association published its “Care Briefs” series.  This care brief, written by Rosemary Dawson, on behavioral changes is especially helpful.  There are also care briefs on sleep, medication, and polypharmacy.

> lbda.org/wp-content/uploads/2013/02/2016caregivingbrief_behaviorchanges.pdf

Lewy Body Dementia: Information for Patients, Families, and Professionals

This 40-page booklet was updated in June 2018 by the National Institute on Aging. It describes the main symptoms of DLB and PDD.

> ninds.nih.gov/Disorders/Patient-Caregiver-Education/Hope-Through-Research/Lewy-Body-Dementia-Hope-Through-Research

LBD Caregiver and Expert Discussion

This recording of a panel discussion after the movie “SPARK” about Robin Williams, featured UCSF’s Bruce Miller, MD, and Brain Support Network local LBD support group members Dianne and Denise. (Both Dianne and Denise donated their loved one’s brains upon death and received a confirmation of the LBD diagnosis.)  BSN’s Robin Riddle moderated.  This June 2021 webinar was co-hosted by Family Caregiver Alliance and Brain Support Network.

> Webinar recording:  youtube.com/watch?v=tOHXqZDyobs

> Brain Support Network notes:

Orthostatic Hypotension (OH) in Parkinson’s Disease (PD), Multiple System Atrophy (MSA), and Lewy Body Dementia (LBD)

Dr. Veronica Santini describes the symptoms of OH, lists the conservative and medication interventions, and answers questions. This September 2017 webinar was co-hosted by Brain Support Network and Stanford.

> Webinar recording:  youtube.com/watch?v=-FzsgUfQ_xIBrain

> Brain Support Network notes:

Parkinson’s Disease: Mind, Mood & Memory

This 100-page publication from the Parkinson Foundation has a terrific chapter on Dementia with Lewy Bodies.

> parkinson.org/site/DocServer/Mind_Mood_Memory.pdf

Psychosis: A Mind Guide to Parkinson’s Disease

This 36-page publication from the Parkinson Foundation offers a description of psychosis, its causes, treatments, and tips for caregivers.  Also available in audio form.  Published 2018.

> parkinson.org/library/books/psychosis

The Reality of LBD – Hallucinations & Delusions and How to Manage Them

This hour-long webinar in July 2017 is a terrific introduction to the psychiatric and behavioral problems in DLB by Dr. James Galvin.  He addresses the challenges in assessment and management of these symptoms.

> Webinar recording:  youtube.com/watch?v=zGSS4qNaJH0

> Brain Support Network notes:

Dementia with Lewy Bodies

This webpage, on the Family Caregiver Alliance website, offers details on symptoms, diagnosis, treatment, and caregiving.  Also available as a downloadable PDF.

> caregiver.org/resource/dementia-lewy-bodies/

Is it Lewy?

This tri-fold pamphlet from the Lewy Body Dementia Association lists symptoms to differentiate LBD from Alzheimer’s and Parkinson’s.  It used to be called “Lewy Who?”

> lbda.org/wp-content/uploads/2020/09/is_it_lewy.pdf

Lewy Body Dementia: The Under-Recognized but Common Foe

This 2013 article was written by Drs. Meera Balasubramaniam and James Galvin.  It addresses diagnostic challenges.  Originally in “Cerebrum,” a publication of The Dana Foundation.

> ncbi.nlm.nih.gov/pmc/articles/PMC3999867

LBDA’s Youtube Channel: “Ask the Experts”

The Lewy Body Dementia Association’s Youtube channel delivers videos on a variety of topics presented by leading experts on Lewy Body Dementia.

> youtube.com/user/LBDAtv

Life in the Balance: A Physician’s Memoir of Life, Love and Loss with Parkinson’s Disease and Dementia

This memoir by Thomas Graboys, MD and Peter Zheutlin, was published in 2008. Many caregivers in our local support group have read aloud parts of this book with their family member with LBD.

> amazon.com/Life-Balance-Physicians-Parkinsons-Dementia/dp/1402768737

New Insights Into Lewy Body Dementias

Dr. James Galvin, one of the US’s top experts on DLB, reviews the diagnostic criteria for both DLB and PDD, and treatment options.  This one-hour webinar in October 2011 was hosted by the LBDA.

> youtube.com/watch?v=bGviUzZBISA&index=6&list=PLoWh_nzWJNnc_7JG8irqKMOPUEZdjnhIr

Treatment of and Research on Dementia with Lewy Bodies

This helpful update on DLB was given by Dr. Geoff Kerchner, a behavioral neurologist, at an October 2012 Stanford University event, that was recorded.  Brain Support Network was one of the organizers.

> youtube.com/watch?v=UGtcvz2yT8M

UCSF Memory & Aging Center Overviews of DLB and PDD

These webpages examine causes, relationship with age, symptoms, and treatment.

> memory.ucsf.edu/education/diseases/dlb
> memory.ucsf.edu/dementia/parkinsons/parkinson-disease-dementia

Understanding Lewy Body Dementia

This thorough presentation on LBD and its treatment, with an extensive Q&A, was presented by Dr. Bradley Boeve in October 2018 in Michigan.

> youtube.com/watch?v=wCJPv0eXeQk

10 Things You Should Know About LBD

This short publication of the Lewy Body Dementia Association provides key facts.

> lbda.org/10-things-you-should-know-about-lbd/

Dementia with Lewy Bodies and Parkinson’s Disease Dementia: Patient, Family, and Clinician Working Together for Better Outcomes

This very useful guidebook by Dr. J. Eric Ahlskog, a neurologist with years of LBD experience, is written for the lay audience. Published in September 2013.

> amazon.com/Dementia-Lewy-Bodies-Parkinsons-Disease/dp/0199977569

LBD Diagnostic Criteria

Lewy Body Dementia (LBD) is an umbrella term that refers to two different diagnoses:  Dementia with Lewy Bodies (DLB) and Parkinson’s Disease Dementia (PDD).

Each of these two disorders is characterized by sets of symptoms.  Symptoms fit into one of the following five categories.  They are:

  • Required: must be present
  • Core: is almost always present
  • Suggestive: is often present
  • Cautionary: generally should not be present
  • Exclusionary: cannot be present

The diagnosis of either disease depends on  the symptoms present.  There are three classes of diagnosis:

  • Definitive (autopsy confirmed)
  • Probable
  • Possible

Because various disorders (and sub-disorders) have been identified and characterized at different times by different researchers, this framework is not universally used to define disorder symptoms and diagnostic criteria.

The two sets of diagnostic criteria are for what we might refer to as “pure” DLB or “pure” PDD. In most brain bank studies, those with Lewy Body Dementia also tend to have Alzheimer’s pathology, vascular pathology, or other co-occurring pathologies. The diagnostic criteria cannot account for “mixed dementia,” where more than one type of dementia occur simultaneously.

It is technically inaccurate to say that someone has both Parkinson’s Disease and Lewy Body Dementia or that someone has “Parkinson’s Disease with Lewy Bodies.” The most common Lewy body disease is Parkinson’s Disease. In terms of brain pathology, the key difference between Parkinson’s Disease and Dementia with Lewy Bodies / Parkinson’s Disease with Dementia is where in the brain the Lewy bodies are to be found. In PD, Lewy bodies are in the brainstem. In DLB or PDD, Lewy bodies are diffuse throughout the cortex or in a transitional stage between the brainstem and the cortex.

Symptoms and Diagnostic Criteria for Dementia with Lewy Bodies (DLB)

The symptoms and diagnostic criteria for Dementia with Lewy Bodies (DLB) are different than those for Parkinson’s Disease Dementia (PDD).  Here we cover DLB.

The source of these criteria is Diagnosis and Management of Dementia with Lewy Bodies: Third Report of the DLB Consortium, McKeith et al, Neurology, December 2005. While only the abstract is free, the full article is available for purchase.

Required Symptoms Core Symptoms Suggestive Symptoms
  • Dementia
  • Fluctuating Cognition
  • Visual Hallucinations
  • Parkinsonism: can occur at the same time or after dementia symptoms
  • REM sleep behavior disorder (RBD)
  • Extreme sensitivity to antipsychotic medication (neuroleptic)
  • Low dopamine transporter (DaT) uptake in the basal ganglia as demonstrated by SPECT or PET scans
Definitive Diagnosis of DLB Probable Diagnosis of DLB Possible Diagnosis of DLB
  • Brain autopsy required
  • All required symptoms (dementia)
  • At least two of four core features (fluctuating cognition, visual hallucinations, parkinsonism, and RBD)
  • All required symptoms (dementia)
  • One of four  core features (fluctuating cognition, visual hallucinations,  parkinsonism, and RBD)
  • At least one suggestive feature (extreme neuroleptic sensitivity, and low DaT uptake)

Symptoms and Diagnostic Criteria for Parkinson’s Disease Dementia (PDD)

The symptoms and diagnostic criteria for Parkinson’s Disease Dementia (PDD) are different than those for Dementia with Lewy Bodies (DLB).  Here we cover PDD.

The source is Clinical diagnostic criteria for dementia associated with Parkinson’s disease, Emre, et al, Movement Disorders, 2007 September 15; 22(12):1689-707.  This article assigns symptoms to “Groups”.  We’ve repeated the Group classification here, but have assigned a descriptive name to the assemblage, as well.

Required Symptoms for PDD (“Group I”)
  • Prior diagnosis of Parkinson’s disease
  • Dementia causing a decline in function severe enough to impair the patient in daily activities and in at least one cognitive domain
Core Symptoms for PDD in Cognitive Domains (“Group II”) Core Symptoms for PDD in Behavioral Domains (“Group II”)
  • Attention – The patient shows a level of impairment in attention, which may fluctuate over time
  • Executive function – Impairment in complex thought processes such as in initiating an action, planning, or organization
  • Visuo-spatial ability – Marked deficits in the processing of visuo-spatial material
  • Memory – There is noticeable impairment in both the recall of existing memories and in the learning of new material
  • Language – Basic language features are largely intact, although there may be difficulties in finding words and understanding complex sentences.
  • Apathy – Decreased spontaneity, motivation, effortful behavior
  • Changes in personality and mood – Can include depression and anxiety
  • Hallucinations – Usually complex and visual
  • Delusions – Usually paranoid delusions, such as infidelity or perceived unknown guests in the home
  • Excessive daytime sleepiness
Cautionary Symptoms for PDD (“Group III”) Exclusionary Symptoms for PDD
(“Group IV”)
  • Existence of an abnormality such as vascular disease which causes cognitive impairment although not determined to cause dementia
  • If the duration of time between the onset of motor and cognitive symptoms is not known
  • Cognitive or behavioral symptoms which occur only in the context of existing conditions, such as systemic diseases, drug intoxication, or major depression
  • Symptoms compatible with vascular dementia, confirmed by an established relationship between brain imaging results and impairment in neurological testing
Definitive Diagnosis of PDD Probable Diagnosis of PDD Possible Diagnosis of PDD
  • Brain autopsy required
  • All required symptoms (dementia)
  • Having deficits in at least two out of four cognitive domains
  • May or may not be behavioral symptoms, although their presence would support a diagnosis of probable PDD
  • No cautionary or exclusionary symptoms, as the abnormalities and conditions described in these categories can cause too much uncertainty in a potential diagnosis.
  • All required symptoms (dementia)
  • Can have a more non-characteristic pattern of core symptoms in at least one of the cognitive domains
  • May or may not be any behavioral core symptoms
  • One or more cautionary symptoms may be present
  • No exclusionary symptoms