The Whitworths of Arizona, bringing science to you in everyday language.

Friday, April 26, 2019

Decoding the DLB Diagnostic Criteria, #5: Formula

This is the last of five blogs about the 2017 diagnostic diagnosis of dementia with Lewy bodies (DLB), a document written for doctors but one which even stressed-out care partners should know about. Thus, over the last month, we've attempted to "decode" its language and present a more care partner-friendly version. In this last blog, we find out how to use these symptoms to identify the likelihood of Probable or Possible DLB. Although this section seems easier to read than other sections, I've still added an "In plain English" segment just for continuity.

The publishers of the criteria use a formula to identify Probable or Possible DLB, and to rule it out to a certain extent. As always, they are careful to never say "always" or "never"!

Probable DLB can be diagnosed if:
  • two or more core clinical features of DLB are present, with or without the presence of indicative biomarkers,
  • or
  • only one core clinical feature is present, but with one or more indicative biomarkers.
Probable DLB should not be diagnosed on the basis of biomarkers alone.

In plain English: Probable DLB can be diagnosed by the presence of a) least two core symptoms with or without biomarkers or b) one core symptom with at least one indicative biomarker but not by biomarkers alone.

Possible DLB can be diagnosed if:
  • only one core clinical feature of DLB is present, with no indicative biomarker evidence,
  • or
  • one or more indicative biomarkers is present but there are no core clinical features.
In plain English: Possible DLB can be diagnosed by the presence of a) at least one core symptom or b) one indicative biomarker.

The criteria also adds this:

DLB is less likely:
  • in the presence of any other physical illness or brain disorder including cerebrovascular disease, sufficient to account in part or in total for the clinical picture, although these do not exclude a DLB diagnosis and may serve to indicate mixed or multiple pathologies contributing to the clinical presentation,
  • or
  • b) if parkinsonian features are the only core clinical feature and appear for the first time at a stage of severe dementia.
In plain English: DLB is less likely in the presence of another physical illness or brain disorder with similar symptoms, although both it and DLB could be present. It is also less likely if the only core symptoms are movement issues that appear only after severe dementia is present.

Note that neither suggestive symptoms nor suggestive biomarkers are not included in these formulas. They simply add weight to a diagnosis. However, as care partners, recognizing these symptoms can definitely signal the need to see a doctor.

For more information, download the 2017 DLB Diagnostic Criteria if you haven't already done so. Also, find lots of information about the various symptoms in our books.

LBD is an umbrella term for all Lewy body diseases and starts with an L for Lewy.
DLB is for Dementia with Lewy bodies and starts with a D for the way the disease starts.
PDD is for Parkinson's disease with dementia and starts with a P for the way that disease starts.
Biomarker: Something measurable that can indicate the presence and severity of whatever you are testing for.
Indicative: A strong sign.
Supportive: A weaker sign that can still be helpful.
Probable Diagnosis: almost--but not quite!-100% accurate.
Possible diagnosis: Likely, but unproven without further evidence.

For more information about Lewy body disorders, read our books:
A Caregivers’ Guide to Lewy Body Dementia
Managing Cognitive Issues in Parkinson's and Lewy Body Dementia
Responsive Dementia Care: Fewer Behaviors Fewer Drugs
Riding A Roller Coaster with Lewy Body Dementia: A Manual for Staff

Helen and James Whitworth are not doctors, lawyers or social workers. As informed caregivers, they share the information here for educational purposes only. It should never be used instead of a professional's advice.

Friday, April 19, 2019

Decoding the DLB Diagnostic Criteria: #4, More Biomarkers

The 2017 diagnostic criteria for dementia with Lewy bodies (DLB) is important for care partners to know but this part of it especially is written in scientific language that is difficult for even a well-educated person to understand. This series of blogs attempts some decoding.

Last week introduced a two-part biomarker section and the three indicative biomarkers. This week's blog presents the three suggestive biomarkers. If you haven't read the previous blogs in this series, please go back and read them now so that you will better understand this one.

Supportive biomarkers are signs indicating the presence and intensity of DLB that cannot stand alone but can support a diagnosis based on other symptoms and biomarkers.

Supportive Biomarker 1. Relative preservation of medial temporal lobe structures on CT/MRI scan.
  • relative preservation: maintenance of function in relation to the norm
  • medial temporal lobe: The part of the brain responsible for memory of facts and events.
  • CT/MRI scans: Two types of 2-D scans of organ tissues.
What are they testing for? The amount of shrinkage in a part of the brain involved with memory.

Why? Shrinkage of this area is significantly related to Alzheimer's, but not to DLB.

In plain English: Little shrinkage of the area of the brain involved with memory of facts and events supports a DLB diagnosis.

Supportive Biomarker 2.  Generalized low uptake on SPECT/PET profusion/metabolism scan with reduced occipital activity +/- the cingulate island sign on FDG-PET imaging.

Let's divide this one into two parts:

Supportive Biomarker 2a. Generalized low uptake on SPECT/PET profusion/metabolism scan with reduced occipital activity
posterier cingulate cortex
location of  the posterier
cingulate cortex
  • Generalized low uptake: All-around low activity
  • SPECT/PET scans: 3D scans using radio-active tracers.
  • Profusion/metabolism scan: scan for brain activity
  • Occipital (lobe): an area at the back of the brain.
What are they looking for? Low levels of activity in the occipital lobe.

Why? This area of the brain controls visual functions related to DLB symptoms, including the core symptom of visual hallucinations. It is usually less damaged by Alzheimer's.

Supportive Biomarker 2b. The cingulate island sign on FDG-PET imaging may or may not accompany 2a.
  • FDG: A radio-active tracer used with PET scanning.
  • Cingulate island sign: a finding of preserved metabolism in the posterior cingulate cortex
  • Preserved metabolism: normal activity
  • Posterior cingulate cortex: An area deep in the back of the brain.
What are they looking for? Fairly normal levels of activity in an area of the brain ordinarily damaged by Alzheimer's.

Why? Brain damage in this area is common with Alzheimer's. The more normal brain activity called "cingulate island sign" is usually present with DLB.

2a and 2b together in plain English: A scan that shows decreased brain activity in the occipital cortex supports a DLB vs. a Alzheimer's diagnosis, as does the presence of the cingulate island sign.

Supportive Biomarker 3. Prominent posterior slow wave activity on EEG with periodic fluctuations in the pre-alpha/theta range.
  • EEG: (Electroencephalogram): measures electrical waves of brain activity through the scalp.
  • posterior slow-wave activity: Slower than normal brain wave activity.
  • periodic fluctuations: periods of changes in wave activity.
  • the pre-alpha/theta range: Alpha waves occur when a person is awake and alert. Theta waves occur during relaxation and light sleep. (I could not find a definition for "pre-alpha/theta range." Help invited!)
What are they looking for? Slow brain activity with periodic episodes of higher functioning.

Why? Cognitive fluctuations are common with DLB but not with Alzheimer's.

In plain English: An EEG that shows slow cognitive activity with periods of an increased level of functioning is supportive of a diagnosis of DLB vs. Alzheimer's.

Next week: The "clinical features" or symptoms.

LBD is an umbrella term for all Lewy body diseases and starts with an L for Lewy.
DLB is for Dementia with Lewy bodies and starts with a D for the way the disease starts.
PDD is for Parkinson's disease with dementia and starts with a P for the way that disease starts.
Biomarker: Something measurable that can indicate the presence and severity of whatever you are testing for.
Indicative: A strong sign.
Supportive: A weaker sign that can still be helpful.
Radio-active imaging: An imaging process that uses a radio-active tracer.
Radio-active tracer: biomarker that can enter the tissues or cells of the body.
Uptake: The process of absorbing a substance so that it can be released on the other side of the cell.

For more information about Lewy body disorders, read our books:
A Caregivers’ Guide to Lewy Body Dementia
Managing Cognitive Issues in Parkinson's and Lewy Body Dementia
Responsive Dementia Care: Fewer Behaviors Fewer Drugs
Riding A Roller Coaster with Lewy Body Dementia: A Manual for Staff

Helen and James Whitworth are not doctors, lawyers or social workers. As informed caregivers, they share the information here for educational purposes only. It should never be used instead of a professional's advice.

Decoding the DLB Diagnostic Criteria, #3: Biomarkers

This series of blogs will attempt to decode the scientific language used to write the latest DLB diagnostic criteria and come up with a plainer version. If you haven't read the previous blogs, please go back and read them before you read more.

A biomarker is a fancy word used to describe a something measurable that can indicate the presence and severity of whatever you are testing for. We are all familiar with blood, urine and saliva tests. These are all used to test for biomarkers for a variety of conditions from pregnancy to strep throat to HIV and much more.

Presently, biomarkers are mainly used for confirming a diagnosis. However, they are the hope of the future. They can reach inside cells to fine minute, early signs of a disease well before there are symptoms, and before it grows too big to eliminate. Many people are now living healthy lives after being treated for a cancer that was found while it was still small enough to treat successfully. Until recently, that was not possible with neurological diseases like DLB. One had to wait for the symptoms to show up to know it was present--and by then the disease is so entrenched that one can do little but treat the symptoms. However, researchers can now focus on finding ways to stop it from growing.

But that is for tomorrow. Today, biomarkers help to diagnose DLB by signaling the presence of Lewy bodies in a tested item and providing a measurement of how plentiful they are--or of the damage they have done.

The criteria divides the biomarkers into "Indicative" (strong) and "Supportive" (helpful). Today's blog will discuss the three Indicative Biomarkers. Next week's blog will go on to discuss the Supportive ones.

The first two indicative biomarkers involve radio-active imaging. To go deep into the body tissues, they use a tiny amount of a radio-active tracer substance that goes to a targeted area and then normally exits the body within 48 hours.

1. Reduced dopamine transporter (DaT) uptake in basal ganglia demonstrated by SPECT or PET scans.
  • dopamine (DA): A brain chemical that is involved in the control of many tasks, including voluntary movement.
  • dopamine transporter (DaT): A protein that the body uses to move dopamine in and out of a cell.
  • uptake: the process of absorbing the dopamine so that it can be released on the other side of the cell.
  • basal ganglia: Area of the brain where movement, speech, posture and much more is regulated.
  • SPECT and PET scans: 3-D imaging technologies that measure the presence and progress of specific radio-active tracer substances inside body cells. See this article for a discussion about these two imaging processes.
What are they looking for? Signs of an inadequate amount of dopamine inside the cells.

Why? Lewy bodies are known to target and damage dopamine in these cells, which require the chemical to function properly.

In plain English: Lewy bodies are probably present if the scan shows signs of inadequate amounts of a dopamine in cells that control functions related to several LBD symptoms.
    2.  Abnormal (low uptake) 123iodineMIBG myocardial scintigraphy
    • Abnormal (low uptake): unusually low activity
    • 123iodineMIBG: a radio-active tracer substance
    • myocardial: of the heart muscle. From myo (muscle) and cardia (heart)
    • scintigraphy: 2-D imaging that measure the presence and progress of specific radio-active tracer substances inside body organs. (More about MIBG imaging)
    What are they looking for? Damage to nerves that control autonomic heart function.

    Why? Lewy bodies are known to damage the nerves that control autonomic functions such as heart beat and blood pressure. (More about LBD's autonomic symptoms.)

    In plain English: DLB is probable if an image of lower than normal tracer activity shows the type of heart muscle nerve damage connected with several DLB symptoms.
      3. Polysomographic confirmation of REM sleep without atonia (muscle relaxation).
      • poly (many) somno (sleep) graph (test): Sleep study that measures brain waves, blood oxygen level, heart rate, breathing, eye movements and leg movements.
      • Rapid Eye Movement (REM) sleep: The part of the sleep cycle when a person dreams.
      • atonia: Muscle relaxation. 
      What they are looking for? Evidence of muscle activity during dreams.

      Why? During REM sleep a person's muscles are normally so relaxed that they can't physically act out their dreams.

      In plain English: DLB is probably present if a sleep study confirms the presence of muscle activity during dream sequences.

      Or: DLB is probably present if a sleep study confirms the presence of REM sleep behavior disorder (RBD), a core DLB symptom. (more about RBD, also called Active Dreams)
        The above biomarkers provide objective tests for inadequate dopamine, a body chemical necessary for good cognition, heart nerve damage known to cause certain DLB-related autonomic dysfunctions, and Active Dreams, a core DLB symptom. None of the tests are considered 100% reliable alone but used with the more subjective clinical symptoms, they make a diagnosis about as accurate as it gets.

        Next week: Exploring the Supportive Biomarkers.

        LBD is an umbrella term for all Lewy body diseases and starts with an L for Lewy.
        DLB is for Dementia with Lewy bodies and starts with a D for the way the disease starts.
        PDD is for Parkinson's disease with dementia and starts with a P for the way that disease starts.
        Biomarker: Something measurable that can indicate the presence and severity of whatever you are testing for.
        Indicative: A strong sign.
        Supportive: A weaker sign that can still be helpful.
        Probable Diagnosis: almost--but not quite!-100% accurate.
        Possible diagnosis: Likely, but unproven without further evidence.
        Radio-active imaging: An imaging process that uses a radio-active tracer.
        Radio-active tracer: biomarker that can enter the tissues or cells of the body.
        Uptake: The process of absorbing a substance so that it can be released on the other side of the cell.

        For more information about Lewy body disorders, read our books:
        A Caregivers’ Guide to Lewy Body Dementia
        Managing Cognitive Issues in Parkinson's and Lewy Body Dementia
        Responsive Dementia Care: Fewer Behaviors Fewer Drugs
        Riding A Roller Coaster with Lewy Body Dementia: A Manual for Staff

        Helen and James Whitworth are not doctors, lawyers or social workers. As informed caregivers, they share the information here for educational purposes only. It should never be used instead of a professional's advice.

        Friday, April 5, 2019

        Decoding the DLB Diagnostic Criteria, #2: Symptoms

        The criteria for diagnosing dementia with Lewy bodies was written for doctors, not stressed-out care partners. Therefore, this series of blogs attempts to decode it. The original language is presented in italics, followed by definitions, a plain English version of the statement and a reference where you can find more information.

        Last week's blog noted that a certain amount of cognitive decline was essential for the diagnosis. If you haven't read it, please go back and do so before you go on. It's all connected! And please understand that this information is for educational purposes only! If you recognized these symptoms in a loved one who hasn't been diagnosed yet, a doctor's visit needs to be your next step!

        Core Clinical Features
        (NOTE: The first 3 typically occur early and may persist throughout the course)
        • clinical features: symptoms
        • occur early: appear prior to obvious cognitive symptoms
        • persist: last to the end
        In plain English: Three lasting symptoms that tend to appear early  plus one which also lasts once it starts.
          Core Symptom #1. Fluctuating cognition with pronounced variations in attention and alertness.
          • cognition: mental ability
          • attention: the ability to maintain focus over time
          In plain English: Mental function that varies in the ability to focus and be alert. More about this.

          Core Symptoms #2. Recurrent visual hallucinations that are typically well formed and detailed.
          • recurrent: appear more than once.
          • visual hallucinations: seeing something that isn't really there.
          • well-formed and detailed: strong appearance of reality 
          In plain English: Visual hallucinations that feel very real and can appear over and over. More about these and other visual problems.

          Core Symptoms #3. REM sleep behavior disorder (RBD) which may precede cognitive decline.
          • REM (rapid eye movement) sleep: the sleep cycle when dreams occur and a person's limbs are normally so relaxed (paralyzed) that they cannot move.
          • RBD: When a person physically acts out their dreams while asleep. 
          In plain English: The person physically acts out their dreams and may start doing so prior to loss of cognitive abilities. More about RBD. (Also called "Active Dreams.")

          Core Symptoms #4. One or more spontaneous cardinal feature of parkinsonism – these are bradykinesia, rest tremor, or rigidity.
          • Parkinsonism: Movement symptoms caused by something other than Parkinson's. Often caused by antipsychotic drugs. More about the difference between Parkinson's and Parkinsonism.
          • spontaneous cardinal feature: A major clinical symptom that occurs without the use of antipsychotic drugs
          • antipsychotic drugs: behavior management drugs that are usually anticholinergic--i.e., drugs that trigger LBD's sensitivity issues. More about these drugs. 
          • bradykinesia: slowness of movement and the impaired ability to move the body swiftly on command.
          • rest tremor: a tremor that only shows up when a muscle is relaxed.
          • rigidity: Stiffness and inflexibility of the limbs
          • postural instability: unstable while standing.
          In plain English: One or more of the following in the absence of antipsychotic drugs: Slowness of movement, difficulty moving swiftly on command, tremors while at rest and rigidity.

          Supportive Clinical Features

          This next group of symptoms also occur regularly with other diseases. However, their presence, while not as clearly indicative, is still quite helpful in making a diagnosis. This section is just a long list in the DLB diagnosis criteria but I've added a bit about each symptom. Go to our books for more information:
          • Severe sensitivity to antipsychotic agents: Although not a core symptom, this is still very important because people living with DLB are often sensitive to the very drugs they receive to treat symptoms involving behavior management, incontinence or even movement.
          • postural instability: a Parkinsonism symptom.
          • repeated falls: usually related to movement issues, but can also be related to poor visual perceptions.
          • severe autonomic dysfunction: The autonomic nervous system controls the automatic body systems such as such as heart beat, blood pressure, breathing, and bladder control. Includes the following symptoms and more:
            • syncope or other transient episodes of unresponsiveness: a loss of consciousness, usually related to a fall in blood pressure.
            • constipation: a backup of processed food in bowel caused at least in part by an ineffectively functioning digestive system.
            • orthostatic hypotension: Low blood pressure on rising
            • urinary incontinence: Poor bladder and sphincter control.
          • hypersomnia: Excessive daytime sleeping.
          • hyposmia: Loss of smell.
          • hallucinations in other modalities: All senses can foster hallucinations, but audio ones are the next most common after visual ones.
          • systematized delusions: Well-structured (systematized) dramas built around false beliefs (delusions).
          • apathy: The inability to respond emotionally. Lack of interest, enthusiasm or concern.
          • anxiety: Restlessness, worry, nervousness, the feeling that something terrible is going to happen.
          • depression: Feeling sad, hopeless, without energy.
          Next week: On to the biomarkers!

          In the meantime, download this Patient Checklist for Diagnostic Symptoms. You can fill it out and take it to your loved one's doctor the next time you go. (If you tried to download it from the 2017 criteria last week, this is a different address. It works!)

          For more information about Lewy body disorders, read our books:
          A Caregivers’ Guide to Lewy Body Dementia
          Managing Cognitive Issues in Parkinson's and Lewy Body Dementia
          Responsive Dementia Care: Fewer Behaviors Fewer Drugs
          Riding A Roller Coaster with Lewy Body Dementia: A Manual for Staff

          Helen and James Whitworth are not doctors, lawyers or social workers. As informed caregivers, they share the information here for educational purposes only. It should never be used instead of a professional's advice.