LBD preceded by burning mouth syndrome

LBD folks –
Someone posted about the problem of a “burning mouth” over a year ago on the LBDA Forum. Now we have a published case report about it.
Robin


Revue Neurologique (Paris). 2009 Dec 30.

[Atypical Lewy body disease revealed by burning mouth syndrome and a pseudo-psychiatric syndrome.] [Article in French]

Varvat J, Thomas-Anterion C, Decousus M, Perret-Liaudet A, Laurent B.
Service de neurologie, CHU Nord, Saint-Etienne cedex, France.

INTRODUCTION: Among the degenerative diseases of the nervous system, Lewy body disease has the most psychiatric symptoms especially hallucinations, delusion and identification disorders.

CASE REPORT: We report a case of Lewy body disease that started with a burning mouth syndrome for three year as the only symptom before the development of a pseudo-psychiatric syndrome (melancholy and Capgras). None of the usual cardinal criteria were present. MRI, cerebrospinal fluid, and DAT scan((R)) findings enabled the diagnosis.

CONCLUSION: The dopaminergic hypothesis put forward in some cases of burning mouth syndrome might explain this symptom in Lewy body disease.

PMID: 20045161

DAT-SPECT: useful for DLBvAD, not useful for MSA, PSP, CBD

This recently-published article touches upon the four disorders in our group.

It’s a review article is about the use of DAT-SPECT — dopamine transporter SPECT scans — in diagnosing movement disorders. The authors have done a great job in reviewing all the data and then presenting understandable one-sentence conclusions, which I will now share…

For MSA, PSP, and CBD, the authors conclude: In “clinical practice, DAT-SPECTs are not useful in differentiating between PD and atypical parkinsonian syndromes (MSA, PSP, CBD).”

For DLB, the authors conclude: “DAT-SPECT cannot discriminate between PD/PD-dementia and DLB but can be very useful in the differential diagnosis between DLB and Alzheimer disease and can also be of some value in the differential diagnosis between DLB and vascular dementia.”

I remember learning back in 2008 that there was some type of legal issue with bringing SPECT scans to the US, though they are already widely used in Europe. SPECT imaging is important for some disorders (such as DLB) so it’s been frustrating that SPECT imaging is not approved for use in the US except in a few research settings. In 2008, there was a Q&A with Dr. Mark Stacy from Duke about this:

“Question: Why are SPECT scans not available in the US?
Answer: Because of corporate changes. GE bought Amersham (sp?). Amersham wanted to bring another type of SPECT agent to market. It’s been found that the drug that GE started to bring to market in Europe is easier to use. So it got slowed down bringing this agent to the US. GE is talking to the FDA about using European trial data.”

Recently, I asked Dr. Hubert Fernandez (on NPF’s “Ask the Doctor” Forum) about the status of bringing DAT-SPECT scans to the US. He first explained what a DAT ligand is and then answered the question:

“DAT (dopamine transporter) is a type of ligand (vehicle or medium) to conduct the SPECT scan. [It] ‘tags’ dopamine. It is important that the medium used is the correct one. Good examples are altropane or B-CIT….these are ligands that are used for SPECT scans to evaluate for PD.

Yes, for now, they DAT SPECT scans are not commercially available….but soon they they will be. One of the companies that manufactures a DAT ligand has received an ‘approvable letter’ from the FDA.”

OK, that’s probably all any of you want to know about DAT-SPECT imaging.

I’ve copied the article’s abstract and a few excerpts below, if any of you want to go further…

Robin


Journal of Neurology, Neurosurgery & Psychiatry. 2010 Jan;81(1):5-12.

The role of DAT-SPECT in movement disorders.

Kägi G, Bhatia KP, Tolosa E.
Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, National Hospital for Neurology and Neurosurgery, London, UK.

Dopamine transporter (DAT) imaging is a sensitive method to detect presynaptic dopamine neuronal dysfunction, which is a hallmark of neurodegenerative parkinsonism. DAT imaging can therefore assist the differentiation between conditions with and without presynaptic dopaminergic deficit.

Diagnosis of Parkinson disease or tremor disorders can be achieved with high degrees of accuracy in cases with full expression of classical clinical features; however, diagnosis can be difficult, since there is a substantial clinical overlap especially in monosymptomatic tremor (dystonic tremor, essential tremor, Parkinson tremor).

The use of DAT-SPECT can prove or excludes with high sensitivity nigrostriatal dysfunction in those cases and facilitates early and accurate diagnosis.

Furthermore, a normal DAT-SPECT is helpful in supporting a diagnosis of drug-induced-, psychogenic- and vascular parkinsonism by excluding underlying true nigrostriatal dysfunction.

This review addresses the value of DAT-SPECT and its impact on diagnostic accuracy in movement disorders presenting with tremor and/or parkinsonism.

PubMed ID#: 20019219 (see pubmed.gov for abstract only)

———-

Excerpts (in case you didn’t get enough already):

“Atypical parkinsonism (MSA, PSP, CBD)
The differentiation of atypical parkinsonian disorders from PD and between each other can raise considerable difficulties, particularly in early disease stages. This difficulty is reflected in clinicopathological studies where atypical parkinsonism accounts for a large part of misdiagnosis in PD. MSA, especially the parkinsonian subtype (MSA-P), can initially be very difficult to distinguish from PD before more specific symptoms like pronounced autonomic involvement, laryngeal stridor or lack of response to dopaminergic therapy occur. The same is true for the parkinsonian type of PSP (PSP-P) in which the more disease-specific signs and symptoms such as supranuclear vertical gaze palsy and imbalance with falls occur. Also, corticobasal degeneration (CBD) can initially easily be mistaken as PD because of its marked asymmetrical akinetic-rigid syndrome before apraxia, myoclonus and cognitive problems occur. A faster disease progression and a poor responsiveness to levodopa are common features in atypical forms and is explained by the pre- and postsynaptic dopaminergic degeneration. However,
some responsiveness to levodopa is not uncommon in early MSA-P or PSP-P. Previously, several studies have been carried out to establish the value of DAT-SPECT for the differentiation between PD and atypical PD. It has been shown that DAT-SPECT is sensitive in detecting presynaptic nigrostriatal degeneration in PD and atypical PD but not useful in the differential diagnosis of PD and atypical PD.”

“The amount and pattern of reduced striatal DAT binding in MSA have been shown to be in the range of PD with a more pronounced loss of DAT binding in the posterior putamen compared with the caudate to be typical for both. Asymmetry of DAT binding loss tends to be more pronounced in PD, and progression is faster in MSA compared with PD. PET and DAT-SPECT studies have shown that even clinically pure forms of MSA-C have some decrease in DAT binding but less compared with MSA-P or PD. This finding could be of some diagnostic impact in the differential diagnosis of MSA-C to idiopathic late-onset cerebellar ataxia (ILOCA). For separating MSA from PD,
other techniques such as voxelwise analysis of DAT-SPECT combined DAT/D2 receptor SPECT (IBZM, Epidepride,
Iodolisuride and IBF) or D2 PET (raclopride) can provide more information, although D2 receptor binding imaging methods are influenced by dopaminergic therapy and are therefore most useful in drug-naive patients. In drug-naive PD, D2 binding exceeds normal levels because of D2 receptor upregulation, whereas D2 binding is reduced in MSA early on because of postsynaptic degeneration. PET studies may contribute in the differential diagnosis of these entities. Striatal metabolic studies using FDG have shown to be of value in the differential diagnosis of atypical parkinsonism with hypermetoablism in the dorsolateral putamen in PD, bilateral hypometabolism in the putamen in MSA and hypometabolism of the brainstem and the middle frontal cortex in PSP. In CBD, unlike PSP or PD,
unilateral balanced (caudate/putamen) reduction in tracer uptake has been observed. In addition, cardiac imaging with MIBG has shown changes consistent with heart denervation in patients with PD which are not present in patients with MSA or PSP.”

“DAT-SPECT is also of limited value in the differential between PD and PSP, although PSP seem to have a more
symmetrical and profound DAT loss in the whole striatum, whereas in PD the posterior part of the putamen shows more loss of DAT density compared with the anterior part and the caudate.”

“DAT loss in CBD is in the same range as it is in PD and atypical PD, although DAT loss is much more asymmetrical and less pronounced than that seen in MSA and PSP. D2 SPECT seems to be of less value compared with MSA and PSP because D2 binding in CBD is more often in normal range than it is in MSA and PSP.”

“In conclusion, DAT-SPECT imaging does not help to differentiate between the neurodegenerative parkinsonian disorders. Hence, in clinical practice, DAT-SPECTs are not useful in differentiating between PD and atypical parkinsonian syndromes (MSA, PSP, CBD).”

“Dementia with Lewy bodies
In dementia with Lewy bodies (DLB), the extent of DAT loss in the striatum is in the range of PD and therefore not useful in the differential of PD and atypical PD. Neuropathological data suggest that 50­60% of dementia in people aged 65 or older is due to Alzheimer disease, with a further 10­20% each attributable to DLB or vascular cognitive impairment. Operationalised clinical diagnostic criteria have been agreed for all of these syndromes, but even in specialist research settings, they have limited accuracy when compared with neuropathological autopsy findings. Distinguishing Alzheimer disease from DLB is clinically relevant in terms of prognosis and appropriate treatment. A striking biological difference between DLB and Alzheimer disease is the severe nigrostriatal degeneration and consequent DAT loss that occurs in DLB, but not to any significant extent in Alzheimer disease. Several imaging
studies have shown that DAT imaging improves diagnostic accuracy with a sensitivity of 78% and a specificity of up to 94% in the separation between DLB and AD. Most of these studies have used clinical diagnosis as the gold standard, and the results have to be taken with some caution. One study with 20 cases with pathologically proven dementias (DLB/non-DLB) and with an FP-CIT SPECT at initial clinical workup showed that the DAT imaging substantially enhanced the accuracy of diagnosis of DLB by comparison with clinical criteria alone. Abnormal DAT imaging has therefore also been included as a suggestive feature in the DLB consensus criteria in 2005.”

“In conclusion, DAT-SPECT cannot discriminate between PD/PD-dementia and DLB but can be very useful in the differential diagnosis between DLB and Alzheimer disease and can also be of some value in the differential diagnosis between DLB and vascular dementia.”

The 6 R’s of Managing Difficult Behavior (from The 36-Hour Day)

The Johns Hopkins Health Alert from Monday may be of interest to those dealing
with challenging behavior. It’s on “The 6 R’s of Managing Difficult Behavior,”
according to Dr. Peter Rabins and Nancy Mace, as discussed in their book The
36-Hour Day, which I highly recommend to anyone dealing with dementia.

The 6 R’s are:
* Restrict
* Reassess
* Reconsider
* Rechannel
* Reassure
* Review

You can sign up for these health alerts (they come to your email) here:
http://www.johnshopkinshealthalerts.com

Robin


http://www.johnshopkinshealthalerts.com/alerts/memory/JohnsHopkinsHealthAlertsMemory_3178-1.html

The 6 R’s of Managing Difficult Behavior
Johns Hopkins Health Alert: Memory
Dated 1/4/10

Restrict, Reassess, Reconsider, Rechannel, Reassure, Review

In their groundbreaking book on Alzheimer’s caregiving — The 36-Hour Day — Peter Rabins, M.D. (author of the Johns Hopkins Memory White Paper) and Nancy Mace discuss the six R’s of managing difficult behavior in people with dementia. Here they are…

People with dementia often exhibit behaviors that are frustrating, embarrassing, and sometimes even dangerous to the caregiver and others. These may include angry outbursts, agitation, aggression, wandering, vocalizations, hoarding or hiding things, and inappropriate sexual behavior.

For many caregivers, these difficult behaviors are the most challenging and exhausting aspect of caring for a person with dementia. Unfortunately, the available medications to treat Alzheimer’s disease have little effect on behavioral problems.

Here are Dr. Rabins’ six coping strategies:

Dementia Strategy 1 — Restrict. First, calmly attempt to get the person to stop the behavior, especially if the behavior is potentially dangerous.

Dementia Strategy 2 — Reassess. Consider what might have provoked the behavior. Could a physical problem (toothache, urinary tract infection, osteoarthritis) be behind the agitation or anger? Is a particular person or the noise level in the room triggering the negative reaction? Could the time of day and fatigue be contributing to the problem?

Dementia Strategy 3 — Reconsider. Put yourself in the dementia patient’s shoes. Try to imagine what it must be like to not understand what is happening to you or to be unable to accomplish a simple task. Consider how frustrating or upsetting the current situation or environment might be for a person with dementia.

Dementia Strategy 4 — Rechannel. Try to redirect the behavior to a safer, less disruptive activity. For example, if the person constantly disassembles household items, try finding simple unused devices, such as an old telephone or a fishing reel, that can be taken apart and put back together repeatedly. For someone who hoards or hides things, put away valuables and replace them with an array of inexpensive items.

Distraction often works well to curtail disruptive repetitive behaviors and restlessness. For example, try asking the person you’re caring for to “help” with simple tasks, such as holding spoons or potholders while you cook.

Dementia Strategy 5 — Reassure. The demented person’s brain injury and the resulting confusion and frustration can lead to anger, anxiety, and outright fear in certain situations. Calmly reassure the person that everything is okay and that you will continue to take care of him or her.

Dementia Strategy 6 — Review. After an unsettling experience with your loved one, take time to review how you managed the problem and what you might have done differently. Think about what may have triggered the problem, how it might have been avoided, and what you might try the next time a similar situation arises.

It also helps to create a patient-friendly environment. This might include soothing music in the background; pictures, words, or arrows to help orient the person in the house; or a secure place to sit outside or walk in the backyard.

New LBD Caregiver Blog

This blog was started in November 2009 by Gilli whose 80-year-old mother may have Lewy Body Dementia. I believe they live in the UK. The family is dealing with many behavioral issues. The mother is currently in a hospital; I don’t know if this is a skilled nursing facility or a psychiatric ward.

Here’s a brief excerpt:
“It seems that this illness became noticeable in Sept 2008 after going on a cruise… A brief spell in hospital followed a ‘passing out’ not unconscious, aware of what was said around her but not responding to anyone.Various tests followed …perhaps a small stroke or TIA it was thought, perhaps vascular dementia but as time has passed it is thought that it is Lewy Body dementia. ”

See:
http://mummeandlewybodydisease.blogspot.com/

Robin

The “Other” Dementias (featuring Lewy Body Dementia story)

There’s a wonderful article in the November/December 2009 issue of Neurology Now magazine.  It features Jerome and Renata Rafferty; Jerome had Lewy Body Dementia and Renata was his caregiver.

Renata is a fixture on the LBDA Forum (“raffcons”).  (She and Jerome used to live near Palm Springs; they moved to Indiana this spring.)  Renata emailed me on Sunday about the article:

“The writer interviewed me just a  few days before Jerome died, and it was a fitting cap to bring at least some usefulness to what Jerome went through. I think the article is pretty good and would like to see it disseminated as widely as possible.”

Here’s the full text of the article, and a link to it online.  In the online version, you can see a nice photo of Jerome and, of course, the formatting is prettier.  You can also download the PDF of the article.

Robin

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journals.lww.com/neurologynow/Fulltext/2009/05060/The__Other__Dementias.14.aspx –> HTML version

The “Other” Dementias
Alzheimer’s disease is not the only cause of dementia. Knowing the others may help you or your loved one get the right diagnosis and treatment.
by Tom Valeo
Neurology Now:
November/December 2009 – Volume 5 – Issue 6 – p 26-27, 31-34

Renata Rafferty first suspected trouble when her late husband Jerome, a bright, curious, and articulate man, couldn’t tell her about an article he had just read.

“He would start to tell me and then say, ‘I’d better go find the article and give it to you’,” she recalls.

Jerome was nearly 70 at the time (he died on Oct. 20, 2009, at the age of 76), so Rafferty attributed such lapses to typical age-related forgetfulness. But that wasn’t the first disturbing change she had noticed in him. For more than two years he had been having terrifying dreams several nights a week.

“They were scary, violent dreams, and he would act them out,” Rafferty remembers. “He would kick, push, and speak angrily, and if I tried to wake him he’d lash out at me. I learned to get out of bed, shake his foot, and call to him so I wouldn’t be close enough to get hurt.” Their doctor attributed the dreams to the pain medication Jerome had been taking for a ruptured disc in his back. But he prescribed the Alzheimer’s drug donepezil when Jerome could no longer follow the plot of Law and Order, one of his favorite TV shows. A neurologist added another Alzheimer’s medication, memantine.

After Jerome went through eight hours of neuropsychiatric testing over two days, the doctor who administered the tests concluded he did not have Alzheimer’s disease (AD) but rather vascular dementia, which is caused by the damage that accumulates from several small strokes.

Since strokes can occur in any part of the brain, the symptoms of vascular dementia can vary greatly. But they often cause memory problems, mood disorders, and difficulty with walking and other movements-symptoms found in some Alzheimer’s patients as well.

If the strokes accumulate in the front of the brain, they may produce symptoms of frontotemporal dementia (FTD). This group of disorders affects the prefrontal cortex, which modulates mood, judgment, speech, creativity, and other distinctly human functions.

Still, the neuropsychologist who performed the testing insisted Jerome had vascular dementia, and predicted that unlike patients with AD, who decline steadily, Jerome would decline, remain stable for a while, then have another small stroke and decline again, and so on.

“We went for a year or so thinking it was AD, and then we went for another year or so thinking it was vascular dementia,” Rafferty says.

Then Jerome went to the Mayo Clinic in Scottsdale, AZ, seeking relief from his persistent back pain. After a thorough exam his doctors concluded that Jerome did not have vascular dementia or AD. They had noticed that the toes on one foot were constantly wiggling, a sign of a very rare condition known as painful leg moving toe syndrome.

“Everyone was very excited about that,” Rafferty says. “They wanted to enroll him in a study, videotape his foot and leg.”

But during the exam she heard the senior neurologist on the team mention–in passing–that Jerome did not have vascular dementia, so she followed him into the hall and asked him what he meant.

“I’m so sorry to tell you this, but it’s obviously Lewy body dementia,” he said, and rushed off.

“That was the first time I heard those words,” Renata says.

Now that she knows more about Lewy body dementia (LBD), she can see early symptoms that should have pointed to the diagnosis. Acting out violent dreams, for example, is one poorly understood symptom of the disorder. And when Jerome took olanzapine, one of the newer drugs used to treat psychiatric symptoms, he had a violent reaction that produced high blood pressure and delirium.

“It turns out that this is a sign of LBD too,” Rafferty says. “We found out that people with LBD often have a severe reaction to atypical antipsychotic medications-also, that LBD patients should not be put under general anesthesia because they may proceed rapidly to end-stage disease.”

To complicate the diagnosis further, LBD may overlap with other conditions, including AD, Parkinson’s disease, FTD, and vascular dementia. Although Jerome did not have vascular dementia, he did have a fourth transient ischemic attack-a temporary interruption of blood flow to a part of the brain. A brain scan revealed signs of a previous stroke, which could have produced symptoms of its own.

Despite his memory problems, and occasional hallucinations, and fleeing bouts with anxiety and aggression, Jerome remained acutely aware of his condition in a way that Alzheimer’s patients seldom are. When a hospice nurse recently asked him if he needed anything, he replied with a mordant, “Yeah, a getaway car.”

THE BIG FOUR

Everyone knows about AD, which accounts for 65 percent of all dementia in the United States. Alzheimer’s begins with degeneration of the hippocampus, a brain structure essential for the creation of new memories, and spreads to other brain areas, producing problems with speech, mood, judgment, motor skills, and other abilities.

But the hippocampus is not the only region subject to degeneration. Other brain structures can develop problems, and although they may produce similar symptoms, the underlying diseases each have a life of their own.

“There are well over 100 causes of dementia, but the big four that make up 94 to 98 percent are Alzheimer’s disease, Lewy body dementia, frontotemporal dementia, and vascular dementia,” notes James E. Galvin, M.D. M.P.H., assistant professor of neurology, anatomy, and neurobiology at Washington University School of Medicine and director of the Memory Diagnostic Center and the Wolff Neuroscience Laboratory. If you take 100 people with dementia, 65 will have AD, 10 or 12 will have LBD, 10 or 12 will have vascular, and eight will have FTD.

Because Alzheimer’s was identified more than 100 years ago and accounts for the vast majority of dementia, it attracts the largest number of research dollars, and therefore is better understood than the others.

But the other types of dementia tend to strike earlier, consuming many years of productive life.

“These other diseases affect people in their 50s, 60s, and early 70s,” observes Dr. Galvin. “Alzheimer’s affects people in their late 70s and early 80s.”

Although the precise causes of these different dementias (including AD) remain obscure, they all seem to involve the faulty production or management of proteins in the brain. In AD, tau protein accumulates within the body of neurons, while amyloid protein forms clumps in between neurons.

In LBD, a protein known as alpha-synuclein aggregates into clumps named after Frederich Lewy, the German-American physician who described them in 1912. (Dr. Lewy worked in the same lab as Dr. Alois Alzheimer, who identified the protein clumps and tangles characteristic of the disease named after him.)

FTD involves the accumulation of a protein known as TDP-43, which also plays a role in amyotrophic lateral sclerosis (ALS), or Lou Gehrig’s disease. Discovered just three years ago, TDP-43 plays such a decisive role in both diseases that some researchers suspect that FTD and ALS may be different manifestations of the same disease process.

One type of FTD known as Pick’s disease, named after Arnold Pick, a professor of psychiatry at the University of Prague who described the disease in 1892, involves the accumulation of tau protein-one of the two proteins associated with Alzheimer’s disease. In Pick’s disease, however, the protein accumulates in the frontal lobes, where it causes erratic behavior and the loss of normal inhibitions. A normally reserved man with Pick’s might make lewd sexual comments to women or become belligerent. Pick’s disease may also produce speech difficulties that eventually leave the patient mute.

Vascular dementia is an imprecise term that refers to dementia caused by brain cells that have been damaged by lack of oxygen from several small strokes. Some research suggests that the most common form of vascular dementia, known as multi-infarct dementia, merely causes or accelerates AD, producing a decline in memory and cognitive function.

“There can be some overlap in pathology, but in vascular dementia you think the primary dementing component is due to vascular disease,” says Dr. Galvin. “If you have AD and then have a stroke, you don’t then have vascular dementia too; you have AD and a stroke. It’s not clear cut, though.”

WHAT IS DEMENTIA?

Understanding dementia, which is a complex and varied dysfunction, requires understanding the complex and varied function of the brain itself.

What we experience as consciousness involves the seamless integration of signals generated by dispersed regions of the brain. To produce accurate perceptions of the environment, appropriate emotions, reliable memories, and good judgment, brain regions must perform efficiently, and the fibers that link those regions must transmit signals smoothly and swiftly.

All this activity depends on the ability of brain cells, known as neurons, to manufacture, transport, and recycle proteins, a process that requires huge amounts of glucose and oxygen. (The brain accounts for two percent of the body’s weight, but consumes 20 percent of the body’s energy.)

This constant and arduous process provides many opportunities for mistakes. A neuron may start to manufacture defective or misfolded proteins, or fail to manufacture enough to provide the chemical signals that enable neurons to communicate with each other. Proteins may not be broken down or recycled efficiently enough, causing debris to build up within and between the neurons, which can result in harmful inflammation.

This variety of brain functions points to one of the great mysteries of dementia: Why do various regions of the brain degenerate so differently?

“It’s what we call selective vulnerability, and no one understands why it exists,” says Bradley Boeve, M.D., professor of neurology at Mayo Clinic College of Medicine in Rochester, MN. “Why does AD affect the hippocampus, while FTD affects the frontal and temporal lobes and LBD affects the brainstem and neurochemical centers? I’ve never heard a good hypothesis as to why. Even in patients with end-stage FTD, their parietal and occipital regions [other major brain regions] look pretty normal. If dementia is a protein dysfunction, why is it so selective for certain parts of the brain?”

The variety of dementia makes treatment extremely difficult. Antipsychotic drugs, for example, quell the voices and hallucinations of schizophrenia and help some people with AD, but often produce delirium in LBD patients.

And the complexity of the brain-from protein synthesis within the neuron to the dense highways that transmit signals-makes effective treatments difficult to devise, leaving physicians with little to offer but relief for some symptoms. Donepezil, for example, developed to stimulate the memory of AD patients, may help people suffering from another form of dementia that causes memory problems. Patients with LBD who develop rigidity of movement may benefit from drugs used to treat Parkinson’s disease. Such drugs do nothing to treat the underlying cause of the dementia but may provide some relief from the consequences.

WHAT GOES WRONG?

The investigation of Alzheimer’s disease demonstrates how elusive the cause of dementia can be. For nearly a century scientists believed that AD was caused by the plaques and tangles that Alois Alzheimer spotted through his microscope in the brain tissue of a women who had been severely demented. (The tissue had been taken at autopsy.) Inside of the neurons he found neurofibrillary tangles-strands of tau protein that looked like a length of thread crammed into a ball. Between the neurons he found clumps of amyloid protein, which he dubbed amyloid plaques.

The solution seemed obvious: Get rid of the plaques and tangles. But treatments that clear the brain of these toxic proteins have failed to cure the disease, suggesting that tangles and plaques develop relatively late in the disease process.

The same may be true of other dementias. The toxic proteins they produce probably are not the cause of the problem but the consequence, and an understanding of the cause may be many years away.

In the meantime, is there anything we can do to reduce the risk of dementia?

“Pick your parents well,” says Dr. Galvin, noting that genes seem to predispose some people to dementia. In addition, exercise that promotes cardiovascular health will help deliver a generous supply of blood to the brain, providing neurons with the nutrients they need. Keeping the brain active also helps, according to Dr. Galvin.

“But that’s not absolute,” he adds. “There are astrophysicists who are also vegetarian marathoners who get dementia, and couch potatoes who don’t. But from a population perspective, those behaviors seem to afford some protection.”

Other advice: If someone diagnosed with AD doesn’t appear to have the right symptoms, voice skepticism.

“If you suspect that it’s not AD but one of these other dementias, see a neurologist, preferably a cognitive neurologist well versed in these disorders,” says Dr. Boeve. “A lot of primary care physicians haven’t been as well educated in these less common disorders, so they may not recognize them. I hear this from families all the time: My doctor diagnosed AD, but I read about AD and it doesn’t sound like AD. And they’re usually right.”

That’s why Renata Rafferty spoke to Neurology Now about her husband’s long and arduous illness: to encourage others to be skeptical of a diagnosis of Alzheimer’s disease when the symptoms don’t seem right, and to educate themselves about other dementias that the doctor may not be considering.

“I have made it my personal mission to talk to people about Lewy body dementia, she says. I have my little elevator speech ready in which I describe symptoms that are not typical of Alzheimer’s, and I don’t hesitate to suggest that people with those symptoms be evaluated for one of the other dementias.”