Tagged: results

Dementia with Lewy Bodies: New recommendations

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Last year – two years after actor Robin Williams died – his wife Susan Schneider Williams wrote an essay entitled The terrorist inside my husband’s head, published in the journal Neurology.

It is a heartfelt/heartbreaking insight into the actor’s final years. It also highlights the plight of many who are diagnosed with Parkinson’s disease, but experience an array of additional symptoms that leave them feeling that something else is actually wrong.

Today’s post is all about Dementia with Lewy bodies (or DLB). In particular, we will review the latest refinements and recommendations of the Dementia with Lewy Bodies Consortium, regarding the clinical and pathologic diagnosis of DLB.


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Robin Williams. Source: Quotesgram

On the 28th May of 2014, the actor Robin Williams was diagnosed with Parkinson’s disease.

At the time, he had a slight tremor in his left hand, a slow shuffling gait and mask-like face – some of the classical features of Parkinson’s disease.

According to his wife, the diagnosis gave the symptoms Robin had been experiencing a name. And this brought her a sense of relief and comfort. Now they could do something about the problem. Better to know what you are dealing with rather than be left unsure and asking questions.

But Mr Williams sensed that something else was wrong, and he was left unsure and asking questions. While filming the movie Night at the Museum 3, Williams experienced panic attacks and regularly forgot his lines. He kept asking the doctors “Do I have Alzheimer’s? Dementia? Am I schizophrenic?”

Williams took his own life on the 11th August 2014, and the world mourned the tragic loss of a uniquely talented performer.

Source: WSJ

When the autopsy report came back from the coroner, however, it indicated that the actor had been misdiagnosed.

He didn’t have Parkinson’s disease.

What he actually had was Dementia with Lewy bodies (or DLB).

What is Dementia with Lewy bodies?

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The next killer APP: LRRK2 inhibitors?

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In Silicon valley (California), everyone is always looking for the “next killer app” – the piece of software (or application) that is going to change the world. The revolutionary next step that will solve all of our problems.

The title of today’s post is a play on the words ‘killer app’, but the ‘app’ part doesn’t refer to the word application. Rather it relates to the Alzheimer’s disease-related protein Amyloid Precursor Protein (or APP). Recently new research has been published suggesting that APP is interacting with a Parkinson’s disease-related protein called Leucine-rich repeat kinase 2 (or LRRK2).

The outcome of that interaction can have negative consequences though.

In today’s post we will discuss what is known about both proteins, what the new research suggests and what it could mean for Parkinson’s disease.


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Seattle. Source: Thousandwonders

In the mid 1980’s James Leverenz and Mark Sumi of the University of Washington School of Medicine (Seattle) made a curious observation.

After noting the high number of people with Alzheimer’s disease that often displayed some of the clinical features of Parkinson’s disease, they decided to examined the postmortem brains of 40 people who had passed away with pathologically confirmed Alzheimer’s disease – that is, an analysis of their brains confirmed that they had Alzheimer’s.

What the two researchers found shocked them:

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Title: Parkinson’s disease in patients with Alzheimer’s disease.
Authors: Leverenz J, Sumi SM.
Journal: Arch Neurol. 1986 Jul;43(7):662-4.
PMID: 3729742

Of the 40 Alzheimer’s disease brains that they looked at nearly half of them (18 cases) had either dopamine cell loss or Lewy bodies – the characteristic features of Parkinsonian brain – in a region called the substantia nigra (where the dopamine neurons are located). They next went back and reviewed the clinical records of these cases and found that rigidity, with or without tremor, had been reported in 13 of those patients. According to their analysis 11 of those patients had the pathologic changes that warranted a diagnosis of Parkinson’s disease.

And the most surprising aspect of this research report: Almost all of the follow up studies, conducted by independent investigators found exactly the same thing!

It is now generally agreed by neuropathologists (the folks who analyse sections of brain for a living) that 20% to 50% of cases of Alzheimer’s disease have the characteristic round, cellular inclusions that we call Lewy bodies which are typically associated with Parkinson disease. In fact, in one analysis of 145 Alzheimer’s brains, 88 (that is 60%!) had chemically verified Lewy bodies (Click here to read more about that study).

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A lewy body (brown with a black arrow) inside a cell. Source: Cure Dementia

Oh, and if you are wondering whether this is just a one way street, the answer is “No sir, this phenomenon works both ways”: the features of the Alzheimer’s brain (such as the clustering of a protein called beta-amyloid) are also found in many cases of pathologically confirmed Parkinson’s disease (Click here and here to read more about this).

So what are you saying? Alzheimer’s and Parkinson’s disease are the same thing???

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Nilotinib: the other phase II trial

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In October 2015, researchers from Georgetown University announced the results of a small clinical trial that got the Parkinson’s community very excited. The study involved a cancer drug called Nilotinib, and the results were rather spectacular.

What happened next, however, was a bizarre sequence of disagreements over exactly what should happen next and who should be taking the drug forward. This caused delays to subsequent clinical trials and confusion for the entire Parkinson’s community who were so keenly awaiting fresh news about the drug.

Earlier this year, Georgetown University announced their own follow up phase II clinical trial and this week a second phase II clinical trial funded by a group led by the Michael J Fox foundation was initiated.

In todays post we will look at what Nilotinib is, how it apparently works for Parkinson’s disease, what is planned with the new trial, and how it differs from the  ongoing Georgetown Phase II trial.


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The FDA. Source: Vaporb2b

This week the U.S. Food and Drug Administration (FDA) has given approval for a multi-centre, double-blind, randomised, placebo-controlled Phase IIa clinical trial to be conducted, testing the safety and tolerability of Nilotinib (Tasigna) in Parkinson’s disease.

This is exciting and welcomed news.

What is Nilotinib?

Nilotinib (pronounced ‘nil-ot-in-ib’ and also known by its brand name Tasigna) is a small-molecule tyrosine kinase inhibitor, that has been approved for the treatment of imatinib-resistant chronic myelogenous leukemia (CML).

What does any that mean?

Basically, it is the drug that is used to treat a type of blood cancer (leukemia) when the other drugs have failed. It was approved for treating this cancer by the FDA in 2007.

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The myth of Spring babies

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In large datasets, strange anomalies can appear that may tell us something new about a condition, such as the curious association between melanoma and Parkinson’s disease.

These anomalies can also appear in small datasets, such as the idea that spring babies are more at risk of developing Parkinson’s disease. But the smaller dataset results may be a bit misleading.

In today’s post, we will look at what evidence there is supporting the idea that people born in the spring are more vulnerable to Parkinson’s disease.


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Spring lambs. Source: Wenatcheemumblog

When is your birthday?

More specifically, which month were you born in? Please feel free to leave your answer in the comments section below this post.

Why do I ask?

In 1987, an interesting research report was published in a scientific research book:

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Title: Season of birth in parkinsonism.
Authors: Miura, T., Shimura, M., and Kimura, T.
Book: Miura T. (ed) Seasonality of birth:Progress in biometeorology, 1987.p157-162. Hague, Netherlands.
PMID: N/A

In the report, the researchers outlined a study that they had conducted on the inhabitants of an asylum for the aged in Tokyo (Japan). They had found not only a very high rate of Parkinsonism (6.5% of the inhabitants), but also that the majority of those individuals affected by the Parkinsonism were born in the first half of the year (regardless of which year they were actually born).

Sounds crazy right? (excuse the pun)

And that was probably what everyone who read the report thought….

…except that one year later this independent group in the UK published a very similar result:

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The Agony and the Ecstasy

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The contents of today’s post may not be appropriate for all readers. An illegal and potentially damaging drug is discussed. Please proceed with caution. 

3,4-Methylenedioxymethamphetamine (or MDMA) is more commonly known as Ecstasy, ‘Molly’ or simply ‘E’. It is a controlled Class A, synthetic, psychoactive drug that was very popular with the New York and London club scene of the 1980-90s.

It is chemically similar to both stimulants and hallucinogens, producing a feeling of increased energy, pleasure, emotional warmth, but also distorted sensory perception. 

Another curious effect of the drug: it has the ability to reduce dyskinesias – the involuntary movements associated with long-term Levodopa treatment.

In today’s post, we will (try not to get ourselves into trouble by) discussing the biology of MDMA, the research that has been done on it with regards to Parkinson’s disease, and what that may tell us about dyskinesias.


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Good times. Source: Carwash

You may have heard this story before.

It is about a stuntman.

His name is Tim Lawrence, and in 1994 – at 34 years of age – he was diagnosed with Parkinson’s disease.

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Tim Lawrence. Source: BBC

Following the diagnosis, Tim was placed on the standard treatment for Parkinson’s disease: Levodopa. But after just a few years of taking this treatment, he began to develop dyskinesias.

Dyskinesias are involuntary movements that can develop after regular long-term use of Levodopa. There are currently few clinically approved medications for treating this debilitating side effect of Levodopa treatment. I have previously discussed dyskinesias (Click here and here for more of an explanation about them).

As his dyskinesias progressively got worse, Tim was offered and turned down deep brain stimulation as a treatment option. But by 1997, Tim says that he spent most of his waking hours with “twitching, spasmodic, involuntary, sometimes violent movements of the body’s muscles, over which the brain has absolutely no control“.

And the dyskinesias continued to get worse…

…until one night while he was out at a night club, something amazing happened:

Standing in the club with thumping music claiming the air, I was suddenly aware that I was totally still. I felt and looked completely normal. No big deal for you, perhaps, but, for me, it was a revelation” he said.

His dyskinesias had stopped.

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Higher socioeconomic status jobs

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People with high socioeconomic status jobs are believed to be better off in life.

New research published last week by the Centre for Disease Control, however, suggests that this may not be the case with regards to one’s risk of developing Parkinson’s disease.

In today’s post we will review the research and discuss what it means for our understanding of Parkinson’s disease.


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The impact of socioeconomic status. Source: Medicalxpress

In 2013, a group of researchers at Carnegie Mellon University found a rather astonishing but very interesting association:

Children from lower socioeconomic status have shorter telomeres as adults.

Strange, right?

Yeah, wow, strange… sorry, but what are telomeres?

Do you remember how all of your DNA is wound up tightly into 23 pairs of chromosomes? Well, telomeres are at the very ends of each of those chromosomes. They are literally the cap on each end. The name is derived from the Greek words ‘telos‘ meaning “end”, and ‘merοs‘ meaning “part”.

Telomeres are regions of repetitive nucleotide sequences (think the As, Gs, Ts, & Cs that make up your DNA) at each end of a chromosome. Their purpose seems to involve protecting the end of each chromosome from deteriorating or fusing with neighbouring chromosomes. Researchers also use their length is a marker of ageing because every time a cell divides, the telomeres on each chromosome gradually get shorter.

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Helicobacter pylori: Unwanted passengers?

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Whether we like it or not, we house a great deal of microbes.

Many of these tiny creatures aid us in our daily living by conducting important functions. Some of these microbes, however, may not be helping us, getting a free ride, and potentially causing trouble.

In today’s post we will review recent research regarding one particular family of bacteria, Helicobacter pylori, and what they might be doing in relations to Parkinson’s disease.


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Source: ScienceFriday

In his magnificent book, I contain multitudes, science writer/journalist Ed Yong writes that we – every single one of us – release approximately 37 million bacteria per hour. By talking, breathing, touching, or simply being present in the world, we are losing and also picking up the little passengers everywhere we go.

Reminds me of that Pascal Mercier book “Night Train to Lisbon” – We leave something of ourselves behind when we leave a place,… I’m not sure if this is what he was referring to though.

Yong also points out that: 80% of the bacteria on your right thumb are different to the bacteria on your left thumb.

It’s a fascinating book (and no, I am not receiving any royalties for saying that).

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Microbes. Source: NYmag

We have discussed microbes several times on this blog, particularly in the context of the gut and its connection to Parkinson’s disease (Click here, here and here to read some of those posts). Today we are going to re-visit one particular type of microbe that we have also discussed in a previous postHelicobacter pylori.

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Helicobacter pylori. Source: Helico

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DBS2.0: Look mum, no electrodes!

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Deep brain stimulation is a surgical procedure that can provide immediate motor-related benefits to people with Parkinson’s disease.

The approach involves placing electrodes deep inside the brain. This procedure requires invasive surgery and there are no guarantees that it will actually work for everybody.

Recently, researchers at MIT have devised a new technique that could one day allow for a new kind of deep brain stimulation – one without the electrodes and surgery.

In today’s post we will review the science behind deep brain stimulation and the research leading to non-invasive deep brain stimulation.


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Source: Youtube

In 2002, deep brain stimulation (or DBS) was granted approval for the treatment of Parkinson’s disease by the US Food and Drug Administration (FDA). The historical starting point for this technology, however, dates quite far back…

Further back than many of you may be thinking actually…

In his text “Compositiones medicamentorum” (46 AD), Scribonius Largo, head physician of the Roman emperor Claudius, first suggested using pulses of electricity to treat afflictions of the mind.

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Roman emperor Claudius. Source: Travelwithme

He proposed that the application of the electric ray (Torpedo nobiliana) on to the cranium could be a beneficial remedy for headaches (and no, I’m not kidding here – this was high tech at the time!).

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Torpedo nobiliana. Source: Wikipedia

These Atlantic fish are known to be very capable of producing an electric discharge (approximately 200 volts). The shock is quite severe and painful – the fish get their name from the Latin “torpere,” meaning to be stiffened or paralysed, referring specifically to the response of those who try to pick these fish up – but the shock is not fatal.

Now, whether Largo was ever actually allowed to apply this treatment to the august ruler is unknown, and beyond the point. What matters here is that physicians have been considering and using this approach for a long time. And more recently, the application of it has become more refined.

What is deep brain stimulation?

The modern version of deep brain stimulation is a surgical procedure in which electrodes are implanted into the brain. It is used to treat a variety of debilitating symptoms, particularly those associated with Parkinson’s disease, such as tremor, rigidity, and walking problems.

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An interesting commentary on the interpretation of the Nilotinib trial results

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“The devil is in the detail”

A frequently used quote and sage words when analysing scientific data, especially clinical trial data.

Nilotinib is a cancer drug from Novartis that has the Parkinson’s community very excited. In October 2015, researchers at Georgetown University announced that a phase 1 open-label clinical study involving 12 people with Parkinson’s had demonstrated some pretty impressive results (click here to read more about this). The results of that first clinical trial have been published (click here to read more on this), but follow up studies have been hampered by study design issues (click here for more on this).

Today a letter to the editor of the Journal of Parkinson’s disease (published in this months issue) was brought to our attention (click here to read the letter). It queries one important aspect of the results from that first Nilotinib clinical trial for Parkinson’s disease.

In the letter, Prof Michael Schwarzschild of Massachusetts General Hospital (Boston) notes that 8 of the 11 subjects in the study had their monoamine oxidase-B (MAO-B) inhibitor treatment withdrawn less than a month after starting the trial. The change of treatment regime was made due to “increased psychosis in the first 2–4 weeks after Nilotinib administration”.


For reasons which we will outline below, a small change like this in a clinical trial could have major implications for the end results.

What are MAO-B inhibitors?

After the chemical dopamine is used by a neuron, it is reabsorbed by the dopamine cell and broken down for disposal. MAO-B is the enzyme that breaks down dopamine.

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Selegiline is an example of a MAO-B inhibitor. Source: KnowMental

As the schematic above illustrates, dopamine is released by dopamine neurons and then binds to a receptor on a neighbouring cell. After this process has occurred, the dopamine detaches and it is reabsorbed by the dopamine neuron via a particular pathway called the dopamine transporter. Back inside the dopamine cell, dopamine is quickly broken down by the enzyme MAO-B into 3,4-Dihydroxyphenylacetic acid (or DOPAC).

Now, by blocking MAO-B, more dopamine is left hanging around inside the cell where it can be recycled and used again. Thus, this blockade increases the level of dopamine in the brain, which helps with alleviating the motor features of Parkinson’s disease. This simple concept has lead to the development of MAO-B inhibitors which are used in the treatment of the condition.

Why is this important to the Nilotinib results?

Dopamine is broken down by MAO-B into DOPAC. DOPAC can be further broken down into Homovanillic acid (HVA), and both DOPAC and HVA are often used in research studies to indicate levels of dopamine activity. Higher levels of both (in theory) should indicate higher levels of dopamine. It is a means of inferring greater dopamine production.

In the published results of the Nilotinib clinical trial, the researchers used increased HVA levels as an indication of greater dopamine production as a result of taking Nilotinib. But Prof Schwarzschild is correct in providing a cautionary warning of over-interpreting this result. You see, by discontinuing the treatment of MAO-B inhibitors shortly after starting the study, one would expect to see a rise in HVA levels regardless of any effect Nilotinib may be having. Without the MAO-B inhibitors, more dopamine will be broken down thus resulting in increased levels of HVA (compared to the baseline measurements at the start of the study).

And this issue is particularly important since HVA measurements taken at the start of the study (before the MAO-B inhibitors were removed) were compared with HVA measurement taken at the end of the study.

Another commentary discussing the Nilotinib results published in July of last year (in the same journal) actually questioned the value of measuring HVA levels, saying that prior studies have suggested that HVA levels can vary greatly between subjects at similar disease stages, and in general do not correlate well with disease progression.

Whether the removal of MAO-B inhibitors alters the overall interpretation of the first clinical study results is a subject for debate. Something interesting did appear to be happening in the participants involved in the first trial (whether this could have been a placebo effect could also be debated). Obviously, as Prof Schwarzschild’s letter indicates, what we really require now is a carefully designed, placebo-controlled, randomised clinical trial to determine if the initial results can be replicated.

And we are still awaiting news regarding a start date for that delayed trial.

The GDNF trial (Bristol) initial results

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We learned today that the phase 2 GDNF clinical trial in Bristol (UK) has failed to meet the primary efficacy end point. That is to say, the initial results suggest that the drug has not worked. In this post we will review what we know and discuss what will happen next.


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GDNF was pumped into the striatum (green area). Source: Bankiewicz lab

We have previously discussed GDNF and Parkinson’s disease (Click here to read that post). This drug was considered the great hope for Parkinson’s disease and a lot was riding on the results. Today’s announcement is extremely unwelcomed news, but it is not necessarily the end of the road for GDNF.

What is GDNF?

Glial cell-derived neurotrophic factor (or GDNF) is a neurotrophic factor (neurotrophic = Greek: neuron – nerve; trophikós – pertaining to food/to feed). It is a chemical produced in the brain. GDNF has previously been found to have miraculous effects on some of the neurons in the brain that are most affected by Parkinson’s disease (particularly the dopamine neurons).

Given the amazing results in laboratories around the world, clinical trials were set up for people with Parkinson’s disease. The first study had astounding results, but a larger follow up study failed to replicate those results and so a third GDNF clinical trial was initiated: the Bristol GDNF study

What is the Bristol GDNF study?

The Bristol GDNF study run by the the North Bristol NHS Trust, was funded by Parkinson’s UK, with support from The Cure Parkinson’s Trust. The company MedGenesis Therapeutix supplied the GDNF and additional project resources/funding. MedGenesis Therapeutix itself has funding support from the Michael J. Fox Foundation for Parkinson’s Research.

The study involved participants having GDNF (or a placebo drug) pumped directly into their brains, into an area called the putamen. The putamen is where the greatest loss of dopamine occurs in people with Parkinson’s disease.

All together there were 41 people with Parkinson’s disease enrolled in the clinical trial. The trial was divided into two phases and the first of those is now complete. During the first phase 35 participants received either GDNF or a placebo drug over 9-months in a double blind fashion

What does double blind mean?

It means that neither the researchers nor the participants know which drug they are receiving. Everyone is ‘blind’ to the treatment. Single blind studies involve the researchers being aware of the treatment allocation, but the participants are blind. Single blind studies can be affected by what is called ‘investigator bias’ – where the investigators start to think that they see an effect when there may not be an effect. Double blind is considered the gold standard, but there are problems with this type of study as well.

If phase one has finished what is phase two of the trial?

The second phase of the study will involve all participants receiving GDNF. This part is already underway.

What was the “primary efficacy end point”?

The press release from the company behind the study, MedGenesis, suggested that:

‘The primary endpoint of the study is the percentage change from baseline in the practically defined OFF-state Unified Parkinson’s Disease Rating Scale (UPDRS) motor score (part III) after nine months of double-blind treatment’

With the limited information we currently have, we are assuming that the researchers were looking for a significant improvement in the motor symptoms rating scale (‘UPDRS’) of the subjects when compared to how they were at the start of the trial (‘baseline’). The subject’s motor features were assessed during periods when they were not taking their medication (‘OFF-state’), and the initial indications are that the researchers failed to see any improvement.

Is this negative result the end of the world?

NO. Most definitely not.

There are many reasons why the trial may have failed to achieve its primary end point, and the researchers have emphasized that they need time to analyse all of the results. It will be interesting to see the final analysis (and we will summarise it here when it is available – end of 2016 apparently).

It will also be important to follow up the participants to determine if there are any delayed positive outcomes. It may take longer than 9 months to see improvements (fetal transplant studies, for example, usually require 2-3 years before improvements are observed).

 

Maybe GDNF just needs a bit more time. We will keep you updated as more information comes to hand.


For more on the study, please see Parkinson’s UK and MedGenesis.