JUNE 2009


30th June 2009 - New research


Around 25% of Annals of Neurology [2009] 65 (5) : 586-595 (Okun MS, Fernandez HH, Wu SS, Kirsch-Darrow L, Bowers D, Bova F, Suelter M, Jacobson CE 4th, Wang X, Gordon CW Jr, Zeilman P, Romrell J, Martin P, Ward H, Rodriguez RL, Foote KD.) Complete abstract 

Deep Brain Stimulation (DBS)
involves the use of electrodes that are implanted into the brain and connected to a small electrical device called a pulse generator that can be externally programmed. DBS can reduce the need for L-dopa and related drugs.  For more information go to Deep brain stimulation. The two most common sites in the brain used for Deep Brain Stimulation (DBS) are the subthalamic nucleus (STN) and the globus pallidus interna.

This study compared the effects of the two main types of DBS. There was no difference between the two methods in physical movement on the main Parkinson's Disease score (the UPDRS). The effect on mood and intellectual function was similar for both methods. Worsening of verbal fluency was seen in STN. The deterioration in verbal fluency in the off STN DBS state was suggestive of a surgical effect rather than due to the stimulation. Adverse mood effects occurred in both types. The direction of the surgical method (either optimal, dorsal or ventral) also had effect, as subjects in both types were less happy, less energetic and more confused when stimulated ventrally. In order to refer to this article on its own click here.


29th June 2009 - New book


Carrie Fredericks

Publisher's description : These unique anthologies provide accessible information about diseases and disorders, focusing on controversies and first-person accounts. Each volume explores a particular disease or disorder in detail, beginning with an overview chapter that covers symptoms, causes and effects, treatments, cures and medical advances. The second chapter presents essays on controversies surrounding the disorder, including its causes and treatments. The final chapter, which contains engaging first-person accounts from people coping with the disease, provides readers with personal perspectives on the disease or disorder. Click here for more details, and here for contents. For more books concerning Parkinson's Disease go to Parkinson's Disease Books.


24th June 2009 - New research


European Journal of Neurology [2009] Jun 15 [Epub ahead of print] (Mylne AQ, Griffiths C, Rooney C, Doyle P.) Complete abstract 

A study carried out in Britain has shown that mortality rates in Parkinson's Disease are declining. Mortality rates were assessed by checking for any mention of Parkinson's Disease on death certificates. The mortality rates amongst men with Parkinson's Disease decreased by over 20%. The mortality rates amongst women with Parkinson's Disease also decreased by over 20%. Even greater reductions in mortality rates were found in older people with Parkinson's Disease.

The researchers are unable to ascertain whether the decrease of Parkinson's Disease recorded on death certificates is because of a reduction in the incidence of Parkinson's Disease, improved survival due to advancements in Parkinson's Disease treatments, or to improvements in general medical care. Research earlier this year showed that claims of death being much more likely in Parkinson's Disease are greatly exaggerated. For more information click here. After 10 years of Parkinson's Disease, the death rate actually remained lower than for people without Parkinson's Disease. In order to refer to this article on its own click here.

                                                                                                                                                                              19th June 2009 - New research


Journal of neuropathology and experimental neurology [2009] Jun 16. [Epub ahead of print] (Markesbery WR, Jicha GA, Liu H, Schmitt FA.) Complete abstract 

Lewy bodies are often claimed to be the hallmark of Parkinson's Disease. Lewy bodies are basically rubbish bins in the nerve cells, that accumulate debris caused by cell damage. For more information and links go to Lewy Bodies. It is claimed that Lewy Bodies can cause Parkinson's Disease by interfering with the formation of dopamine, and also cause dementia by interfering with the formation of acetylcholine. So researchers assessed the prevalence of Lewy Bodies in people that did not have Parkinson's Disease or dementia, by carrying out autopsies. None of the people assessed had Parkinson's Disease. However, nearly a quarter of the brains were found to include Lewy Bodies in various regions of the brain. This finding contradicts the assertion that Lewy Bodies cause Parkinson's Disease,
because so many people have Lewy Bodies without having Parkinson's Disease.

It has also been previously found that there are many people with Parkinson's Disease that do not have Lewy Bodies either. The researchers still claimed Lewy Bodies "most likely represents preclinical or pre-symptomatic Parkinson disease, Parkinson disease with dementia, or dementia with Lewy bodies." However, their own findings contradict their own suggestion. Rather than Lewy Bodies cause Parkinson's Disease, the results show that Parkinson's Disease, and other medical disorders can sometimes cause Lewy Bodies. In order to refer to this article on its own click here.


17th June 2009 - New research


European journal of nuclear medicine and molecular imaging [2009] 36 (3) : 454-462 (Eshuis SA, Jager PL, Maguire RP, Jonkman S, Dierckx RA, Leenders KL.) Complete abstract 

Around 25% of people with Parkinson's Disease are wrongly diagnosed, due to the diversity of symptoms and the coincidence with other medical disorders. There are two methods of scanning the brain that enable the diagnosis of Parkinson's Disease by measuring the activity of dopamine in the brain : the
SPECT scan and the PET scan.

The aim of this study was to determine and compare the sensitivity and specificity of the two methods in the diagnosis of Parkinson's Disease. The patients underwent both types of brain scan. The SPECT scan and the PET scan were both able to distinguish people with Parkinson's Disease. For the early phases of Parkinson's Disease, sensitivity and specificity was 100%. When only one part of the brain was assessed, the accuracy was still 100% for the SPECT scan, but was 90% for the PET scan. This level of efficacy makes scanning, especially the SPECT scan, the most reliable method of diagnosing Parkinson's Disease.  In order to refer to this article on its own click here.


14th June 2009 - New research


Lancet Neurology [2009] Jun 9 [Epub ahead of print] (Aarsland D, Ballard C, Walker Z, Bostrom F, Alves G, Kossakowski K, Leroi I, Pozo-Rodriguez F, Minthon L, Londos E.) Complete abstract 

The biochemistry of Dementia is completely distinct from that of Parkinson's Disease. However, dementia often occurs alongside Parkinson's Disease. Researchers tested the safety and efficacy of Memantine (an N-methyl D-aspartate [NMDA] receptor antagonist) in people with Parkinson's Disease Dementia.

The primary measure of efficacy was clinical global impression of change (CGIC), which is not a precise measure of symptoms. It was concluded that "Patients with Parkinson's Disease Dementia might benefit from treatment with memantine, which was well tolerated" but that "Large-scale studies are now required to confirm" the preliminary findings. However, nearly a quarter of the participants did not complete the study due to adverse events, the difference in scores between those people taking Memantine and those taking a placebo was very marginal, there were no significant differences between the groups in secondary measures, and no comparison was made of the side effects caused by taking Memantine. In order to refer to this article on its own click here.


12th June 2009 - New research


Archives of Ophthalmology [2009] 127 (6) : 737-741 (Hajee ME, March WF, Lazzaro DR, Wolintz AH, Shrier EM, Glazman S, Bodis-Wollner IG.) Complete abstract 

People with Parkinson's Disease have been found to suffer a thinning of the retina. The retina is a light sensitive tissue lining the inner surface of the eye that is essential for vision. For more information about the retina go to Retina. A study quantified the thickness of the retina in people with Parkinson's Disease. No difference was found in the thickness of the outer retinal layer in Parkinson's Disease, when compared to people of the same age that don't have Parkinson's Disease. However, the thickness of the inner layer of the retina was found to be significantly reduced in Parkinson's Disease. This lessening of the retina could affect eyesight as Parkinson's Disease progresses. This effect on the retina may be because dopamine, whose deficiency causes Parkinson's Disease, besides being produced in the brain, is also produced in the retina, and so is liable to cause deficiency symptoms there as well. In order to refer to this article on its own click here.


11th June 2009 - New research


Annals of Human Genetics [2009] May 21 [ahead of print] (PaisŠn-Ruiz C, Washecka N, Nath P, Singleton AB, Corder EH.) Complete abstract 

There are a number of genetic forms of Parkinson's Disease that can incline somebody towards Parkinson's Disease rather than inevitably cause it. It has previously been assumed that the number of people with Parkinson's Disease that are genetically inclined towards developing symptoms in this way was relatively small. However, researchers have found that just one of these genetic forms of Parkinson's Disease occurs in a third of people with Parkinson's Disease. Given that there are other genes that can incline somebody towards Parkinson's Disease means that the
number of people genetically inclined towards Parkinson's Disease is far more than previously thought.

The gene is called LRRK2 (leucine risk repeat kinase 2), which produces a protein called dardarin, a word derived from the Basque word dardara, meaning tremor. Mutations in LRRK2 are a common cause of familial Parkinsonís disease. A combination of four gene variants are found in a third of people with Parkinsonís Disease, but they are infrequent in the general population. This advance is expected to enable the identification of people at the greatest risk of Parkinson's Disease before symptoms arise. In order to refer to this article on its own click here.


6th June 2009 - New review


It is widely claimed that there is a massive loss of the cells involved in Parkinson's Disease (the dopaminergic neurons), and that the loss of these cells is responsible for causing Parkinson's Disease. However, not a single study has ever shown this. This false assumption came about during the 1990's after researchers carried out autopsy studies on people that had Parkinson's Disease. They mistakenly claimed that they had found a considerable loss of the cells that produce dopamine. However, their methods did not even measure cell loss. They measured cell activity instead.

Their results and methods of those of others have shown that, in Parkinson's Disease, there is a large reduction in the activity of the dopaminergic neurons rather than a loss of them - down to about 20%-25% in mild Parkinson's Disease, and down to 5%-10% in severe Parkinson's Disease. There have been subsequent claims of massive cell loss in Parkinson's Disease. However, those claims have also been based on methods, such as the f-Dopa PET scan, that only measure cell activity rather than actual cell loss. Failure to properly scrutinise these studies has enabled the myth of massive cell loss in Parkinson's Disease to persist and become a prevalent assumption - even though not a single study has ever shown it to be true.  In order to refer to this article on its own click here.


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