News Round-Up: March 2011 3rd Edition

Dementia

There is a write-up of the 2011 International Conference on Alzheimer’s and Parkinson’s Disease in Barcelona at the Alzheimer’s Research Forum. Feedback from the conference includes a more critical discussion of the Amyloid hypothesis as well as a consideration of multimodal therapeutic approaches. There was a post-mortem study comparing brains of 4 people with Down Syndrome (average age 66) with 6 controls (average age 70). As Down Syndrome is associated with age related degenerative changes, this study was able to provide useful information in describing age related changes more accurately. The researchers were interested in the number of glial and neuronal cells in the neocortex in both groups using stereological analysis which means estimating 3-dimensional information about the brain from 2-dimensional microscopic slices. Based on their analysis the researchers estimated that in the brains of the sample group with Down Syndrome there were 30% less glial cells and 40% less neuronal cells than in the control group. Interestingly there were similar numbers of cells in the Basal Ganglia in both groups. This may represent a combination of neurodevelopmental and neurodegenerative processes and it will be interesting to how these results might be influenced by therapeutic interventions in future studies. The researchers in a recent case-control study in Spain (n=690) concluded from their analysis that variations in the Amyloid Precursor Protein gene did not contribute to risk of Late Onset Alzheimer’s Disease (LOAD) in their sample group although effect sizes can be small. A Spanish group write about their experience of a 3-year longitudinal study of Mild Cognitive Impairment. Although there is a body of evidence relating amnestic MCI with conversion to Alzheimer’s Disease in their study, the researchers found this was more likely to be associated with multi-domain MCI. An American group have published research in which they identify a syndrome which precedes MCI and which they refer to as Pre-MCI. For those with Pre-MCI 28% converted to MCI or dementia at 3-year follow-up whereas only 5% converted in the Non-Cognitive Impaired group. The researchers identified Pre-MCI as

‘At baseline, Pre-MCI subjects showed impairment on tests of executive function and language, higher apathy scores, and lower left hippocampal volumes (HPCV) in comparison to NCI subjects‘

The researchers in a small German neuroimaging study (n=31) provided evidence of a relationship between connectivity in frontal-parietal networks and attention (assessed using the Attentional Network Task)  in people with early Alzheimer’s Disease. A moderately sized study (n=239) in a sample of people over the age of 85 showed a significant inverse correlation between intracranial volume, which the researchers used as a proxy marker of premorbid brain volume and risk of Dementia and more specifically Alzheimer’s Disease and Vascular Dementia. Interestingly in the group with the largest intracranial volume, dementia risk was not associated with white matter lesions. There is a write-up of the 2010 Leon Thal Symposium which covered amongst other subjects the establishment of a registry as well as approaches to data gathering. An American group have estimated the incidence of dementia and cognitive impairment not-dementia in the USA and over a 6 year period they estimate that there are 1.4 times as many incident cases of dementia cognitive impairment not-dementia as cases of dementia cognitive impairment not-dementia. NICE have just published their revised Technology Appraisal for drugs for Alzheimer’s Disease here.

Miscellaneous

There is a write-up of one study which provides preliminary evidence of a benefit from Transcranial Magnetic Stimulation in post-stroke dysphagia. This was a small trial and it will be interesting to see the results of further studies in this area. One cross-sectional study provided evidence of a positive correlation between hippocampal volume and recovery from PTSD in war veterans although replication of these findings with a longitudinal design is needed.

Index: An index of the site can be found here. The page contains links to all of the articles in the blog in chronological order. Twitter: You can follow ‘The Amazing World of Psychiatry’ Twitter by clicking on this link. Podcast: You can listen to this post on Odiogo by clicking on this link (there may be a small delay between publishing of the blog article and the availability of the podcast). It is available for a limited period. TAWOP Channel: You can follow the TAWOP Channel on YouTube by clicking on this link. Responses: If you have any comments, you can leave them below or alternatively e-mail justinmarley17@yahoo.co.uk. Disclaimer: The comments made here represent the opinions of the author and do not represent the profession or any body/organisation. The comments made here are not meant as a source of medical advice and those seeking medical advice are advised to consult with their own doctor. The author is not responsible for the contents of any external sites that are linked to in this blog.