News Round-Up: May 2009 4th Edition

In this week’s news round-up there has been further clarification of the subtypes of Frontotemporal Lobar Degeneration and also another study looking at discriminating amnestic and non-amnestic executive mild cognitive impairment. A big finding that was reported this week was the discovery of a fossil (although it was initially brought to the attention of researchers a few years ago) primate ancestor from a site in Germany – the specimen is known as Ida. This was an intact specimen which  allows researchers a glimpse into how primate evolution compared with that of other mammals.

Research in Dementia

In the KAME project, 1836 people with a mean age of 71.8 years were followed-up and there was found to be a significant association between rapidly declining BMI or higher baseline BMI and subsequent development of dementia (Hughes et al, 2009)(STT4). Early insulin response to a glucose challenge was significantly associated with conversion to dementia in this prospective cohort study (Rönnemaa et al, 2009)(STT4). A further clarification of the clinical subtypes of frontotemporal lobar degeneration (FTLD) has been published in a study which included 39 people with tau positive FTLD. Among the findings, the researchers found that type I in which there was a progressive non-fluent  was associated with neuronal cytoplasmic inclusions and dystrophic neurites (Josephs et al, 2009)(STT3). Performance on a colour discrimination task was found to be inversely correlated with MMSE scores in this cross-sectional comparison of 20 people with Alzheimer’s disease compared to controls (Salamone et al, 2009)(STT4). A review paper looked at the role of disordered proteins in dementia (Raychaudhuri et al, 2009). GluR1/2 antigen reactive antibodies were found to be associated with a paraneoplastic limbic encephalitis and thought to mediate their action through AMPA receptors (Lai et al, 2009). Dysexecutive MCI and amnestic MCI could be distinguished by patterns of brain atrophy in one study (Pa et al, 2009). Rivastigmine was found to be associated with no significant decrease in white matter volume over a 20-week period in one report (Venneri et al, 2009). An EEG study provided evidence that thalamocortical circuit functioning discriminated people who did and did not convert to dementia (Cantero et al, 2009). The researchers in one study found that the clock drawing test was a useful additional measure for discriminating between people with Alzheimer’s Disease and Parkinson’s Disease with Dementia (Saka and Elibol, 2009).

News in Brief

An important finding that has been discussed this week is a 47-million year old lemur-like primate ancestor of humans – Ida with forward facing eyes reported on here and here.

The author of a thesis using data from the H70 study, a scandinavian follow-up study of 70 year olds concluded that tests that assessed memory were most likely to predict conversion from non-dementia to dementia and that higher levels of education were making it more difficult to establish a diagnosis of dementia at an early stage. Evidence from one study suggests that sleep apnoea is underdiagnosed in people with diabetes II and obesity. A marker within the von Willebrand factor gene was found to be significantly associated with depression in people with cardiovascular disease . It wold be interesting to see if such cases were more likely to be classed as vascular depression. An fMRI study by Dr Graham Murray and colleagues provided evidence of an association between a measure of  sociability and orbitofrontal cortical thickness (here and here). A gene whose product confers resistance to the effects of alcohol and blocks the epidermal growth factor pathway in flies is suggested as a potential therapeutic target for alcohol misuse. A Canadian study provided evidence that men were underusing mental health services and that 10% of people were using services much less than the percentage of the population that would be expected to be experiencing mental illness.

A web-based program was found to be effective in a randomised-controlled trial in reducing alcohol consumption in a group of people who used the program and a reduction was maintained at follow-up. In a web-based survey of readers of a popular magazine which included 700 women aged 18-50, 60% of respondents indicated that they would spend more money if they were feeling low in mood. 70% of women also indicated that they wanted more control over the spending. The full report can be found here on the Sheconomics website where Professor Pine looks at some of the triggers for shopping (triggers for shopping from an evolutionary psychology perspective have also been written about elsewhere), the possible economic implications and the ‘seven laws of sheconomics’ a set of practical rules for managing spending and finances. Now someone needs to repeat the study with men! The authors of a paper suggest that online learning is changing the role of the learner from that seen in the typical teacher-pupil role to one in which the learning is more self-directed with implications for how online courses might be developed. The authors of a recent study identified a small percentage of people termed ‘super-recognisers’ who are able to identify and recall faces at a rate far greater than average. Since many psychometric properties are normally distributed this shouldn’t be surprising although the neurobiological explanation may have many implications. The authors consider this as being the reverse of prosopagnosia which is an impairment in the ability to recognise faces. Indeed in certain social situations this skill was sometimes concealed. Another study provided evidence of a role for synaptotagmin-IV (Syt-IV) in maintaining homeostasis in memory formation through Long Term Potentiation (LTP). The researchers found that if they modified the levels of Syt-IV they could produce a corresponding change in LTP and that an optimal range was identifed.

A team have identified a group of proteins – MAGUK Associated Signalling Complexes using a new method in which they were able to remove and identify aggregated proteins with a neuronal synapse. A combined MRI and MEG study showed an association between GABA levels and frequency of gamma oscillations when subjects were presented with a visual stimulus and the authors suggest that gamma oscillation frequency could be used as a marker of GABA levels. Mice with a disrupted calcium channel receptor didn’t gain weight on a high-fat diet and this same receptor has been associated with maintenance of the sleep-wake cycle suggesting a molecular link between the two and a potential target for treatment of sleep disorders or for weight dysregulation.

An intriguing study is underway into developing robots that operate in the home environment as companions and the researchers are looking at how comfortable people feel having them around. As such machines are not yet pervasive or ‘accepted’ within culture, it will perhaps take some time for their other applications to be developed but there are many potential mental health applications.

References

Cantero JL, Atienza M, Gomez-Herrero G, Cruz-Vadell A, Gil-Neciga E, Rodriguez-Romero R, Garcia-Solis D. Hum Brain Mapp. 2009 May 15. [Epub ahead of print]. Functional integrity of thalamocortical circuits differentiates normal aging frommild cognitive impairment.

Hughes TF, Borenstein AR, Schofield E, Wu Y, Larson EB. Neurology. 2009 May 19;72(20):1741-6.Association between late-life body mass index and dementia: The Kame Project.

Josephs KA, Stroh A, Dugger B, Dickson DW. Acta Neuropathol. 2009 May 20. [Epub ahead of print]. Evaluation of subcortical pathology and clinical correlations in FTLD-U subtypes.

Lai M, Hughes EG, Peng X, Zhou L, Gleichman AJ, Shu H, Matà S, Kremens D, Vitaliani R, Geschwind MD, Bataller L, Kalb RG, Davis R, Graus F, Lynch DR, Balice-Gordon R, Dalmau J.Ann Neurol. 2009 Apr;65(4):424-34. AMPA receptor antibodies in limbic encephalitis alter synaptic receptor location.

Pa J, Boxer A, Chao LL, Gazzaley A, Freeman K, Kramer J, Miller BL, Weiner MW,Neuhaus J, Johnson JK.Ann Neurol. 2009 Apr;65(4):414-23. Clinical-neuroimaging characteristics of dysexecutive mild cognitive impairment.

Raychaudhuri S, Dey S, Bhattacharyya NP, Mukhopadhyay D.PLoS ONE. 2009;4(5):e5566. Epub 2009 May 15. The role of intrinsically unstructured proteins in neurodegenerative diseases.

Rönnemaa E, Zethelius B, Sundelöf J, Sundström J, Degerman-Gunnarsson M, Lannfelt L, Berne C, Kilander L. Diabetologia. 2009 May 20. [Epub ahead of print]. Glucose metabolism and the risk of Alzheimer’s disease and dementia: a population-based 12 year follow-up study in 71-year-old men.

Saka E, Elibol B. Parkinsonism Relat Disord. 2009 May 14. [Epub ahead of print]. Enhanced cued recall and clock drawing test performances differ in Parkinson’s and Alzheimer’s disease-related cognitive dysfunction.

Salamone G, Di Lorenzo C, Mosti S, Lupo F, Cravello L, Palmer K, Musicco M, Caltagirone C.Dement Geriatr Cogn Disord. 2009 May 15;27(6):501-507. [Epub ahead of print]. Color Discrimination Performance in Patients with Alzheimer’s Disease.

Venneri A, Lane R. Neuroreport. 2009 Feb 18;20(3):285-8. Effects of cholinesterase inhibition on brain white matter volume in Alzheimer’s disease.

Steps To Treatment (STT)

STT = Steps To Treatment. An estimate of the number of steps between the results and translation into treatment. This is an opinion.

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.