News Round-Up: May 2009 2nd Edition

Research in Dementia

The authors of one study concluded that of four executive functions, verbal fluency was the best indicator of the processes involved in regulating emotions.  Participants in this study included a small control group (n=17) and people with Frontotemporal Lobar Degeneration and Alzheimer’s disease.  They used the startle response as a proxy measure of emotional regulation although ecologically, emotions are regulated in various sometimes complex scenarios which can involve more than one emotion. Therefore the generalisability of such results is complex itself (Gyurak et al, 2009)(STT5).  Using Diffuse Tensor Imaging, a group in America have identified pathways in humans between the amygdala and the mid-fusiform gyrus as well as the hippocampus and the mid-fusiform gyrus which potentially explains the findings of some fMRI studies in which subjects were presented with emotionally valued stimuli (Smith et al, 2009)(STT4).  In another study serum antibodies against ABeta (IgM) did not significantly discriminate between people with Alzheimer’s disease and people with mild cognitive impairment or healthy controls (Marcello et al, 2009).  An American team has taken MRI images from the Alzheimer’s Disease Neuroimaging Initiative and developed a pattern classifier that discriminates people with Alzheimer’s disease from controls and then applied this to longitudinal data from the Baltimore longitudinal study of ageing neuroimaging study. The authors go on to suggest that this method can be successfully used to discriminate controls that will go on to develop cognitive decline from those that will not (Davatzikos et al, 2009)(STT4).  A group from Pennsylvania have used MRI volumetric data to examine neuropsychological correlates and the findings were in keeping with the literature including dysexecutive function related to bilateral prefrontal cortical atrophy.  Interestingly the authors also found evidence to support the concept of ” double dissociation” (Listerud et al, 2009)(STT4).  In a post-mortem study of 10 cases of post-encephalitic parkinsonism there was found to be an absence of alpha synuclein deposits (Jellinger, 2009).

Research in Psychosis

In a six week double-blind randomised placebo controlled study of Paliperidone Extended-Release versus Quetiapine in people with a recent exacerbation of schizophrenia only Paliperidone Extended-Release was significantly better than placebo in improving PANSS scores at two weeks (Canuso et al, 2009)(STT4). A Nigerian study looked at quality of life in people with schizophrenia using the WHOQOL-BREF.  The research is found but er in their sample of 99 people 21% were classed as having a ‘good’  quality of life and and 36% having a ‘poor’ quality of life.  Several factors correlated with quality of life measures including medical conditions, unemployment and social support which are suggested as factors that could be addressed (Adewuya and Makanjuola, 2009)(STT3).

Miscellaneous research

The Norwegian study combining data on over four million prescriptions of psychotropic medication with general practitioner identified 705230 people taking at least one psychotropic medication. This represented just over 15 per cent of the population.  2.4% were prescribed antipsychotics.  The mean annual drug volume peaked in those aged 40 to 59 while four hypnotics it continued to increase.  Interestingly 80% of the psychotropic drug volume was prescribed by General Practitioners (Kjosavik et al, 2009)(STT3).  Greater purpose in life were significantly associated with a reduction in all causes of mortality in a community study of elderly people (n=1238)(Boyle et al, 2009)(STT4).

News in Brief

The authors of a Swedish study provided evidence of malnutrition in 14.5 % of people aged 75 and 80 living at home.  The risk of malnutrition was associated with depression and perception of health. Another study provided evidence of an impairment in prioritising information for learning in people with Alzheimer’s Disease compared to healthy controls. An association has been found between the Neuroglobin gene and risk of Alzheimer’s disease has been identified in one study. Increased levels of Neuroglobin were found in people with Alzheimer’s disease compared to controls and previous research has suggested a protective role Neuroglobin.A potentially important study may cause a re-evaluation of glutamate induced cell death.  Glutamate induced cell death in retinal cells could be modified by interfering with signals in the local glial cells.  This type of cell death is implicated in optic neuropathy he’s but also speculated to be one of the many mechanisms that can play a role in dementia. In a secondary analysis the authors of one paper found that delirium was associated with an accelerating rate of decline in people with Alzheimer’s disease. Indirect evidence has been provided a possible role for the gene HDAC2 in Alzheimer’s disease.  HDAC stands for Histone Deacetylase.  DNA is tightly coiled around Histones and D acetylation the of Histones would influence the coiling process.  In mice an inhibitor of HDAC2 produce an improvement in memory formation and recall.

A genome-wide analysis, found evidence of an association between a T-cell variant and narcolepsy, which builds upon another association with narcolepsy –  the HLA gene.  Researchers are speculating that the T-cell variants and the HLA gene might interact in the pathogenesis of narcolepsy. An interesting study which traverses numerous domains, provides evidence of a role for a variant of a potassium channel gene referred to as KCNH 2 in schizophrenia.  The variant 3.1 isoform was identified from a post-mortem study where it was identified as being 2.5 times more prevalent in people with schizophrenia than controls in the hippocampus.  Healthy controls who carried the variant were identified and found to have significantly lower measures on IQ tests.  They also showed differences from non-carriers in hippocampal activity on fMRI studies involving memory. Moderate alcohol consumption was associated with a significant decrease in vigilance in a reading task as well as reduced insight into this deficit.

Another study provided evidence that five month old babies generate hypotheses based on observational data of babies presented with solids or liquids behaving differently. A study which looked at teenagers in a driving stimulation bounds that sending text messages on a mobile phone was associated with significant variations in speed and course and associated virtual accidents. Another study looked at tensions parent-child relationships looking at how factors such as gender and age impact on tension. In particular they found that ‘unsolicited advice’ from parents was associated with tension. In a qualitative study which involved focus groups and a semi-structured interview of 17 women who had recently been in jail the researchers found evidence that being an ex-prisoner and also an ex-substance user is associated with a double stigma which interacted with social policies to limits the perception of available choices. Evidence in an in vitro study but suggests that lithium may protect cells from radiation-induced injury by influencing DNA repair mechanisms while the same protection is not evident in malignant cells. An association between increased levels of glutamate and disease burden in multiple sclerosis has been identified in a longitudinal study involving 265 people with multiple sclerosis followed for an average of 1.8 years. Contactin-2 which exists in both grey and white matter has recently been identified as an auto antigen which may be of relevance in multiple sclerosis where whites matter lesions manifest initially but later followed by grey matter lesions which correlates with functioning. A study has provided evidence that Gliomas can originate in the oligodendrocyte progenitor cells.  The authors of one study found evidence of a significant increase in olfactory impairment in people with SLE compared to controls.  Approximately 10 per cent of the SLE participants experienced olfactory dysfunction.

References

Adewuya AO, Makanjuola RO.  Subjective quality of life of Nigerian schizophrenia patients: sociodemographic and clinical correlates. Acta Psychiatr Scand. 2009 Apr 30. [Epub ahead of print]

Boyle PA, Barnes LL, Buchman AS, Bennett DA. Purpose in Life Is Associated With Mortality Among Community-Dwelling Older Persons. Psychosom Med. 2009 May 4. [Epub ahead of print]

Canuso CM, Dirks B, Carothers J, Kosik-Gonzalez C, Bossie CA, Zhu Y, Damaraju CV,Kalali AH, Mahmoud R. Randomized, Double-Blind, Placebo-Controlled Study of Paliperidone Extended-Release and Quetiapine in Inpatients With Recently Exacerbated Schizophrenia.Am J Psychiatry. 2009 May 1. [Epub ahead of print].

Davatzikos C, Xu F, An Y, Fan Y, Resnick SM. Brain. 2009 May 4. [Epub ahead of print]. Longitudinal progression of Alzheimer’s-like patterns of atrophy in normal older adults: the SPARE-AD index.

Gyurak A, Goodkind MS, Madan A, Kramer JH, Miller BL, Levenson RW. Do tests of executive functioning predict ability to downregulate emotions spontaneously and when instructed to suppress? Cogn Affect Behav Neurosci. 2009 Jun. 9(2). 144-52.

Jellinger KA. Absence of alpha-synuclein pathology in postencephalitic parkinsonism. Acta Neuropathol. 2009 Apr 30. [Epub ahead of print].

Kjosavik SR, Ruths S, Hunskaar S. Psychotropic drug use in the Norwegian general population in 2005: data from the Norwegian Prescription Database.Pharmacoepidemiol Drug Saf. 2009 Apr 28. [Epub ahead of print].

Listerud J, Powers C, Moore P, Libon DJ, Grossman M. J Int Neuropsychol Soc. 2009 May;15(3):459-70. Neuropsychological patterns in magnetic resonance imaging-defined subgroups of patients with degenerative dementia.

Marcello A, Wirths O, Schneider-Axmann T, Degerman-Gunnarsson M, Lannfelt L,Bayer TA.J.Circulating immune complexes of Abeta and IgM in plasma of patients with Alzheimer’s disease.Neural Transm. 2009 May 5. [Epub ahead of print]

Smith CD, Lori NF, Akbudak E, Sorar E, Gultepe E, Shimony JS, McKinstry RC, Conturo TE.. MRI diffusion tensor tracking of a new amygdalo-fusiform and hippocampo-fusiform pathway system in humans. J Magn Reson Imaging. 2009 May 5. [Epub ahead of print].

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.

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