Identifying parkinsonism in mild cognitive impairment

INTRODUCTION

Clinical parkinsonism is a core diagnostic feature for mild cognitive impairment with Lewy bodies (MCI-LB) but can be challenging to identify. A five-item scale derived from the Unified Parkinson's Disease Rating Scale (UPDRS) has been recommended for the assessment of parkinsonism in dementia. This study aimed to determine whether the five-item scale is effective to identify parkinsonism in MCI.

METHODS

Participants with MCI from two cohorts (n = 146) had a physical examination including the UPDRS and [123I]-FP-CIT SPECT striatal dopaminergic imaging. Participants were classified as having clinical parkinsonism (P+) or no parkinsonism (P-), and with abnormal striatal dopaminergic imaging (D+) or normal imaging (D-). The five-item scale was the sum of UPDRS tremor at rest, bradykinesia, action tremor, facial expression, and rigidity scores. The ability of the scale to differentiate P+D+ and P-D- participants was examined.

RESULTS

The five-item scale had an AUROC of 0.92 in Cohort 1, but the 7/8 cut-off defined for dementia had low sensitivity to identify P+D+ participants (sensitivity 25%, specificity 100%). Optimal sensitivity and specificity was obtained at a 3/4 cut-off (sensitivity 83%, specificity 88%). In Cohort 2, the five-item scale had an AUROC of 0.97, and the 3/4 cut-off derived from Cohort 1 showed sensitivity of 100% and a specificity of 82% to differentiate P+D+ from P-D- participants. The five-item scale was not effective in differentiating D+ from D- participants.

CONCLUSIONS

The five-item scale is effective to identify parkinsonism in MCI, but a lower threshold must be used in MCI compared with dementia.

Clinical symptoms in mild cognitive impairment with Lewy bodies: Frequency, time of onset, and discriminant ability

BACKGROUND AND PURPOSE

Mild cognitive impairment with Lewy bodies (MCI-LB) is associated with a range of cognitive, motor, neuropsychiatric, sleep, autonomic, and visual symptoms. We investigated the cumulative frequency of symptoms in a longitudinal cohort of MCI-LB compared with MCI due to Alzheimer disease (MCI-AD) and analysed the ability of a previously described 10-point symptom scale to differentiate MCI-LB and MCI-AD, in an independent cohort.

METHODS

Participants with probable MCI-LB (n = 70), MCI-AD (n = 51), and controls (n = 34) had a detailed clinical assessment and annual follow-up (mean duration = 1.7 years). The presence of a range of symptoms was ascertained using a modified version of the Lewy Body Disease Association Comprehensive LBD Symptom Checklist at baseline assessment and then annually.

RESULTS

MCI-LB participants experienced a greater mean number of symptoms (24.2, SD = 7.6) compared with MCI-AD (11.3, SD = 7.4) and controls (4.2, SD = 3.1; p < 0.001 for all comparisons). A range of cognitive, parkinsonian, neuropsychiatric, sleep, and autonomic symptoms were significantly more common in MCI-LB than MCI-AD, although when present, the time of onset was similar between the two groups. A previously defined 10-point symptom scale demonstrated very good discrimination between MCI-LB and MCI-AD (area under the receiver operating characteristic curve = 0.91, 95% confidence interval = 0.84-0.98), replicating our previous finding in a new cohort.

CONCLUSIONS

MCI-LB is associated with the frequent presence of a particular profile of symptoms compared to MCI-AD. Clinicians should look for evidence of these symptoms in MCI and be aware of the potential for treatment. The presence of these symptoms may help to discriminate MCI-LB from MCI-AD.

Transcranial Direct Current Stimulation in the Treatment of Visual Hallucinations in Charles Bonnet Syndrome: A Randomized Placebo-Controlled Crossover Trial

OBJECTIVE

To investigate the potential therapeutic benefits and tolerability of inhibitory transcranial direct current stimulation (tDCS) on the remediation of visual hallucinations in Charles Bonnet syndrome (CBS).

DESIGN

Randomized, double-masked, placebo-controlled crossover trial.

PARTICIPANTS

Sixteen individuals diagnosed with CBS secondary to visual impairment caused by eye disease experiencing recurrent visual hallucinations.

INTERVENTION

All participants received 4 consecutive days of active and placebo cathodal stimulation (current density: 0.29 mA/cm²) to the visual cortex (Oz) over 2 defined treatment weeks, separated by a 4-week washout period.

MAIN OUTCOME MEASURES

Ratings of visual hallucination frequency and duration following active and placebo stimulation, accounting for treatment order, using a 2 × 2 repeated-measures model. Secondary outcomes included impact ratings of visual hallucinations and electrophysiological measures.

RESULTS

When compared with placebo treatment, active inhibitory stimulation of visual cortex resulted in a significant reduction in the frequency of visual hallucinations measured by the North East Visual Hallucinations Interview, with a moderate-to-large effect size. Impact measures of visual hallucinations improved in both placebo and active conditions, suggesting support and education for CBS may have therapeutic benefits. Participants who demonstrated greater occipital excitability on electroencephalography assessment at the start of treatment were more likely to report a positive treatment response. Stimulation was found to be tolerable in all participants, with no significant adverse effects reported, including no deterioration in preexisting visual impairment.

CONCLUSIONS

Findings indicate that inhibitory tDCS of visual cortex may reduce the frequency of visual hallucinations in people with CBS, particularly individuals who demonstrate greater occipital excitability prior to stimulation. tDCS may offer a feasible intervention option for CBS with no significant side effects, warranting larger-scale clinical trials to further characterize its efficacy.

The relationship between plasma biomarkers and amyloid PET in dementia with Lewy bodies

INTRODUCTION

Amyloid-β (Aβ) deposition is common in dementia with Lewy bodies (DLB) and has been associated with more rapid disease progression. An effective biomarker that identified the presence of significant brain Aβ in people with DLB may be useful to identify and stratify participants for research studies and to inform prognosis in clinical practice. Plasma biomarkers are emerging as candidates to fulfil this role.

METHODS

Thirty-two participants with DLB had brain amyloid (18F-florbetapir) PET, of whom 27 also had an MRI to enable the calculation of 18F-florbetapir SUVR. Plasma Aβ42/40, phosphorylated tau (p-tau181), glial fibrillary acidic protein (GFAP) and neurofilament light (NfL) were measured using single molecule array (Simoa). The plasma biomarkers were investigated for correlation with 18F-florbetapir SUVR, discriminant ability to identify Aβ-positive cases based on a predefined SUVR threshold of 1.10 and correlation with subsequent cognitive decline over one year.

RESULTS

All four plasma markers significantly correlated with 18F-florbetapir SUVR (|β| = 0.40-0.49; p < .05). NfL had the greatest area under the receiver operating characteristic curve to identify Aβ-positive cases (AUROC 0.84 (95% CI 0.66, 1); β = 0.46, p = .001), whereas Aβ42/40 had the smallest (AUROC 0.73 (95% CI 0.52, 0.95); β = -0.47, p = .01). Accuracy was highest when combining all four biomarkers (AUROC 0.92 (95% CI 0.80, 1)). Lower plasma Aβ42/40 was significantly associated with more rapid decline in cognition (β = 0.53, p < .01).

CONCLUSIONS

Plasma biomarkers have the potential to identify Aβ deposition in DLB. Further work in other cohorts is required to determine and validate optimal cut-offs for these biomarkers.

Investigation of structural brain changes in Charles Bonnet Syndrome

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Reduced grey matter in the occipital cortex in eye disease groups.

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Widespread altered diffusivity in eye disease groups.

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No cortical or white matter changes associated with presence of visual hallucinations.

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Negative association between hippocampal volume and Hallucination severity.

Background and objectives

In Charles Bonnet Syndrome (CBS), visual hallucinations (VH) are experienced by people with sight loss due to eye disease or lesional damage to early visual pathways. The aim of this cross-sectional study was to investigate structural brain changes using magnetic resonance imaging (MRI) in CBS.

Methods

Sixteen CBS patients, 17 with eye disease but no VH, and 19 normally sighted people took part. Participants were imaged on a 3T scanner, with 1 mm resolution T1 weighted structural imaging, and diffusion tensor imaging with 64 diffusion directions.

Results

The three groups were well matched for age, sex and cognitive scores (MMSE). The two eye disease groups were matched on visual acuity. Compared to the sighted controls, we found reduced grey matter in the occipital cortex in both eye disease groups. We also found reductions of fractional anisotropy and increased diffusivity in widespread areas, including occipital tracts, the corpus callosum, and the anterior thalamic radiation. We did not find any significant differences between the eye disease participants with VH versus without VH, but did observe a negative association between hippocampal volume and VH severity in the CBS group.

Discussion

Our findings suggest that although there are cortical and subcortical effects associated with sight loss, structural changes do not explain the occurrence of VHs. CBS may relate instead to connectivity or excitability changes in brain networks linked to vision.

Prospective predictors of decline v. stability in mild cognitive impairment with Lewy bodies or Alzheimer's disease

BACKGROUND

Mild cognitive impairment (MCI) may gradually worsen to dementia, but often remains stable for extended periods of time. Little is known about the predictors of decline to help explain this variation. We aimed to explore whether this heterogeneous course of MCI may be predicted by the presence of Lewy body (LB) symptoms in a prospectively-recruited longitudinal cohort of MCI with Lewy bodies (MCI-LB) and Alzheimer's disease (MCI-AD).

METHODS

A prospective cohort (n = 76) aged ⩾60 years underwent detailed assessment after recent MCI diagnosis, and were followed up annually with repeated neuropsychological testing and clinical review of cognitive status and LB symptoms. Latent class mixture modelling identified data-driven sub-groups with distinct trajectories of global cognitive function.

RESULTS

Three distinct trajectories were identified in the full cohort: slow/stable progression (46%), intermediate progressive decline (41%) and a small group with a much faster decline (13%). The presence of LB symptomology, and visual hallucinations in particular, predicted decline v. a stable cognitive trajectory. With time zeroed on study end (death, dementia or withdrawal) where available (n = 39), the same subgroups were identified. Adjustment for baseline functioning obscured the presence of any latent classes, suggesting that baseline function is an important parameter in prospective decline.

CONCLUSIONS

These results highlight some potential signals for impending decline in MCI; poorer baseline function and the presence of probable LB symptoms - particularly visual hallucinations. Identifying people with a rapid decline is important but our findings are preliminary given the modest cohort size.

Measurements of Argon-39 from locations near historic underground nuclear explosions

Measurement of radioactive gas seepage from an underground nuclear explosion is one of the primary methods to confirm whether an event was nuclear in nature. Radioactive noble gas indicators that are commonly targeted by such measurements (e.g. ¹³³Xe, ³⁷Ar) have half-lives of 35 days or less. Argon-39, an activation product similar to ³⁷Ar, is produced by the interaction between neutrons and potassium in the surrounding geology and has a half-life of 269 years. Measurements taken at three sites near three historic underground nuclear test locations at the Nevada National Security Site have all shown highly elevated levels of ³⁹Ar in soil gas decades after the test events. Elevated levels of ³⁹Ar were also detected in atmospheric air collected near two of these sites, and outside the entrance of the one tunnel site. These measurements demonstrate that ³⁹Ar has the potential to be a long-term signature of an underground nuclear event which can be reliably detected at the surface or in the shallow subsurface. This radionuclide detection of an underground nuclear event decades after the event takes place is in contrast to the commonly held assumption that detecting underground nuclear events via radionuclides at the surface needs to be done in a matter of months. Depending upon what further studies show about the robustness of this signature in a variety of geological settings, it may in fact be easy to detect underground nuclear events at the surface for a very long time post-detonation.

Continuity of care in heart failure patients

Funding Acknowledgements

Type of funding sources: None.

Background

 Heart failure (HF) requires follow-up over time and by several different health services. The positive effects of follow-up care in secondary care services is well known. However, there is a lack of knowledge in how HF patients experience continuity of care a through various health care services in secondary and primary care.

Purpose

To explore how HF patients experience continuity of care through secondary and primary health care services.

Methods

The study used an inductive design by performing four semi-structured focus group interviews. Overall, 17 patients, mean age of 71 years (range 42-95), 11 men and 6 women, All patients were receiving regular and individual follow-up by cardiac nurses in primary care after hospital discharge The interviews were analysed through qualitative content analysis.

Results

Gaps in continuity of care were described as challenging. Information about HF at the time of discharge from hospital were not always fully comprehended. Patients experienced physical strain of being lost and abandoned after discharge from hospital. They did not know whom to contact for follow-up.  Appointments with the GP was not agreed or scheduled weeks ahead. Patients appreciated home visit by a cardiac nurse in primary care who provided the patients with knowledge in self-care administration. When experiencing deterioration they could call the cardiac nurse, who could facilitate fast track to the hospital. Self-care was difficult to comprehend, especially for those experiencing comorbidities. Patients also  described the importance of sharing knowledge and experience of living with HF with other patients in a secondary care setting, organized by specialised cardiac nurses.

Conclusions

There are gaps in continuity in patients’ pathways, throughout both secondary and primary healthcare. Even though patients receive information at discharge from hospital, they felt insecure when returning home. Health care services in the primary care provided the patients with both knowledge and confidence as they regularly met the patients, both at home and in organized primary care meetings.

Progression to Dementia in Mild Cognitive Impairment With Lewy Bodies or Alzheimer Disease

OBJECTIVE

To determine whether mild cognitive impairment with Lewy bodies or mild cognitive impairment with Alzheimer disease differ in their rates of clinical progression to dementia, we undertook longitudinal observation of mild cognitive impairment cases with detailed clinical assessment of Lewy body diagnostic characteristics.

METHODS

Two prospective longitudinal cohorts including 111 individuals ≥60 years of age with mild cognitive impairment were assessed annually to track cognitive and clinical progression, including the presence or absence of core clinical features and proposed biomarkers of dementia with Lewy bodies. Multistate modeling was used to assess the associations of diagnostic characteristics of dementia with Lewy bodies with clinical progression from mild cognitive impairment to dementia, with death as a competing outcome.

RESULTS

After a mean follow-up of 2.2 years (range 1-6.7 years), 38 of the 111 (34%) participants progressed to dementia: 10 with AD, 3 with possible dementia with Lewy bodies, and 25 with probable dementia with Lewy bodies. The presence of any Lewy body disease characteristic was associated with an increased hazard of transition to dementia; this risk further increased as more diagnostic characteristics were observed (hazard ratio 1.33 per characteristic, 95% confidence interval [CI] 1.11-1.60) and was especially high for those experiencing complex visual hallucinations (hazard ratio 1.98, 95% CI 0.92-4.29) or cognitive fluctuations (hazard ratio 3.99, 95% CI 2.03-7.84).

CONCLUSIONS

Diagnostic characteristics of Lewy body disease are associated with an increased risk of transition from mild cognitive impairment to dementia.

Accuracy of dopaminergic imaging as a biomarker for mild cognitive impairment with Lewy bodies

BACKGROUND

Dopaminergic imaging is an established biomarker for dementia with Lewy bodies, but its diagnostic accuracy at the mild cognitive impairment (MCI) stage remains uncertain.

AIMS

To provide robust prospective evidence of the diagnostic accuracy of dopaminergic imaging at the MCI stage to either support or refute its inclusion as a biomarker for the diagnosis of MCI with Lewy bodies.

METHOD

We conducted a prospective diagnostic accuracy study of baseline dopaminergic imaging with [123I]N-ω-fluoropropyl-2β-carbomethoxy-3β-(4-iodophenyl)nortropane single-photon emission computerised tomography (123I-FP-CIT SPECT) in 144 patients with MCI. Images were rated as normal or abnormal by a panel of experts with access to striatal binding ratio results. Follow-up consensus diagnosis based on the presence of core features of Lewy body disease was used as the reference standard.

RESULTS

At latest assessment (mean 2 years) 61 patients had probable MCI with Lewy bodies, 26 possible MCI with Lewy bodies and 57 MCI due to Alzheimer's disease. The sensitivity of baseline FP-CIT visual rating for probable MCI with Lewy bodies was 66% (95% CI 52-77%), specificity 88% (76-95%) and accuracy 76% (68-84%), with positive likelihood ratio 5.3.

CONCLUSIONS

It is over five times as likely for an abnormal scan to be found in probable MCI with Lewy bodies than MCI due to Alzheimer's disease. Dopaminergic imaging appears to be useful at the MCI stage in cases where Lewy body disease is suspected clinically.

Cognitive Decline in Mild Cognitive Impairment With Lewy Bodies or Alzheimer Disease: A Prospective Cohort Study

OBJECTIVE

We explored whether the mild cognitive impairment (MCI) stages of dementia with Lewy bodies (DLB) and Alzheimer disease (AD) differ in their cognitive profiles, and longitudinal progression.

DESIGN

A prospective, longitudinal design was utilized with annual follow-up (Max 5 years, Mean 1.9, standard deviation 1.1) after diagnosis. Participants underwent repeated cognitive testing, and review of their clinical diagnosis and symptoms, including evaluation of core features of DLB.

SETTING

This was an observational study of independently living individuals, recruited from local healthcare trusts in North East England, UK.

PARTICIPANTS

An MCI cohort (n = 76) aged ≥60 years was utilized, differentially diagnosed with MCI due to AD (MCI-AD), or possible/probable MCI with Lewy bodies (MCI-LB).

MEASUREMENTS

A comprehensive clinical and neuropsychological testing battery was administered, including ACE-R, trailmaking tests, FAS verbal fluency, and computerized battery of attention and perception tasks.

RESULTS

Probable MCI-LB presented with less impaired recognition memory than MCI-AD, greater initial impairments in verbal fluency and perception of line orientation, and thereafter demonstrated an expedited decline in visuo-constructional functions in the ACE-R compared to MCI-AD. No clear diagnostic group differences were found in deterioration speeds for global cognition, language, overall memory, attention or other executive functions.

CONCLUSION

These findings provide further evidence for differences in severity and decline of visuospatial dysfunctions in DLB compared with AD; further exploration is required to clarify when and how differences in attention, executive, and memory functions emerge, as well as speed of decline to dementia.

Prospective longitudinal evaluation of cytokines in mild cognitive impairment due to AD and Lewy body disease

OBJECTIVES

We conducted a prospective longitudinal study of plasma cytokines during the Mild Cognitive Impairment (MCI) stage of Lewy body disease and Alzheimer's disease, hypothesizing that cytokine levels would decrease over time and that this would be correlated with decline in cognition.

METHODS

Older (≥60) people with MCI were recruited from memory services in healthcare trusts in North East England, UK. MCI was diagnosed as due to Alzheimer's disease (MCI-AD) or Lewy body disease (MCI-LB). Baseline and repeat annual clinical and cognitive assessments were undertaken and plasma samples were obtained at the same time. Cytokine assays were performed on all samples using the Meso Scale Discovery V-Plex Plus Proinflammatory Panel 1, which included IFNγ, IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p70, IL-13 and TNFα.

RESULTS

Fifty-six patients (21 MCI-AD, 35 MCI-LB) completed prospective evaluations and provided samples up to 3 years after baseline. Six cytokines (IFNγ, IL-1β, IL-2, IL-4, IL-6 and IL-10) showed highly significant (P < .002) decreases over time. AD and LB did not differ in rate of decrease nor were there any effects related to age or general morbidity. Decrease in five of these cytokines (IFNγ, IL-1β, IL-2, IL-4, and IL-10) was highly correlated with decrease in cognition (P < .003).

CONCLUSIONS

Peripheral inflammation decreased in both disease groups during MCI suggesting this may be a therapeutic window for future anti-inflammatory agents.

Diffusion imaging in dementia with Lewy bodies: Associations with amyloid burden, atrophy, vascular factors and clinical features

INTRODUCTION

White matter disruption in dementia has been linked to a variety of factors including vascular disease and cortical pathology. We aimed to examine the relationship between white matter changes on diffusion tensor imaging (DTI) in DLB and factors including vascular disease, structural atrophy and amyloid burden.

METHODS

Participants with DLB (n = 29), Alzheimer's disease (AD, n = 17) and healthy controls (n = 20) had clinical and neuropsychological assessments followed by structural and diffusion tensor 3T MRI and ¹⁸F-Florbetapir PET-CT imaging. Voxelwise statistical analysis of white matter fractional anisotropy (FA) and mean diffusivity (MD) was carried out using Tract-Based Spatial Statistics with family-wise error correction (p < 0.05).

RESULTS

DLB and AD groups demonstrated widespread increased MD and decreased FA when compared with controls. There were no differences between the DLB and AD groups. In DLB, increased MD and decreased FA correlated with decreased grey matter and hippocampal volumes as well as vascular disease. There was no correlation with cortical florbetapir SUVR. The relationship between DTI changes and grey matter/hippocampal volumes remained after including Cumulative Illness Rating Scale-Geriatric vascular score as a covariate.

CONCLUSIONS

Widespread disruption of white matter tracts is present in DLB and is associated with vascular disease, reduced hippocampal volume and reduced grey matter volume, but not with cortical amyloid deposition. The mechanism behind the correlation observed between hippocampal volume and white matter tract disruption should be investigated in future cohorts using tau imaging, as hippocampal atrophy has been shown to correlate with tau deposition in DLB.

Amyloid Imaging and Longitudinal Clinical Progression in Dementia With Lewy Bodies

OBJECTIVE

Significant amyloid deposition is present in approximately half of all cases of dementia with Lewy bodies (DLB). We sought to determine whether amyloid deposition was associated with more rapid clinical decline over 1 year.

METHODS

Twenty-eight participants had a baseline clinical assessment and amyloid PET scan, followed by a further clinical assessment after 1 year. Changes in clinical measures were compared with amyloid deposition assessed by visual rating and cortical standardized uptake value ratio.

RESULTS

Amyloid deposition on visual rating was associated with greater decline in Mini-Mental State Examination and daily function over 1 year. There was no correlation between cortical standardized uptake value ratio and clinical measures.

CONCLUSIONS

This study provides further evidence for a link between amyloid deposition and clinical progression in DLB. Pathologies such as amyloid, and their interaction with α-synuclein, remain possible treatment targets in DLB.

Visual hallucinations in neurological and ophthalmological disease: pathophysiology and management

Visual hallucinations are common in older people and are especially associated with ophthalmological and neurological disorders, including dementia and Parkinson's disease. Uncertainties remain whether there is a single underlying mechanism for visual hallucinations or they have different disease-dependent causes. However, irrespective of mechanism, visual hallucinations are difficult to treat. The National Institute for Health Research (NIHR) funded a research programme to investigate visual hallucinations in the key and high burden areas of eye disease, dementia and Parkinson's disease, culminating in a workshop to develop a unified framework for their clinical management. Here we summarise the evidence base, current practice and consensus guidelines that emerged from the workshop.Irrespective of clinical condition, case ascertainment strategies are required to overcome reporting stigma. Once hallucinations are identified, physical, cognitive and ophthalmological health should be reviewed, with education and self-help techniques provided. Not all hallucinations require intervention but for those that are clinically significant, current evidence supports pharmacological modification of cholinergic, GABAergic, serotonergic or dopaminergic systems, or reduction of cortical excitability. A broad treatment perspective is needed, including carer support. Despite their frequency and clinical significance, there is a paucity of randomised, placebo-controlled clinical trial evidence where the primary outcome is an improvement in visual hallucinations. Key areas for future research include the development of valid and reliable assessment tools for use in mechanistic studies and clinical trials, transdiagnostic studies of shared and distinct mechanisms and when and how to treat visual hallucinations.

Microbleeds in dementia with Lewy bodies

INTRODUCTION

Microbleeds are associated with the development of dementia in older people and are common in Alzheimer's disease (AD). Their prevalence and clinical importance in dementia with Lewy bodies (DLB) is unclear. The objective of this study was to compare the rates of microbleeds in DLB with those in AD and healthy older people, and investigate associations between microbleeds and amyloid deposition, vascular risk and disease severity in DLB.

METHODS

DLB (n = 30), AD (n = 18) and control (n = 20) participants underwent clinical assessment at baseline and 1 year in this longitudinal observational study. 3T MRI (including T2* susceptibility weighted imaging) and florbetapir PET were carried out at baseline. Microbleeds were rated visually and a standardised uptake value ratio (SUVR) was calculated from florbetapir PET scans.

RESULTS

40% of DLB subjects had microbleeds compared with 50% of AD and 15% of controls. Compared to DLB without microbleeds, those with microbleeds had higher systolic BP (156 ± 26 v. 135 ± 19 mmHg; p = 0.03), but did not have greater levels of vascular disease or amyloid deposition (SUVR 1.25 ± 0.24 v. 1.25 ± 0.22; p = 0.33). There was evidence of less severe dementia in DLB participants with microbleeds, but these differences may have been driven by a shorter disease duration in those with microbleeds.

CONCLUSION

The presence of microbleeds in DLB is associated with higher blood pressure, but not with other measures of vascular disease or amyloid deposition. The relationship between microbleeds and clinical presentation remains unclear.

Inflammation in mild cognitive impairment due to Parkinson's disease, Lewy body disease, and Alzheimer's disease

BACKGROUND

Inflammation appears to play a role in the progression of neurodegenerative diseases. However, little is known about inflammation during early stages of cognitive decline or whether this differs in different disease groups. We sought to investigate this by assessing the inflammatory profile in patients with Parkinson disease with the early stages of cognitive impairment (PD-MCI), patients with prodromal Alzheimer disease (MCI-AD), prodromal Lewy body disease (MCI-LB), and controls.

METHODS

We obtained venous blood samples from participants with PD-MCI (n = 44), PD-normal cognition (n = 112), MCI-LB (n = 38), MCI-AD (n = 21), and controls (n = 84). We measured 10 cytokines using Meso Scale Discovery V-Plex Plus including interferon gamma, interleukin (IL)-10, IL-12p70, IL-13, IL-1beta, IL-2, IL-4, IL-6, IL-8, and tumour necrosis factor alpha. High-sensitivity C-reactive protein was measured.

RESULTS

There was a higher level of inflammation in patients with MCI-AD and MCI-LB compared with controls. PD noncognitively impaired had higher inflammatory markers than controls, but there was no difference between PD-MCI and controls. There was a decrease in inflammatory markers with increasing motor severity based on the Unified Parkinson's Disease Rating Scale.

CONCLUSIONS

Inflammation may be involved in the onset of cognitive decline in patients with MCI-AD and MCI-LB but appears to be less prominent PD-MCI albeit in a small data set. This suggests that anti-inflammatory medications may have most benefit at the earliest stages of neurodegenerative diseases. For PD cases, this might be in advance of the development of MCI.

Prevalence and severity of symptoms suggestive of gastroparesis in prodromal dementia with Lewy bodies

INTRODUCTION

Lewy body disease is postulated, by the Braak model, to originate in the enteric nervous system, before spreading to the central nervous system. Therefore, a high prevalence of gastroparesis symptoms would be expected in prodromal dementia with Lewy bodies (DLB) and be highest in those with a dopaminergic deficit on imaging. The aim of this study was to explore whether gastroparesis symptoms are an early diagnostic marker of prodromal DLB and explore the relationship between symptoms and dopaminergic imaging findings on FP-CIT SPECT.

METHODS

We recruited 75 patients over 60 with mild cognitive impairment (MCI), 48 with MCI with suspected Lewy body disease (MCI-LB) and 27 with MCI with suspected Alzheimer's disease (MCI-AD). All patients completed the Gastroparesis Cardinal Symptom Index (GSCI) questionnaire and also underwent FP-CIT [¹²³ I-N-fluoropropyl-2β-carbomethoxy-3β-(4-iodophenyl)] dopaminergic imaging.

RESULTS

At least one symptom suggestive of gastroparesis was reported in 48% (n = 23) MCI-LB vs 37% MCI-AD (n = 10) (P = 0.36). Rates of definite symptoms of gastroparesis, as defined by a GCSI total score ≥ 1.90, were rare and rates in MCI-LB were not different from MCI-AD (6% vs 0%, p = 0.55). After adjusting for gender differences between groups, no difference in gastroparesis symptom prevalence (2.27 vs 0.81 P = 0.05) or severity score (0.62 vs 0.28, p = 0.28) was noted between normally and abnormally visually rated FP-CIT SPECT scans.

CONCLUSION

The GCSI is not a useful tool for differentiating MCI-LB from MCI-AD. A low rate of definite gastroparesis was detected in prodromal DLB. No association was found between gastroparesis symptoms and FP-CIT SPECT findings.

Diagnostic accuracy of dopaminergic imaging in prodromal dementia with Lewy bodies

BACKGROUND

Dopaminergic imaging has high diagnostic accuracy for dementia with Lewy bodies (DLB) at the dementia stage. We report the first investigation of dopaminergic imaging at the prodromal stage.

METHODS

We recruited 75 patients over 60 with mild cognitive impairment (MCI), 33 with probable MCI with Lewy body disease (MCI-LB), 15 with possible MCI-LB and 27 with MCI with Alzheimer's disease. All underwent detailed clinical, neurological and neuropsychological assessments and FP-CIT [123I-N-fluoropropyl-2β-carbomethoxy-3β-(4-iodophenyl)] dopaminergic imaging. FP-CIT scans were blindly rated by a consensus panel and classified as normal or abnormal.

RESULTS

The sensitivity of visually rated FP-CIT imaging to detect combined possible or probable MCI-LB was 54.2% [95% confidence interval (CI) 39.2-68.6], with a specificity of 89.0% (95% CI 70.8-97.6) and a likelihood ratio for MCI-LB of 4.9, indicating that FP-CIT may be a clinically important test in MCI where any characteristic symptoms of Lewy body (LB) disease are present. The sensitivity in probable MCI-LB was 61.0% (95% CI 42.5-77.4) and in possible MCI-LB was 40.0% (95% CI 16.4-67.7).

CONCLUSIONS

Dopaminergic imaging had high specificity at the pre-dementia stage and gave a clinically important increase in diagnostic confidence and so should be considered in all patients with MCI who have any of the diagnostic symptoms of DLB. As expected, the sensitivity was lower in MCI-LB than in established DLB, although over 50% still had an abnormal scan. Accurate diagnosis of LB disease is important to enable early optimal treatment for LB symptoms.

Neuropsychiatric symptoms and cognitive profile in mild cognitive impairment with Lewy bodies

BACKGROUND

The accurate clinical characterisation of mild cognitive impairment (MCI) is becoming increasingly important. The aim of this study was to compare the neuropsychiatric symptoms and cognitive profile of MCI with Lewy bodies (MCI-LB) with Alzheimer's disease MCI (MCI-AD).

METHODS

Participants were ⩾60 years old with MCI. Each had a thorough clinical and neuropsychological assessment and 2β-carbomethoxy-3β-(4-iodophenyl)-N-(3-fluoropropyl)-nortropane single photon emission computed tomography FP-CIT SPECT). MCI-LB was diagnosed if two or more diagnostic features of dementia with Lewy bodies were present (visual hallucinations, cognitive fluctuations, motor parkinsonism, rapid eye movement sleep behaviour disorder or positive FP-CIT SPECT). A Lewy body Neuropsychiatric Supportive Symptom Count (LBNSSC) was calculated based on the presence or absence of the supportive neuropsychiatric symptoms defined by the 2017 DLB diagnostic criteria: non-visual hallucinations, delusions, anxiety, depression and apathy.

RESULTS

MCI-LB (n = 41) had a higher LBNSSC than MCI-AD (n = 24; 1.8 ± 1.1 v. 0.7 ± 0.9, p = 0.001). 67% of MCI-LB had two or more of those symptoms, compared with 16% of MCI-AD (Likelihood ratio = 4.2, p < 0.001). MCI-LB subjects scored lower on tests of attention, visuospatial function and verbal fluency. However, cognitive test scores alone did not accurately differentiate MCI-LB from MCI-AD.

CONCLUSIONS

MCI-LB is associated with neuropsychiatric symptoms and a cognitive profile similar to established DLB. This supports the concept of identifying MCI-LB based on the presence of core diagnostic features of DLB and abnormal FP-CIT SPECT imaging. The presence of supportive neuropsychiatric clinical features identified in the 2017 DLB diagnostic criteria was helpful in differentiating between MCI-LB and MCI-AD.

Oxidative Stress and Cardiovascular Risk in Type 1 Diabetes Mellitus: Insights From the DCCT/EDIC Study

Background

Hyperglycemia leading to increased oxidative stress is implicated in the increased risk for the development of macrovascular and microvascular complications in patients with type 1 diabetes mellitus.

Methods and Results

A random subcohort of 349 participants was selected from the DCCT / EDIC (Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications) cohort. This included 320 controls and 29 cardiovascular disease cases that were augmented with 98 additional known cases to yield a case cohort of 447 participants (320 controls, 127 cases). Biosamples from DCCT baseline, year 1, and closeout of DCCT , and 1 to 2 years post‐ DCCT ( EDIC years 1 and 2) were measured for markers of oxidative stress, including plasma myeloperoxidase, paraoxonase activity, urinary F 2α isoprostanes, and its metabolite, 2,3 dinor‐8 iso prostaglandin F 2α . Following adjustment for glycated hemoblobin and weighting the observations inversely proportional to the sampling selection probabilities, higher paraoxonase activity, reflective of antioxidant activity, and 2,3 dinor‐8 iso prostaglandin F 2α , an oxidative marker, were significantly associated with lower risk of cardiovascular disease (−4.5% risk for 10% higher paraoxonase, P <0.003; −5.3% risk for 10% higher 2,3 dinor‐8 iso prostaglandin F 2α , P =0.0092). In contrast, the oxidative markers myeloperoxidase and F 2α isoprostanes were not significantly associated with cardiovascular disease after adjustment for glycated hemoblobin. There were no significant differences between DCCT intensive and conventional treatment groups in the change in all biomarkers across time segments.

Conclusions

Heightened antioxidant activity (rather than diminished oxidative stress markers) is associated with lower cardiovascular disease risk in type 1 diabetes mellitus, but these biomarkers did not change over time with intensification of glycemic control.

Clinical Trial Registration

URL : https://www.clinicaltrials.gov . Unique identifiers: NCT 00360815 and NCT 00360893.

Clinical and imaging correlates of amyloid deposition in dementia with Lewy bodies

Background: Amyloid deposition is common in dementia with Lewy bodies, but its pathophysiological significance is unclear.

Objective: The objective of this study was to investigate the relationship between amyloid deposition and clinical profile, gray matter volume, and brain perfusion in dementia with Lewy bodies.

Methods: Dementia with Lewy bodies (n = 37), Alzheimer's disease (n = 20), and controls (n = 20) underwent a thorough clinical assessment, 3T MRI, and early‐ and late‐phase ¹⁸F‐Florbetapir PET‐CT to assess cortical perfusion and amyloid deposition, respectively. Amyloid scans were visually categorized as positive or negative. Image analysis was carried out using statistical parametric mapping (SPM) 8.

Results: There were no significant differences between amyloid‐positive and amyloid‐negative dementia with Lewy bodies cases in age (P = .78), overall cognitive impairment (P = .83), level of functional impairment (P = .80), or any other clinical or cognitive scale. There were also no significant differences in hippocampal or gray matter volumes. However, amyloid‐positive dementia with Lewy bodies cases had lower medial temporal lobe perfusion (P = .03) than amyloid‐negative cases, although a combination of medial temporal lobe perfusion, hippocampal volume, and cognitive measures was unable to accurately predict amyloid status in dementia with Lewy bodies.

Conclusions: Amyloid deposition was not associated with differences in clinical or neuropsychological profiles in dementia with Lewy bodies, but was associated with imaging evidence of medial temporal lobe dysfunction. The presence of amyloid in dementia with Lewy bodies cannot be identified on the basis of clinical and other imaging features and will require direct assessment via PET imaging or CSF. © 2018 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.

Peripheral inflammation in prodromal Alzheimer's and Lewy body dementias

OBJECTIVES

There is growing evidence for the role of systemic inflammation in Alzheimer's disease (AD) and other neurodegenerative diseases; however the systemic inflammatory profile in dementia with Lewy bodies (DLB) has never before been investigated. This study aimed to characterise systemic inflammatory mediators in established DLB and AD, as well as in their prodromal, mild cognitive impairment (MCI) phases.

METHODS

We obtained plasma samples from patients with DLB (n=37), AD (n=20), MCI with DLB profile (n=38), MCI with AD profile (n=20) and healthy control subjects (n=20). The following inflammatory biomarkers were measured using Roche cobas c702 and Meso Scale Discovery V-Plex Plus: high-sensitivity C-reactive protein, interferon-gamma, interleukin (IL)-10, IL-12p70, IL-13, IL-1beta, IL-2, IL-4, IL-6, IL-8 and tumour necrosis factor-alpha.

RESULTS

We found significantly higher levels of IL-10, IL-1beta, IL-4 and IL-2 in both MCI groups (P<0.001), while there was no significant difference in inflammatory markers between dementia groups and controls. Furthermore, increased disease severity was associated with lower levels of IL-1beta, IL-2 and IL-4 (P<0.05).

INTERPRETATION

We have shown for the first time that in both DLB and AD, increased peripheral inflammation occurs early at the MCI disease stages. These data support a role for inflammation early in the disease process, and have important implications for the stage of disease where trials of anti-inflammatory medication should be focused.

Update on the Risk of Motor Vehicle Collision or Driving Impairment with Dementia: A Collaborative International Systematic Review and Meta-Analysis

Guidelines that physicians use to assess fitness to drive for dementia are limited in their currency, applicability, and rigor of development. Therefore, we performed a systematic review to determine the risk of motor vehicle collisions (MVCs) or driving impairment caused by dementia, in order to update international guidelines on driving with dementia. Seven literature databases (MEDLINE, CINAHL, Embase, etc.) were searched for all research studies published after 2004 containing participants with mild, moderate, or severe dementia. From the retrieved 12,860 search results, we included nine studies in this analysis, involving 378 participants with dementia and 416 healthy controls. Two studies reported on self-/informant-reported MVC risk, one revealing a four-fold increase in MVCs per 1,000 miles driven per week in 3 years prior, and the other showing no statistically significant increase over the same time span. We found medium to large effects of dementia on driving abilities in six of the seven recent studies that examined driving impairment. We also found that persons with dementia were much more likely to fail a road test than healthy controls (RR: 10.77, 95% CI: 3.00-38.62, z = 3.65, p < 0.001), with no significant heterogeneity (χ² = 1.50, p = 0.68, I² = 0%) in a pooled analysis of four studies. Although the limited data regarding MVCs are equivocal, even mild stages of dementia place patients at a substantially higher risk of failing a performance-based road test and of demonstrating impaired driving abilities on the road.

Symptoms associated with Lewy body disease in mild cognitive impairment

OBJECTIVE

Dementia with Lewy bodies (DLB) is associated with a range of cognitive and non-cognitive symptoms. We aimed to identify if some of these symptoms might aid early diagnosis of Lewy body disease in cases of mild cognitive impairment (MCI).

METHODS

Lewy body MCI (MCI-LB; n = 36), Alzheimer's disease MCI (MCI-AD; n = 21), DLB (n = 36), AD (n = 21) and control (n = 20) participants were recruited. An interview-based questionnaire about the presence of symptoms thought to be associated with Lewy body disease was completed by participants with, where possible, their carer/relative. The prevalence of each symptom was compared between MCI-LB and MCI-AD and between established DLB and AD, and a symptom scale based on these findings was devised.

RESULTS

Fluctuating concentration/attention; episodes of confusion; muscle rigidity; changes in hand-writing, gait and posture; falls; drooling; weak voice; symptoms of REM sleep behaviour disorder (RBD) and misjudging objects were more common in MCI-LB compared with MCI-AD, and also in DLB compared with AD. Hyposmia, tremor, slowness and autonomic symptoms were not specific to Lewy body disease. REM sleep behaviour disorder and hyposmia were reported to develop several years prior to the onset of cognitive symptoms in Lewy body disease. A 10-point symptom scale differentiated between MCI-LB and MCI-AD with a sensitivity of 83% and a specificity of 100%.

CONCLUSIONS

Drooling, misjudging objects and symptoms related to parkinsonism, fluctuating cognition and RBD may be the most characteristic symptoms of MCI-LB. Slowness, tremor, autonomic symptoms and hyposmia are all common in MCI-LB but are not specific to the disease. Copyright © 2017 John Wiley & Sons, Ltd.

Short communication: Iodine concentrations in serum, milk, and tears after feeding Ascophyllum nodosum to dairy cows-A pilot study

Kelp (Ascophyllum nodosum) is rich in iodine and often fed by organic dairy producers as a mineral supplement to support animal health. A commonly held belief is that kelp supplementation decreases susceptibility to infectious bovine keratoconjunctivitis due to increased iodine concentrations in tears. Whereas serum and milk iodine concentrations are positively correlated and modulated by oral iodine supplementation, nothing is known about the iodine concentration of tears. Therefore, the 3 objectives of this pilot study were to determine (1) the iodine content of tears, milk, and serum of cows after being fed kelp for 30d; (2) the trace mineral and thyroid status of cows before (d 0) and after being fed kelp for 30d; and (3) the in vitro growth rate of bacteria in tears (Moraxella bovis) or milk (Staphylococcus aureus, Escherichia coli, Streptococcus uberis) collected from cows fed no kelp (d 0) or kelp (d 30). Cows (n=3/treatment) were individually fed 56g of kelp per day (n=3/treatment) or not (n=3/no treatment) for 30 d. Daily feed intake of the TMR was recorded and weekly TMR, kelp, milk, blood and tear samples were collected and analyzed for iodine. The feed samples were pooled and further analyzed for other minerals. On d 0 and 30, liver biopsies and blood samples were collected and analyzed for mineral content and thyroid hormone concentrations, respectively. An inhibition test used milk and tear-soaked plates from kelp-fed cows (d 0 and 30) as well as 1 and 7.5% iodine as positive and distilled water as negative control. As expected, serum iodine concentrations were positively correlated with milk and tear iodine concentrations. Whereas the iodine concentrations in serum increased significantly in the kelp-fed cows during the 30-d study, milk and tear iodine concentrations increased only numerically in these cows compared with the control group. Liver mineral profiles were comparable between groups and generally did not change over the course of the study. Thyroid hormones remained overall within the reference range throughout the trial. Neither milk nor tears from kelp-fed cows inhibited in vitro growth of any of the plated bacteria. In summary, serum iodine concentration was correlated with the iodine concentration in milk and tears and feeding kelp increased only the serum iodine levels of cows in this trial. Bacterial growth was not inhibited in milk and tears of kelp-fed cattle in vitro, and prevention of infectious bovine keratoconjunctivitis would not be based solely on increased iodine concentrations in tears.

An evidence-based algorithm for the utility of FDG-PET for diagnosing Alzheimer's disease according to presence of medial temporal lobe atrophy

BACKGROUND

Imaging biomarkers for Alzheimer's disease include medial temporal lobe atrophy (MTLA) depicted on computed tomography (CT) or magnetic resonance imaging (MRI) and patterns of reduced metabolism on fluorodeoxyglucose positron emission tomography (FDG-PET).

AIMS

To investigate whether MTLA on head CT predicts the diagnostic usefulness of an additional FDG-PET scan.

METHOD

Participants had a clinical diagnosis of Alzheimer's disease (n = 37) or dementia with Lewy bodies (DLB; n = 30) or were similarly aged controls (n = 30). We visually rated MTLA on coronally reconstructed CT scans and, separately and blind to CT ratings, abnormal appearances on FDG-PET scans.

RESULTS

Using a pre-defined cut-off of MTLA ⩾5 on the Scheltens (0-8) scale, 0/30 controls, 6/30 DLB and 23/30 Alzheimer's disease had marked MTLA. FDG-PET performed well for diagnosing Alzheimer's disease v DLB in the low-MTLA group (sensitivity/specificity of 71%/79%), but in the high-MTLA group diagnostic performance of FDG-PET was not better than chance.

CONCLUSIONS

In the presence of a high degree of MTLA, the most likely diagnosis is Alzheimer's disease, and an FDG-PET scan will probably not provide significant diagnostic information. However, in cases without MTLA, if the diagnosis is unclear, an FDG-PET scan may provide additional clinically useful diagnostic information.

Lessons from a pilot and feasibility randomised trial in depression (Blood pressure Rapid Intensive Lowering And Normal Treatment for Mood and cognition in persistent depression (BRILiANT mood study))

BACKGROUND

The blood pressure rapid intensive lowering and normal treatment for mood and cognition in persistent depression (BRILiANT mood study) was devised as a pilot study to investigate the feasibility and safety of intensive blood pressure lowering as treatment for persistent mood and cognitive symptoms in older adults with major depressive disorder and to assess the availability of this population for recruitment. In addition, the relationship between reduced blood pressure and the change in cerebral blood flow and mood was to be investigated.

METHODS

A single centre pilot randomised controlled trial (RCT), with two parallel groups of intensive or normal treatment for hypertension, recruiting from primary and secondary care and newspaper advert, with an aim of recruiting 66 participants, was observed in this study. At the end of the recruitment period, in order to explore the reasons for failure to recruit to target, surveys were developed and issued to those involved in recruitment.

RESULTS

Recruitment rates were lower than expected which led to the study being expanded to further areas and opened to self-referral via advertisement. However, because of better management of hypertension due to changes in the UK Quality and Outcomes Framework guidelines for blood pressure treatment, few eligible patients were identified and the study closed at the end of the recruitment period, with 13 participants consenting, but 12 failing screening resulting in one recruited participant.

CONCLUSIONS

Overall, the BRILiANT mood study was found not to be feasible, and results suggest that the expected patient population no longer exists. To overcome such recruitment difficulties, a prompt commencement of a study after funding so no relevant care changes occur might help prevent similar problems in future studies. In addition, self-referral, in this case via advertisement in papers, may be a useful tool to increase response rate. When recruiting in primary care, direct access to primary care databases, in a secure and anonymised way, may enable more effective screening. Ultimately, the BRILiANT mood study was shown not to be feasible; this was a useful conclusion from this pilot study.

TRIAL REGISTRATION

ISRCTN 64524251; UKCRN Portfolio No: 13284.

MAVEN observations of the response of Mars to an interplanetary coronal mass ejection

Coupling between the lower and upper atmosphere, combined with loss of gas from the upper atmosphere to space, likely contributed to the thin, cold, dry atmosphere of modern Mars. To help understand ongoing ion loss to space, the Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft made comprehensive measurements of the Mars upper atmosphere, ionosphere, and interactions with the Sun and solar wind during an interplanetary coronal mass ejection impact in March 2015. Responses include changes in the bow shock and magnetosheath, formation of widespread diffuse aurora, and enhancement of pick-up ions. Observations and models both show an enhancement in escape rate of ions to space during the event. Ion loss during solar events early in Mars history may have been a major contributor to the long-term evolution of the Mars atmosphere.

Early MAVEN Deep Dip campaign reveals thermosphere and ionosphere variability

The Mars Atmosphere and Volatile Evolution (MAVEN) mission, during the second of its Deep Dip campaigns, made comprehensive measurements of martian thermosphere and ionosphere composition, structure, and variability at altitudes down to ~130 kilometers in the subsolar region. This altitude range contains the diffusively separated upper atmosphere just above the well-mixed atmosphere, the layer of peak extreme ultraviolet heating and primary reservoir for atmospheric escape. In situ measurements of the upper atmosphere reveal previously unmeasured populations of neutral and charged particles, the homopause altitude at approximately 130 kilometers, and an unexpected level of variability both on an orbit-to-orbit basis and within individual orbits. These observations help constrain volatile escape processes controlled by thermosphere and ionosphere structure and variability.

Elevated odds of metabolic syndrome in psoriasis: a population-based study of age and sex differences

BACKGROUND

Questions remain concerning to what extent age and sex may modify the suggested association between psoriasis and the metabolic syndrome in the general population.

OBJECTIVES

To investigate the association between psoriasis and the metabolic syndrome within a large population-based cohort by age and sex.

METHODS

A cross-sectional study including 10 521 participants aged 30-79 years from the Tromsø Study cohort was performed; 1137 participants reported lifetime psoriasis of a mainly mild character. The new harmonized definition of metabolic syndrome was used in the multivariable logistic regression analysis.

RESULTS

There was a uniformly higher prevalence of metabolic syndrome in men and women with psoriasis compared with those without across all age groups. In women, psoriasis was associated with a 3·8-times higher odds of metabolic syndrome at age 30 years (95% confidence interval 1·5-9·7), with a decreasing odds ratio with increasing age. In men, psoriasis was associated with a stable 1·35-times higher odds of metabolic syndrome (95% confidence interval 1·1-1·6) at all ages. Abdominal obesity was the most frequent metabolic syndrome component in women in this study, and there was indication of a dose-response relationship between psoriasis severity, indicated through treatment, and having a high waistline in women.

CONCLUSIONS

This study suggests age and sex variations in the risk of metabolic syndrome among individuals with psoriasis. Given the high prevalence of psoriasis and the significantly elevated burden of metabolic syndrome in this patient group, there may be a benefit from targeted screening of metabolic syndrome among individuals with psoriasis regardless of age and disease severity.

Mild cognitive impairment: safe to drive?

Driving is an important aspect of daily living and for many older people provides autonomy and psycho-social benefits. Cognitive impairment has been found to impact driving skills at the level of dementia, however, uncertainty remains around the impact of a diagnosis of the pre-dementia condition mild cognitive impairment. Current official guidelines are unclear, and assessment of fitness to drive can be problematical. This editorial examines current official guidance available to the clinician and problems with existing assessment as well as the current position of research specifically into MCI and driving, and considers future direction for research in this field.

Gene flow and population structure of a common agricultural wild species (Microtus agrestis) under different land management regimes

The impact of landscape structure and land management on dispersal of populations of wild species inhabiting the agricultural landscape was investigated focusing on the field vole (Microtus agrestis) in three different areas in Denmark using molecular genetic markers. The main hypotheses were the following: (i) organic farms act as genetic sources and diversity reservoirs for species living in agricultural areas and (ii) gene flow and genetic structure in the agricultural landscape are influenced by the degree of landscape complexity and connectivity. A total of 443 individual voles were sampled within 2 consecutive years from two agricultural areas and one relatively undisturbed grassland area. As genetic markers, 15 polymorphic microsatellite loci (nuclear markers) and the central part of the cytochrome-b (mitochondrial sequence) were analysed for all samples. The results indicate that management (that is, organic or conventional management) was important for genetic population structure across the landscape, but that landscape structure was the main factor shaping gene flow and genetic diversity. More importantly, the presence of organically managed areas did not act as a genetic reservoir for conventional areas, instead the most important predictor of effective population size was the amount of unmanaged available habitat (core area). The relatively undisturbed natural area showed a lower level of genetic structuring and genetic diversity compared with the two agricultural areas. These findings altogether suggest that political decisions for supporting wildlife friendly land management should take into account both management and landscape structure factors.