No link between handedness and spatial navigation: evidence from over 400 000 participants in 41 countries

There is an active debate concerning the association of handedness and spatial ability. Past studies used small sample sizes. Determining the effect of handedness on spatial ability requires a large, cross-cultural sample of participants and a navigation task with real-world validity. Here, we overcome these challenges via the mobile app Sea Hero Quest. We analysed the navigation performance from 422 772 participants from 41 countries and found no reliable evidence for any difference in spatial ability between left- and right-handers across all countries. A small but growing gap in performance appears for participants over 64 years old, with left-handers outperforming right-handers. Further analysis, however, suggests that this gap is most likely due to selection bias. Overall, our study clarifies the factors associated with spatial ability and shows that left-handedness is not associated with either a benefit or a deficit in spatial ability.

Cultural determinants of the gap between self-estimated navigation ability and wayfinding performance: evidence from 46 countries

Cognitive abilities can vary widely. Some people excel in certain skills, others struggle. However, not all those who describe themselves as gifted are. One possible influence on self-estimates is the surrounding culture. Some cultures may amplify self-assurance and others cultivate humility. Past research has shown that people in different countries can be grouped into a set of consistent cultural clusters with similar values and tendencies, such as attitudes to masculinity or individualism. Here we explored whether such cultural dimensions might relate to the extent to which populations in 46 countries overestimate or underestimate their cognitive abilities in the domain of spatial navigation. Using the Sea Hero Quest navigation test and a large sample (N = 383,187) we found cultural clusters of countries tend to be similar in how they self-rate ability relative to their actual performance. Across the world population sampled, higher self-ratings were associated with better performance. However, at the national level, higher self-ratings as a nation were not associated with better performance as a nation. Germanic and Near East countries were found to be most overconfident in their abilities and Nordic countries to be most under-confident in their abilities. Gender stereotypes may play a role in mediating this pattern, with larger national positive attitudes to male stereotyped roles (Hofstede's masculinity dimension) associated with a greater overconfidence in performance at the national level. We also replicate, with higher precision than prior studies, evidence that older men tend to overestimate their navigation skill more than other groups. These findings give insight into how culture and demographics may impact self-estimates of our abilities.

Entropy and a sub-group of geometric measures of paths predict the navigability of an environment

Despite extensive research on navigation, it remains unclear which features of an environment predict how difficult it will be to navigate. We analysed 478,170 trajectories from 10,626 participants who navigated 45 virtual environments in the research app-based game Sea Hero Quest. Virtual environments were designed to vary in a range of properties such as their layout, number of goals, visibility (varying fog) and map condition. We calculated 58 spatial measures grouped into four families: task-specific metrics, space syntax configurational metrics, space syntax geometric metrics, and general geometric metrics. We used Lasso, a variable selection method, to select the most predictive measures of navigation difficulty. Geometric features such as entropy, area of navigable space, number of rings and closeness centrality of path networks were among the most significant factors determining the navigational difficulty. By contrast a range of other measures did not predict difficulty, including measures of intelligibility. Unsurprisingly, other task-specific features (e.g. number of destinations) and fog also predicted navigation difficulty. These findings have implications for the study of spatial behaviour in ecological settings, as well as predicting human movements in different settings, such as complex buildings and transport networks and may aid the design of more navigable environments.

Zero the hero: Evidence for involvement of the ventromedial prefrontal cortex in affective bias for free items

Recent evidence from psycho-economics shows that when the price of an item decreases to the extent that it becomes available for free, one can observe a remarkable increase of subjective utility toward this item. This phenomenon, which is not observed for any other price but zero, has been termed the zero-price effect (ZPE). The ZPE is attributed to an affective heuristic where the positive affect elicited by the free status of an item provides a mental shortcut biasing choice towards that item. Given that the ZPE relies on affective processing, a key role of the ventromedial prefrontal cortex (vmPFC) has been proposed, yet neuroscientific studies of the ZPE remain scarce. This study aimed to explore the role of the vmPFC in the ZPE using a novel, within-subject assessment in participants with either an acquired (lesion patients) or degenerative (behavioural-variant frontotemporal dementia patients) lesion of the vmPFC, and age-matched healthy controls. All participants were asked to make a series of choices between pairs of items that varied in price. One choice trial involved an equal decrease of both item prices, such that one of the items was priced zero. In contrast to controls, patients with both vmPFC-lesion and behavioural-variant frontotemporal dementia showed marked reductions in zero-related changes of preference in pairs of gift-cards, but not for pairs of food items. Our findings suggest that affective evaluations driving the ZPE are altered in patients with focal or degenerative damage to the vmPFC. This supports the notion of a key role of the vmPFC in the ZPE and, more generally, the importance of this region in value-based affective decision-making. Our findings also highlight the potential utility of affective heuristic tasks in future clinical assessments.

Reported sleep duration reveals segmentation of the adult life-course into three phases

Classically the human life-course is characterized by youth, middle age and old age. A wide range of biological, health and cognitive functions vary across this life-course. Here, using reported sleep duration from 730,187 participants across 63 countries, we find three distinct phases in the adult human life-course: early adulthood (19-33yrs), mid-adulthood (34-53yrs), and late adulthood (54+yrs). They appear stable across culture, gender, education and other demographics. During the third phase, where self-reported sleep duration increases with age, cognitive performance, as measured by spatial navigation, was found to have an inverted u-shape relationship with reported sleep duration: optimal performance peaks at 7 hours reported sleep. World-wide self-reported sleep duration patterns are geographically clustered, and are associated with economy, culture, and latitude.

AB1430 COMPARISON OF COGNITIVE ABILITY ACROSS THE IMMUNE MEDIATED INFLAMMATORY DISEASES: SYSTEMATIC REVIEW AND META-REGRESSION

Background

Age strongly influences cognitive ability. Previous studies have tried to compare the cognitive ability of people with different immune mediated inflammatory diseases (IMIDS: systemic lupus erythematosus [SLE], rheumatoid arthritis [RA], axial spondyloarthritis [axSpA], psoriatic arthritis [PsA], psoriasis [PsO]) in age-matched analyses. However, given the varying age of onset of these conditions, within direct age-matched comparisons one of the disease groups is necessarily older/younger than typical.

Objectives

(i) To perform a systematic review of the cognitive ability of people with IMIDs compared with age-matched controls, and (ii) use meta-regression to indirectly compare the cognitive ability of people with different IMIDs.

Methods

A search strategy was implemented in the Medline, Embase and PsychInfo databases on 29.5.2021. Identified studies were screened by two reviewers, selecting observational studies comparing the cognitive ability of people with an IMID against healthy controls. This abstract only includes studies reporting overall cognition scores, memory scores and attention scores. The standardised mean differences (SMDs) of the cognitive assessments between people with IMIDs and controls were pooled using random-effects meta-analysis, stratified by IMID. The IMIDs were compared using meta-regression, to identify the IMID with the greatest impairment in cognitive ability compared with healthy people of a similar age (inclusion cut-off: ≥5 studies).

Results

In total, 62 studies (SLE: 37, RA: 18, axSpA: 1, PsA: 2, PsO: 4) were included in the meta-analyses. People with IMIDs had moderate impairments in overall cognition, memory and attention compared with controls (Table 1), with similar results seen when limiting analyses to studies which included age-matched controls (N=48 studies). People with SLE and RA had similar levels of impairment compared with controls of comparable age in terms of overall cognition (coef: -0.12 (95% CI -0.42, 0.19) and attention (coef: -0.35 (95% CI -0.73, 0.04)). Other IMIDs and cognition dimensions were not included in the meta-regression analysis due to lack of studies.

Table 1.

Results of meta-analyses

Standardised mean difference (95% Confidence Interval) [N studies]Systemic lupus erythematosusRheumatoid arthritisAxial spondyloarthritisPsoriatic arthritisPsoriasisOverall cognitionAll-0.55 (-0.70. -0.39) [18]-0.59 (-0.82, -0.35) [13]-0.66 (-1.11, -0.21) [1]-0.50 (-0.78, -0.21) [2]-0.51 (-1.09, 0.07) [3]Age-matched-0.55 (-0.72, -0.38) [14]-0.66 (-0.92, -0.41) [11]-0.66 (-0.11, -0.21) [1]-0.61 (-1.08, -0.14) [1]-0.77 (-1.39, -0.16) [2]AttentionAll-0.51 (-0.63, -0.38) [27]-0.79 (-1.10, -0.47) [9]-0.58 (-1.03, -0.13) [1]--0.14 (-0.42, 0.14) [2]Age-matched-0.51 (-0.67, -0.36) [21]-0.87 (-1.35, -0.39) [6]-0.58 (-1.03, -0.14) [1]--0.36 (-0.75, 0.04) [1]Verbal memory (immediate)All-0.59 (-0.79, -0.38) [19]-1.00 (-1.47, -0.53) [7]---0.52 (-1.05, 0.02) [3]Age-matched-0.61 (-0.90, -0.32) [12]-1.42 (-1.73, -1.12) [4]---0.72 (-1.42, -0.02) [2]Verbal memory (delayed)All-0.44 (-0.57, -0.31) [18]-0.93 (-1.48, -0.38) [5]-0.23 (-0.67, 0.21) [1]--0.52 (-1.52, 0.49) [2]Age-matched-0.39 (-0.56, -0.21) [12]-1.40 (-1.76, -1.03) [3]-0.23 (-0.67, 0.21) [1]--1.05 (-1.47, -0.63) [1]Non-Verbal memory (immediate)All-0.41 (-0.57, -0.25) [15]-0.32 (-1.23, 0.58) [1]-0.21 (-0.62, 0.23) [1]--Age-matched-0.34 (-0.52, -0.16) [10]--0.21 (-0.62, 0.23) [1]--Non-Verbal memory (delayed)All-0.45 (-0.63, -0.27) [16]-0.41 (-0.91, 0.08) [1]-0.14 (-0.58, 0.30) [1]--Age-matched-0.46 (-0.75, -0.17) [10]-0.41 (-0.91, 0.08) [1]-0.14 (-0.58, 0.30) [1]--

Conclusion

People with IMIDs have significant impairments in terms of overall cognition, memory and attention. Whilst this indirect analysis shows that people with SLE and RA have a similar magnitude of impairment compared with healthy controls of a similar age, a number of factors could be influencing this finding (e.g. selection bias, demographic differences).

Disclosure of Interests

None declared

THU0130 PATTERNS OF COGNITIVE DECLINE IN RHEUMATOID ARTHRITIS: RESULTS OF CASE CONTROL STUDY NESTED IN A POPULATION-BASED COHORT

Background:

The risk of cognitive decline and dementia is of particular interest for patients exposed to prolonged inflammation. In rheumatoid arthritis (RA), the inflammatory mechanisms that are central to the disease’s pathology share many features with those seen in Alzheimer’s disease (AD). However, published reports on the strength and direction of the putative associations with cognitive decline and dementia in RA are conflicting and the potential impact of immunomodulation has not been fully established. This study reports on a case control analysis comparing the results of a cognitive test conducted in RA cases from a longitudinal population register with healthy controls. The relationship between test outcomes, disease characteristics, and treatment is examined.

Objectives:

To characterise differences in cognitive function as assessed by a validated test battery between a group of patients with RA and a matched sample of healthy controls.

To investigate disease and treatment related factors that might have an impact on the cognitive function of patients with RA.

Methods:

A total of 38 people with RA were selected at random from subjects who had enrolled on the Norfolk Arthritis Register as part of the ICORA (Investigation of Cognition in RA) Study. The register is a large longitudinal inception cohort of patients recruited from both primary and secondary care. The study subjects were over 55 years old with a diagnosis of RA defined by the ACR criteria. Cognitive function was assessed using the Addenbrooke’s Cognitive Examination III (ACE-III) battery. The ACE-III is a validated screening test for dementia that evaluates five cognitive domains (attention, memory, verbal fluency, language and visuospatial skills). A cut off value of 82 is indicative of cognitive impairment. The ACE-III scores in the cases were compared with scores from 29 healthy population-based controls matched for age and sex.

Results:

The mean age of the patient and control groups was 69 years. The RA patients had a mean disease duration of 9.8 years and had been taking DMARDs for 7.1 years. Among the patient group with RA, 14 (37%) scored below 82 compared with none in the group of healthy controls. The mean ACE-III scores of both groups are shown in the table below:

Controls N=29RA N=38ACE-III Total95.2 (3.7)85.2 (7.4)•Attention17.7 (0.5)16.5 (1.9)•Memory24.6 (1.9)19.8 (4.0)•Fluency12 (1.4)9.9 (2.6)•Language25.5 (0.8)24.6 (1.7)•Visuospatial15.8 (0.5)14.4 (1.5)

After adjusting for age, sex, BMI and smoking status, significant differences were seen in the ACE-III total (adjusted mean difference(SE)=8.67(1.77); p<0.001), memory (adjusted mean difference(SE)=4.16(1.03); p<0.001), fluency (adjusted mean difference(SE)=2.29(0.67); p=0.001) and visuospatial (adjusted mean difference(SE)=1.36(0.38); p<0.001). There was no difference in attention (p=0.19) or language (p=0.10).

Among the patients with RA there was no clear association between disease duration and ACE-III Total scores; however, there was a trend for increasing cognitive scores in those who had been taking DMARDs for longer (<5 years: mean ACE-III Total=84.1; 5-10 years: 85.0: 11-14 years: 85.4; >14 years: 89.6).

Conclusion:

This study provides evidence to suggest that patients with established RA are at increased risk of cognitive decline when compared with healthy controls. The pattern of cognitive deficit, predominantly involving visuospatial and memory function, is consistent with an Alzheimer’s disease profile. Our data suggest a potential role for DMARDs in reducing the rate of cognitive decline in patients with RA.

Disclosure of Interests:

Tasuku Toyoda: None declared, Jacqueline Chipping: None declared, Jack Dainty: None declared, Stephen Jeffs: None declared, Michael Hornberger: None declared, Eneida Mioshi: None declared, Suzanne Verstappen Grant/research support from: BMS, Consultant of: Celltrion, Speakers bureau: Pfizer, Max Yates: None declared, Alex MacGregor: None declared

Menopause, cognition and dementia - A review

There is increasing evidence that menopausal changes can have an impact on women’s cognition and potentially, the future development of dementia. In particular, the role of reduced levels of estrogen in postmenopausal changes has been linked to an increased risk of developing dementia in observational studies. Not surprisingly, this has led to several clinical trials investigating whether postmenopausal hormone replacement therapy can potentially delay/avoid cognitive changes and subsequently, the onset of dementia. However, the evidence of these trials has been mixed, with some showing positive effects while others show no or even negative effects. In the current review, we investigate this controversy further by reviewing the existing studies and trials in cognition and dementia. Based on the current evidence, we conclude that previous approaches may have used a mixture of women with different genetic risk factors for dementia which might explain these contradicting findings. Therefore, it is recommended that future interventional studies take a more personalised approach towards hormone replacement therapy use in postmenopausal women, by taking into account the women’s genetic status for dementia risk.

Eye tracking - The overlooked method to measure cognition in neurodegeneration?

Eye tracking (ET) studies are becoming increasingly popular due to rapid methodological and technological advances as well as the development of cost efficient and portable eye trackers. Although historically ET has been mostly employed in psychophysics or developmental cognition studies, there is also promising scope to use ET for movement disorders and measuring cognitive processes in neurodegeneration. Particularly, ET can be a powerful tool for cognitive and neuropsychological assessments of patients with pathologies affecting motor and verbal abilities, as tasks can be adapted without requiring motor (except eye movements) or verbal responses. In this review, we will examine the existing evidence of ET methods in neurodegenerative conditions and its potential clinical impact for cognitive assessment. We highlight that current evidence for ET is mostly focused on diagnostics of cognitive impairments in neurodegenerative disorders, where it is debatable whether it has any more sensitivity or specificity than existing cognitive assessments. By contrast, there is currently a lack of ET studies in more advanced disease stages, when patients' motor and verbal functions can be significantly affected, and standard cognitive assessments are challenging or often not possible. We conclude that ET is a promising method not only for cognitive diagnostics but more importantly, for potential cognitive disease tracking in progressive neurodegenerative conditions.

The behavioural variant frontotemporal dementia phenocopy syndrome is a distinct entity - evidence from a longitudinal study

Background

This study aimed to i) examine the frequency of C9orf72 expansions in a cohort of patients with the behavioural variant frontotemporal dementia (bvFTD) phenocopy syndrome, ii) observe outcomes in a group of phenocopy syndrome with very long term follow-up and iii) compare progression in a cohort of patients with the phenocopy syndrome to a cohort of patients with probable bvFTD.

Methods

Blood was obtained from 16 phenocopy cases. All met criteria for possible bvFTD and were labeled as phenocopy cases if they showed no functional decline, normal cognitive performance on the Addenbrooke’s Cognitive Examination-Revised (ACE-R) and a lack of atrophy on brain imaging, over at least 3 years of follow-up. In addition, we obtained very long term follow-up data in 6 cases. A mixed model analysis approach determined the pattern of change in cognition and behaviour over time in phenocopy cases compared to 27 probable bvFTD cases.

Results

All 16 patients were screened for the C9orf72 expansion that was present in only one (6.25%). Of the 6 cases available for very long-term follow-up (13 - 21 years) none showed progression to frank dementia. Moreover, there was a decrease in the caregiver ratings of behavioural symptoms over time. Phenocopy cases showed significantly slower rates of progression compared to probable bvFTD patients (p < 0.006).

Conclusion

The vast majority of patients with the bvFTD phenocopy syndrome remain stable over many years. An occasional patient can harbor the C9orf72 expansion. The aetiology of the remaining cases remains unknown but it appears very unlikely to reflect a neurodegenerative syndrome due to lack of clinical progression or atrophy on imaging.

Dissociation of explicit and implicit long-term memory consolidation in semantic dementia: a case study

We report a case study of a semantic dementia patient, whose episodic memory consolidation was tested over a 2-month period. The results reveal that despite early retention of information, the patient lost all explicit information of the newly learnt material after 2 weeks. By contrast, he retained implicit word information even after a 4-week delay. These findings highlight the critical time window of 2-4 weeks in which newly learnt information should be re-encoded in rehabilitations studies. The results also indicate that learnt information can be still accessed with implicit retrieval strategies when explicit retrieval fails.

Neural correlates of activities of daily living in frontotemporal dementia

BACKGROUND

Little research to date has investigated neural correlates of functional disability in frontotemporal dementia (FTD).

METHODS

Activities of daily living (ADL) were covaried against gray matter atrophy regions via Voxel-based morphometry in FTD (n = 52) and contrasted against a dementia control Alzheimer disease (AD) group (n = 20) and healthy age-matched controls (n = 18).

RESULTS

Both patient groups had similar ADL scores. However, FTD and AD differed on the gray matter atrophy areas associated with ADL scores. The FTD showed involvement of prefrontal and thalamus regions while AD showed widespread temporal, parietal, frontal, and caudate atrophy correlating with ADL dysfunction. Importantly, only the left superior frontal gyrus was implicated in ADL dysfunction for both FTD and AD.

CONCLUSIONS

Differences in underlying neural correlates of ADL impairment have important clinical implications as these differences should be taken into account when interventions are planned. Dementia subtypes might require specifically tailored interventions for functional disability.

Saccadic abnormalities in frontotemporal dementia

OBJECTIVE

To characterize saccadic eye movements, as a marker of decision-making processes, in frontotemporal dementia (FTD).

METHODS

Saccadometry was performed on a cross-section of patients with FTD, using a portable saccadometer, and results compared to matched control subjects. We used the Linear Approach to Threshold with Ergodic Rate model to generate measures of decision-making speed and incidence of early saccades. Patterns of cortical atrophy were related to decision-making processes using voxel-based morphometry (VBM) analysis.

RESULTS

A total of 45 subjects (22 FTD: 10 with behavioral variant FTD and 12 with primary progressive aphasia, and 23 controls) were studied. A measure of decision-making speed, μ, was reduced in FTD, resulting in prolonged saccadic latency, but the incidence of early saccades was increased compared to controls. In addition, performance on an antisaccade task was poor in FTD compared to controls. Decision-making speed and the incidence of early saccades were independently correlated with atrophy of the left frontal eye field, and decision-making speed also correlated with atrophy of the left cingulate eye field.

CONCLUSION

Saccades are abnormal in FTD, reflecting reduced decision-making speed, and these abnormalities related to atrophy of the left frontal eye field. In addition, patients with FTD had an increased incidence of early saccades, which may be due to reduced inhibition of primitive responses.

Brain correlates of musical and facial emotion recognition: evidence from the dementias

The recognition of facial expressions of emotion is impaired in semantic dementia (SD) and is associated with right-sided brain atrophy in areas known to be involved in emotion processing, notably the amygdala. Whether patients with SD also experience difficulty recognizing emotions conveyed by other media, such as music, is unclear. Prior studies have used excerpts of known music from classical or film repertoire but not unfamiliar melodies designed to convey distinct emotions. Patients with SD (n = 11), Alzheimer's disease (n = 12) and healthy control participants (n = 20) underwent tests of emotion recognition in two modalities: unfamiliar musical tunes and unknown faces as well as volumetric MRI. Patients with SD were most impaired with the recognition of facial and musical emotions, particularly for negative emotions. Voxel-based morphometry showed that the labelling of emotions, regardless of modality, correlated with the degree of atrophy in the right temporal pole, amygdala and insula. The recognition of musical (but not facial) emotions was also associated with atrophy of the left anterior and inferior temporal lobe, which overlapped with regions correlating with standardized measures of verbal semantic memory. These findings highlight the common neural substrates supporting the processing of emotions by facial and musical stimuli but also indicate that the recognition of emotions from music draws upon brain regions that are associated with semantics in language.

Orbitofrontal dysfunction discriminates behavioral variant frontotemporal dementia from Alzheimer's disease

BACKGROUND

Behavioral variant frontotemporal dementia (bvFTD) patients show prefrontal cortex dysfunction and atrophy.

METHODS

We investigated whether executive function in conjunction with prefrontal cortex atrophy discriminates bvFTD and Alzheimer's disease (AD) patients efficiently at presentation.

RESULTS

AD and bvFTD patients were distinguishable by 89.5% on their performance of 3 executive tasks: the Hayling Test of Inhibitory Control, Digit Span Backward and Letter Fluency. Similarly, scan ratings showed that orbitofrontal cortex (OFC) and dorsolateral prefrontal cortex regions distinguish both patient groups. More importantly, employing the Hayling error score in conjunction with the OFC atrophy rating showed that 92% of patients can be correctly classified into bvFTD and AD.

CONCLUSION

A combination of OFC and disinhibition measures appears to be a powerful diagnostic tool in differentiating bvFTD from AD patients in this preliminary study.

How preserved is episodic memory in behavioral variant frontotemporal dementia?

OBJECTIVE

Studies have shown variable memory performance in patients with behavioral variant frontotemporal dementia (bvFTD). Our study investigated whether this variability is due to the admixture of patients with true bvFTD and phenocopy patients. We also sought to compare performance of patients with bvFTD and patients with Alzheimer disease (AD).

METHODS

We analyzed neuropsychological memory performance in patients with a clinical diagnosis of bvFTD divided into those who progressed (n = 50) and those who remained stable (n = 39), patients with AD (n = 64), and healthy controls (n = 64).

RESULTS

Patients with progressive bvFTD were impaired on most memory tests to a similar level to that of patients with early AD. Findings from a subset of patients with progressive bvFTD with confirmed FTLD pathology (n = 10) corroborated these findings. By contrast, patients with phenocopy bvFTD performed significantly better than progressors and patients with AD. Logistic regression revealed that patients with bvFTD can be distinguished to a high degree (85%) on the immediate recall score of a word list learning test (Rey Auditory Verbal Learning Test).

CONCLUSIONS

Our results provide evidence for an underlying memory deficit in "real" or progressive behavioral variant frontotemporal dementia (bvFTD) similar to Alzheimer disease, though the groups differ in orientation scores, with patients with bvFTD being intact. Exclusion solely based on impaired neuropsychological memory performance can potentially lead to an underdiagnosis of FTD.

Determinants of survival in behavioral variant frontotemporal dementia

BACKGROUND

Behavioral variant frontotemporal dementia (bvFTD) is a common cause of younger onset dementia. Little is known about its rate of progression but a recently identified subgroup seems to have an excellent prognosis. Other determinants of survival are unclear.

METHODS

We analyzed survival in a large group of clinically diagnosed bvFTD patients (n = 91) with particular attention to demographic and clinical features at presentation. Of the 91 cases, 50 have died, with pathologic confirmation in 28.

RESULTS

Median survival in the whole group was 9.0 years from symptom onset, and 5.4 years from diagnosis. After the exclusion of 24 "phenocopy" cases, the analysis was repeated in a subgroup of 67 patients. The mean age at symptom onset of the pathologic group was 58.5 years and 16% had a positive family history. Their median survival was 7.6 years (95% confidence interval [CI] 6.6-8.6) from symptom onset and 4.2 years (95% CI 3.4-5.0) from diagnosis. The only factor associated with shorter survival was the presence of language impairment at diagnosis.

CONCLUSIONS

Patients with definite frontotemporal dementia have a poor prognosis which is worse if language deficits are also present. This contrasts with the extremely good outcome in those with the phenocopy syndrome: of our 24 patients only 1 has died (of coincident pathology) despite, in some cases, many years of follow-up.

Are judgments of semantic relatedness systematically impaired in Alzheimer's disease?

We employed a triadic comparison task in patients with Alzheimer's disease (AD) and healthy controls to contrast (a) multidimensional scaling (MDS) and accuracy-based assessments of semantic memory, and (b) degraded-store versus degraded-access accounts of semantic impairment in Alzheimer's disease (AD). Similar to other studies using triadic comparison tasks, participants were asked to indicate which two out of three words (animal names) were most similar in meaning. Novel to this investigation, we contrasted performance on two semantic dimensions of strong and equal saliency to controls, but varying in their specificity (land/water versus bird/non-bird). Degraded-store accounts predict that the more specific bird/non-bird dimension should be more consistently impaired in AD, whereas degraded-access accounts predict that both dimensions, because they are equally salient, should be equivalently impaired in the disorder. The MDS results suggested that both patient and control group responses were not discriminable from random responding, consistent with previous studies. By contrast an accuracy-based analysis on the same data showed that controls showed good knowledge of both salient dimensions, and were evenly split in their individual preference for one dimension over another. In contrast, patients showed higher accuracy and sensitivity to the broader land/water dimension than to the more specific bird/non-bird dimension, consistent with a storage-based account of the semantic impairment in AD. Our results further suggest that MDS methods can fail to reveal important and systematic behaviour in semantic tasks, in both patient and control groups.

Can progressive and non-progressive behavioural variant frontotemporal dementia be distinguished at presentation?

BACKGROUND

Recent findings suggest that patients with behavioural variant frontotemporal dementia (bv-FTD) differ in their disease progression (progressive vs non-progressive patients). The current study investigates whether the two groups can be discriminated by their clinical features at first presentation.

METHODS

Archival clinical data of the Early Onset Dementia Clinic, Cambridge, UK, were analysed for 71 patients with bv-FTD: 45 progressive and 26 non-progressive cases with more than 3 years of follow-up.

RESULTS

The subgroups were largely indistinguishable on the basis of the presenting clinical features but could be distinguished on general cognitive (Addenbrooke's Cognitive Examination-revised) and selected supportive diagnostic features (distractibility, stereotypic speech, impaired activities of daily living (ADLs) and current depression).

CONCLUSIONS

Progressive and non-progressive patients are difficult to differentiate on the basis of current clinical diagnostic criteria for FTD but a combination of general cognitive, executive dysfunction and impaired ADL measures appear to be the most promising discriminators.

Sensitivity of current criteria for the diagnosis of behavioral variant frontotemporal dementia

BACKGROUND

Diagnosis of behavioral variant frontotemporal dementia (bvFTD) relies on criteria that are constraining and potentially ambiguous. Some features are open to clinical interpretation and their prevalence unknown. This study investigated the sensitivity of current diagnostic criteria in a large group of patients with bvFTD.

METHODS

Forty-five patients with clear evidence of bvFTD as judged by progressive clinical decline (>3 years) with marked frontal features and significant frontal brain atrophy on brain MRI were included. Thirty-two have died; pathologic confirmation of frontotemporal lobar degeneration was found in all 18 coming to autopsy. We established the prevalence of core and supportive diagnostic features at presentation and with disease progression.

RESULTS

Only 25/45 patients (56%) showed all five core features necessary for a diagnosis of bvFTD at initial presentation and 33/45 (73%) as their disease progressed. Two core features, emotional blunting and loss of insight, were never observed in 25% and 13% of cases. Executive dysfunction, hyperorality, mental inflexibility, and distractibility were the only supportive features present in >50% of cases at initial presentation. Although not a diagnostic feature, impaired activities of daily living was present in 33/45 patients (73%).

CONCLUSIONS

Strict application of the criteria misses a significant proportion of patients. Many supportive features have low prevalence and are clinically not useful. Revision of the criteria to include level of certainty (definite, probable, possible) dependent on the number of features present and the presence of ancillary information (e.g., brain atrophy, neuropsychological abnormalities, impaired activities of daily living) is encouraged.

Structure-specificity relationship of cardiac glycosides as a substrate for glucohydrolase II

Cardenolide glucohydrolase II (CGH II) is a cardenolide-specific glucohydrolase obtained from Digitalis lanata leaves. We investigated the structure-specificity relationship of several cardenolide disaccharides as a substrate for CGH II. Conformation analysis of the substrates was performed using molecular mechanics calculations. The sugar chain conformation of two inert glycosides was significantly different from that of the other glycosides. The other two glycosides, which were weak substrates of CGH II, were suggested to have an intramolecular hydrogen bond between the sugar groups. It was deduced that this hydrogen bond restricts the conformational change of the sugar chain and prevents the glycosides from enzymatic recognition.

[Ulrich and Ulrich oculo-oscillodynamography: results in patients with healthy eyes]

Ulrich and Ulrich's method of oculo-oscillodynamography (OODG) is a relatively new method which enables the systolic retinal, systolic ciliary, and systolic ocular perfusion pressure or respectively blood pressure to be measured. The results obtained by the present authors are in good agreement with those of Ulrich and Ulrich (n = 30). The intraocular pressure values obtained with this method correlate somewhat less well with the systemic blood pressure than is the case with suction cup ophthalmodynamometry. However, the correlation coefficients are sufficiently high to permit their application in ophthalmological diagnosis. The results presented here indicate that the diastolic ocular pressure should be determined by applying the formoscillatory criterion. The positive intercept in the regression equations can be explained by the assumption that the regression is curvilinear at systemic blood pressure values which are generally not encountered in humans in whom OODG is of diagnostic importance. It is suggested that the linear regression is a sufficiently exact model at the systemic blood pressures most frequently measured. Normal OODG values can be read off easily from the diagrams published here.

[Solid tumours of human primary hepatocellular carcinoma cell-lines in hypothymic mice: a model for biochemical and therapeutic studies (author's transl)]

HBsAg producing cell-lines of human primary hepatocellular carcinomas express a multitude of differentiated hepatocyte functions. They also grow in hypothymic (nude) mice as solid tumours. Here we describe the subcutaneous injection of cell-lines PLC/PRF/5, Hep 3B and Mahlavu (HBsAg negative) into hypothymic mice to produce a high tumour take without prior immunosuppressive treatment. Serial transplantation of tumour fragments into new animals allows the development of large homogeneous experimental groups and a substantial multiplication of tumour cell mass. The transplanted tumours from PLC/PRF/5 and Hep 3B cells continue to synthesize HBsAg and alpha-fetoprotein, and they secrete these proteins into the blood of their hosts. Fibrinogen and alpha 1-antitrypsin can be demonstrated in the cells of these two tumours but not in tumours originating from Mahlavu cells. This model offers experimental conditions to study the function of solid human primary liver cell carcinomas under the influence of an intact organism.

Demonstration of antiinflammatory activity of fibrinogen and fibrinopeptides in rats

Carrageenin-induced inflammatory rat paw swelling was significantly inhibited by intraperitoneal injection of rat fibrinogen. Whole-body radioscanning of the rat after intraperitoneal administration of 131I-labeled fibrinogen revealed the accumulation of radiolabeled material in the inflammed rat paw. Resorption studies showed that not more than 4% of the intraperitoneally administered [125I] fibrinogen could be demonstrated in the peripheral blood. Furthermore only 1/3 of this circulating radiolabeled protein was able to take part in clot formation, suggesting that inhibition of edema formation is mediated by fibrinogen-derived split products. This is further supported by the finding that rat fibrinopeptides, released by the action of thrombin, also diminish edema formation both after intracardial and intraperitoneal injection into carrageenin-stimulated rats.