BACKGROUND:Impaired cognition is a prominent feature of schizophrenia. To what extent the heterogeneous cognitive impairments can be accounted for by considering only a single underlying impairment or a small number of core impairments remains elusive. This study examined whether cognitive impairments in antipsychotic-naïve, first-episode schizophrenia patients may be determined by a relative slower speed of information processing.METHOD:Forty-eight antipsychotic-naïve patients with first-episode schizophrenia and 48 matched healthy controls were administered a comprehensive battery of neuropsychological tests to assess domains of cognitive impairments in schizophrenia. Composite scores were calculated, grouping tests into cognitive domains.RESULTS:There were significant differences between patients and healthy controls on global cognition and all cognitive domains, including verbal intelligence, processing speed, sustained attention, working memory, reasoning and problem solving, verbal learning and memory, visual learning and memory, and reaction time. All these significant differences, except for verbal intelligence and global cognition, disappeared when processing speed was included as a covariate.CONCLUSION:At the first stage of illness, antipsychotic-naïve patients with schizophrenia display moderate/severe impairments in all the cognitive domains assessed. The results support the contention of a global cognitive dysfunction in schizophrenia that to some extent may be determined by impaired processing speed.

OBJECTIVE:To investigate whether the cumulative number, duration and subtypes (severity and presence of psychotic features) of previous episodes of depression in patients with unipolar depressive disorder in a remitted state are associated with decreased global cognitive function.METHODS:Via the Danish registers individuals between 40 and 80 years of age were identified: (1) patients with a diagnosis of unipolar disorder at their first discharge from a psychiatric hospital in the period 1994 to 2002, and (2) gender and age matched control individuals. The participants were assessed with the Cambridge Cognitive Examination (CAMCOG), which provides a composite measure of global cognitive function.RESULTS:A total of 88 patients and 50 controls accepted our invitation to participate, fulfilled the selection criteria and were included in the study. The cumulative duration of depressive episodes was associated with a decreased CAMCOG score adjusted for age, gender, education, premorbid IQ and residual depressive symptoms (B=-0.14, 95% C.I. (-0.26, -0.02), R(2)adj=0.31, P=.02). Significant associations were also found between CAMCOG score and the cumulative duration and total number of depressive episodes with psychotic features, respectively.CONCLUSION:Our findings suggest that cognitive dysfunction is associated with the cumulative duration of depressive episodes, and that, in particular, depressive episodes with psychotic features in the course of illness may be a significant predictor of future impairment of cognitive function.

Methods for culturally and linguistically appropriate cognitive testing of elderly minority populations are lacking in Europe. The aim of this study was to compare performance on the Rowland Universal Dementia Assessment Scale (RUDAS) and the Mini Mental State Examination (MMSE) in Turkish immigrants in Denmark and determine the impact of demographic and health-related variables on test performance. A sample of non-demented community-dwelling Turkish immigrants was recruited from the greater Copenhagen area. All participants completed a structured interview regarding demographic, physical and mental health status, as well as measures of depression and acculturation, and cognitive testing with the RUDAS and the MMSE. A total of 76 non-demented participants aged 50 or more were included in the study. The mean performance on the RUDAS and the MMSE was 26.8 (SD 2.4) and 23.7 (SD 4.3), respectively. In group comparisons, correlation analyses and regression analyses, level of schooling represented a more significant variable for RUDAS and MMSE performance than any other variable. However, the impact of schooling was considerably more pronounced on the MMSE and the test was not found to be a valid measure of general cognitive function in subjects with less than five years of schooling. Although not entirely free of educational bias, the RUDAS can be a valuable supplement to the MMSE for assessment of general cognitive function in Turkish minority populations.

Objective: Among dementia professionals in several European countries, it is believed that dementia is under-diagnosed and under-treated to a greater extent among ethnic minorities than in the native population. It is unknown whether this belief holds true. The objective of this study was to compare the prevalence of register-based dementia diagnoses in the largest ethnic minority groups in Denmark with the prevalence of register-based dementia diagnoses in the general Danish population.Methods: By linking the Danish hospital registers with the Danish Civil Registration System, nationwide dementia cases for three main ethnic minorities were identified. Age- and gender-specific prevalence rates for dementia were calculated and compared to previously published data for the general population.Results: The study population consisted of 68 219 persons aged 20 and older. A total of 174 dementia cases were identified. The mean age at diagnosis was 57.7 years (SD = 16.2). Compared to the general population, there was a higher prevalence of dementia among those younger than 60 years, and a markedly lower prevalence of dementia among those 60 years and older.Conclusions: Dementia is under-diagnosed to a greater extent among ethnic minorities in the age group 60 years and older but is over-diagnosed in the age group younger than 60 years. Several factors may contribute to this pattern, including cultural differences in help-seeking behaviour, and problems in navigating the health-care system. Furthermore, cross-cultural assessment of dementia can be difficult because of language barriers and cultural differences. Copyright (C) 2010 John Wiley & Sons, Ltd.

Episodic memory tests that measure cued recall may be particularly effective in the diagnosis of early Alzheimer's disease (AD) because they examine both episodic and semantic memory functions. The Category Cued Recall (CCR) test provides super-ordinate semantic cues at encoding and retrieval, and high discriminative validity has been claimed for this test. The aim of this study was to investigate the discriminative validity for this test when compared with the 10-word memory list from Alzheimer's Disease Assessment Scale (ADAS-cog) that measures free recall. The clinical diagnosis of AD was taken as the standard. It was also investigated whether the two episodic memory tests correlated with measures of semantic memory. The tests were administered to 35 patients with very mild AD (Mini Mental State Examination score > 22) and 28 control subjects. Both tests had high sensitivity (> 88%) with high specificity (> 89%). One out of the five semantic memory tests was significantly correlated to performances on CCR, whereas delayed recall on the ADAS-cog memory test was significantly correlated to two semantic tests. In conclusion, the discriminative validity of the CCR test and the ADAS-cog memory test was equivalent in very mild AD. This may be because CCR did not tap more semantic processes, which are impaired in the earliest phases of AD, than a test of free recall.

We describe a patient, HE, who was left with a remarkably selective deficit in intermediate vision following an infarct in the right occipito-temporal region. Thus, HE was able to group elements by colour and proximity but impaired in grouping based on similarity in shape. This finding supports the notion that grouping may be divided into two general steps: (i) element clustering and (ii) shape configuration, with the latter operation being impaired in HE. As opposed to previous cases with shape integration deficits, HE was able to name objects accurately. Initially, this might suggest that shape integration is not a prerequisite for normal object naming. However, on more demanding tests of visual object recognition, HE's performance deteriorated, with her performance being inversely related to the demand placed on integration of local elements into more elaborate shape descriptions. From this we conclude that shape integration is important for normal object recognition.

Objectives To investigate the correlation between anosognosia and behavioural symptoms, performance on executive tests, and frontal cortex regional cerebral blood flow (rCBF) in patients with 'amnestic mild cognitive impairment' (MCI) and mild Alzheimer's disease (AD).Methods From a prospective Memory Clinic cohort including consecutively referred patients, age 60 years or above, and with MMSE score 20 or above, 36 patients with AD and 30 with MCI were included in this study. Anosognosia was assessed using a categorical scale and discrepancy scores between patients' and relatives' reports on a 20-item Memory Questionnaire (MQ). Behavioural symptoms were assessed with Frontal Behavioural Inventory (FBI). Executive functions were examined with a range of neuropsychological tests. Tc99m-HMPAO SPECT was obtained in an unselected sample of 55 of the 66 patients, and rCBF was analysed in six cortical frontal regions.Results Insight was equally impaired in the two patient groups. A significant correlation was found between impaired awareness and dementia severity (MMSE). Discrepancy-scores on the MQ were significantly correlated to scores on FBI and to rCBF in the right inferior frontal gyrus, but not to executive tests. The groups classified by the categorical ratings 'full', 'shallow' and 'no' awareness were not characterized by differences in behavioural symptoms, executive performance or frontal rCBF.Conclusions Impaired awareness is associated with behavioural symptoms and may reflect functional impairment in the right inferior frontal cortex. Copyright (c) 2005 John Wiley & Sons, Ltd.

Individuals with obsessive-compulsive disorder (OCD) display frontal lobe deficits, but there are inconsistencies between various tests of frontal lobe functions and between the results from different studies. The objective of this work was to characterize frontal lobe dysfunctions in OCD patients. Fifteen patients and 17 control subjects matched for age, sex and intelligence were tested on classic tests of frontal lobe functions [Wisconsin Card Sorting Test (WCST) and tests of fluency], a smell identification test and one computerized test: the Intra/Extra Dimension test. The Intra/Extra Dimension test showed a significant difference between the two groups in reversal of response. The test of Figural fluency showed a significant difference between the two groups in numbers of produced figures. There were no differences on the WCST, verbal fluency and the smell identification test.

Hereditary spastic paraplegia (HSP) linked to the spastic gait gene 4 (SPG4) is controversial, as the "pure" form traditionally has been considered confined to the long axons of the spinal cord. However, recent immunolabeling experiments have demonstrated extensive Spastin expression in the cortex and striatum. This could indicate a more widespread neuropathology from mutations in the SPG4 gene than previously assumed. The aim of this study was therefore to ascertain the extent of cerebral involvement in SPG4 linked HSP by neuropsychological examination and measurement of the regional cerebral blood flow (rCBF) as an indirect marker of regional neuronal activity. Eighteen SPG4 patients and 18 matched control subjects were studied. Resting state rCBF was measured using Positron Emission Tomography (PET) and the (15)O-labelled water bolus technique and relative group differences were explored using Statistical Parametric Mapping (SPM 99). Neuropsychological assessment was performed using established and nationally validated tests (RH Basic Battery). Compared to healthy controls, the patient group had significantly decreased rCBF in the left fronto-temporal cortex (P<0.05), and more extensive changes were observed in a separate analysis of the most disabled individuals. The neuropsychological assessment revealed only significantly impaired recognition memory for faces. In summary, the findings support cerebral pathology in SPG4-linked HSP, although the decreased rCBF in fronto-temporal cortex was not associated with severe cognitive impairment.

In this study we investigated impaired awareness of cognitive deficits in patients with mild cognitive impairment (MCI) and Alzheimer’s disease (AD). Very few studies have addressed this topic, and methodological inconsistencies make the comparison of previous studies difficult. From a prospective research program 36 consecutive patients with mild AD (MMSE above 19), 30 with amnesic MCI and 33 matched controls were examined. Using three methods for awareness assessment we found no significant differences in the level of awareness between MCI and AD. Both groups had impaired awareness and significant heterogeneity in the clinical presentation of awareness. The results demonstrate that subjective memory problems should not be a mandatory prerequisite in suspected dementia or MCI, which makes reports from informants together with thorough clinical interview and observation central when assessing suspected dementia disorders.

The presence and the nature of semantic memory dysfunction in Alzheimer's disease (AD) have been widely debated. This study aimed to determine the frequency of impaired semantic test performances in mild AD and to study whether incipient semantic impairments could be identified in predementia AD. Five short neuropsychological tests sensitive to semantic memory and easily applicable in routine practice were administered to 102 patients with mild AD (Mini-Mental State Examination score above 19), 22 predementia AD patients and 58 healthy subjects. 'Category fluency' and 'naming of famous faces' were the most frequently impaired tests in both patient groups. The study demonstrated that impairments on semantically related tests are common in mild AD and may exist prior to the clinical diagnosis. The results imply that assessment of semantic memory is relevant in the evaluation of patients with suspected AD.