The MAPP Room Memory Test: Examining Contextual Memory Using a Novel Computerized Test in Cognitively-Unimpaired Individuals with Autosomal Dominant Alzheimer's Disease

Contextual memory, the ability to remember spatial or temporal features related to an event, is affected in Alzheimer's disease (AD). There is a shortfall of tests that measure contextual memory. To evaluate visuospatial contextual memory, we developed a computerized cognitive test, the MAPP Room Memory Test, which requires participants to identify in which visual scene target items were previously presented. We hypothesized that cognitively-unimpaired carriers of an autosomal dominant AD mutation (Presenilin-1 E280A, n=15) would perform more poorly on this test than non-carrier family members (n=31). Compared to non-carriers, the carriers had significantly worse delayed room recognition. The results indicate that the MAPP Room Memory Test may be sensitive to subtle cognitive changes associated with risk of AD. Future studies with larger samples using the MAPP Room Memory Test and biomarkers are needed to examine whether this test may also be sensitive to the earliest pathological changes in preclinical AD.

Memory for Semantically Related Objects Differentiates Cognitively Unimpaired Autosomal Dominant Mutation Carriers from Non-Carrier Family Members

Early cognitive changes due to Alzheimer's disease (AD) include difficulties in semantic access and working memory. Using a computerized cognitive test developed by our group, called the Memory for Semantically Related Objects test (MESERO), we evaluated if cognitively unimpaired carriers of an autosomal dominant AD (ADAD) mutation performed worse on this test than non-carrier family members. 35 cognitively unimpaired ADAD mutation carriers and 26 non-carrier family members from a Colombian ADAD cohort took the MESERO on a laptop computer. Cognitively unimpaired ADAD carriers had significantly worse MESERO total scores than non-carrier family members, driven by worse performance in semantically-related object sets; group performances did not differ on semantically unrelated object sets. Findings suggest that MESERO performance may be sensitive to subtle cognitive changes associated with AD. Future MESERO research should examine performances between healthy older adults and people at risk for sporadic AD.

Characterization of neuropsychiatric symptoms in a group of individuals with manifest or pre-motor Huntington’s disease in Medellín, Colombia

Introduction

Huntington’s disease (HD) is a rare (1-9/100 000), inherited disease characterized by an elongated CAG repeat on chromosome 4p, leading to a degeneration of neurons. Also, psychiatric symptoms are very common in the early stage and may appear before motor symptoms.

Objectives

To characterize neuropsychiatric symptoms in a group of individuals with manifest or pre-motor Huntington’s disease in Medellín, Colombia.

Methods

Data obtained from clinical records of individuals with HD (motor-manifest or pre-motor with triplets count) evaluated for ENROLL-HD project in the Group of Neuroscience of Antioquia. We explored variables related to substances abuse, neuropsychiatric symptoms, the respective age of onset, sex, and triplet count when available.

Results

Twenty-six (53%) were women, 8% had a familiar history of psychotic illness in a first-degree relative and 88% presented motor symptoms. Also, 59% had a history of depression, 53% irritability, 57% aggressiveness, 34% apathy, 29% perseverative/obsessive behavior, 14% psychosis, and 30% mild cognitive impairment. Ten individuals (20%) had motor without neuropsychiatric symptoms. Also, thirty-seven individuals (76%) presented motor and neuropsychiatric symptoms; of these, 41% had neuropsychiatric symptoms before motor symptoms. No psychiatric symptoms were associated with the use of alcohol, cigarettes, or drugs of abuse.

Conclusions

Neuropsychiatric symptoms are highly prevalent among individuals with HD and studies oriented to create relevant knowledge for the development of advice oriented to people with this disease are necessary.

Disclosure

No significant relationships.

Nutritional Assessment in Patients with Early-Onset Autosomal Dominant Alzheimer's Disease Due to PSEN1- E280A Genetic Variant: A Cross-Sectional Study

Background

Weight loss and malnutrition are frequent findings in late-onset and sporadic presentations of Alzheimer's Disease (AD). However, less is known about nutritional status in Early-Onset Autosomal Dominant AD (EO-ADAD).

Objective

To analyze the association between nutritional status and other clinical and sociodemographic characteristics in individuals with a genetic form of EO-ADAD.

Design settings and participants

Cross-sectional study with 75 non-institutionalized participants from a cohort of Autosomal Dominant AD (13 with mild cognitive impairment and 61 with dementia, ages from 38 to 67 years) underwent a structured clinical assessment with emphasis on nutritional status.

Measurements

Primary outcome was nutritional status and it was measured using the Mini Nutritional Assessment (MNA). Patients were categorized according to MNA total score, as undernourished (MNA ≤23.5) and well-nourished (MNA ≥ 24). Sociodemographic and clinical variables identified as potential predictors or confounders of nutritional status were also collected.

Results

Undernourishment by MNA was present in 57.3% of the sample. Forty-two percent of participants had abnormal BMI values considered lower than 18.5 or higher than 24.9 kg/m2. Total BMI values were similar in well and undernourished patients (median 24.2 IQR 3.59 and median 23.9 IQR 4.42, respectively, p=0.476). When comparing well and undernourished groups, we found statistically significant differences for variables: severity of dementia (p=0.034), frailty (p=0.001), multimorbidity (p=0.035) and, polymedication (p=0.045). Neither adjusted logistic regression nor the Poisson regression showed that any clinical or sociodemographic variables explained undernourishment.

Conclusions

Undernourishment was a frequent finding in our sample of EO-ADAD, especially in later stages of the disease. Patients with polymedication, multimorbidity, frailty and severe dementia show differences in their nutritional status with a tendency to be more frequently undernourished. Further studies with larger sample sizes are needed to establish this association.

A-05 The Latin American Spanish Version of the Face-Name Associative Memory Exam is Sensitive to Cognitive and Pathological Changes in Preclinical Autosomal Dominant Alzheimer’s Disease

Objective

To determine whether performance on the Latin American Spanish version of the Face-Name Associative Memory Exam (LAS-FNAME) can differentiate between cognitively intact carriers of an autosomal dominant Alzheimer’s disease mutation (E280A) in Presenilin-1, who are destined to develop early-onset dementia, from matched non-carriers. We also sought to examine whether LAS-FNAME performance is associated with amyloid-β and regional tau burden in mutation carriers.

Methods

35 cognitively intact mutation carriers (age range 26–41), 48 matched non-carriers (aged 27 to 44), and 19 symptomatic carriers (13 with subjective cognitive concerns, 6 with mild cognitive impairment [MCI]) completed the LAS-FNAME. A subset of participants (31 carriers [12 symptomatic] and 35 non-carriers) traveled from Colombia to Boston to undergo positron emission tomography (PET) using Pittsburgh compound B to measure mean cortical amyloid-β and Flortaucipir for regional tau tangles. ANOVA analyses and Spearman correlations were used to examine group differences and relationships among LAS-FNAME performance, Aβ and tau accumulation.

Results

Compared to non-carriers, cognitively intact carriers had lower scores on the LAS-FNAME total scores (p = .040). Across all carriers (including symptomatic carriers), higher levels of amyloid-β (r = −.436, p = .018) and regional tau in the entorhinal (r = −.394, p = .031) and inferior temporal cortex (r = −.563, p = .001) were associated with lower LAS-FNAME total scores (see Figure).

Conclusions

Performance on the LAS-FNAME differentiated between cognitively intact mutation carriers from non-carriers, and was associated with greater amyloid and tau burden when examining all carriers. Findings suggest that the LAS-FNAME is sensitive to early clinical and pathological changes and can potentially help track disease progression in Spanish-speaking individuals.

Biological and Cognitive Markers of Presenilin1 E280A Autosomal Dominant Alzheimer's Disease: A Comprehensive Review of the Colombian Kindred

The study of individuals with autosomal dominant Alzheimer's disease affords one of the best opportunities to characterize the biological and cognitive changes of Alzheimer's disease that occur over the course of the preclinical and symptomatic stages. Unifying the knowledge gained from the past three decades of research in the world's largest single-mutation autosomal dominant Alzheimer's disease kindred - a family in Antioquia, Colombia with the E280A mutation in the Presenilin1 gene - will provide new directions for Alzheimer's research and a framework for generalizing the findings from this cohort to the more common sporadic form of Alzheimer's disease. As this specific mutation is virtually 100% penetrant for the development of the disease by midlife, we use a previously defined median age of onset for mild cognitive impairment for this cohort to examine the trajectory of the biological and cognitive markers of the disease as a function of the carriers' estimated years to clinical onset. Studies from this cohort suggest that structural and functional brain abnormalities - such as cortical thinning and hyperactivation in memory networks - as well as differences in biofluid and in vivo measurements of Alzheimer's-related pathological proteins distinguish Presenilin1 E280A mutation carriers from non-carriers as early as childhood, or approximately three decades before the median age of onset of clinical symptoms. We conclude our review with discussion on future directions for Alzheimer's disease research, with specific emphasis on ways to design studies that compare the generalizability of research in autosomal dominant Alzheimer's disease to the larger sporadic Alzheimer's disease population.

0421 Decreased Actigraphic Daytime Activity is Associated with Lower Memory Performance in Cognitively-Unimpaired Individuals with Autosomal Dominant Alzheimer’s Disease

Introduction

Alzheimer’s disease (AD) impacts brain regions that control circadian regulation systems such as wakefulness and daytime physical activity. Recent evidence shows that AD pathology is damaging for wake-promoting neurons. Whether early changes in wakefulness and daytime activity occur during asymptomatic stages of familial AD (fAD) remains unknown. In this study, we aimed to investigate whether daytime activity differs between cognitively-unimpaired carriers of early-onset fAD and age-matched non-carrier family members. Further, we examined the associations between daytime activity and memory performance.

Methods

A total of 25 members of the large Colombian kindred with the Presenilin1 (PSEN1) E280A mutation were included in the study (9 mutation carriers and 16 non-carriers, mean age=38.2). PSEN1 mutation carriers develop dementia before the age of 50. All subjects underwent wrist actigraphy for 7-14 days to measure daytime activity (average activity per minute and per epoch), and completed the CERAD Word List Learning and the Free and Cued Selective Reminding Test (FCSRT).

Results

Compared to non-carriers, mutation carriers had less average daytime activity (Mann-Whitney U Test p=.04). Higher average daytime activity was associated with better memory recall in both the CERAD word list delayed recall (r=.47, p=.05) and the FCRST delayed total recall (r=.53, p=.02). No associations with age were observed.

Conclusion

Our results suggest that cognitively-unimpaired mutation carriers have reduced daytime activity, years before the onset of dementia. Reduced daytime activity in carriers is also associated with lower memory performance. Our preliminary findings add to the growing evidence that circadian dysfunction is present in early AD, and may play an important role in subsequent memory impairment. Future research with large samples is needed to further examine sleep and circadian dysfunction in asymptomatic individuals at genetic risk for AD.

Support

NIA 5R01AG054671-03 to YTQ

The Value of Pre-Screening in the Alzheimer's Prevention Initiative (API) Autosomal Dominant Alzheimer's Disease Trial

The Alzheimer's Prevention Initiative (API) Autosomal Dominant Alzheimer's Disease (ADAD) trial evaluates the anti-amyloid-β antibody crenezumab in cognitively unimpaired persons who, based on genetic background and age, are at high imminent risk of clinical progression, and provides a powerful test of the amyloid hypothesis. The Neurosciences Group of Antioquia implemented a pre-screening process with the goals of decreasing screen failures and identifying participants most likely to adhere to trial requirements of the API ADAD trial in cognitively unimpaired members of Presenilin1 E280A mutation kindreds. The pre-screening failure rate was 48.2%: the primary reason was expected inability to comply with the protocol, chiefly due to work requirements. More carriers compared to non-carriers, and more males compared to females, failed pre-screening. Carriers with illiteracy or learning/comprehension difficulties failed pre-screening more than non-carriers. With the Colombian API Registry and our prescreening efforts, we randomized 169 30-60 year-old cognitively unimpaired carriers and 83 non-carriers who agreed to participate in the trial for at least 60 months. Our findings suggest multiple benefits of implementing a pre-screening process for enrolling prevention trials in ADAD.

Neuropsychiatric Symptoms in Parkinson’s Disease with and without Mild Cognitive Impairment

Objective

Neuropsychiatric symptoms (NPS) are common clinical features of patients with Parkinson’s disease (PD). However, such symptoms in non-demented PD patients have scarcely been investigated. To address this issue, we describe the neuropsychiatric profile in PD patients with and without Mild Cognitive Impairment (MCI).

Participants and Method

Eighty non-demented PD patients were included. The patients were divided into two groups depending on the presence or absence of MCI (PD-MCI and PD-nMCI, respectively). MCI diagnosis was made according to the Movement Disorder Society Task Force Level I criteria. NPS were evaluated using the Neuropsychiatric Inventory (NPI). For each domain, the presence and magnitude of symptoms (frequency x severity) was calculated. The total NPI score was also computed, in which higher scores suggest greater behavioral disturbance.

Results

PD-nMCI (n = 59, 74%) and PD-MCI (n = 21, 26%) groups were similar in the disease stage and years since diagnosis. In contrast with the PD-nMCI group, participants in the PD-MCI group were older. Fourteen PD-MCI (66%) and 45 PD-nMCI (76%) patients reported at least one neuropsychiatric symptom in the previous month. In both groups, the most frequent NPS were sleep disorders, depression, anxiety, apathy, irritability, and disinhibition. Additionally, the proportion of these symptoms between groups did not differ significantly (p > 0.05). There was only a tendency of greater score in the disinhibition subscale in PD-MCI group (p < 0.02). In both groups, NPS were not associated with clinical variables (years since diagnosis, Unified Parkinson's Disease Rating Scale -III) after adjusting for age.

Conclusions

Preliminary findings suggest that NPS are frequent in PD patients independent of the degree of cognitive impairment, and they may encompass non-motor features of the clinical spectrum of the disease. Further longitudinal investigations are needed to determine whether such symptoms may predict the cognitive decline in these patients.

Analysis and evaluation of handwriting in patients with Parkinson's disease using kinematic, geometrical, and non-linear features

BACKGROUND AND OBJECTIVES

Parkinson's disease is a neurological disorder that affects the motor system producing lack of coordination, resting tremor, and rigidity. Impairments in handwriting are among the main symptoms of the disease. Handwriting analysis can help in supporting the diagnosis and in monitoring the progress of the disease. This paper aims to evaluate the importance of different groups of features to model handwriting deficits that appear due to Parkinson's disease; and how those features are able to discriminate between Parkinson's disease patients and healthy subjects.

METHODS

Features based on kinematic, geometrical and non-linear dynamics analyses were evaluated to classify Parkinson's disease and healthy subjects. Classifiers based on K-nearest neighbors, support vector machines, and random forest were considered.

RESULTS

Accuracies of up to 93.1% were obtained in the classification of patients and healthy control subjects. A relevance analysis of the features indicated that those related to speed, acceleration, and pressure are the most discriminant. The automatic classification of patients in different stages of the disease shows κ indexes between 0.36 and 0.44. Accuracies of up to 83.3% were obtained in a different dataset used only for validation purposes.

CONCLUSIONS

The results confirmed the negative impact of aging in the classification process when we considered different groups of healthy subjects. In addition, the results reported with the separate validation set comprise a step towards the development of automated tools to support the diagnosis process in clinical practice.

APOE*E2 allele delays age of onset in PSEN1 E280A Alzheimer's disease

Alzheimer's disease (AD) age of onset (ADAOO) varies greatly between individuals, with unique causal mutations suggesting the role of modifying genetic and environmental interactions. We analyzed ~50 000 common and rare functional genomic variants from 71 individuals of the 'Paisa' pedigree, the world's largest pedigree segregating a severe form of early-onset AD, who were affected carriers of the fully penetrant E280A mutation in the presenilin-1 (PSEN1) gene. Affected carriers with ages at the extremes of the ADAOO distribution (30s-70s age range), and linear mixed-effects models were used to build single-locus regression models outlining the ADAOO. We identified the rs7412 (APOE*E2 allele) as a whole exome-wide ADAOO modifier that delays ADAOO by ~12 years (β=11.74, 95% confidence interval (CI): 8.07-15.41, P=6.31 × 10(-8), PFDR=2.48 × 10(-3)). Subsequently, to evaluate comprehensively the APOE (apolipoprotein E) haplotype variants (E1/E2/E3/E4), the markers rs7412 and rs429358 were genotyped in 93 AD affected carriers of the E280A mutation. We found that the APOE*E2 allele, and not APOE*E4, modifies ADAOO in carriers of the E280A mutation (β=8.24, 95% CI: 4.45-12.01, P=3.84 × 10(-5)). Exploratory linear mixed-effects multilocus analysis suggested that other functional variants harbored in genes involved in cell proliferation, protein degradation, apoptotic and immune dysregulation processes (i.e., GPR20, TRIM22, FCRL5, AOAH, PINLYP, IFI16, RC3H1 and DFNA5) might interact with the APOE*E2 allele. Interestingly, suggestive evidence as an ADAOO modifier was found for one of these variants (GPR20) in a set of patients with sporadic AD from the Paisa genetic isolate. This is the first study demonstrating that the APOE*E2 allele modifies the natural history of AD typified by the age of onset in E280A mutation carriers. To the best of our knowledge, this is the largest analyzed sample of patients with a unique mutation sharing uniform environment. Formal replication of our results in other populations and in other forms of AD will be crucial for prediction, follow-up and presumably developing new therapeutic strategies for patients either at risk or affected by AD.

Whole-genome sequencing suggests a chemokine gene cluster that modifies age at onset in familial Alzheimer's disease

We have sequenced the complete genomes of 72 individuals affected with early-onset familial Alzheimer's disease caused by an autosomal dominant, highly penetrant mutation in the presenilin-1 (PSEN1) gene, and performed genome-wide association testing to identify variants that modify age at onset (AAO) of Alzheimer's disease. Our analysis identified a haplotype of single-nucleotide polymorphisms (SNPs) on chromosome 17 within a chemokine gene cluster associated with delayed onset of mild-cognitive impairment and dementia. Individuals carrying this haplotype had a mean AAO of mild-cognitive impairment at 51.0 ± 5.2 years compared with 41.1 ± 7.4 years for those without these SNPs. This haplotype thus appears to modify Alzheimer's AAO, conferring a large (~10 years) protective effect. The associated locus harbors several chemokines including eotaxin-1 encoded by CCL11, and the haplotype includes a missense polymorphism in this gene. Validating this association, we found plasma eotaxin-1 levels were correlated with disease AAO in an independent cohort from the University of California San Francisco Memory and Aging Center. In this second cohort, the associated haplotype disrupted the typical age-associated increase of eotaxin-1 levels, suggesting a complex regulatory role for this haplotype in the general population. Altogether, these results suggest eotaxin-1 as a novel modifier of Alzheimer's disease AAO and open potential avenues for therapy.

Deciphering interference control in adults with ADHD by using distribution analyses and electromyographic activity

A deficit in "interference control" is commonly found in adults with Attention Deficit Hyperactivity Disorder (ADHD). This has mainly been interpreted as difficulties in inhibiting inappropriate responses. However, interference control involves processes other than simply the ability to inhibit. Consequently, we used sophisticated analysis to decipher the additional processes of interference control in these patients. We compared interference control between 16 adults with ADHD and 15 control adults performing a Simon task. In most studies, performance is generally reported in terms of mean error rates and reaction times (RTs). However, here we used distribution analyses of behavioral data, complemented by analyses of electromyographic (EMG) activity. This allowed us to better quantify the control of interference, specifically the part that remains hidden when pure correct trials are not distinguished from partial errors. Partial errors correspond to sub-threshold EMG bursts induced by incorrect responses that immediately precede a correct response. Moreover, besides "online" control, we also investigated cognitive control effects manifesting across consecutive trials. The main findings were that adults with ADHD were slower and showed a larger interference effect in comparison to controls. However, the data revealed that the larger interference effect was due neither to higher impulse expression, nor to a deficit in inhibition but that these patients presented a larger interference effect than the controls after congruent trials. We propose and discuss the hypothesis that the interference control deficit found in adults with ADHD is secondary to impairments in sustained attention.

Pooling/bootstrap-based GWAS (pbGWAS) identifies new loci modifying the age of onset in PSEN1 p.Glu280Ala Alzheimer's disease

The literature on GWAS (genome-wide association studies) data suggests that very large sample sizes (for example, 50,000 cases and 50,000 controls) may be required to detect significant associations of genomic regions for complex disorders such as Alzheimer's disease (AD). Because of the challenges of obtaining such large cohorts, we describe here a novel sequential strategy that combines pooling of DNA and bootstrapping (pbGWAS) in order to significantly increase the statistical power and exponentially reduce expenses. We applied this method to a very homogeneous sample of patients belonging to a unique and clinically well-characterized multigenerational pedigree with one of the most severe forms of early onset AD, carrying the PSEN1 p.Glu280Ala mutation (often referred to as E280A mutation), which originated as a consequence of a founder effect. In this cohort, we identified novel loci genome-wide significantly associated as modifiers of the age of onset of AD (CD44, rs187116, P=1.29 × 10⁻¹²; NPHP1, rs10173717, P=1.74 × 10⁻¹²; CADPS2, rs3757536, P=1.54 × 10⁻¹⁰; GREM2, rs12129547, P=1.69 × 10⁻¹³, among others) as well as other loci known to be associated with AD. Regions identified by pbGWAS were confirmed by subsequent individual genotyping. The pbGWAS methodology and the genes it targeted could provide important insights in determining the genetic causes of AD and other complex conditions.

A cooperative interaction between LPHN3 and 11q doubles the risk for ADHD

In previous studies of a genetic isolate, we identified significant linkage of attention deficit hyperactivity disorder (ADHD) to 4q, 5q, 8q, 11q and 17p. The existence of unique large size families linked to multiple regions, and the fact that these families came from an isolated population, we hypothesized that two-locus interaction contributions to ADHD were plausible. Several analytical models converged to show significant interaction between 4q and 11q (P<1 × 10(-8)) and 11q and 17p (P<1 × 10(-6)). As we have identified that common variants of the LPHN3 gene were responsible for the 4q linkage signal, we focused on 4q-11q interaction to determine that single-nucleotide polymorphisms (SNPs) harbored in the LPHN3 gene interact with SNPs spanning the 11q region that contains DRD2 and NCAM1 genes, to double the risk of developing ADHD. This interaction not only explains genetic effects much better than taking each of these loci effects by separated but also differences in brain metabolism as depicted by proton magnetic resonance spectroscopy data and pharmacogenetic response to stimulant medication. These findings not only add information about how high order genetic interactions might be implicated in conferring susceptibility to develop ADHD but also show that future studies of the effects of genetic interactions on ADHD clinical information will help to shape predictive models of individual outcome.

Event-related potential markers of brain changes in preclinical familial Alzheimer disease

OBJECTIVES

Event-related potentials (ERPs) can reflect differences in brain electrophysiology underlying cognitive functions in brain disorders such as dementia and mild cognitive impairment. To identify individuals at risk for Alzheimer disease (AD) we used high-density ERPs to examine brain physiology in young presymptomatic individuals (average age 34.2 years) who carry the E280A mutation in the presenilin-1 (PSEN1) gene and will go on to develop AD around the age of 45.

METHODS

Twenty-one subjects from a Colombian population with familial AD participated: 10 presymptomatic subjects positive for the PSEN1 mutation (carriers) and 11 siblings without the mutation (controls). Subjects performed a visual recognition memory test while 128-channel ERPs were recorded.

RESULTS

Despite identical behavioral performance, PSEN1 mutation carriers showed less positivity in frontal regions and more positivity in occipital regions, compared to controls. These differences were more pronounced during the 200-300 msec period. Discriminant analysis at this time interval showed promising sensitivity (72.7%) and specificity (81.8%) of the ERP measures to predict the presence of AD pathology.

CONCLUSIONS

Presymptomatic PSEN1 mutation carriers show changes in brain physiology that can be detected by high-density ERPs. The relative differences observed showing greater frontal positivity in controls and greater occipital positivity in carriers indicates that control subjects may use frontally mediated processes to distinguish between studied and unstudied visual items, whereas carriers appear to rely more upon perceptual details of the items to distinguish between them. These findings also demonstrate the potential usefulness of ERP brain correlates as preclinical markers of AD.

[Periodontal disease as an early clinical sign of cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL)]

INTRODUCTION

The clinical signs of cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) are expressed mainly in the nervous system and recently reports also situate them in the retina.

AIM

To determine the prevalence and risk of periodontal disease in subjects from families with a history of CADASIL mutation in the department of Antioquia, Colombia.

SUBJECTS AND METHODS

A cross-sectional study was conducted, with subjects being assigned to the CADASIL group or a control group according to genotyping for the R1031C and C455R mutation in Notch3. Each participant voluntarily signed the informed consent document and was submitted to neurological, neuropsychological and periodontal evaluation.

RESULTS

No significant differences were found between the two groups according to age, sex, schooling, tobacco smoking, cognitive status, functional status and the presence of natural teeth. The frequency of soft plaque, gingivitis and periodontal disease was significantly higher in the group of carriers of the CADASIL mutation than in the control group. The CADASIL group had six times more risk of having soft plaque above or equal to 20% than the control group. Prevalence of gingivitis above or equal to 10% was observed in all the members of the CADASIL group. The people in the CADASIL group had five times more risk of suffering periodontal disease than the control group.

CONCLUSIONS

Carriers of the CADASIL mutation displayed a higher prevalence and risk of periodontal disease.

[Comparison of neuropsychological performance according to the age of onset in subjects with Parkinson's disease and Parkinsonism]

INTRODUCTION

Parkinson's disease (PD) is the second most common neurodegenerative disorder after Alzheimer's disease, and it is characterised by tremor, bradykinesia, rigidity and postural instability. The most frequent cognitive disorder is executive dysfunction, although global deficits associated to late onset of the disease have also been reported.

AIMS

To describe and to compare cognitive performance in three groups with PD and one with Parkinsonism.

PATIENTS AND METHODS

A neurological and neuropsychological evaluation was carried out on 175 patients with idiopathic PD and Parkinsonism. The data analysis was performed by comparing the results of the tests carried out on the four groups: three with PD (age of onset: juvenile, adult and late) and one with Parkinsonism, while controlling for age, schooling and time of progression.

RESULTS

In the juvenile PD group, alterations were observed in the number of intrusions in verbal memory; in the adult PD and late PD groups, there were alterations in time in continuous visual execution. These differences disappeared when the groups were compared to each other while also controlling for age. The Parkinsonism group obtained results that were lower than those of all the groups with PD for most of the cognitive and functional variables.

CONCLUSIONS

Idiopathic PD would not be the cause of multiple cognitive impairment, but of a specific alteration, mainly involving the speed of processing and information recall. Age of onset would not be a decisive factor in the degree of impairment of cognitive functioning; important cognitive impairment was only present in the group with Parkinsonism.

[Attention deficit hyperactivity behavioral phenotype dimensions of adults from Antioquian families using the Wender-Utah Scale -Spanish version]

INTRODUCTION

The Wender-Utah Rating Scale (WURS) has been used for retrospective screening of attention deficit hyperactivity disorders (ADHD) symptoms and its comorbidities.

AIM

To establish the ADHD behavioral phenotype dimensions of adults from 140 Antioquian families with genetic segregation for ADHD diagnosis, using the WURS -Spanish version.

SUBJECTS AND METHODS

392 adults from both genders, belonging to nuclear and multigenerational families with one or more ADHD affected members were selected. The Composite International Diagnostic Interview (CIDI) for mental disorder was administered to establish the gold standard diagnosis of ADHD through the long life. All participants fulfill the WURS. Exploratory and confirmatory factor analyses were done to determine the behavioral dimensions of the ADHD phenotype.

RESULTS

A factor structure of four dimensions was derived, measuring behavioral decontrol, hyperactivity, inattention and anxiety, and which explained the 60% of the total variance.

CONCLUSIONS

The behavioral adult ADHD phenotype in the Antioquian families was conformed by four dimensions, which could be used in heritability and linkage future studies.

[Analysis of intrusive errors in a memory test as possible pre-clinical marker of familial Alzheimer disease, in E280A presenilin-1 mutation carrier]

INTRODUCTION

Intrusive errors in verbal memory tests could be considered as a preclinical marker of familial Alzheimer disease (AD). AIMS. To analyze and to compare the number and types of intrusive errors in the CERAD verbal memory test, administered to a genealogy of affected by familial AD, with E280A presenilin-1 mutation.

PATIENTS AND METHODS

Sample was constituted by 30 asymptomatic non-carriers (ANC), 39 non-demented carriers (NDC) and 21 demented carriers (DC). CERAD verbal memory test was administered to the sample. Comparisons, with non parametric Kruskal-Wallis' analysis, were done.

RESULTS

NDC participants presented more intrusive errors than ANC group in the first and second trials and in the delay recall of the memory task; also they had more intrusive errors than the DC patients in intrusive errors of the first trial and delay recall of the same task. The ANC and DC groups had significantly more intrusions only in third trial.

CONCLUSION

Intrusive errors could be considered as a cognitive preclinical marker for familial AD.

[Prevalence of mild cognitive impairment, amnestic-type, in a Colombian population]

INTRODUCTION

Mild cognitive impairment (MCI) is a clinical syndrome that presents with memory disorders, normal general cognition, and no compromise of activities of daily living or dementia. Its diagnosis has important clinical implications, since it behaves as a possible predictor of cognitive disorders that would suggest the onset of dementia. Amnestic-type MCI is considered to be a stage prior to Alzheimer-type dementia. The prevalence of MCI varies from 1-29% and the existence of this diagnosis implies a risk of presenting dementia at 12% per year.

AIM

To establish the prevalence of amnestic-type MCI in a group of persons over the age of 50 years from the Valle de Aburra.

PATIENTS AND METHODS

The sample was made up of 848 participants of both genders, over 50 years old, who lived in the metropolitan area of Medellin and had different socioeconomic and educational levels. Amnestic MCI was diagnosed according to the criteria proposed by the American Academy of Neurology.

RESULTS

Prevalence of amnestic MCI was 9.7%, and was more predominant in males (p = 0.01) than in females. The prevalence was significantly lower in the group with more than 12 years of schooling (p < 0.05), and no significant differences in the prevalence were found in relation to age or economic status.

CONCLUSION

The prevalence of amnestic MCI, 9.7%, found in our study is within the range reported by other researchers.

[Cognitive effects of combined memory and psychomotor training in elderly adults]

INTRODUCTION

As part of the normal ageing process, cognitive deterioration clearly takes place in memory, attention and the information processing speed (IPS). Among the intervention strategies commonly used, combined programmes like those involving memory and psychomotor skills have the greatest beneficial effects on cognition in the short and long term.

AIM

To evaluate the effects of a combined memory and psychomotor training programme entitled 'Independence in Older age' (SIMA) on the cognitive performance of a population sample of healthy elderly adults.

SUBJECTS AND METHODS

A cross-sectional study was conducted on 95 elderly adults (49 in the intervention group and 46 in the control group) before and after a 20-session training programme. Both intergroup (intervention group versus control group) and intragroup (each group individually) cognitive performance was analysed. The two groups were paired by age, sex and schooling.

RESULTS

The intergroup analysis following the training showed statistically and clinically significant differences in two IPS variables: conflict and interference in the colour-word test, which had a size effect of -1.31 and -1.38, respectively; the performance of the group of trained elderly adults was better than that of the controls. Likewise, in the intragroup analysis significant differences were found in these two variables in the group that received the intervention, with a size effect of -1.27 and -1.15.

CONCLUSION

Findings show positive effects of combined SIMA memory and psychomotor training, especially in selective attention and the IPS with a healthy elderly adult population.

[Monitoring cognitive characteristics in a population with hereditary cerebrovascular disease (CADASIL) in Colombia]

INTRODUCTION

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a hereditary disease that affects small vessels and presents with vascular episodes, neuropsychiatric disorders, migraine and cognitive impairment. The cognitive disorder varies according to the time elapsed since onset. It is a condition with a subcortical origin related to executive dysfunction, slowing, attention-related disorders and memory disorders.

AIM

To define the cognitive characteristics in two neuropsychological evaluations of carriers of Notch3 gene mutations as compared to non-carriers belonging to Colombian families with CADASIL.

SUBJECTS AND METHODS

The study followed a longitudinal, retrospective design with 140 participants, including both carriers and non-carriers of the mutation. Cognitive performance was analysed by comparing the first and the last neuropsychological evaluation carried out on each subject at a four-year interval.

RESULTS

There were statistically significant differences (p < 0.05) between the two groups in the last evaluation, but only in some tests. Carriers and non-carriers did not display any significant changes between the first and the last evaluation.

CONCLUSIONS

No differences were found between both groups in the two evaluations. Cognitive impairment is not observed with the passage of time in carriers, probably owing to the fact that most of them were young, asymptomatic subjects. We believe that four years' follow-up is not enough time to observe a significant progression in the alterations affecting the cognitive functions in carriers of mutations in the Notch3 gene, which causes CADASIL. We also consider that more sensitive cognitive tools are needed to perform the neuropsychological evaluation.

[Validity and reliability of the CERAD-Col neuropsychological battery]

INTRODUCTION

Alzheimer's disease (AD) is an important public health problem due to its disabling character and high individual, familial and social costs. The CERAD neuropsychological battery has been widely used for evaluation and diagnosis of the cognitive deficit associated with AD. This instrument has been adapted to the Colombian culture (CERAD-Col) for the Neurosciences Group.

SUBJECTS AND METHODS

A study was carried out to establish the validity and reliability of the CERAD-Col in Colombian, Spanish-speaking individuals aged 50 years or more. It included 151 controls and 151 AD patients. Controls were selected from a convenience sample of 848 adults aged 50 years or more. The construct validity was determined in three ways: 1) factorial analysis; 2) correlation with the functional scales FAST and GDS (convergent-type validity) and, 3) comparison between the two groups. Internal consistency was determined by means of Cronbach's alpha coefficient.

RESULTS

Three factors -memory, language and praxis- explained 88% of the total variance. Moderate but statistically significant correlations were found between neuropsychological tests and functional scales. Internal consistency and test-retest reproducibility were high. The AD group exhibited significantly lower scores (p < 0.05) than the control one.

CONCLUSION

CERAD-Col is valid and reliable for the diagnosis of AD in Colombian Spanish-speaking population aged 50 years or more.

[Specific impaired language development: a selective or generalised cognition problem]

INTRODUCTION

Specific developmental language disorder (SDLD) is a diagnostic entity in which language is expected to be the only cognitive function that is affected. Nevertheless, difficulties in other cognitive functions may also appear, either because the language disorder is an expression of an underlying condition or because the retarded language development gives rise to cognitive deficits in general.

AIM

To determine whether there are any differences in the cognitive performance of children with SDLD and that of children who have developed normally.

SUBJECTS AND METHODS

The study involved a sample of 51 children with SDLD, aged between 6 and 16 years, and 49 children in a control group, who were paired by chronological age, sex and socioeconomic level. Verbal cognitive capacity, attention, memory, visual-constructional and executive functioning were all evaluated.

RESULTS

Statistically and clinically significant differences were found in the verbal-type skills, such as language comprehension and verbal cognitive capacity, which showed effect sizes of -1.31 and -1.33, respectively. In the other functions that were assessed, the performance of the SDLD group was slightly lower than that of the control group, but with no clinically significant differences.

CONCLUSION

These findings show that the group of children with SDLD was well selected, since the only differences between the two groups involve linguistic aspects; moreover, this evidence supports the idea that language and other cognitive functions are relatively independent and that a language disorder would only generate an unspecific general effect in the other cognitive functions.

[Tumour of the corpus callosum: the association between interhemispheric disconnection and an anterograde amnesia syndrome]

INTRODUCTION

Sperry, or interhemispheric disconnection, syndrome was reported in patients who had undergone surgical section of the corpus callosum carried out in an attempt to control medication-resistant epilepsy. It has occasionally been linked to tumours of the corpus callosum and, although even more rarely, it has also been associated to an amnesic syndrome. In this paper we report the anatomical and neuropsychological findings in a patient with interhemispheric disconnection syndrome associated to a hippocampal-type amnesic syndrome, caused by a tumour in the splenius of the corpus callosum that extended into the fornix.

CASE REPORT

A 52-year-old white male who visited because of loss of memory; on admission to hospital the physical examination revealed a certain degree of asomatognosia with regard to the left-hand side of the body. An axial tomography brain scan showed a dense central lesion in the brain that extended laterally and occluded the body of both lateral ventricles. A biopsy study revealed an undifferentiated astrocytoma that affected the corpus callosum and the fornix.

CONCLUSIONS

Sperry, or interhemispheric disconnection, syndrome produced by a tumour in the splenius of the corpus callosum is very likely to course with an amnesic syndrome due to disconnection caused by destruction of the fornix. This association, which characterised our patient's clinical picture, has only previously been described in three cases.

[A description of semantic memory performance in a sample of the Antioquian population]

INTRODUCTION

Available treatments for Alzheimer disease allow that early diagnosis become an important issue, because treatment only are useful during the earliest stage, especially during the mild cognitive impairment (MCI), when the most of the cognitive function is preserved.

AIM

To observe the performance on a shortened version of a Semantic Cue Recall Memory Test (SCRMT) from a group of adult aged over 50 years old, living in Medellin city and with dementia of Alzheimer type (DAT).

SUBJECTS AND METHODS

The sample was constituted by 30 patients with DAT, 30 with MCI, and 59 healthy controls, which were matched by socio economic strata and school achievement. The SCRMT was administered to the sample. For the analyses two groups of age (50-69 and over 70 years) were conformed.

RESULTS

Comparisons statistically significant differences between the groups (p < 0.05). The scores were not significant affected by age. A combination of low scores with the presence of intrusions on the free, immediate cue, and delay cue recalls suggested the diagnosis of DAT, which allow recommending a complete neuropsychological assessment. Statistically significant differences were preserved when the groups were divided by age. The effect of the gender could not determine because the small size of the male sample.

CONCLUSION

The shortened version of the SCMRT would appear be useful for the DAT diagnosis.

[Specific developmental language disorder: a theoretical approach to its diagnosis, aetiology and clinical symptoms]

AIM

This article presents an updated review about the definition, diagnostic criteria, classifications, etiology and the evolution of the specific language impairment (SLI).

DEVELOPMENT

The specific language impairment is characterized by a developmental language delay and an impaired language, that persist over time and it is not explained by sensorial, motor and mental disabilities, neither by psycopathological disorders, socio-emotional deprivation, nor brain injury. The diagnosis is based on exclusional criteria. Some researchers propose different classifications considering the children performance in language comprehension and language production. Genetical linkage to the FOXP2 gen in the SPCH1 region of the chromosome 7 and to the chromosomes 13, 16 y 19 has been reported. The neuroimage studies have shown alterations in the volume and perfusion of some brain structures related to language. The manifestations of SLI may change during the development of the children and may disturb the self-esteem, the academic performance and the social abilities.

CONCLUSIONS

The variability in the linguistic and cognitive performance, and the variety in the etiological findings in children with SLI, don't allow to settle the affected population as an homogeneous group. Different theoretical positions have emerged as a consequence of this condition.

[Performance of carriers and non-carriers of the E280A mutation for familial Alzheimer's disease in a naming test]

INTRODUCTION

Early preclinical diagnosis is the greatest challenge faced by researchers into dementia. Cognitive, neuroanatomical, neurophysiological and genetic markers have been reported. One of the preclinical cognitive markers is anomia and it is often assessed using visual naming tests.

AIMS

The aim of this study was to analyse the type of mistakes made in a visual naming test in a group of carriers and non-carriers of the E280A PS1 mutation.

PATIENTS AND METHODS

The sample was made up of 91 participants who were genotyped for the E280A PS1 mutation and divided into three groups: non-carriers (n = 30), asymptomatic carriers (n = 39) and sick carriers (n = 22). Selection was performed using the Minimental and the Fast and EDG scales and mistakes in the CERAD naming test were classified. The types of mistakes taken into account were: no answer, visual, semantic, phonological, the whole for the part, and not related.

RESULTS

There is a significant difference in the number of semantic errors between non-carriers and asymptomatic carriers; on comparing the three groups, no statistically significant differences were found in visual mistakes.

CONCLUSIONS

Visual mistakes are a general characteristic, even in healthy subjects and, therefore, these errors did not provide any information that could be used to classify patients with or without dementia. Semantic mistakes can be considered as being a preclinical sign in familial Alzheimer's disease (FAD). Both visual and auditory naming tests must be applied when evaluating patients with FAD.

Pedigree disequilibrium test (PDT) replicates association and linkage between DRD4 and ADHD in multigenerational and extended pedigrees from a genetic isolate

Association/linkage between dopamine D4 receptor (DRD4) polymorphisms and attention-deficit/hyperactivity disorder (ADHD) has been suggested by case-control- and nuclear-family-based studies. Here, we present a candidate gene analysis for DRD4 using 14 extended and multigenerational families segregating ADHD derived from the 'Paisa' community of Antioquia, Colombia, a genetic isolate. Two DRD4 polymorphisms (a 120 bp tandem duplication at the promoter and a 48 bp-VNTR at exon 3), reported associated to ADHD, were genotyped. Parametric and non-parametric linkage analyses, and a family-based association test (FBAT), the pedigree disequilibrium test (PDT), were applied to search for evidence of association/linkage. Two-point LOD scores were significantly negative, with values ranging from -3.21 (P=0.011158) to -7.66 (P=0.000091 at theta=0). Non-parametrical analysis resulted in nonsignificant evidence for linkage. The PDT showed a moderate trend toward significance of association/linkage between the 7-repeat (7R) allele at the 48 bp VNTR and ADHD (P=0.0578). Furthermore, the haplotype analysis shows a significant association/linkage of the 7R-240 bp haplotype (P=0.0467) with ADHD. Results suggest that either a moderate DRD4 genetic effect, or linkage disequilibrium of DRD4 with an ADHD disease locus in the vicinity or the linkage to a phenotypic component of the ADHD spectrum could be underlying this association/linkage. These results provide further evidence for the association of ADHD to genetic variation in or near to DRD4 and replicate the previously reported association between ADHD and the 7R allele.

[Clinical and neuropsychological characteristics of Huntington's disease: a review]

INTRODUCTION

Huntington's disease is a dominant autosomic neurodegenerative disorder. This article's objective is to provide an up-to-date description of the clinical and neuropsychological manifestations over the course of the disease.

METHOD

According to clinical studies, the main characteristics of Huntington's disease include motor deficits, psychiatric problems and cognitive deficits. Many investigations have shown that a fronto-subcortical circuit dysfunction is responsible for these deficits. As the disease progresses, patients tend to have more cognitive difficulties which include attention/concentration problems, slowed cognitive processing, memory and language deficits, visuo-spatial problems and executive functioning difficulties.

CONCLUSION

Studies with asymptomatic carriers of Huntington's disease have shown that cognitive deterioration may begin long before a clinical diagnosis of the disease is possible.

[A neuropsychological study of Huntington's disease in families in Antioquia, Colombia]

INTRODUCTION

Various neuropsychological studies have been conducted to determine the cognitive functioning of patients with Huntington s disease and their results have shown that the pattern of cognitive decline is thought to be typical of a frontal subcortical dementia.

OBJECTIVES

To determine if significant differences exist between the cognitive performances of a group diagnosed with Huntington s disease and a group of healthy, at risk relatives on a series of neuropsychological tests, and to examine the extent to which the Huntington group s cognitive performance profile corresponds to frontal subcortical damage as reported in other studies.

PATIENTS AND METHODS

The sample was comprised of a group of 18 subjects with a clinical diagnosis of initial stage Huntington s disease and a group of 15 healthy relatives at risk for Huntington s disease. A battery of tests (the CERAD) and additional neuropsychological tests were administered to all subjects.

RESULTS

Compared to the at risk group, the Huntington s disease group scored significantly lower on 85.41% of the tests.

CONCLUSIONS

The neuropsychological tests utilized in this study were useful to discriminate between diagnosed and at risk groups. The Huntington s disease group s global neuropsychological profile was similar to that of a frontal subcortical dementia in which the predominant features include executive functioning deficits, memory problems, visuo constructive alterations, attention deficits, verbal fluency problems and naming deficits.

[Neuronal DNA damage correlates with a positive detection of c-Jun, nuclear factor kB, p53 and Par-4 transcription factors in Alzheimer's disease]

INTRODUCTION AND OBJECTIVES

Alzheimer s disease is a neurodegenerative disorder characterized neuropathologically by beta amyloid plaques, neurofibrillary tangles, gliosis and neuronal loss. Recently, we have elucidated a molecular cascade of cell death induced by A beta 25 35 involving the activation of nuclear factor kappa B (NF kB), p53, and c Jun transcription factors in vitro. At present, no comparative reports have been published to establish a similar cell death signalization pathway in in vitro and in in vivo. The aim of this investigation was to determine if AD brains might activate NF kB, p53, c Jun, Par 4 transcription factors and to establish whether there exist a relationship between neuronal DNA damage and transcription factors activation.

PATIENTS AND METHODS

We investigated Ab plaques, neurofibrillary tangles and NF kB, p53, and c Jun transcription factor activation in five cerebral regions from 3 normal subjects and from six demented patient with sporadic AD and one patient with AD familiar according to CERAD criteria. Using TUNEL we determine neuronal damage.

RESULTS

We demonstrated neuronal damage in 17 out of 50 regions evaluated as TUNEL positive, and their distribution was heterogeneous in all brain regions evaluated; and the activation of NF kB, p53, c Jun and Par 4 transcription factors from case # 24 and #22, corresponding to TUNEL positive.

CONCLUSIONS

We found a correlation between severity of DNA damage and nuclear activation of the transcription factors. These findings suggest that the AD brain may induce cell death by a molecular signalization similar to a non neuronal model by Ab exposure. This in situ study might validate previous Ab induced cell death observations in vitro.

[Perinatal factors associated with attention deficit/hyperactivity diagnosis in Colombian Paisa children]

INTRODUCTION

Some perinatal factors have been associated with attention d ficit/hyperactivity disorder (ADHD).

OBJECTIVE

To estimate the association between perinatal factor and ADHD diagnosis in school, aged 6 to 11 years, children from Medell n city (Colombia).

PATIENTS AND METHODS

A randomized sample of 200 cases, 6 to 11 year old, with standardized ADHD diagnosis was selected. A randomized sample of 200 control children, 6 to 11 year old, was selected from a data base of 70 schools of Medell n city. The same diagnostic protocol was administered to controls. A questionnaire with questions about pregnancy, delivery an neonatal period was given to the mothers. Data were analyzed using cross tabulation and stepwise logistic multiple regression analyses.

RESULTS

Miscarriage symptoms, premature delivery symptoms, severe flu attacks (cold with fever, without virus confirmation), tobacco abuse, alcohol abuse (to become drunk), minor congenital malformations, neonatal seizures and hospitalizations during newborn period were factors associated with ADHD diagnosis (p< 0.05). However, stepwise logistic multiple regression analysis selected a block of variables formed by premature delivery symptoms, severe flu attacks and neonatal seizures as significant perinatal risk factors (p< 0.01) for ADHD diagnosis.

C455R notch3 mutation in a Colombian CADASIL kindred with early onset of stroke

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is caused by mutations in the notch3 epidermal growth factor-like repeats. A Colombian kindred carries a novel C455R mutation located in the predicted ligand-binding domain. Stroke occurred in the patients at an unusually early age (median age: 31 years) in comparison to the more frequent onset in the fourth decade of life in other CADASIL populations, including a second Colombian kindred with an R1031C mutation.

Attention-deficit/hyperactivity disorder (ADHD): feasibility of linkage analysis in a genetic isolate using extended and multigenerational pedigrees

Segregation analyses converge in explaining the predisposition to attention-deficit/hyperactivity disorder (ADHD) as the consequence of a major gene and exclude purely environmental or cultural transmission. As a result of the ADHD phenotype restrictions, collection of extended families or design of linkage studies using families has been extremely difficult and thus currently linkage studies have been performed using only concordant or discordant sib-pairs rather than large families. On the other hand, intergenerational studies are represented by the transmission disequilibrium test (TDT) using trios. We collected pedigree data on ADHD from the Paisa community from Antioquia, Colombia, a genetic isolate. The goal of this study was to genetically map a putative gene predisposing to ADHD in a set of 27 multigenerational Paisa families. Here we present the results of a power simulation using SIMLINK to detect linkage of ADHD. ADHD was assumed to be a dichotomous trait with incomplete penetrance and a phenocopy rate of 3% in males and 0.2% in females. We simulated cosegregation of the trait and a marker locus in our pedigrees. We assumed Hardy-Weinberg and linkage equilibrium, equally frequent marker alleles and evaluated power at several recombination fractions between the trait and marker loci. Also, the ADHD trait was assumed to be genetically heterogeneous and different functions of age-dependent penetrance were simulated. We found exceptionally good power to detect linkage (expected LOD > 14 if theta is 0.1 or less), and that the presence of heterogeneity up to 50% does not affect substantially the projected LOD scores even for a theta recombination value of 0.05 (eLOD > 5.87). Having now obtained blood samples and confirmatory interviews in five families (representing 20% of the projected number of families), we performed a new analysis. The expected mean LOD in these five families reached values close to 10 and remained invariant when heterogeneity and different penetrance models were considered. We discuss the relative benefits of using extended and multigenerational families for genetic mapping studies as opposed to using nuclear families, affected sib pairs or sporadic cases which require the collection of over 1000 analytical units to get the same power exhibited by the small number of pedigrees described here.

Separating depersonalisation and derealisation: the relevance of the "lesion method"

OBJECTIVES

Depersonalisation (DP) and derealisation (DR) are often met with in patients with a wide range of localisable neurological conditions. This suggests that the "lesion method" might be a valid approach to study the neurobiology of DP/DR. However, the fact that anxiety can trigger DP/DR makes it difficult to establish whether the presence of DP/DR in neurological patients is mainly determined by coexisting anxiety or by lesion location. To overcome this difficulty, we suggest the study of neurological phenomena, which although not considered as DP/DR, bear enough phenomenological resemblance with them as to warrant their use as models.

METHODS

One patient with "visual hypoemotionality" and another with "hemiasomatognosia" are described in detail together with a selective literature review.

RESULTS

Complaints of patients with visual hypoemotionality are indistinguishable from those of patients with "visual derealisation". There is also a phenomenological overlap between "asomatognosia" and the symptom of "body alienation", which is a central feature of depersonalisation.

CONCLUSIONS

Phenomenological similarities between visual hypoemotionality and DR suggest that a disruption of the process by means of which perception becomes emotionally coloured may be an underlying mechanism in both conditions. Likewise, phenomenological overlaps with asomatognosia suggest that DP might result from parietal mechanisms disrupting the experience of body ownership and agency. These findings give validity to the notion that DP and DR may have distinct neurobiological mechanisms.

[Clinical history in the study of a patient with dementia]

OBJECTIVES

To carry out a detailed review of the keys to diagnosis of different types of dementia whilst taking a clinical history.

DEVELOPMENT

Dementia is a syndrome with many different aetiologies. Correct diagnosis depends on recording data of the history of the dementia, particularly of complaints regarding cognition and behavior. The keys to the clinical history should be based on questions about cognitive disorders, with emphasis on how they started, their evolution and particular form of dysfunction, Although Alzheimer's dementia is the most frequent, this diagnosis should only be made when the other forms of dementia have been ruled out. In this article we describe some of the keys to a good clinical history to facilitate the etiological and differential diagnosis of dementia.

CONCLUSIONS

Establishment of a full clinical history is the first and most important step in the diagnosis of dementia and cognitive disorders. On this will depend the plan to be followed to study the aetiology and most suitable treatment. Success or failure in the study of a patient with dementia depends on the quality of the clinical history obtained.

Presenilin-1-associated abnormalities in regional cerebral perfusion

OBJECTIVE

To investigate the influence of the presenilin-1 gene (PS-1) mutation on regional cerebral perfusion, SPECT was evaluated in 57 individuals. The subjects were members of a large pedigree from Colombia, South America, many of whom carry a PS-1 mutation for early-onset AD.

METHODS

Members of this large kindred who were cognitively normal and did not carry the PS-1 mutation (n = 23) were compared with subjects who were carriers of the mutation but were asymptomatic (n = 18) and with individuals with the mutation and a clinical diagnosis of AD (n = 16). Cerebral perfusion was measured in each subject using hexamethylpropyleneamine oxime SPECT. The data were analyzed in two ways: 1) Mean cerebral perfusion in each of 4320 voxels in the brain was compared among the groups using t-tests (t-maps); and 2) each individual received a weighted score on 20 vectors (factors), based on a large normative sample (n = 200), using a method known as singular value decomposition (SVD).

RESULTS

Based on t-maps, subjects with the PS-1 mutation who were asymptomatic demonstrated reduced perfusion in comparison with the normal control subjects in the hippocampal complex, anterior and posterior cingulate, posterior parietal lobe, and anterior frontal lobe. The AD patients demonstrated decreased perfusion in the posterior parietal and superior frontal cortex in comparison with the normal control subjects. Discriminant function analysis of the vector scores derived from SVD (adjusted for age and gender) accurately discriminated 86% of the subjects in the three groups (p < 0.0005).

CONCLUSION

Regional cerebral perfusion abnormalities based on SPECT are detectable before development of the clinical symptoms of AD in carriers of the PS-1 mutation.

A novel Cys212Tyr founder mutation in parkin and allelic heterogeneity of juvenile Parkinsonism in a population from North West Colombia

We report the molecular characterization of three multiplex families and a sporadic case of juvenile Parkinsonism identified in the province of Antioquia (Colombia). Linkage and haplotype analysis using markers in 6q25.2-27 indicated that Parkinsonism in the pedigrees is linked to the parkin gene (maximum LOD-score of 3.85) but that they carry two different mutant haplotypes. Sequence analysis revealed a novel G to A transition in exon 6 at position 736 (G736A) of parkin. This change results in a non-conservative cysteine for tyrosine substitution. All affected individuals from two families were homozygous for this mutation, which was not detected in 100 normal controls. Patients from the family carrying the second haplotype and the sporadic case were homozygous for a GT insertion in exon 3. This mutation has been previously identified in French families with juvenile Parkinsonism. The concomitant presence of founder effects and allelic heterogeneity in Antioquia might relate to the founding admixture at the origin of this population.

[Confirmation of the high prevalence of attention deficit disorder in a Colombian community]

INTRODUCTION

Using a shortened rating scale, the prevalence of Attention Deficit Hyperactivity Disorder (ADHD) has been reported to be very higher in a Colombian population. However, these data require clinical confirmation.

OBJECTIVE

To confirm clinically the prevalence of ADHD in Colombian children and adolescents.

PATIENTS AND METHODS

A randomized sample of 4 to 17 year old children and adolescents--184 males and 157 females--was selected from the schools. Sample was stratified in two socioeconomic status: high (4, 5, 6) and low (1, 2, 3). Several parents' and teachers' rating scales for the diagnosis of ADHD, standardized and validated in the Colombian population, were applied to the sample. The diagnosis of ADHD was confirmed using a semi-structured psychiatric and neurological interview, and medical histories revisions.

RESULTS

Analysis found that prevalence of ADHD is 17.1%. Distribution for ADHD types was: combined 9.4%, inattentive 6.7% and hyperactive-impulsive 1%. Prevalence for boys was significant higher (21.8%) than for girls (10.9%) (chi 2 = 11.8, p < 0.01). In male predominate combined type and in female inattentive. Higher prevalence was found in low socioeconomic strata. Preschool children have lower prevalence (6.2%) than school 6 to 11 year old children (22.6%) and adolescents (21.6%).

CONCLUSION

A higher prevalence of ADHD was confirmed in Colombian population.

[Analysis of complex segregation in a large family with hereditary cerebrovascular disease in Antioquia, Colombia]

INTRODUCTION

Among different kinds of cerebrovascular diseases, few of them are caused by genetic disturbances, such as CADASIL (caused by Notch3 mutations), CARASIL, mitochondrial encephalopathy, MELAS and dementia typed Binswanger. However, to describe these type of cerebrovascular diseases related with genetic mutations could permit to determinate the causes of both hereditary and sporadic cerebrovascular diseases and then lead solutions.

OBJECTIVE

To describe the genetic, environmental and cohort factors that determinate the presence of many affected people by a several cerebrovascular diseases in the pedigree of a large family from Antioquia (Colombia).

PATIENTS AND METHODS

We performed one pedigree (268 individuals), through singular recruit and then complex segregation analysis with POINTER program.

RESULTS

The model that more close to data is autosomal dominant mayor locus without influence of environmental factors. Frequency of allele of susceptibility to develop stroke or subcortical vascular dementia was 0.0006. Mayor gene is over epistatic effects or interactions with other gene.

CONCLUSIONS

Described an autosomal dominant hereditary model through complex segregation analysis in a pedigree of patients with hereditary cerebral vascular diseases characterized by recurrent strokes, early onset subcortical dementia, hearing loss, antecedent of migraine and MRI signal abnormalities, subcortical infarcts and leukoencephalopathy. In this family the parameter calculated, autosomal dominant model, and clinical feature strongly support the diagnostic of CADASIL, linkage analysis and sequentiation will be performed to determinate if mutant gene is Notch3.

Clinical and cerebral blood flow changes in catatonic patients treated with ECT

OBJECTIVE

To determine changes in clinical manifestations and cerebral blood flow (CBF) before and after administration of ECT to patients with catatonia due to schizophrenia or mood disorders.

METHODS

A sample of nine patients who met DSM-IV criteria for catatonia was studied. Patients received between 5 and 15 sessions (thrice per week) of ECT. Severity of catatonia was measured with the Modified Rogers Scale (MRS). Changes in CBF were measured with a brain single positron emission computer tomography (SPECT) that was performed 1 week before the first ECT and 1 week after the last ECT.

RESULTS

Catatonia was due to schizophrenia in five patients and mood disorders in four patients. There were no significant clinical and brain SPECT differences between these two groups before treatment. Pre- vs. post-ECT comparisons showed significant reduction of catatonic symptoms in both groups. However, patients with mood disorders needed less ECT sessions and showed greater clinical improvement. Brain SPECT showed significant increase in CBF in parietal, temporal, and occipital regions in patients with mood disorder and no significant changes in patients with schizophrenia.

CONCLUSIONS

These results support the efficacy of ECT for treatment of catatonic patients, especially secondary to mood disorders, which seem to be correlated with improvements in CBF.

[Clinical characteristics of hereditary cerebrovascular disease in a large family from Colombia]

INTRODUCTION

The cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is caused by mutations of the Notch3 gene in the chromosome 19p13.1. and is characterized by small-vessel disease of the cerebral. The clinical feature consists of migraine, recurrent strokes, mood changes and dementia.

OBJECTIVE

To describe the clinical phenotype of a Colombian family with hereditary cerebrovascular disease.

PATIENTS AND METHODS

We performed one pedigree with 268 individuals, neurologic examination to 57 members and magnetic resonance imaging (MRI) to 25 of them.

RESULTS

Clinical analysis strongly support the diagnosis of CADASIL because 12 individuals had suffered recurrent stroke, five of them later developed subcortical dementia. Two patients developed dementia without preceding stroke. All affected individuals by stroke or dementia whom were tested with MRI had white matter hyperintensities and subcortical infarcts (nine cases). Others seven individuals have MRI signal abnormalities like CADASIL, four of them are asymptomatic, one had suffered ischemic transient attacks and two had suffered migraine. Other 22 individuals had only migraine. We outstand the high frequency of MRI signal abnormalities in corpus callosum that we found in five individuals with stroke or dementia, the patient with ischemic transient attack and one asymptomatic patient, either the presence of hearing loss in seven individuals with stroke or dementia.

CONCLUSIONS

We describe one large family with hereditary cerebrovascular disease characterized by recurrent strokes, subcortical dementia, hearing loss, migraine, and MRI signal abnormalities typed leukoencephalopathy, subcortical infarcts and alterations in corpus callosum. Clinical analysis strongly support the diagnosis of CADASIL.

[Pneuropsychological disorders after occupational exposure to mercury vapors in El Bagre (Antioquia, Colombia)]

INTRODUCTION

The department of Antioquia in Columbia is the main producer of gold in Columbia. In the gold-producing regions the population is exposed to high levels of mercury used in the processes of extraction and purification. Studies done in Columbia on neurotoxicity underline the hazards of mercury from the environmental and occupational-health point of view, but the effect of long-term exposure on cognitive function has not been studied.

OBJECTIVE

To determine whether the miners of El Bagre (Antioquia, Columbia) have neuropsychological and/or behavior disorders as a result of occupational exposure to toxic mercury vapor.

PATIENTS AND METHODS

The sample was made up of 22 right-handed men, residents of El Bagre, aged between 20 and 45 years old who had been exposed to mercury vapor for at least three years. The control group consisted of 22 men who lived in the non-mining regions of the department and had not been exposed to mercury, paired with the cases considered for age and educational status. Neuropsychological assessment, a medical examination and behavioral performance tests were applied to all the men (in both groups).

RESULTS

In the study group alterations were seen and classified as: intellectual damage (mainly alteration of executive function and constructional praxis); emotional changes (symptoms of depression and anxiety) and neurological changes (amnesia, insomnia and tremor of the tongue). No changes were found in the control group.

CONCLUSION

Exposure to mercury causes specific neuropsychological and behavior disorders in the absence of clinically detectable physical or physiological damage.

[Factorial and discriminant analyses of neuropsychological variables in familial and sporadic late onset Alzheimer disease]

INTRODUCTION

Prevalence of late onset Alzheimer's disease (LOAD) both familial and sporadic is increasing with the raising proportion of third-age population. There are evidences either supporting or rejecting the existence of differences in the behavior of neuropsychological variables between familial and sporadic cases of LOAD.

OBJECTIVE

To identify neuropsychological variables discriminating between familial and sporadic cases of LOAD, in order to detect clinical manifestations that may provide information on the pathological process of the neurodegenerative process.

PATIENTS AND METHODS

Using sequential sampling, we selected individuals affected by LOAD according to the criteria of the DSM-IV and NINCS-ADRDA. The following neuropsychological protocol was used: CERAD, Wisconsin, Phonological Fluency, Rey's Figure, Raven, A Cancellation Test, WAIS (Arithmetic); also used were: Global Deterioration Scale, Functional Assessment Staging of Reisberg (FAST), Barthel and Yesavage. Parametrical and non-parametrical univariate, factorial (principal components) and discriminant analyses were performed. In total, 52 patients were analyzed (average age: 74.8 years; mean age at onset of the disease: 69 years; time of disease's evolution: 5.7 years; average of educational level: 6.4 years).

RESULTS

No significant statistical differences were found in clinical or neuropsychological variables between familial and sporadic cases of LOAD. Additionally, neither variables nor models were detected discriminating significantly between them.

CONCLUSION

Familial and sporadic cases of LOAD present the same clinical and neuropsychological phenotype which makes very probable that sporadic cases are low penetrance familial ones.