Multimodal Preventive Trial for Alzheimer's Disease: MIND-ADmini Pilot Trial Study Design and Progress

Background

Interventions simultaneously targeting multiple risk factors and mechanisms are most likely to be effective in preventing cognitive impairment. This was indicated in the Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability (FINGER) testing a multidomain lifestyle intervention among at-risk individuals. The importance of medical food at the early symptomatic disease stage, prodromal Alzheimer’s disease (AD), was emphasized in the LipiDiDiet trial. The feasibility and effects of multimodal interventions in prodromal AD are unclear.

Objectives

To evaluate the feasibility of an adapted FINGER-based multimodal lifestyle intervention, with or without medical food, among individuals with prodromal AD.

Methods

MIND-ADmini is a multinational proof-of-concept 6-month randomized controlled trial (RCT), with four trial sites (Sweden, Finland, Germany, France). The trial targeted individuals with prodromal AD defined using the International Working Group-1 criteria, and with vascular or lifestyle-related risk factors. The parallel-group RCT includes three arms: 1) multimodal lifestyle intervention (nutritional guidance, exercise, cognitive training, vascular/metabolic risk management and social stimulation); 2) multimodal lifestyle intervention+medical food (Fortasyn Connect); and 3) regular health advice/ care (control group). Primary outcomes are feasibility and adherence. Secondary outcomes are adherence to the individual intervention domains and healthy lifestyle changes.

Results

Screening began on 28 September 2017 and was completed on 21 May 2019. Altogether 93 participants were randomized and enrolled. The intervention proceeded as planned.

Conclusions

For the first time, this pilot trial tests the feasibility and adherence to a multimodal lifestyle intervention, alone or combined with medical food, among individuals with prodromal AD. It can serve as a model for combination therapy trials (non-pharma, nutrition-based and/or pharmacological interventions).

Communication skills in nursing home residents with dementia : Results of a prospective intervention study over 21 months

BACKGROUND

The dementia syndrome compromises effective communication and may thus lead to social isolation, psychological distress and decreased quality of life. It is therefore of importance to maintain communication capacity in dementia as long as possible.

MATERIAL AND METHODS

A total of 24 professional caregivers from 8 nursing homes were assigned to train 254 of their respective colleagues using the train-the-trainer program MultiTANDEMplus. As in the 6 control nursing homes, severity of dementia, depressive symptoms and communication capacity were assessed in a total of 358 residents at baseline and 21 months later. Overall, 189 residents completed the study.

RESULTS

Communication capacity declined in control home residents but remained stable in the intervention group although dementia severity increased in both groups. The intervention group exhibited significantly fewer depressive symptoms after the intervention than the control group.

CONCLUSION

A standardized training of communication skills for professional caregivers can stabilize communication capacity and reduce depressive symptoms in nursing home residents. These effects are likely sustainable and could be demonstrated 21 months postintervention.

[COVID-19 in old age-The geriatric perspective]

Predominantly the older population is affected by a severe course of COVID-19. The mortality of hospitalized patients with COVID-19 above the age of 80 years is up to 54% in international studies. These observations indicate the necessity to highlight the geriatric perspective on this disease. The diagnostics and treatment of COVID-19 do not differ between younger and older patients but atypical symptoms should be expected more frequently in old age. Older subjects show an increased need for rehabilitation after COVID-19. Paradoxically, increasing rehabilitation demands go along with a reduced availability of geriatric rehabilitation options, the latter being a consequence of closure or downsizing of rehabilitation departments during the pandemic. In general, measures of isolation and quarantine should be diligently balanced as the health and emotional consequences of such measures may be severe in older persons. In light of the poor prognosis of older COVID-19 patients, advanced care planning becomes even more relevant. Caregivers and physicians should be encouraged to compose advanced care directives that also reflect the specific circumstances of COVID-19. Fortunately, current data suggest that the effectiveness of the vaccination with the mRNA-vaccines approved in Germany may be equally high in older compared to younger persons.

Sex-associated differences in mitochondrial function in human peripheral blood mononuclear cells (PBMCs) and brain

BACKGROUND

Alzheimer's disease (AD) is the most common form of dementia, and it affects more women than men. Mitochondrial dysfunction (MD) plays a key role in AD, and it is detectable at an early stage of the degenerative process in peripheral tissues, such as peripheral mononuclear blood cells (PBMCs). However, whether these changes are also reflected in cerebral energy metabolism and whether sex-specific differences in mitochondrial function occur are not clear. Therefore, we estimated the correlation between mitochondrial function in PBMCs and brain energy metabolites and examined sex-specific differences in healthy participants to elucidate these issues.

METHODS

The current pilot study included 9 male and 15 female healthy adults (mean age 30.8 ± 7.1 years). Respiration and activity of mitochondrial respiratory complexes were measured using a Clarke-electrode (Oxygraph-2k system), and adenosine triphosphate (ATP) levels were determined using a bioluminescence-based assay in isolated PBMCs. Citrate synthase activity as a mitochondrial marker was measured using a photometric assay. Concentrations of brain energy metabolites were quantified in the same individuals using 1H-magnetic resonance spectroscopy (MRS).

RESULTS

We detected sex-associated differences in mitochondrial function. Mitochondrial complexes I, I+II, and IV and uncoupled respiration and electron transport system (ETS) capacity in PBMCs isolated from blood samples of females were significantly (p < 0.05; p < 0.01) higher compared to males. ATP levels in the PBMCs of female participants were approximately 10% higher compared to males. Citrate synthase (CS) activity, a marker of mitochondrial content, was significantly (p < 0.05) higher in females compared to males. Sex-associated differences were also found for brain metabolites. The N-acetylaspartate (NAA) concentration was significantly higher in female participants compared to males in targeted regions. This difference was observed in white matter (WM) and an area with a high percentage (> 50%) of gray matter (GM) (p < 0.05; p < 0.01). The effect sizes indicated a strong influence of sex on these parameters. Sex-associated differences were found in PBMCs and brain, but the determined parameters were not significantly correlated.

CONCLUSIONS

Our study revealed sex-associated differences in mitochondrial function in healthy participants. The underlying mechanisms must be elucidated in more detail, but our study suggests that mitochondrial function in PBMCs is a feasible surrogate marker to detect differences in mitochondrial function and energy metabolism in humans and it underscores the necessity of sex-specific approaches in therapies that target mitochondrial dysfunction.

Effects of aerobic exercise on brain metabolism and grey matter volume in older adults: results of the randomised controlled SMART trial

There is mounting evidence that aerobic exercise has a positive effect on cognitive functions in older adults. To date, little is known about the neurometabolic and molecular mechanisms underlying this positive effect. The present study used magnetic resonance spectroscopy and quantitative MRI to systematically explore the effects of physical activity on human brain metabolism and grey matter (GM) volume in healthy aging. This is a randomised controlled assessor-blinded two-armed trial (n=53) to explore exercise-induced neuroprotective and metabolic effects on the brain in cognitively healthy older adults. Participants (age >65) were allocated to a 12-week individualised aerobic exercise programme intervention (n=29) or a 12-week waiting control group (n=24). The main outcomes were the change in cerebral metabolism and its association to brain-derived neurotrophic factor (BDNF) levels as well as changes in GM volume. We found that cerebral choline concentrations remained stable after 12 weeks of aerobic exercise in the intervention group, whereas they increased in the waiting control group. No effect of training was seen on cerebral N-acetyl-aspartate concentrations, nor on markers of neuronal energy reserve or BDNF levels. Further, we observed no change in cortical GM volume in response to aerobic exercise. The finding of stable choline concentrations in the intervention group over the 3 month period might indicate a neuroprotective effect of aerobic exercise. Choline might constitute a valid marker for an effect of aerobic exercise on cerebral metabolism in healthy aging.

Genetic Variants of the FADS Gene Cluster Are Associated with Erythrocyte Membrane LC PUFA Levels in Patients with Mild Cognitive Impairment

BACKGROUND

Long-chain (> 20 C-atoms) polyunsaturated fatty acids (LC PUFAs) of both the omega-6 (n-6) and omega-3 (n-3) series are important for the functional integrity of brain and thereby cognition, memory and mood. Clinical studies observed associations between altered LC PUFA levels and neurodegenerative diseases such as Alzheimer´s disease and its prodromal stage, mild cognitive impairment (MCI).

METHODS

The present study examined the LC PUFA status of MCI patients with specific view on the relative LC n-3 PUFA levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in erythrocyte membranes (omega-3 index). 12 single nucleotide polymorphisms (SNPs) of the FADS1, FADS2, and FADS3 gene clusters were genotyped in 111 MCI patients and evaluated associations with PUFA levels in erythrocyte membranes (primary outcome). In addition, the associations between FADS SNPs and LC PUFA levels with serum lipid levels as well as depressive symptoms were examined (secondary outcomes).

RESULTS

Minor allele carrier of rs174546, rs174548 (FADS1), rs3834458, rs1535, rs174574, rs174575, rs174576, and rs174578 (FADS2) showed significant higher n-6 and n-3 precursor PUFA levels (linoleic acid, and alpha-linolenic acid, respectively) and lower arachidonic acid (AA) levels in erythrocyte membranes compared to the major allele carriers. Differences in EPA and DHA levels were not significant. Minor allele carriers of rs174574, rs174576 and rs174578 (FADS2) and rs174455 (FADS3) exhibited significant higher triglyceride levels, whereas minor allele carriers for rs174449 and rs174455 (FADS3) exhibited significant higher total- and LDL-cholesterol levels compared to the more common variant. The mean omega-3 index of the study cohort was 6.19 ± 1.55 %. In more than 85 % of the patients, the omega-3 index was below 8 % and in 23 % below 5 %. Moreover, it was shown that a low DHA status and omega-3 index was associated with depressive symptoms (Beck's depression-inventory).

DISCUSSION AND CONCLUSION

These findings indicate an association between several FADS genotypes for higher n-6 and n-3 precursor PUFA and lower AA levels in erythrocyte membranes in minor compared to major allele carriers. To what extent FADS genotypes and a lower conversion of LA and ALA to biologically important LC PUFAs such as AA, EPA and DHA contributes to cognitive decline should be investigated in further trials. Nevertheless, the omega-3 index in this cohort of MCI patients can be classified as insufficient.

Targeting the cis-dimerization of LINGO-1 with low MW compounds affects its downstream signalling

BACKGROUND AND PURPOSE

The transmembrane protein LINGO-1 is a negative regulator in the nervous system mainly affecting axonal regeneration, neuronal survival, oligodendrocyte differentiation and myelination. However, the molecular mechanisms regulating its functions are poorly understood. In the present study, we investigated the formation and the role of LINGO-1 cis-dimers in the regulation of its biological activity.

EXPERIMENTAL APPROACH

LINGO-1 homodimers were identified in both HEK293 and SH-SY5Y cells using co-immunoprecipitation experiments and BRET saturation analysis. We performed a hypothesis-driven screen for identification of small-molecule protein-protein interaction modulators of LINGO-1 using a BRET-based assay, adapted for screening. The compound identified was further assessed for effects on LINGO-1 downstream signalling pathways using Western blotting analysis and AlphaScreen technology.

KEY RESULTS

LINGO-1 was present as homodimers in primary neuronal cultures. LINGO-1 interacted homotypically in cis-orientation and LINGO-1 cis-dimers were formed early during LINGO-1 biosynthesis. A BRET-based assay allowed us to identify phenoxybenzamine as the first conformational modulator of LINGO-1 dimers. In HEK-293 cells, phenoxybenzamine was a positive modulator of LINGO-1 function, increasing the LINGO-1-mediated inhibition of EGF receptor signalling and Erk phosphorylation.

CONCLUSIONS AND IMPLICATIONS

Our data suggest that LINGO-1 forms constitutive cis-dimers at the plasma membrane and that low MW compounds affecting the conformational state of these dimers can regulate LINGO-1 downstream signalling pathways. We propose that targeting the LINGO-1 dimerization interface opens a new pharmacological approach to the modulation of its function and provides a new strategy for drug discovery.

A genome-wide association study of anorexia nervosa

Anorexia nervosa (AN) is a complex and heritable eating disorder characterized by dangerously low body weight. Neither candidate gene studies nor an initial genome-wide association study (GWAS) have yielded significant and replicated results. We performed a GWAS in 2907 cases with AN from 14 countries (15 sites) and 14 860 ancestrally matched controls as part of the Genetic Consortium for AN (GCAN) and the Wellcome Trust Case Control Consortium 3 (WTCCC3). Individual association analyses were conducted in each stratum and meta-analyzed across all 15 discovery data sets. Seventy-six (72 independent) single nucleotide polymorphisms were taken forward for in silico (two data sets) or de novo (13 data sets) replication genotyping in 2677 independent AN cases and 8629 European ancestry controls along with 458 AN cases and 421 controls from Japan. The final global meta-analysis across discovery and replication data sets comprised 5551 AN cases and 21 080 controls. AN subtype analyses (1606 AN restricting; 1445 AN binge-purge) were performed. No findings reached genome-wide significance. Two intronic variants were suggestively associated: rs9839776 (P=3.01 × 10(-7)) in SOX2OT and rs17030795 (P=5.84 × 10(-6)) in PPP3CA. Two additional signals were specific to Europeans: rs1523921 (P=5.76 × 10(-)(6)) between CUL3 and FAM124B and rs1886797 (P=8.05 × 10(-)(6)) near SPATA13. Comparing discovery with replication results, 76% of the effects were in the same direction, an observation highly unlikely to be due to chance (P=4 × 10(-6)), strongly suggesting that true findings exist but our sample, the largest yet reported, was underpowered for their detection. The accrual of large genotyped AN case-control samples should be an immediate priority for the field.

A combination of galantamine and memantine modifies cognitive function in subjects with amnestic MCI

OBJECTIVES

Mild cognitive impairment (MCI) is etiologically heterogeneous, and a substantial proportion of MCI subjects will develop different dementia disorders. One subtype of this syndrome, amnestic MCI, occurs preferentially but not exclusively in prodromal AD and is characterized by defined deficits of episodic memory.

DESIGN, SETTING AND PARTICIPANTS

For a 2-year, double-blinded, placebo-controlled study MCI patients, presenting with an amnestic syndrome but not necessarily based on presumed prodromal AD were randomized.

INTERVENTION

Patients received (a) a combination of 16 mg galantamine plus 20 mg memantine, or (b) 16 mg galantamine alone or (c) placebo.

MEASUREMENTS

The primary objective was to explore the differential impact of these interventions on the progression to dementia and on cognitive changes as measured by the ADAScog.

RESULTS

After recruitment of 232 subjects, the trial was halted before reaching the planned sample size, because safety concerns arose in other studies with galantamine in MCI. This resulted in a variable treatment duration of 2-52 weeks. The statistical analysis plan was amended for studying cognitive effects of discontinuing the study medication, which was done separately for galantamine and memantine, and under double-blind conditions. There was one death, no unexpected severe adverse events, and no differences of severe adverse events between the treatment arms. The cognitive changes on the ADAScog were not different among the groups. Only for the subgroup of amnestic MCI with presumed AD etiology, a significant improvement of ADAScog score over placebo before the discontinuation of medication was observed, while amnestic MCI presumably due to other etiologies showed no cognitive changes with broad variation. Cognitive improvement was numerically larger in the combination treatment group than under galantamine alone. Patients who received placebo declined as expected. Discontinuation of galantamine, either as part of the combination regimen or as mono treatment, resulted in a transient decline of the ADAScog score in amnestic MCI of presumed AD etiology, while discontinuation of Memantine did not change the cognitive status.

CONCLUSION

In an interrupted trial with amnestic MCI subjects the combination of galantamine plus memantine were generally well tolerated. In the subgroup of MCI subjects with presumed AD etiology, a cognitive benefit of a short-term combination treatment of galantamine plus memantine was observed, and cognitive decline occurred after discontinuation of galantamine.

Soluble amyloid precursor proteins in the cerebrospinal fluid as novel potential biomarkers of Alzheimer's disease: a multicenter study

In this report, we present the results of a multicenter study to test analytic and diagnostic performance of soluble forms of amyloid precursor proteins alpha and beta (sAPP alpha and sAPP beta) in the cerebrospinal fluid (CSF) of patients with different forms of dementing conditions. CSF samples were collected from 188 patients with early dementia (mini-mental state examination >or=20 in majority of cases) and mild cognitive impairment (MCI) in 12 gerontopsychiatric centers, and the clinical diagnoses were supported by neurochemical dementia diagnostic (NDD) tools: CSF amyloid beta peptides, Tau and phospho-Tau. sAPP alpha and sAPP beta were measured with multiplexing method based on electrochemiluminescence. sAPP alpha and sAPP beta CSF concentrations correlated with each other with very high correlation ratio (R=0.96, P<0.001). We observed highly significantly increased sAPP alpha and sAPP beta CSF concentrations in patients with NDD characteristic for Alzheimer's disease (AD) compared to those with NDD negative results. sAPP alpha and sAPP beta highly significantly separated patients with AD, whose diagnosis was supported by NDD findings (sAPP alpha: cutoff, 117.4 ng ml(-1), sensitivity, 68%, specificity, 85%, P<0.001; sAPP beta: cutoff, 181.8 ng ml(-1), sensitivity, 75%, specificity, 85%, P<0.001), from the patients clinically assessed as having other dementias and supported by NDD untypical for AD. We conclude sAPP alpha and sAPP beta might be regarded as novel promising biomarkers supporting the clinical diagnosis of AD.

Amyloid beta peptides in plasma in early diagnosis of Alzheimer's disease: A multicenter study with multiplexing

We measured concentrations of Abeta peptides 1-42 and 1-40, and their ratio in plasma of patients carefully categorized clinically and neurochemically as having AD or other dementias with a newly commercially available multiplexing assay, characterized by reasonable laboratory performance (intra-assay imprecision in the range of 1.3-3.8% for Abeta1-42, and 1.8-4.1% for Abeta1-40, inter-assay imprecision for Abeta1-42, Abeta1-40, and Abeta1-42/Abeta1-40 concentration ratio in the range of 2.3-11.5%, 2.2-10.4% and 4.2-9.7%, respectively). Patients with AD or mild cognitive impairment of AD type (MCI-AD) whose clinical diagnosis was supported with CSF biomarkers (n=193) had significantly lower Abeta1-42 plasma concentrations (p<0.007), and Abeta1-42/1-40 ratios (p<0.003) compared to patients with other dementias and MCI of other types (n=64). No significant differences between persons with MCI of AD type and patients with early AD were observed, or between MCI of other types versus patients with early dementia of other types. Our findings reconfirm the hypothesis that alterations of biomarker concentrations occur early in a preclinical AD stage and that these alterations are also reflected in plasma.

[MCI-plus: mild cognitive impairment with rapid progression. Part II: Biomarkers and research methods]

Long-term studies will be pivotal in order to examine the efficacy of preventive and early therapeutic interventions during the preclinical phase of dementia. Biomarkers will be of importance due to the large sample sizes and the necessary logistic efforts, high drop-out rates and slow clinical progression. The validity of functional and even structural imaging methods is currently investigated with early and promising results; it is presently unclear whether conventional csf-markers of Alzheimer's disease (beta-amyloid and tau-proteins) are sufficiently sensitive to monitor the effects of early interventions. It also remains doubtful whether modifications of these methods will ever be useful and available for practical purposes.

[MCI-plus: mild cognitive impairment with rapid progression. Part I: prevention and therapy]

Mild Cognitive Impairment (MCI) is a prevalent problem in the elderly and many patients show predictors of rapid cognitive decline ("MCI-plus"). MCI-plus represents a syndrome with growing importance in an ageing society, which will increasingly affect primary medicine and most other clinical specialties. We will have to face the dilemma of fast progress in the field of neurodiagnostics with innovative therapeutic strategies lagging behind. Psychological and medical co-morbidity in MCI-plus will therefore offer important opportunities to delay and to avoid the manifestation of dementia. We will review and discuss current training and treatment options including symptomatic and causal interventions.

[Development and evaluation of a training program for nursing home professionals to improve communication in dementia care]

The purpose of this study was to develop and evaluate a skill training aimed at increasing the social competence of caregivers of nursing home residents suffering from dementia. Herewith, the professional burden and occupational stress of the caregivers should be reduced and the quality of life of dementia patients should be increased. The contents of the training focused on problems and strategies in the communication with dementia patients and the communication with colleagues. The effectiveness of the intervention was tested in a controlled training study using a multiple control group design and process measurement. The participants of the trainings were 53 nursing home professionals, who were in daily contact with residents suffering from dementia. The results of the study verify effects for all relevant variables. The "social competence" of the caregivers increased and their "work stress" decreased while the "quality of life of dementia patients" increased. Therefore it can be concluded that training the social competence of nursing home professionals is a method to indirectly reduce their work stress and support dementia patients. The results of research in this program underline very clearly that the developed training is an effective option to improve the situation of dementia care in nursing homes. To make the intervention widely applicable we are currently developing a "multiplier program" in a follow-up project.

Enhanced apoptosis, oxidative stress and mitochondrial dysfunction in lymphocytes as potential biomarkers for Alzheimer's disease

Alzheimer's disease (AD) is the most common progressive neurodegenerative disease. Today, AD affects millions of people worldwide and the number of AD cases will increase with increased life expectancy. The AD brain is marked by severe neurodegeneration like the loss of synapses and neurons, atrophy and depletion of neurotransmitter systems in the hippocampus and cerebral cortex. Recent findings suggest that these pathological changes are causally induced by mitochondrial dysfunction, increased oxidative stress and elevated apoptosis. Until now, AD cannot be diagnosed by a valid clinical method or a biomarker before the disease has progressed so far that dementia is present. Furthermore, no valid method is available to determine which patient with mild cognitive impairment (MCI) will progress to AD. Therefore, a correct diagnosis in the early stage of AD is not only of importance considering that early drug treatment is more effective but also that the psychological burden of the patients and relatives could be decreased. In this review, we discuss the potential role of elevated apoptosis, increased oxidative stress and mitochondrial dysfunction as biomarker for AD in a peripheral cell model, the lymphocytes.

[Communication training for family caregivers of dementia patients]

The program Kommunikations-TAnDem was developed with the primary purpose of increasing the communication competence of family caregivers of dementia patients. Further aims were to reduce the burden of family caregivers and to increase the quality of life of dementia patients. The effectiveness of the Kommunikations-TAnDem was tested in a controlled training study with 22 participants using a waiting-group control design and process measurement. The results of the study verify effects for the variables "Communication competence", "Caregivers knowledge about communication in dementia", "Quality of life of dementia patients" and "Directly perceived burden of family caregivers. Therefore it can be concluded that the Kommunikations-TAnDem is a method of indirectly supporting dementia patients by training the family caregivers. The results of research in this program underline very clearly the relevance of the inclusion of the family caregivers in intervention programs and the importance of communication competence for the well-being of dementia patients and their caregivers.

Temporal horn index and volume of medial temporal lobe atrophy using a new semiautomated method for rapid and precise assessment

BACKGROUND AND PURPOSE

Quantitative markers of Alzheimer disease (AD), particularly in the early stages, are needed for clinical assessment and monitoring. We have evaluated a novel method to segment and visualize the ventricular system and obtain volumetric measures thereof. The temporal horn volume (THV) and index in patients with mild cognitive impairment (MCI) and in those with AD were evaluated.

METHODS

High-resolution T1-weighted volume imaging was performed in 52 subjects (21 patients with MCI, 10 with AD, and 21 healthy control subjects). An interactive watershed transformation and semiautomated histogram analysis were implemented to produce segmented THV and temporal horn indices (THI) (ratio of THV to lateral ventricular volume).

RESULTS

Cerebral ventricular and temporal horn size could be semiautomatically quantified from all 52 datasets. The method was fast and rater-independent. Qualitative ventricular inspections using surface rendering shading could uncover atrophic process with enlargement of the whole and especially temporal horn volume. Both THV and THI of patients with AD were significantly larger than those of patients with MCI or control subjects (P < .005). There was no significant difference in THV and THI between patients with MCI or control subjects (P > .05). There was a significant correlation between the neuropsychologic performance and both THI and THV across groups (P < .01).

CONCLUSION

THV and THI could be used as markers of AD in the clinical environment and are expected to be helpful in monitoring therapeutic intervention.

[Mild cognitive impairment and Alzheimer's disease: an investigation of the CERAD-NP test battery]

To investigate the psychometric properties of the German version of the CERAD-NP, neuropsychological deficits were compared between 49 patients with mild cognitive impairment (MCI), 80 patients with Alzheimer's disease (AD), 36 with major depression (MD), and 26 elderly controls. All participants were outpatients of the memory clinic of the Section of Geriatric Psychiatry, Heidelberg University. Diagnoses were established based on clinical examination, laboratory testing, neuroimaging, and routine neuropsychological testing according to the criteria of aging-associated cognitive decline (AACD) for MCI, NINCDS-ADRDA for AD, and DSM-IV for MD, respectively. All CERAD-NP subtests discriminated between controls and AD patients with the latter showing significantly (p< or = 0.05) lower test scores. The subtests verbal fluency and constructive apraxia differed significantly between mildly and moderately AD, while the subtests assessing declarative (epsisodic) memory performance showed only minor, non-significant differences between the respective groups. The LKB patients took an intermediate position between controls and AD patients with significantly lower scores in verbal fluency and declarative memory performance than the controls. When compared with the AD patients, MCI patients were significantly impaired in all subtests except constructive apraxia. Relative to the controls, the patients with MD showed a decreased episodic memory performance but no evidence suggesting an impairment in other neuropsychological domains. Our results indicate that the CERAD-NP is a psychometric instrument which allows a sensitive discrimination between mild and moderate AD, MCI, MD and healthy controls. However, sensitivity of discrimination between different stages of dementia varies with respect to the different subtest. While the subtest for episodic memory showed floor effects already for mild dementia, subtests for verbal fluency and constructive apraxia were able to discriminate even between more advanced stages of the disease.

Psychiatric symptoms in alpha-mannosidosis

Alpha-mannosidosis is characterized by mild to moderate intellectual disability (ID), moderate to severe neurosensory hearing loss, frequent infections, psychomotor disturbances and skeletal dysmorphism. For the first time, a panel of nine alpha-mannosidosis patients with psychiatric symptoms is presented. The clinical picture has several similarities: a physical or psychological stressor precedes a rapid development of a state of confusion, delusions, hallucinations, anxiety and often depression leading to a severe loss of function. This usually lasts 3-12 weeks, and is followed by a period of somnolence and asthenia. It may be more prevalent in females. In four of the described patients search for organic causes of the syndrome was performed, but revealed only negative findings. Because of the limited number of cases no firm conclusion about the benefit of various psychotropic drugs can be drawn from our observation. Psychiatric symptoms could affect as many as 25% of patients with alpha-mannosidosis. First onset is typically in late puberty to early adolescence. The episodes may be recurrent, and of limited duration although medication may be necessary to alleviate symptoms. Our observations indicate that alpha-mannosidosis is associated with an increased risk of psychiatric symptoms. These should not be dismissed as part of the ID but should give rise to the initiation of adequate diagnostic work-up, treatment and support.

Ungew�hnlicher Verlauf einer ?-Mannosidose mit Symptomen einer paranoid-halluzinatorischen Psychose

We report the case of a 27-year-old female with recurrent paranoid-hallucinatory episodes who was initially diagnosed as suffering from schizophrenic psychosis. After 10 years of treatment under this diagnosis, alpha-mannosidosis was identified to be the underlying cause of her psychiatric symptoms. alpha-Mannosidosis is a rare autosomal recessive lysosomal storage disorder associated with decreased activity of the enzyme mannosidase. In the present case, diagnosis was made late in the illness after failure of a response to antipsychotic treatment and with the patient additionally showing progressive cognitive decline. Only after extensive investigation was the diagnosis made by showing decreased alpha-mannosidase enzyme activity in serum and blood leukocytes. This case demonstrates that an unusual clinical course or striking symptom patterns, especially in association with somatic comorbidity, in psychotic patients should lead to diagnostic consideration of inherited metabolic disease.

[Neuropsychological correlates of cerebral atrophy in Alzheimer's dementia]

This study aims to systematically analyze the relationship between neuropsychological deficits and regional cerebral atrophic changes in Alzheimer's dementia (AD). As an extension of previous studies we not only investigated substructures of the medial temporal lobe but also included other relevant cerebral regions such as frontal, temporal, and parietal lobes. This approach was based on the assumption that morphological correlates of global and specific cognitive dysfunction might reflect to a certain degree the neuronal basis of the respective function. Accordingly, the functional role assigned to a certain cerebral structure or region can be further elucidated which might lead to a better understanding of the clinical and neuropsychological heterogeneity of AD. Fifty patients with AD (NINCDS-ADRDA criteria) and 20 healthy elderly control subjects were included. All patients and controls were examined on a standardized neuropsychological test battery. In addition, magnetic resonance imaging (MRI) of the brain was performed. Volumes of the whole brain, CSF-spaces, amygdala-hippocampus complex, frontal lobes, temporal lobes, and parietal lobes were measured using a standardized protocol. AD-patients were characterized by neuropsychological deficits with respect to memory, language, praxia, cognitive speed as well as attention and concentration. These deficits were differentially correlated with regional atrophic changes. In particular, volumes of the right amygdala-hippocampus complex were correlated with declarative memory performance in the non-verbal visual domain. Furthermore, an association between left temporo-parietal regions and aspects of semantic memory, as well as verbal recall and left frontal regions could be established. The validity of our results is supported by recent findings from neuropathological and functional neuroimaging studies. In conclusion, our data indicate that MRI-based volumetry can be successfully used to detect morphological correlates of neuropsychological heterogeneity in AD and that this methodological approach allows to fruitfully study the neuronal basis of cognitive functions.

Corpus callosum in first-episode patients with schizophrenia--a magnetic resonance imaging study

BACKGROUND

Morphometric studies on the corpus callosum (CC) in schizophrenia have yielded contradictory results. The aim of the present study was to investigate magnetic resonance imaging (MRI) abnormalities of the CC in first-episode patients with schizophrenic psychoses.

METHOD

We assessed volumetric MRI in 31 patients with diagnoses of schizophrenia, schizophreniform or schizoaffective disorder (DSM-IV) and a maximum exposure to neuroleptics of 2 weeks. As a control group, 12 healthy age- and sex-matched individuals were included in the study. A whole body scanner at 1.5 Tesla was used to obtain 3D T1- and T2-weighted MR datasets. The data were evaluated semi-automatically (intracranial volume, total brain volume) and manually (CC) with the software NMRwin.

RESULTS

Patients had smaller CC and CC subdivisions than controls. Schizophrenic and unaffected women exhibited larger total CC and rostral subdivisions than men in both groups. Handedness did not exert an influence.

CONCLUSIONS

Our findings are in line with other in vivo morphometric studies on the CC in schizophrenia. The larger CC area in women may reflect general gender-related differences in CC size as described in healthy individuals.

[Magnetic resonance imaging in clinical diagnosis of dementia]

Dementing disorders belong to the most frequent neuropsychiatric diseases of the elderly population with prevalence rates of 5% in the 75 year old, but more than 10% in subjects older than 80 years. It is broadly accepted that the dementias are not caused by a single etiological factor but are attributed to a variety of different disease processes that affect the brain either directly or indirectly. According to pathoanatomic studies, two thirds of all dementias are caused by Alzheimer's disease (AD). Early recognition and differential diagnosis, which represent an important prerequisite for an optimized therapy, can be facilitated considerably by neuroimaging as well as by molecular biological findings. Therapeutic approaches include general medical management, psychosocial interventions as well as pharmacotherapy of cognitive and non-cognitive deficits. In general, early intervention using a combination of different therapeutic measures is recommended. In future, structural and functional neuroimaging might not only be used for diagnostic purposes but also to objectify and monitor the effect of treatment on relevant brain structures

[Structural cerebral changes in subjects with mild cognitive impairment]

The aim of the present study was to investigate the morphological changes in subjects with mild cognitive impairment (MCI) revealed by quantitative magnetic resonance imaging (MRI). Twenty-one subjects with cognitive impairment and 22 healthy controls were compared with 12 patients suffering from mild Alzheimer's disease (AD). The volumes of the following brain structures were assessed: total intracranial compartment, cerebrospinal fluid compartment, whole brain, and medial temporal substructures (hippocampus and parahippocampal gyrus). Subjects with mild cognitive impairment showed a significantly reduced volume of the right parahippocampal gyrus over healthy controls. Volumes of the other regions and structures did not differ between the MCI group and controls. The volumetric and neuropsychological findings of the present study support the hypothesis that mild cognitive impairment - at least in some of the affected individuals - can be seen as a preclinical stage of AD and that atrophy of the parahippocampal gyrus might be useful as an early marker of AD.

Frontotemporal dementia: clinical, neuroimaging, and molecular biological findings in 6 patients

Establishing the diagnosis in patients with clinical signs and symptoms suggesting primary degenerative disease with marked frontal lobe involvement is difficult. Neuroimaging methods, in particular positron emission tomography (PET) with the tracer 18fluoro-2-deoxyglucose (FDG) and cerebrospinal fluid (CSF) examination of beta-amyloid and tau-protein levels may give additional information. We report five patients with clinical and radiological features of degenerative dementia with predominantly frontal involvement and one patient with primary progressive aphasia Diagnostic work-up included computed tomography (CT), magnetic resonance imaging (MRI), PET and tau-protein and beta-amyloid level determination in CSF. While neuropsychological performance varied among patients, CT and MRI demonstrated persistently frontal lobe involvement. PET revealed corresponding changes with frontal hypometabolism, but in addition, four patients (among them two with no corresponding temporal changes in CT or MRI) showed a decreased glucose uptake in the temporal cortices. CSF samples from five patients revealed elevated beta-amyloid 1-42 and tau levels in three and two patients, respectively. Reduced beta-amyloid 1-40 was found in two patients. We conclude that occurrence of clinical symptoms of frontotemporal dementia is accompanied by frontal hypometabolism regardless of additional clinical findings. The value of determination of beta-amyloid and tau protein levels remains to be determined.

Reduced cerebrospinal fluid estradiol levels are associated with increased beta-amyloid levels in female patients with Alzheimer's disease

Recent in-vitro studies indicate that estrogens such as 17beta-estradiol (E2) may decrease the production of beta-amyloid 1-42 (Abeta42), a peptide central for the formation of senile plaques in Alzheimer's disease (AD). To test this hypothesis in a clinical study, cerebrospinal fluid levels of E2 were compared between 30 female AD patients and 11 female patients with non-dementing diseases such as major depression and investigated with respect to beta-amyloid 1-40 and Abeta42 levels. E2 levels were significantly (P<0.05) lower in the AD group than in controls; within the AD group E2 levels were inversely correlated with Abeta42 concentrations (r=-0.36, P=0.05). This is the first clinical study providing evidence for an influence of E2 on Abeta42 metabolism in vivo. This observation corresponds to the putative beneficial effects of estrogen replacement therapy on the development and course of AD.

[Quantitative magnetic resonance tomography in diagnosis of Alzheimer dementia]

Alzheimer's disease (AD) is a degenerative dementing disorder which is characterised by a progressive atrophy of several brain regions. This process may be visualised in vivo by the use of magnetic resonance imaging (MRI) in combination with appropriate volumetric post-processing techniques. Recent volumetric MRI studies in AD consistently found an extensive volume loss of the medial temporal lobe structures including amygdala and hippocampus which appeared already in the early clinical stages of the disorder. This finding is progressive during the clinical course of AD and is associated with other biological markers of the disease such as cerebrospinal fluid beta A 4 levels and apolipoprotein E genotype. With respect to the extent and the distribution of the structural changes, AD may be differentiated from other neuropsychiatric disorders which could facilitate the differential diagnosis in vivo.

A new method for the in vivo volumetric measurement of the human hippocampus with high neuroanatomical accuracy

Accurate and reproducible in vivo measurement of hippocampal volumes using magnetic resonance (MR) imaging is complicated by the morphological complexity of the structure. Additionally, separation of certain parts of the hippocampus from the adjacent brain structures on MR images is sometimes very difficult. These difficulties have led most investigators to either use arbitrary landmarks or to exclude certain parts of the structure from their measurements. Based on three-dimensional MR data, we have developed a reliable in vivo volumetric measurement of the human hippocampus. In contrast to most of the previously described volumetric MR-based methods, we aimed to sample the entire hippocampal formation using its true anatomical definition. This was accomplished by relying on the capacity of the BRAINS software to simultaneously visualize in multiple planes, to "telegraph" tracings or cursor position from one plane to another, and to simultaneously rely on multispectral data from three different image sets (T1, T2, and tissue classified). The methods for identifying boundaries and measuring the hippocampal volume are described. The method has excellent reliability, sensitivity, and specificity. The method may be of use in studies of structure-function relationships in neuropsychiatric disorders such as schizophrenia, temporal lobe epilepsy, and Alzheimer's disease. Future work will use these measurements as training data for a neural net-based technique to identify the anatomical boundaries automatically.

Alternative splicing at the MEFV locus involved in familial Mediterranean fever regulates translocation of the marenostrin/pyrin protein to the nucleus

Mutations in MEFV, a gene encoding a protein (marenostrin/pyrin) of unknown function, are associated with familial Mediterranean fever, a genetic condition characterized by febrile episodes of serosal inflammation. Based on its primary structure, this 781 residue protein is thought to function as a nuclear effector molecule. However, recent transient expression studies indicated a perinuclear cytoplasmic localization. Here, we describe the isolation and expression of a novel human MEFV isoform, MEFV-d2, generated by in-frame alternative splicing of exon 2. This transcript, expressed in leukocytes, predicts a 570 residue protein designated marenostrin-d2. To investigate differences in subcellular localization between the full-length protein (marenostrin-fl) and marenostrin-d2, while providing against the overexpression of transiently expressed proteins, we have generated CHO cell lines stably expressing these two isoforms fused to the green fluorescent protein. The localization pattern of marenostrin-d2 differs dramatically from that of marenostrin-fl. Marenostrin-fl is homogeneously distributed over the entire cytoplasm, whereas marenostrin-d2 concentrates into the nucleus. To map the critical domain(s) specifying these differences, deletion mutants have been generated. Deletion of the putative nuclear localization signals (NLS) does not alter the nuclear localization of marenostrin-d2 whereas, despite the lack of discernible NLS in the domain encoded by the exon 1-exon 3 splice junction, deletion of this domain indeed disrupts this localization. These data, which challenge the current domain organization model of marenostrin, strongly suggest that MEFV encodes a nuclear protein and raises the possibility that MEFV alternative splicing may control functions of wild-type and mutant marenostrin proteins by regulating their translocation to the nucleus.

G-CSF plasma levels in clozapine-induced neutropenia

BACKGROUND

Clinical reports emphasize the therapeutic usefulness of granulocyte colony-stimulating factor (G-CSF) in clozapine-induced granulocytopenia. Only sparse information exists, however, on the natural course of endogenous G-CSF plasma levels in this condition.

METHODS

We monitored G-CSF and white blood cell (WBC) counts in a 73-year-old patient who developed granulocytopenia while being treated with clozapine for schizoaffective disorder. Clozapine treatment was discontinued immediately, and G-CSF serum levels were determined repeatedly during the clinical course.

RESULTS

Whereas WBC counts increased again within 6 days after discontinuation of clozapine, G-CSF level decreased significantly within the same period. The rapid decrease of endogenous G-CSF levels paralleled by a normalization of neutrophil count was interpreted as the result of an intact regulatory mechanism of granulocytopoesis. Therefore G-CSF therapy was not initiated. Owing to lack of therapeutic alternatives, it was decided to reintroduce clozapine. G-CSF levels decreased further, accompanied by an increase of WBCs, indicating stable bone marrow functioning.

CONCLUSIONS

Based on this observation, we assume that the course of G-CSF and WBC counts indicated an abortive form of toxic bone marrow damage with subsequent recovery. We conclude that monitoring of G-CSF levels may serve as a useful tool in the follow-up of patients in whom clozapine-induced bone marrow damage is suspected.

[Cerebrospinal fluid protein tau levels in the differential diagnosis of Alzheimer's disease]

Tau protein concentration in cerebrospinal fluid was determined in 55 patients with Alzheimer's disease (AD), 18 patients with vascular dementia (VD), 19 patients with dementia caused by other disorders and 14 patients with major depression. Significantly (p < 0.05) elevated protein tau concentrations were found in AD patients (564.5 +/- 275.5 pg/ml) compared to all other patient groups (VD: 406.5 +/- 263.9 pg/ml; other dementia: 275.0 +/- 135.4 pg/ml; depression: 212.9 +/- 115.6 pg/ml). However, tau levels in AD patients covered a broad range (163.2 pg/ml-1200 pg/ml). AD patients with tau levels below the 25%-percentile of the distribution (among them a high percentage of patients with presenile onset) showed tau levels similar to those of the patients with late life depression. No significant correlations between tau levels and clinical variables such as severity of dementia, age, age of onset, duration of illness, and cerebral changes as assessed by volumetric magnetic resonance imaging could be demonstrated. Similarly, we could not find an influence of either APO-E genotype or psychotropic medication on the tau levels in AD patients. In accordance with other studies our results confirm elevated tau levels in AD compared to elderly not demented control subjects. Comparing groups, this finding applies as well with respect to VD and other dementing disorders. However, elevated tau levels cannot be detected in a subgroup of AD patients. This finding needs to be further investigated in future studies.

NF1 gene analysis focused on CpG-rich exons in a cohort of 93 patients with neurofibromatosis type 1

We studied the NF1 gene in 93 unrelated patients with neurofibromatosis type1, focusing the analysis on four exons that contain the highest number of possible mutations occurring at CpG sites. We used denaturing gradient gel electrophoresis to analyse exons 16, 28, 29 and 49, which contain 45 (25%) of the 183 possible mutations that could occur at the 120 CpG dinucleotides of the coding sequence. Six different mutations were identified, five of which are novel: two truncating mutations, W1810X and 5448insG, located in exon29; two splice defects leading to exon29 skipping, 5206-2A>G and 5546G>A; and one missense mutation, L844F, located in exon16. The already described R1748X mutation located in exon29 was found in two unrelated patients. The 5546G>A and R1748X mutations are located at CpG sites, whereas the W1810X involves a CpNpG site. Four novel polymorphisms, which may be helpful for family studies, were also identified. Overall, all but one mutations were found in exon29, a result which suggests that all the CpG sites of the NF1 coding sequence do not have the same mutability, and that exon29, the most CpG-rich exon, contains mutational hotspots associated with NF1.

Species-specific alternative splice mimicry at the growth hormone receptor locus revealed by the lineage of retroelements during primate evolution

In humans, growth hormone receptor (GHR) transcripts exist in two isoforms differing by the retention (GHRfl) or exclusion (GHRd3) of exon 3, whereas in mice GHRfl is solely expressed. This species-specific expression pattern is believed to result from an alternative splice event that, on the basis of conflicting data obtained in humans, has been considered to be tissue-, developmentally, and/or individual-specific. To decipher the molecular basis of this unusual trait, we isolated a 6.8-kilobase fragment spanning exon 3 from individuals expressing GHRfl. Sequence analysis revealed the existence of two 99% identical retroelements flanking this exon. Unexpectedly, individuals expressing GHRd3 displayed a 2.7-kilobase deletion involving exon 3, which most likely results from an ancestral homologous recombination between the two retroelements. The lineage of these retroelements during primate evolution revealed the species specificity of the GHRd3 allele. These findings led us to propose a model underlying the existence of the sole GHRfl allele in most species. Such a retrovirus-mediated alternative splice mimicry, which clears up several as yet unexplained phenomena (i.e. the above-mentioned expression data, the Mendelian inheritance of GHR expression patterns, and the deletion of nonconsecutive exons in growth hormone resistant patients), represents a novel physiological mechanism accounting for protein diversity between and within species.