Cerebral small vessel disease affects white matter microstructure in mild cognitive impairment.

Microstructural white matter deterioration is a frequent finding in mild cognitive impairment (MCI), potentially underlying default mode network (DMN) dysfunctioning. Thus far, microstructural damage in MCI has been attributed to Alzheimer's disease pathophysiology. A cerebrovascular role, in particular the role of cerebral small vessel disease (CSVD), received less interest. Here, we used diffusion tensor imaging (DTI) to examine the role of CSVD in microstructural deterioration within the normal appearing white matter (NAWM) in MCI. MCI patients were subdivided into those with (n = 20) and without (n = 31) macrostructural CSVD evidence on MRI. Using TBSS we performed microstructural integrity comparisons within the whole brain NAWM. Secondly, we segmented white matter tracts interconnecting DMN brain regions by means of automated tractography segmentation. We used NAWM DTI measures from these tracts as dependent variables in a stepwise-linear regression analysis, with structural and demographical predictors. Our results indicated microstructural deterioration within the anterior corpus callosum, internal and external capsule and periventricular white matter in MCI patients with CSVD, while in MCI patients without CSVD, deterioration was restricted to the right perforant path, a tract along the hippocampus. Within the full cohort of MCI patients, microstructure within the NAWM of the DMN fiber tracts was affected by the presence of CSVD. Within the cingulum along the hippocampal cortex we found a relationship between microstructural integrity and ipsilateral hippocampal volume and the extent of white matter hyperintensity. In conclusion, we found evidence of CSVD-related microstructural damage in fiber tracts subserving the DMN in MCI.

The clinical and pathological phenotype of C9ORF72 hexanucleotide repeat expansions.

There is increasing evidence that frontotemporal dementia and amyotrophic lateral sclerosis are part of a disease continuum. Recently, a hexanucleotide repeat expansion in C9orf72 was identified as a major cause of both sporadic and familial frontotemporal dementia and amyotrophic lateral sclerosis. The aim of this study was to investigate clinical and neuropathological characteristics of hexanucleotide repeat expansions in C9orf72 in a large cohort of Dutch patients with frontotemporal dementia. Repeat expansions were successfully determined in a cohort of 353 patients with sporadic or familial frontotemporal dementia with or without amyotrophic lateral sclerosis, and 522 neurologically normal controls. Immunohistochemistry was performed in a series of 10 brains from patients carrying expanded repeats using a panel of antibodies. In addition, the presence of RNA containing GGGGCC repeats in paraffin-embedded sections of post-mortem brain tissue was investigated using fluorescence in situ hybridization with a locked nucleic acid probe targeting the GGGGCC repeat. Hexanucleotide repeat expansions in C9orf72 were found in 37 patients with familial (28.7%) and five with sporadic frontotemporal dementia (2.2%). The mean age at onset was 56.9 ± 8.3 years (range 39-76), and disease duration 7.6 ± 4.6 years (range 1-22). The clinical phenotype of these patients varied between the behavioural variant of frontotemporal dementia (n = 34) and primary progressive aphasia (n = 8), with concomitant amyotrophic lateral sclerosis in seven patients. Predominant temporal atrophy on neuroimaging was present in 13 of 32 patients. Pathological examination of the 10 brains from patients carrying expanded repeats revealed frontotemporal lobar degeneration with neuronal transactive response DNA binding protein-positive inclusions of variable type, size and morphology in all brains. Fluorescence in situ hybridization analysis of brain material from patients with the repeat expansion, a microtubule-associated protein tau or a progranulin mutation, and controls did not show RNA-positive inclusions specific for brains with the GGGGCC repeat expansion. The hexanucleotide repeat expansion in C9orf72 is an important cause of frontotemporal dementia with and without amyotrophic lateral sclerosis, and is sometimes associated with primary progressive aphasia. Neuropathological hallmarks include neuronal and glial inclusions, and dystrophic neurites containing transactive response DNA binding protein. Future studies are needed to explain the wide variation in clinical presentation.

Midcingulate involvement in progressive supranuclear palsy and tau positive frontotemporal dementia.

BACKGROUND: Progressive supranuclear palsy (PSP) patients often exhibit cognitive decline and behavioural changes during the disease course. In a subset, these symptoms may be the presenting manifestation and can be similar to those in frontotemporal dementia (FTD). However, correlation studies between quantitative imaging measures and detailed neuropsychological assessment are scarce. The aim of this study was to investigate the functional role of affected brain regions in cognition in PSP compared with controls and subsequently examine these regions in FTD patients with known tau pathology (FTD tau). METHODS: 21 PSP patients, 27 healthy controls and 11 FTD tau patients were enrolled. All participants underwent neuropsychological testing and technetium-99m-hexamethyl-propylenamine-oxime single photon emission CT. Regression slope analyses were performed in statistical parametric mapping to find significant associations between neuropsychological test results and brain perfusion. RESULTS: PSP patients showed hypoperfusion in the midcingulate cortex (MCC) of which the posterior part correlated with Stroop III and Weigl. In FTD tau patients, MCC involvement was located more anterior and correlated with Stroop III and Wisconsin Card Sorting Test concepts. The degree of hypoperfusion in the anterior cortex and MCC in the disorders differed in the subgenual anterior cingulate cortex only. CONCLUSIONS: The posterior part of the MCC is prominently involved in the neurodegenerative process of PSP, and the severity of its hypoperfusion correlated with the extent of executive dysfunction. In FTD tau, this cognitive domain was associated with anterior MCC involvement. The degree of hypoperfusion in these regions did not differ between PSP and FTD tau. These observations provide insight into the role of the cingulate cortex in cognitive dysfunction in these neurodegenerative disorders and warrant further investigations.

Adaptive cognitive testing in cerebrovascular disease and vascular dementia.

BACKGROUND/AIMS: To examine whether brevity can be combined with precision in measuring global cognitive ability in patients with cerebrovascular disease (CVD) or vascular dementia (VaD). Longer tests (e.g. the CAMCOG) are precise but inefficient, whereas brief tests (e.g. the MMSE) are efficient but imprecise. METHODS: A simulated computerized adaptive testing (CAT) algorithm using existing CAMCOG data from 284 patients with CVD of whom 55 were diagnosed with VaD. CAT was used to estimate each individual patient's total score on a large precise test (the CAMCOG). CAT repeatedly selected only items of appropriate difficulty, depending on whether the previous item was (in)correctly responded to. CAT estimates were compared with total scores on the whole CAMCOG. RESULTS: Even though there was an average test reduction of more than 40%, CAT estimates were in very high agreement with the whole test results (intraclass correlation >0.97) and had similar accuracy for the diagnosis of dementia (area under the curve = 0.94). CONCLUSION: CAT combines efficiency with precision in the measurement of global cognitive ability in CVD patients.

Impaired maternal cognitive functioning after pregnancies complicated by severe pre-eclampsia: a pilot case-control study.

BACKGROUND: Pre-eclampsia is the most significant cause of neurological symptoms in pregnancy. Neurological symptoms may persist even after pregnancy. Somatic symptoms of pre-eclampsia, such as hypertension and proteinuria, generally disappear after delivery. However, formerly pre-eclamptic women more often complain of cognitive disturbances compared to women after uncomplicated pregnancies. METHODS: Three to eight months postpartum, a neuropsychological test battery was performed in 10 former severely pre-eclamptic women (according to the guidelines of the American College Obstetricians and Gynecologists) and 10 women after uncomplicated normotensive pregnancies. The control group was matched for age, educational level and mode of anesthesia. All women delivered by cesarean section either under general or regional anesthesia. Tests were performed for premorbid intelligence, short- and long-term memory, attention, concentration, executive functions, visual and spatial abilities. Anxiety and depression levels were measured. RESULTS: The formerly pre-eclamptic women had significantly lower scores on most indices of the auditory-verbal memory test. Formerly pre-eclamptic patients learned considerably fewer words than controls and recalled less after interference. Both case and control group did not differ in age, parity or level of education. There were no differences in the level of intellectual functioning and language tests, such as naming and word fluency. No persistent differences were observed in tests for attention/concentration and executive functioning. There were no significant differences on depression and anxiety scales. CONCLUSIONS: Maternal memory seems to be impaired after pregnancies complicated by severe pre-eclampsia. This effect cannot be attributed to depression and/or anxiety or method of anesthesia.

Cognition, Health-Related Quality of Life, and Depression Ten Years after Moderate to Severe Traumatic Brain Injury: A Prospective Cohort Study.

The aim of this study was to evaluate cognitive function 10 years after moderate-severe traumatic brain injury (TBI) and to investigate the associations among cognitive function, depression, and health-related quality of life (HRQoL). In this prospective cohort study, with measurements at 3, 6, 12, 18, 24, 36, and 120 months post-TBI, patients 18-67 years of age (n = 113) with moderate-severe TBI were recruited. Main outcome measures were depression (Center for Epidemiologic Studies-Depression Scale [CES-D]), subjective cognitive functioning (Cognitive Failure Questionnaire [CFQ]), objective cognitive functioning, and HRQoL (Medical Outcomes Study 36-Item Short Form Health Survey [SF-36]). Fifty of the initial 113 patients completed the 10 year follow-up. Twenty percent showed symptoms of depression (CES-D ≥ 16). These patients had more psychiatric symptoms at hospital discharge (p = 0.048) and were more often referred to rehabilitation or nursing homes (p = 0.015) than non-depressed patients. Further, they also had significantly lower scores in six of the eight subdomains of the SF-36. The non-depressed patients had equivalent scores to those of the Dutch norm-population on all subdomains of the SF-36. Cognitive problems at hospital discharge were related with worse cognitive outcome 10 years post-TBI, but not with depression or HRQoL. Ten years after moderate-severe TBI, only weak associations (p < 0.05) between depression scores and two objective cognitive functioning scores were found. However, there were moderate associations (p < 0.01) among depression scores, HRQoL, and subjective cognitive functioning. Therefore, signaling and treatment of depressive symptoms after moderate-severe TBI may be of major importance for optimizing HRQoL in the long term. We did not find strong evidence for associations between depression and objective cognitive functioning in the long term post-TBI. Disease awareness and selective dropping out may play a role in long-term follow-up studies in moderate-severe TBI. More long-term research is needed in this field.

Structural and functional brain abnormalities place phenocopy frontotemporal dementia (FTD) in the FTD spectrum.

PURPOSE: 'Phenocopy' frontotemporal dementia (phFTD) patients may clinically mimic the behavioral variant of FTD (bvFTD), but do not show functional decline or abnormalities upon visual inspection of routine neuroimaging. We aimed to identify abnormalities in gray matter (GM) volume and perfusion in phFTD and to assess whether phFTD belongs to the FTD spectrum. We compared phFTD patients with both healthy controls and bvFTD patients. MATERIALS & METHODS: Seven phFTD and 11 bvFTD patients, and 20 age-matched controls underwent structural T1-weighted magnetic resonance imaging (MRI) and 3D pseudo-continuous arterial spin labeling (pCASL) at 3T. Normalized GM (nGM) volumes and perfusion, corrected for partial volume effects, were quantified regionally as well as in the entire supratentorial cortex, and compared between groups taking into account potential confounding effects of gender and scanner. RESULTS: PhFTD patients showed cortical atrophy, most prominently in the right temporal lobe. Apart from this regional atrophy, GM volume was generally not different from either controls or from bvFTD. BvFTD however showed extensive frontotemporal atrophy. Perfusion was increased in the left prefrontal cortex compared to bvFTD and to a lesser extent to controls. CONCLUSION: PhFTD and bvFTD show overlapping cortical structural abnormalities indicating a continuum of changes especially in the frontotemporal regions. Together with functional changes suggestive of a compensatory response to incipient pathology in the left prefrontal regions, these findings are the first to support a possible neuropathological etiology of phFTD and suggest that phFTD may be a neurodegenerative disease on the FTD spectrum.

Cerebral blood flow in presymptomatic MAPT and GRN mutation carriers: A longitudinal arterial spin labeling study.

OBJECTIVE: Frontotemporal dementia (FTD) is characterized by behavioral disturbances and language problems. Familial forms can be caused by genetic defects in microtubule-associated protein tau (MAPT), progranulin (GRN), and C9orf72. In light of upcoming clinical trials with potential disease-modifying agents, the development of sensitive biomarkers to evaluate such agents in the earliest stage of FTD is crucial. In the current longitudinal study we used arterial spin labeling MRI (ASL) in presymptomatic carriers of MAPT and GRN mutations to investigate early changes in cerebral blood flow (CBF). METHODS: Healthy first-degree relatives of patients with a MAPT or GRN mutation underwent ASL at baseline and follow-up after two years. We investigated cross-sectional and longitudinal differences in CBF between mutation carriers (n = 34) and controls without a mutation (n = 31). RESULTS: GRN mutation carriers showed significant frontoparietal hypoperfusion compared with controls at follow-up, whereas we found no cross-sectional group differences in the total study group or the MAPT subgroup. Longitudinal analyses revealed a significantly stronger decrease in CBF in frontal, temporal, parietal, and subcortical areas in the total group of mutation carriers and the GRN subgroup, with the strongest decrease in two mutation carriers who converted to clinical FTD during follow-up. INTERPRETATION: We demonstrated longitudinal alterations in CBF in presymptomatic FTD independent of grey matter atrophy, with the strongest decrease in individuals that developed symptoms during follow-up. Therefore, ASL could have the potential to serve as a sensitive biomarker of disease progression in the presymptomatic stage of FTD in future clinical trials.

Assessment methods and prevalence of cognitive dysfunction in patients with low-grade glioma: A systematic review.

OBJECTIVE: To systematically review the literature for studies on cognitive functioning in patients with low-grade glioma to evaluate assessment methods and prevalence of cognitive dysfunction. DATA SOURCES: A search was made in PubMed, Embase, and PsycINFO for articles published between January 2002 and June 2012 using cognition, memory, attention, executive functioning, and low-grade glioma as search terms. STUDY SELECTION: Two reviewers independently performed the study selection and data extraction. Inclusion criteria were: studies including at least 10 adult patients, with suspected or confirmed low-grade glioma and cognitive functioning as outcome measure. DATA EXTRACTION: A standard data extraction form was used, with items regarding study quality, patient characteristics, type of measurement instruments, cognitive domain, definition of cognitive dysfunction, and reported prevalence. DATA SYNTHESIS: Of the 312 articles screened on title/abstract, 69 were screened on full-text and, finally, 17 were included. A total of 46 different measurement instruments were found for the assessment of cognitive functioning; 5 of these were used 5 or more times. There was variability in the definition of cognitive dysfunction. The reported prevalence of cognitive dysfunction ranged from 19% to 83%. CONCLUSION: Many patients with low-grade glioma experience cognitive dysfunction. However, there is no consensus on how to assess cognitive functioning in these patients.

Structural and functional brain connectivity in presymptomatic familial frontotemporal dementia.

OBJECTIVE: We aimed to investigate whether cognitive deficits and structural and functional connectivity changes can be detected before symptom onset in a large cohort of carriers of MAPT (microtubule-associated protein tau) or GRN (progranulin) mutations. METHODS: In this case-control study, 75 healthy individuals (aged 20-70 years) with 50% risk of frontotemporal dementia (FTD) underwent DNA screening, neuropsychological assessment, structural MRI, and fMRI. We used voxel-based morphometry and tract-based spatial statistics for voxel-wise analyses of gray matter volume and diffusion tensor imaging measures. Using resting-state fMRI scans, we assessed whole-brain functional connectivity to frontoinsular, anterior midcingulate, and posterior cingulate cortices. RESULTS: Carriers (n = 39) and noncarriers (n = 36) had similar neuropsychological performance, except for lower Letter Digit Substitution Test scores in carriers. Worse performance on Stroop III, Rivermead Behavioral Memory Test, and Happé Cartoons correlated with higher age in carriers, but not controls. Reduced fractional anisotropy in the right uncinate fasciculus was found in carriers compared with controls. Reductions in functional connectivity between anterior midcingulate cortex and frontoinsula and several other brain regions were found in carriers compared with controls and correlated with higher age in carriers, but not controls. We found no significant differences or age correlations in posterior cingulate cortex connectivity. No differences in regional gray matter volume were found, except for a small cluster of higher volume in the precentral gyrus in carriers. CONCLUSIONS: This study demonstrates that alterations in structural and functional connectivity develop before the first symptoms of FTD arise. These findings suggest that diffusion tensor imaging and resting-state fMRI may have the potential to become sensitive biomarkers for early FTD in future clinical trials.

Episodic memory impairment in frontotemporal dementia; a 99mTc- HMPAO SPECT study.

Alzheimer's disease (AD) and frontotemporal dementia (FTD) are the most common types of dementia in the presenile population. Episodic memory impairment, the clinical hallmark of AD, can also be encountered in patients with FTD, complicating accurate diagnosis. Several studies in FTD have correlated memory deficits with neuroimaging findings, but lacked to compare neuroimaging results in FTD patients with and without memory impairment, while this latter analysis may give us insight into the underlying mechanisms of memory impairment in FTD. The aim of the present study was to compare (99m)Tc-HMPAO SPECT hypoperfusion patterns between FTD with episodic memory impairment (n = 13), FTD patients without episodic memory impairment (n = 10) as well as early onset (< 70 yrs) AD patients (n = 13), and controls (n = 15). We performed our analyses by means of Statistical Parametric Mapping software (SPM5), and showed that FTD patients with episodic memory impairment had lower perfusion in the right temporal lobe compared with FTD patients without memory impairment. Lower perfusion in this region correlated with worse memory performance on the Clinical Dementia Rating scale in FTD patients. With equal performances on memory tests, patients with early onset AD showed posterior temporal and parietal lobe hypoperfusion in comparison with patients with FTD and memory impairment, while vice versa hypoperfusion in the anterior frontotemporal regions was found in FTD patients with memory impairment in comparison with AD.

The influence of cerebral small vessel disease on default mode network deactivation in mild cognitive impairment.

INTRODUCTION: Cerebral small vessel disease (CSVD) is thought to contribute to cognitive dysfunction in patients with mild cognitive impairment (MCI). The underlying mechanisms, and more specifically, the effects of CSVD on brain functioning in MCI are incompletely understood. The objective of the present study was to examine the effects of CSVD on brain functioning, activation and deactivation, in patients with MCI using task-related functional MRI (fMRI). METHODS: We included 16 MCI patients with CSVD, 26 MCI patients without CSVD and 25 controls. All participants underwent a physical and neurological examination, neuropsychological testing, structural MRI, and fMRI during a graded working memory paradigm. RESULTS: MCI patients with and without CSVD had a similar neuropsychological profile and task performance during fMRI, but differed with respect to underlying (de)activation patterns. MCI patients with CSVD showed impaired deactivation in the precuneus/posterior cingulate cortex, a region known to be involved in the default mode network. In MCI patients without CSVD, brain activation depended on working memory load, as they showed relative 'hyperactivation' during vigilance, and 'hypoactivation' at a high working memory load condition in working memory related brain regions. CONCLUSIONS: We present evidence that the potential underlying mechanism of CSVD affecting cognition in MCI is through network interference. The observed differences in brain activation and deactivation between MCI patients with and without CSVD, who had a similar 'clinical phenotype', support the view that, in patients with MCI, different types of pathology can contribute to cognitive impairment through different pathways.

Symmetrical corticobasal syndrome caused by a novel C.314dup progranulin mutation.

Corticobasal syndrome (CBS) is characterised by asymmetrical parkinsonism and cognitive impairment. The underlying pathology varies between corticobasal degeneration, progressive supranuclear palsy, Alzheimer's disease, Creutzfeldt-Jakob disease and frontotemporal lobar degeneration sometimes in association with GRN mutations. A 61-year-old male underwent neurological examination, neuropsychological assessment, MRI, and HMPAO-SPECT at our medical centre. After his death at the age of 63, brain autopsy, genetic screening and mRNA expression analysis were performed. The patient presented with slow progressive walking disabilities, non-fluent language problems, behavioural changes and forgetfulness. His family history was negative. He had primitive reflexes, rigidity of his arms and postural instability. Later in the disease course he developed dystonia of his left leg, pathological crying, mutism and dysphagia. Neuropsychological assessment revealed prominent ideomotor and ideational apraxia, executive dysfunction, non-fluent aphasia and memory deficits. Neuroimaging showed symmetrical predominant frontoparietal atrophy and hypoperfusion. Frontotemporal lobar degeneration (FTLD)-TDP type 3 pathology was found at autopsy. GRN sequencing revealed a novel frameshift mutation c.314dup, p.Cys105fs and GRN mRNA levels showed a 50% decrease. We found a novel GRN mutation in a patient with an atypical (CBS) presentation with symmetric neuroimaging findings. GRN mutations are an important cause of CBS associated with FTLD-TDP type 3 pathology, sometimes in sporadic cases. Screening for GRN mutations should also be considered in CBS patients without a positive family history.

Frequency of ubiquitin and FUS-positive, TDP-43-negative frontotemporal lobar degeneration.

Frontotemporal lobar degeneration (FTLD) is a clinically, genetically and pathologically heterogeneous disorder. Within FTLD with ubiquitin-positive inclusions (FTLD-U), a new pathological subtype named FTLD-FUS was recently found with fused in sarcoma (FUS) positive, TDP-43-negative inclusions, and striking atrophy of the caudate nucleus. The aim of this study was to determine the frequency of FTLD-FUS in our pathological FTLD series, and to describe the clinical, neuroimaging and neuropathological features of FTLD-FUS, especially caudate atrophy. Demographic and clinical data collected prospectively from 387 patients with frontotemporal dementia (FTD) yielded 74 brain specimens. Immunostaining was carried out using a panel of antibodies, including AT-8, ubiquitin, p62, FUS, and TDP-43. Cortical and caudate atrophy on MRI (n = 136) was rated as normal, mild-moderate or severe. Of the 37 FTLD-U cases, 33 were reclassified as FTLD-TDP and four (0.11, 95%: 0.00-0.21) as FTLD-FUS, with ubiquitin and FUS-positive, p62 and TDP-43-negative neuronal intranuclear inclusions (NII). All four FTLD-FUS cases had a negative family history, behavioural variant FTD (bvFTD), and three had an age at onset

Association of cognitive functioning with retinal nerve fiber layer thickness.

PURPOSE: The brain areas that are responsible for cognitive functioning have the same embryonic origin as the retina. The association between cognitive functioning and retinal nerve fiber layer (RNFL) thickness was assessed in a large, population-based sample. METHODS: Neuropsychological and ophthalmic examinations were performed in 1485 healthy individuals (mean age, 46 years; range, 18-85) from the Erasmus Rucphen Family (ERF) study, a study in a genetic isolate from the Netherlands. Different domains of cognitive functioning were assessed with the Dutch Adult Reading Test, the Rey Auditory Verbal Memory Test, semantic fluency, the Trail-Making Test, the Stroop Color-Word Test, and Block Design. RNFL thickness was measured with scanning laser polarimetry. The association between cognitive test scores and peripapillary RNFL thickness was studied with linear regression analyses, adjusting for age, sex, level of inbreeding, and refractive error. RESULTS: After adjustment for confounders, a better cognitive performance was significantly associated with a thicker RNFL in all tests (P < 0.03) except for the Stroop Color-Word Test (P = 0.15). RNFL thickness explained up to 2.8% (R(2) = 0.028) of the total variance in cognitive test scores. The association diminished in age groups beyond 40 years. CONCLUSIONS: The present study shows that cognitive functioning is associated with RNFL thickness in healthy young individuals. The lack of association in older individuals suggests that loss of neurons in the cerebrum and retina is not concomitant and may have different origins.

A study of the SORL1 gene in Alzheimer's disease and cognitive function.

Several studies have investigated the role of the neuronal sortilin-related receptor (SORL1) gene in Alzheimer's disease (AD), but findings have been inconsistent. We conducted a study of 7 single nucleotide polymorphisms (SNPs), rs668387, rs689021, rs641120, rs1699102, rs3824968, rs2282649, and rs1010159, in the SORL1 gene that were associated to AD in previous studies. We tested for association with AD and cognitive function in 6741 participants of the Rotterdam Study and in 2883 individuals from the Erasmus Rucphen Family study. We performed meta-analyses on AD using our data together with those of previous studies published prior to September 2008 in Caucasians. Further, we studied up to 76 SNPs in a 400 kb region within and flanking the gene to evaluate the evidence that other genetic variants are associated with AD or cognitive function. There was no significant evidence for association between SORL1 SNPs and incident AD patients in the Rotterdam Study. In a meta-analysis of our data with those of others, six out of seven SNPs attained borderline significance. However, removal of the first study reporting association from the meta-analysis resulted in non-significant odds ratios for all SNPs. SNPs rs668387, rs689021, and rs641120 were associated with cognitive function in non-demented individuals at borderline statistical significance in two independent Dutch cohorts, but in the opposite direction. Testing for association using dense SNPs in the SORL1 gene did not reveal significant association with AD, or with cognitive function when adjusting for multiple testing. In conclusion, our data do not support the hypothesis that genetic variants in SORL1 are related to the risk of AD.

Post-stroke dementia and depression: frontosubcortical dysfunction as missing link?

OBJECTIVE: Testing the hypothesis that depressive symptoms in dementia reflect dysfunction in fronto-subcortical pathways. BACKGROUND: Both depression and dementia can be the result of vascular damage of the brain. The nature of the depressive symptomatology seems to be related to concommittant cognitive disturbances in that subjects show more so-called motivational symptoms of depression. These symptoms can be the result of frontal-subcortical dysfunction. It could be very helpful for clinical practice if these subjects could be identified by simple diagnostic procedures. METHODS: Associations were computed between measures of depressive symptoms and a set of neuropsychological tests in a sample of 54 subjects with a post-stroke dementia. RESULTS: Although we used an extensive set of neuropsychological tests, most subjects were able to participate only in a small part of them, because of disease severity. Our hypothesis was supported by a negative correlation between scores on the verbal semantic fluency task and the total numbers of motivational depressive symptoms. None of the neuropsychological tests was significantly related to the number of mood symptoms neither did they correlate with the total number of depressive symptoms. CONCLUSION: This study gives further evidence for the assumption that motivational-based depressive symptoms partially originate from fronto-subcortical dysfunction.

Spinocerebellar ataxia associated with a mutation in the fibroblast growth factor 14 gene (SCA27): A new phenotype.

Autosomal dominant cerebellar ataxias (ADCAs) are genetically classified into spinocerebellar ataxias (SCAs). We describe 14 patients of a Dutch pedigree displaying a distinct SCA-phenotype (SCA27) associated with a F145S mutation in the fibroblast growth factor 14 (FGF14) gene on chromosome 13q34. The patients showed a childhood-onset postural tremor and a slowly progressive ataxia evolving from young adulthood. Dyskinesia was often present, suggesting basal ganglia involvement, which was supported by functional imaging in 1 patient. Magnetic resonance imaging (MRI) of the brain showed only moderate cerebellar atrophy in the 2 eldest patients. Neuropsychological testing indicated low IQ and deficits in memory and executive functioning. Behavioral problems were also observed. Further investigations will have to determine the role of FGF14 in the pathogenesis of neurodegeneration and the frequency of this FGF14 mutation in SCA. (c) 2005 Movement Disorder Society.

Depression in vascular dementia.

OBJECTIVE: To study the presence of different dimensions of depression in subjects with vascular dementia. BACKGROUND: After a stroke, cognitive, affective and behavioural disturbances are common. It has been suggested that the nature of affective symptomatology can help to differentiate organic from psychological depression. METHODS: Cognitive and affective symptoms were assessed in 78 stroke patients and a principal component analysis was performed on these symptoms. Also, a discriminant analysis was carried out to establish the contribution of different symptoms on the diagnosis 'depressive disorder' and 'dementia'. RESULTS: (1) Principal component analysis revealed three distinct sub-syndromes: one with predominantly mood symptoms, one with essentially psychomotor symptoms, and one with vegetative symptoms; (2) mood, psychomotor and vegetative symptoms were all independently and strongly related to a diagnosis of major depressive disorder according to DSM-III-R criteria; (3) the psychomotor factor was also firmly associated with dementia; and (4) discriminant analysis gave further support for our conclusion that some of the depressive features, in particular the psychomotor factor, are at least partly related to the organic brain damage from stroke. CONCLUSION: The results indicate that different dimensions of depression could be discerned in a group of stroke patients and that the symptom profile of depression in these patients can be affected by the presence of dementia.