Timed Up and Go in People with Subjective Cognitive Decline Is Associated with Faster Cognitive Deterioration and Cortical Thickness.

INTRODUCTION: Early markers of neurodegeneration provide an opportunity to detect, monitor, and initiate interventions in individuals who have an increased risk of developing dementia. Here, we investigated whether the Timed Up and Go (TUG) test is associated with early brain neurodegeneration and whether the TUG test could be a marker of cognitive decline in people with subjective cognitive decline (SCD). METHODS: This is a longitudinal analysis of the Dementia Disease Initiation Study, a prospective, community-based, cohort study from Norway, designed to investigate early markers of cognitive impairment and dementia. Participants were classified as SCD and healthy controls (HC). The main studied variables were the TUG test and cognition as measured by the Mini-Mental State Examination and the Consortium to Establish a Registry for Alzheimer's Disease memory composite score. Additionally, we investigated the cross-sectional association of brain morphology with the TUG using 1.5T-MRI. RESULTS: The sample included 45 participants (SCD = 21, HC = 24) followed during a mean time of 1.50 ± 0.70 years. At baseline, the cognitive performance did not differ between the groups, but TUG was longer in SCD. Slower baseline TUG was associated with a faster cognitive decline in both groups and it was also associated with reduced cortical thickness especially in motor, executive, associative, and somatosensory cortical regions in people with SCD. DISCUSSION/CONCLUSION: TUG predicted cognitive change in individuals with SCD, and there was a negative association between TUG and cortical thickness. TUG is a promising cheap and noninvasive marker of early cognitive decline and may help initiate interventions in individuals who have an increased risk of dementia.

Brain atrophy and clinical characteristics predicting SDMT performance in multiple sclerosis: A 10-year follow-up study.

OBJECTIVES: To identify Magnetic Resonance Imaging (MRI), clinical and demographic biomarkers predictive of worsening information processing speed (IPS) as measured by Symbol Digit Modalities Test (SDMT). METHODS: Demographic, clinical data and 1.5 T MRI scans were collected in 76 patients at time of inclusion, and after 5 and 10 years. Global and tissue-specific volumes were calculated at each time point. For the primary outcome of analysis, SDMT was used. RESULTS: Worsening SDMT at 5-year follow-up was predicted by baseline age, Expanded Disability Status Scale (EDSS), SDMT, whole brain volume (WBV) and T2 lesion volume (LV), explaining 30.2% of the variance of SDMT. At 10-year follow-up, age, EDSS, grey matter volume (GMV) and T1 LV explained 39.4% of the variance of SDMT change. CONCLUSION: This longitudinal study shows that baseline MRI-markers, demographic and clinical data can help predict worsening IPS. Identification of patients at risk of IPS decline is of importance as follow-up, treatment and rehabilitation can be optimized.

Brain atrophy and employment in multiple sclerosis patients: a 10-year follow-up study.

BACKGROUND: Multiple sclerosis is often associated with unemployment. The contribution of grey matter atrophy to unemployment is unclear. OBJECTIVES: To identify magnetic resonance imaging biomarkers of grey matter and clinical symptoms associated with unemployment in multiple sclerosis patients. METHODS: Demographic, clinical data and 1.5 T magnetic resonance imaging scans were collected in 81 patients at the time of inclusion and after 5 and 10 years. Global and tissue-specific volumes were calculated at each time point. Statistical analysis was performed using a mixed linear model. RESULTS: At baseline 31 (38%) of the patients were unemployed, at 5-year follow-up 44 (59%) and at 10-year follow-up 34 (81%) were unemployed. The unemployed patients had significantly lower subcortical deep grey matter volume (P < 0.001), specifically thalamus, pallidus, putamen and hippocampal volumes, and cortical volume (P = 0.011); and significantly greater T1 (P < 0.001)/T2 (P < 0.001) lesion volume than the employed patient group at baseline. Subcortical deep grey matter volumes, and to a lesser degree cortical volume, were significantly associated with unemployment throughout the follow-up. CONCLUSION: We found significantly greater atrophy of subcortical deep grey matter and cortical volume at baseline and during follow-up in the unemployed patient group. Atrophy of subcortical deep grey matter showed a stronger association to unemployment than atrophy of cortical volume during the follow-up.

A population study of Norwegian psychiatric patients referred for clinical brain scanning.

BACKGROUND: Patients with psychiatric conditions are often referred for a brain scan during the course of their diagnostic workup. AIMS: The aim of our study is to determine frequency and type of organic brain pathology, the relationship to age, gender and psychiatric diagnosis. METHOD: We investigated magnetic resonance imaging and computed tomography brain scans from consecutively referred patients over a 10-year period (January 2002-December 2011). The reasons for referral, estimated psychiatric diagnosis, and the pathology discovered for each patient were registered. RESULTS: A total of 34% of patients demonstrated organic brain pathology, of which 32.8% were considered clinically relevant. This represents a higher frequency of relevant pathology than reported in healthy subjects. Age (P < 0.001) and diagnosis (P = 0.016) were the most important determinants for frequency of pathological findings. CONCLUSIONS: Brain imaging in clinical psychiatry resulted in approximately 30% positive findings mainly associated with increasing pathologies with age, but also with diagnosis. DECLARATION OF INTEREST: Both T.O.D. and M.K.B. have received honorary from Novartis for scientific lectures about multiple sclerosis. M.K.B. also received honoraria from Biogen for scientific lectures. The other authors have no conflicts of interest.

Brain atrophy and disability progression in multiple sclerosis patients: a 10-year follow-up study.

OBJECTIVES: To identify MRI biomarkers associated with long-term disability progression in patients with multiple sclerosis (MS), and to define the rate of evolution of global, tissue-specific and regional atrophy in patients with MS over long-term. METHODS: MRI of the brain and clinical neurological assessment was performed in 81 patients at time of first visit and after 5 and 10 years of follow-up. MRI was acquired on 1.5 T scanners. T1-lesion and T2-lesion volumes (LVs) were calculated. Global and tissue-specific atrophy changes were longitudinally assessed, using a direct measurement approach, by calculating percentage volume changes between different time points. Regional tissue volumes for the subcortical deep grey matter (SDGM) structures were also obtained. Disability progression was defined as an increase in Expanded Disability Status Scale of ≥ 1.0 compared to baseline at 5-year and 10-year follow-up. RESULTS: Over 5 years, patients with disability progression showed significantly increased loss of whole brain (-3.8% vs -2.0%, p<0.001), cortical (-3.4% vs -1.8%, p=0.009) and putamen volume changes (-10.6% vs -3.8%, p=0.003) compared to patients with no disability progression. No significant change in white matter (WM) volume was observed when comparing progressing and non-progressing patients. Over 10 years, there was a trend for greater decrease in whole brain volume (-5.5% vs -3.7%, p=0.015) in the progressing patients. No significant changes in LV measures were detected between the patients with and without disability progression. CONCLUSION: This long-term study shows that whole brain, cortical and putamen atrophy occurs throughout the 10-year follow-up of this MS cohort and is more pronounced in the group that showed disability progression at 5, but not at 10 years of follow-up. Overall, GM atrophy showed better association with disease progression than WM atrophy over 5-year and 10-year follow-up.

Cerebrospinal fluid Aß levels correlate with structural brain changes in Parkinson's disease.

ParkWest is a large Norwegian multicenter study of newly diagnosed drug-naïve subjects with Parkinson's disease (PD). Cognitively normal PD subjects (PDCN) and PD subjects with mild cognitive impairment (PDMCI) from this cohort have significant hippocampal atrophy and ventricular enlargement, compared to normal controls. Here, we aimed to investigate whether the same structural changes are associated with cerebrospinal fluid (CSF) levels of amyloid beta (Aß)38 , Aß40 , Aß42 , total tau (t-tau), and phosphorylated tau (p-tau). We performed three-dimensional radial distance analyses of the hippocampi and lateral ventricles using the MRI data from ParkWest subjects who provided CSF at baseline. Our sample consisted of 73 PDCN and 18 PDMCI subjects. We found significant associations between levels of all three CSF Aß analytes and t-tau and lateral ventricular enlargement in the pooled sample. In the PDCN sample, all three amyloid analytes showed significant associations with the radial distance of the occipital and frontal horns of the lateral ventricles. CSF Aß38 and Aß42 showed negative associations, with enlargement in occipital and frontal horns of the lateral ventricles in the pooled sample, and a negative association with the occipital horns in PDMCI. CSF Aß levels in early PD correlate with ventricular enlargement, previously associated with PD dementia. Therefore, CSF and MRI markers may help identify PD patients at high risk for developing cognitive decline and dementia in the course of their illness. Contrary to Alzheimer's disease, we found no associations between CSF t-tau and p-tau and hippocampal atrophy.

Cerebrospinal fluid amyloid-ß and phenotypic heterogeneity in de novo Parkinson's disease.

BACKGROUND: In Parkinson's disease (PD), the motor presentation characterised by postural instability/gait difficulties (PIGD) heralds accelerated motor, functional and cognitive decline, as compared with the more benign tremor-dominant (TD) variant. This makes the PIGD complex an attractive target for the discovery of prognostic biomarkers in PD. OBJECTIVE: To explore in vivo whether variability in brain amyloid-ß (Aß) metabolism affects the initial motor presentation in PD. METHODS: We quantified cerebrospinal fluid (CSF) concentrations and ratios of Aß42, Aß40 and Aß38 using a triplex immunoassay in 99 patients with de novo PD with the PIGD phenotype (n=39) or the TD phenotype (n=60). All patients underwent standardised assessments of motor and neuropsychological function and cerebral MRI. 46 age-matched normal controls served as external reference. RESULTS: Patients with PD with the PIGD phenotype had significantly reduced CSF Aß42, Aß38, Aß42/40 and Aß38/40 levels compared with patients with the TD phenotype and controls. CSF marker levels in patients with PD-TD did not differ from those in controls. Multivariate regression models demonstrated significant associations of CSF Aß markers with severity of PIGD and lower limb bradykinesia in patients with PD, independently from age, MRI white matter hyperintensities and cognition. No associations were found between CSF markers and other motor features. CONCLUSIONS: Motor heterogeneity in de novo PD independently relates to CSF Aß markers, with low levels found in patients with the PIGD presentation. This suggests that disturbed Aß metabolism has an effect on PD beyond cognition and may contribute to the variable rate of motor and functional decline in PD.

Ventricular enlargement and mild cognitive impairment in early Parkinson's disease.

Mild cognitive impairment (MCI) may predict future development of dementia in Parkinson's disease (PD). We aimed to examine the extent of subcortical brain atrophy in patients with early PD with and without MCI compared to normal controls (NC). Participating in a population-based study were 43 early, drug-naïve PD patients and 41 NC. Eleven patients were classified with MCI (MCI PD) and 32 patients without (non-MCI PD). Volumetric segmentation of 3D-T1 weighted brain MRI was performed using FreeSurfer. Groups were compared applying MANCOVA corrected for total intracranial volume, age, and sex. Results showed that left inferior lateral ventricle and third ventricle volumes were significantly larger in MCI PD than in non-MCI PD and NC. Fourth ventricular size in MCI PD was significantly different from NC and highly correlated with memory performance in MCI PD patients. This suggests that cognitive dysfunction in early PD may be associated with ventricular enlargement.

Gray matter correlations of cognition in incident Parkinson's disease.

We aimed to investigate whether mild cognitive impairment (MCI) in Parkinson's disease (PD) is characterized by region-specific gray matter (GM) atrophy and to explore correlations between GM and cognition in PD. Magnetic resonance images of 42 newly diagnosed PD patients (of which 11 had MCI) and 37 normal controls were analyzed using voxel-based morphometry. Analyses comparing groups showed no regional atrophy, and in patients there were no significant correlations between cognitive domain test performance and GM loss. In conclusion, GM atrophy does not seem to be a major feature of cognitive dysfunction in incident PD.

Brain atrophy and white matter hyperintensities in early Parkinson's disease(a).

The purpose of this research was to examine the extent of global brain atrophy and white matter hyperintensities (WMH) in early Parkinson's disease (PD) compared to normal controls (NC), to explore the relationship between the MRI variables and cognition in PD. In this multicenter study we included 155 PD patients (age 65.6 +/- 9.1 years, disease duration 26.7 +/- 19.9 months) and 101 age-matched NC. On 3D-T1-WI, we calculated normalized brain volumes using SIENAX software. WMH volumes were assessed semiautomatically. In PD patients, correlation and regression analyses investigated the association between atrophy and WMH outcomes and global, attention-executive, visuospatial, and memory cognitive functions. Regression analysis was controlled for age, education, depression score, motor severity, cerebrovascular risk, and sex. No significant MRI variable volume group differences were found. The models did not retain any of the imaging variables as significant predictors of cognitive impairment. There was no evidence of brain atrophy or higher WMH volume in PD compared to NC, and MRI volumetric measurements were not significant predictors of cognitive functions in PD patients. We conclude that global structural brain changes are not a major feature in patients with incident PD.

White matter hyperintensities do not impact cognitive function in patients with newly diagnosed Parkinson's disease.

The objective of this study was to investigate total volume and spatial distribution of white matter hyperintensities (WMH) in a large sample of newly diagnosed Parkinson's disease (PD) patients with and without mild cognitive impairment (MCI) compared to normal controls (NC). Furthermore, we aimed to examine the impact of the WMH on attention-executive performance in PD. MCI is regarded as a pre-dementia stage. Studies on MCI have found WMH associated with reduced cognitive function, especially in the attention and executive domains. The present study included 163 incident, drug-naïve PD patients (66.2+/-9.1 years and disease duration 27.1+/-19.8 months) and 102 age-matched NC (65.7+/-9.4 years). Thirty (30) subjects in the PD sample presented MCI, whereas 133 did not. MCI was classified based on tests for memory, attention-executive and visuospatial function compared to the NC group, taking age, sex and education into consideration. WMH were outlined on FLAIR scans using a semi-automated technique. Total WMH volumes were compared between the 3 study groups, and spatial distribution of normalized WMH masks in each group were compared using voxel-wise probability maps. Regression analysis examined the possible impact of WMH on attention-executive scores in the PD group. Analysis showed that there were no significant differences between the 3 groups in total volume or spatial distribution of WMH. In addition there was no significant relationship between total volume or spatial distribution of WMH and attention-executive functions in PD. We conclude that in this PD cohort, cognitive impairment seems to be independent of WMH damage.

Neuroimaging of cognitive impairments in vascular disease.

Cerebrovascular disease (CVD) is increasingly recognized as a common cause of cognitive impairment and dementia, alone or in conjunction with other neurodegenerative diseases, primarily Alzheimer's disease. The term vascular cognitive impairment (VCI) has been proposed as an umbrella term to recognize the broad spectrum of cognitive changes associated with vascular pathology, mainly characterized by executive impairment together with particular noncognitive features.