Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 54
Filter
1.
Eur Psychiatry ; 63(1): e83, 2020 08 07.
Article in English | MEDLINE | ID: mdl-32762779

ABSTRACT

BACKGROUND: Cerebral glutamate and gamma-aminobutyric acid (GABA) levels might predict clinical outcome in individuals at ultrahigh risk (UHR) for psychosis but have previously primarily been investigated in smaller cohorts. We aimed to study whether baseline levels of glutamate and GABA in anterior cingulate cortex (ACC) and glutamate in thalamus could predict remission status and whether baseline metabolites differed in the remission versus the nonremission group. We also investigated the relationship between baseline metabolite levels and severity of clinical symptoms, functional outcome, and cognitive deficits at follow-up. METHODS: About 124 UHR individuals were recruited at baseline. In this, 74 UHR individuals were clinically and cognitively assessed after 12 months, while remission status was available for 81 (25 remission/56 nonremission). Glutamate and GABA levels were assessed at baseline using 3 T proton magnetic resonance spectroscopy. Psychopathology, symptom severity, and remission were assessed with the Comprehensive Assessment of At-Risk Mental States and Clinical Global Impression and functional outcome with the Social and Occupational Functioning Assessment Scale. Cognitive function was estimated with the Cambridge Neuropsychological Test Automated Battery. RESULTS: There were no differences between baseline glutamate and GABA levels in subjects in the nonremission group compared with the remission group, and baseline metabolites could not predict remission status. However, higher baseline levels of GABA in ACC were associated with clinical global improvement (r = -0.34, N = 51, p = 0.01) in an explorative analysis. CONCLUSIONS: The variety in findings across studies suggests a probable multifactorial influence on clinical outcome in UHR individuals. Future studies should combine multimodal approaches to attempt prediction of long-term outcome.


Subject(s)
Brain Chemistry , Glutamic Acid/metabolism , Gyrus Cinguli/metabolism , Psychotic Disorders/metabolism , Thalamus/metabolism , gamma-Aminobutyric Acid/metabolism , Adolescent , Adult , Cognition , Cognitive Dysfunction/diagnosis , Glutamic Acid/analysis , Humans , Neuropsychological Tests , Prognosis , Psychopathology , Psychotic Disorders/psychology , Time Factors , Treatment Outcome , Young Adult , gamma-Aminobutyric Acid/analysis
2.
Acta Psychiatr Scand ; 140(3): 205-216, 2019 09.
Article in English | MEDLINE | ID: mdl-31265120

ABSTRACT

OBJECTIVE: Several studies have found an increase in hippocampal volume following electroconvulsive therapy (ECT), but the effect on cortical thickness has been less investigated. We aimed to examine the effects of ECT on cortical thickness and their associations with clinical outcome. METHOD: Using 3 Tesla MRI scanner, we obtained T1-weighted brain images of 18 severely depressed patients at three time points: before, right after and 6 months after a series of ECT. The thickness of 68 cortical regions was extracted using Free Surfer, and Linear Mixed Model was used to analyze the longitudinal changes. RESULTS: We found significant increases in cortical thickness of 26 regions right after a series of ECT, mainly within the frontal, temporal and insular cortex. The thickness returned to the baseline values at 6-month follow-up. We detected no significant decreases in cortical thickness. The increase in the thickness of the right lateral orbitofrontal cortex was associated with a greater antidepressant effect, r = 0.75, P = 0.0005. None of the cortical regions showed any associations with cognitive side effects. CONCLUSION: The increases in cortical thickness induced by ECT are transient. Further multimodal MRI studies should examine the neural correlates of these increases and their relationship with the antidepressant effect.


Subject(s)
Cerebral Cortex/pathology , Depressive Disorder/pathology , Depressive Disorder/therapy , Electroconvulsive Therapy , Adolescent , Adult , Aged , Aged, 80 and over , Cerebral Cortex/diagnostic imaging , Depressive Disorder/diagnostic imaging , Female , Humans , Longitudinal Studies , Magnetic Resonance Imaging , Male , Middle Aged , Young Adult
3.
Mol Psychiatry ; 23(11): 2145-2155, 2018 11.
Article in English | MEDLINE | ID: mdl-29880882

ABSTRACT

Conventional antipsychotic medication is ineffective in around a third of patients with schizophrenia, and the nature of the therapeutic response is unpredictable. We investigated whether response to antipsychotics is related to brain glutamate levels prior to treatment. Proton magnetic resonance spectroscopy was used to measure glutamate levels (Glu/Cr) in the anterior cingulate cortex (ACC) and in the thalamus in antipsychotic-naive or minimally medicated patients with first episode psychosis (FEP, n = 71) and healthy volunteers (n = 60), at three sites. Following scanning, patients were treated with amisulpride for 4 weeks (n = 65), then 1H-MRS was repeated (n = 46). Remission status was defined in terms of Positive and Negative Syndrome Scale for Schizophrenia (PANSS) scores. Higher levels of Glu/Cr in the ACC were associated with more severe symptoms at presentation and a lower likelihood of being in remission at 4 weeks (P < 0.05). There were longitudinal reductions in Glu/Cr in both the ACC and thalamus over the treatment period (P < 0.05), but these changes were not associated with the therapeutic response. There were no differences in baseline Glu/Cr between patients and controls. These results extend previous evidence linking higher levels of ACC glutamate with a poor antipsychotic response by showing that the association is evident before the initiation of treatment.


Subject(s)
Antipsychotic Agents/therapeutic use , Glutamic Acid/drug effects , Psychotic Disorders/drug therapy , Adult , Female , Glutamic Acid/analysis , Glutamic Acid/metabolism , Gyrus Cinguli/drug effects , Gyrus Cinguli/metabolism , Humans , Male , Proton Magnetic Resonance Spectroscopy/methods , Psychiatric Status Rating Scales , Schizophrenia/drug therapy , Thalamus/drug effects , Thalamus/metabolism , Young Adult
4.
Acta Psychiatr Scand ; 137(1): 65-78, 2018 Jan.
Article in English | MEDLINE | ID: mdl-29143980

ABSTRACT

OBJECTIVE: The neurodevelopmental hypothesis of psychosis suggests that disrupted white matter (WM) maturation underlies disease onset. In this longitudinal study, we investigated WM connectivity and compared WM changes between individuals at ultra-high-risk for psychosis (UHR) and healthy controls (HCs). METHOD: Thirty UHR individuals and 23 HCs underwent MR diffusion tensor imaging before and after 12 months of non-manualized standard care. Positive and negative symptoms and level of functioning were assessed. Tract-based spatial statistics were employed. RESULTS: During 12 months, none of the UHR individuals transitioned to psychosis. Both UHR individuals and HCs increased significantly in fractional anisotropy (FA). UHR individuals showed significant FA increases predominantly in the left superior longitudinal fasciculus (SLF) (P = 0.01), and HCs showed significant FA increases in the left uncinate fasciculus (P = 0.03). Within UHR individuals, a significant positive correlation between FA change and age was observed predominantly in the left SLF (P = 0.02). Within HCs, no significant correlation between FA change and age was observed. No significant correlations between baseline FA and clinical outcomes were observed; however, FA changes were significantly positively correlated to changes in negative symptoms (P = 0.04). CONCLUSION: As normal brain maturation occurs in a posterior to frontal direction, our findings could suggest disturbed WM maturation in UHR individuals.


Subject(s)
Brain/diagnostic imaging , Prodromal Symptoms , Psychotic Disorders/diagnostic imaging , White Matter/diagnostic imaging , Adolescent , Adult , Anisotropy , Brain/growth & development , Case-Control Studies , Diffusion Tensor Imaging , Female , Humans , Longitudinal Studies , Magnetic Resonance Imaging , Male , Psychotic Disorders/psychology , Risk , Young Adult
5.
Psychol Med ; 47(15): 2689-2707, 2017 Nov.
Article in English | MEDLINE | ID: mdl-28464976

ABSTRACT

BACKGROUND: Individuals at ultra-high-risk (UHR) for psychosis present with emerging symptoms and decline in functioning. Previous univariate analyses have indicated widespread white matter (WM) aberrations in multiple brain regions in UHR individuals and patients with schizophrenia. Using multivariate statistics, we investigated whole brain WM microstructure and associations between WM, clinical symptoms, and level of functioning in UHR individuals. METHODS: Forty-five UHR individuals and 45 matched healthy controls (HCs) underwent magnetic resonance diffusion tensor imaging (DTI) at 3 Tesla. UHR individuals were assessed with the Comprehensive Assessment of At-Risk Mental States, Scale for the Assessment of Negative Symptoms, and Social and Occupational Functioning Assessment Scale. Partial least-squares correlation analysis (PLSC) was used as statistical method. RESULTS: PLSC group comparisons revealed one significant latent variable (LV) accounting for 52% of the cross-block covariance. This LV indicated a pattern of lower fractional anisotropy (FA), axial diffusivity (AD), and mode of anisotropy (MO) concomitant with higher radial diffusivity (RD) in widespread brain regions in UHR individuals compared with HCs. Within UHR individuals, PLSC revealed five significant LVs associated with symptoms and level of functioning. The first LV accounted for 31% of the cross-block covariance and indicated a pattern where higher symptom score and lower level of functioning correlated to lower FA, AD, MO, and higher RD. CONCLUSIONS: UHR individuals demonstrate complex brain patterns of WM abnormalities. Despite the subtle psychopathology of UHR individuals, aberrations in WM appear associated with positive and negative symptoms as well as level of functioning.


Subject(s)
Psychotic Disorders/pathology , Psychotic Disorders/physiopathology , Schizophrenia/pathology , Schizophrenia/physiopathology , White Matter/pathology , Adult , Diffusion Tensor Imaging , Female , Humans , Male , Psychotic Disorders/diagnostic imaging , Risk , Schizophrenia/diagnostic imaging , White Matter/diagnostic imaging , Young Adult
6.
Eur J Neurol ; 22(4): 702-e46, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25573335

ABSTRACT

BACKGROUND AND PURPOSE: Functional neuroimaging studies have shown hyperresponsiveness of cortical areas to visual stimuli in migraine patients with aura outside of attacks. This may be a key feature in the initiation of aura episodes and possibly also migraine headache attacks. It is unknown if cortical dysfunction is present at rest, i.e. in the absence of any external stimuli. Functional magnetic resonance imaging is a powerful technique for evaluating resting state functional connectivity, i.e. coherence of brain activity across cerebral areas. The objective of this study was to investigate resting-state functional brain connectivity in migraineurs with aura outside of attacks using functional magnetic resonance imaging. METHODS: Forty patients suffering from migraine with visual aura and 40 individually age and gender matched healthy controls with no history or family history of migraine were investigated. Following advanced denoising, the data were analyzed both in a hypothesis-driven fashion, testing for abnormalities involving 27 different brain areas of potential relevance to migraine with aura including the cortical visual areas, the amygdala and peri-aqueductal grey matter, and in a data-driven exploratory fashion (dual regression) in order to reveal any possible between-group differences of resting state networks. Age, gender, attack frequency and disease duration were included as nuisance variables. RESULTS: No differences of functional connectivity were found between patients and controls. CONCLUSIONS: The previously reported increased cortical hyperresponsivity in the interictal phase of migraine with aura is unlikely to be caused by abnormalities of intrinsic brain connectivity. The interictal migraine aura brain may be abnormally functioning only during exposure to external stimuli.


Subject(s)
Cerebrum/physiopathology , Connectome , Migraine with Aura/physiopathology , Adult , Female , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Young Adult
7.
Neuroimage Clin ; 4: 182-9, 2014.
Article in English | MEDLINE | ID: mdl-24371801

ABSTRACT

OBJECTIVES: To investigate whether blood-brain barrier (BBB) permeability is disrupted in normal appearing white matter in MS patients, when compared to healthy controls and whether it is correlated with MS clinical characteristics. METHODS: Dynamic contrast-enhanced MRI was used to measure BBB permeability in 27 patients with MS and compared to 24 matched healthy controls. RESULTS: Permeability measured as K(trans) was significantly higher in periventricular normal appearing white matter (NAWM) and thalamic gray matter in MS patients when compared to healthy controls, with periventricular NAWM showing the most pronounced difference. Recent relapse coincided with significantly higher permeability in periventricular NAWM, thalamic gray matter, and MS lesions. Immunomodulatory treatment and recent relapse were significant predictors of permeability in MS lesions and periventricular NAWM. Our results suggest that after an MS relapse permeability gradually decreases, possibly an effect of immunomodulatory treatment. CONCLUSIONS: Our results emphasize the importance of BBB pathology in MS, which we find to be most prominent in the periventricular NAWM, an area prone to development of MS lesions. Both the facts that recent relapse appears to cause widespread BBB disruption and that immunomodulatory treatment seems to attenuate this effect indicate that BBB permeability is intricately linked to the presence of MS relapse activity. This may reveal further insights into the pathophysiology of MS.


Subject(s)
Blood-Brain Barrier/physiopathology , Multiple Sclerosis/pathology , Adult , Capillary Permeability/physiology , Contrast Media , Female , Humans , Imaging, Three-Dimensional , Magnetic Resonance Imaging , Male , Middle Aged , Perfusion Imaging , Severity of Illness Index , White Matter/pathology
8.
Am J Physiol Endocrinol Metab ; 305(4): E496-506, 2013 Aug 15.
Article in English | MEDLINE | ID: mdl-23800880

ABSTRACT

Physical exercise increases peripheral insulin sensitivity, but regional differences are poorly elucidated in humans. We investigated the effect of aerobic exercise training on insulin-stimulated glucose uptake in five individual femoral muscle groups and four different adipose tissue regions, using dynamic (femoral region) and static (abdominal region) 2-deoxy-2-[¹8F]fluoro-d-glucose (FDG) PET/CT methodology during steady-state insulin infusion (40 mU·m⁻²·min⁻¹). Body composition was measured by dual X-ray absorptiometry and MRI. Sixty-one healthy, sedentary [V(O2max) 36(5) ml·kg⁻¹·min⁻¹; mean(SD)], moderately overweight [BMI 28.1(1.8) kg/m²], young [age: 30(6) yr] men were randomized to sedentary living (CON; n = 17 completers) or moderate (MOD; 300 kcal/day, n = 18) or high (HIGH; 600 kcal/day, n = 18) dose physical exercise for 11 wk. At baseline, insulin-stimulated glucose uptake was highest in femoral skeletal muscle followed by intraperitoneal visceral adipose tissue (VAT), retroperitoneal VAT, abdominal (anterior + posterior) subcutaneous adipose tissue (SAT), and femoral SAT (P < 0.0001 between tissues). Metabolic rate of glucose increased similarly (~30%) in the two exercise groups in femoral skeletal muscle (MOD 24[9, 39] µmol·kg⁻¹·min⁻¹, P = 0.004; HIGH 22[9, 35] µmol·kg⁻¹·min⁻¹, P = 0.003) (mean[95% CI]) and in five individual femoral muscle groups but not in femoral SAT. Standardized uptake value of FDG decreased ~24% in anterior abdominal SAT and ~20% in posterior abdominal SAT compared with CON but not in either intra- or retroperitoneal VAT. Total adipose tissue mass decreased in both exercise groups, and the decrease was distributed equally among subcutaneous and intra-abdominal depots. In conclusion, aerobic exercise training increases insulin-stimulated glucose uptake in skeletal muscle but not in adipose tissue, which demonstrates some interregional differences.


Subject(s)
Adipose Tissue, White/metabolism , Exercise , Glucose Transporter Type 4/metabolism , Glucose/metabolism , Insulin Resistance , Muscle, Skeletal/metabolism , Overweight/therapy , Adipose Tissue, White/diagnostic imaging , Adipose Tissue, White/drug effects , Adiposity , Adult , Biological Transport/drug effects , Body Mass Index , Contrast Media/metabolism , Fluorodeoxyglucose F18/metabolism , Glucose Clamp Technique , Glucose Transporter Type 4/biosynthesis , Humans , Hypoglycemic Agents/metabolism , Hypoglycemic Agents/pharmacology , Insulin/metabolism , Insulin/pharmacology , Longitudinal Studies , Male , Multimodal Imaging , Muscle, Skeletal/diagnostic imaging , Muscle, Skeletal/drug effects , Overweight/metabolism , Positron-Emission Tomography , Tomography, X-Ray Computed , Up-Regulation , Young Adult
9.
J Neurol ; 260(10): 2458-71, 2013 Oct.
Article in English | MEDLINE | ID: mdl-23263472

ABSTRACT

Focal lesions and brain atrophy are the most extensively studied aspects of multiple sclerosis (MS), but the image acquisition and analysis techniques used can be further improved, especially those for studying within-patient changes of lesion load and atrophy longitudinally. Improved accuracy and sensitivity will reduce the numbers of patients required to detect a given treatment effect in a trial, and ultimately, will allow reliable characterization of individual patients for personalized treatment. Based on open issues in the field of MS research, and the current state of the art in magnetic resonance image analysis methods for assessing brain lesion load and atrophy, this paper makes recommendations to improve these measures for longitudinal studies of MS. Briefly, they are (1) images should be acquired using 3D pulse sequences, with near-isotropic spatial resolution and multiple image contrasts to allow more comprehensive analyses of lesion load and atrophy, across timepoints. Image artifacts need special attention given their effects on image analysis results. (2) Automated image segmentation methods integrating the assessment of lesion load and atrophy are desirable. (3) A standard dataset with benchmark results should be set up to facilitate development, calibration, and objective evaluation of image analysis methods for MS.


Subject(s)
Brain/pathology , Multiple Sclerosis/pathology , Neuroimaging , Atrophy/etiology , Atrophy/pathology , Humans , Imaging, Three-Dimensional , Longitudinal Studies , Multiple Sclerosis/complications , Neuroimaging/methods , Neuroimaging/standards
10.
Neuroimage ; 60(3): 1597-607, 2012 Apr 15.
Article in English | MEDLINE | ID: mdl-22305990

ABSTRACT

White matter hyperintensities (WMH) are a frequent finding on brain MRI of elderly subjects, and have been associated with various risk factors, as well as with development of cognitive and functional impairment. While an overall association between WMH load and risk factors is well described, possible spatially restricted vulnerability remains to be established. The aim of this study was to investigate the spatial distribution of WMH in normally functioning elderly subjects. We introduce a voxel-based approach in which lesion probability is mapped as a function of clinical risk factors using logistic regression, and validate the method using simulated datasets. The method was then applied in a total of 605 participants of the LADIS study (age 74 ± 5 years, all with WMH), and the location of manually delineated WMH was investigated after spatial normalisation. Particularly strong and widespread associations were found for age, gender and hypertension. Different distribution patterns were found for men and women. Further, increased probability was found in association with self-reported alcohol and tobacco consumption, as well as in those with a history of migraine. It is concluded that the location of WMH is dependent on the risk factors involved pointing towards a regionally different pathogenesis and/or vulnerability of the white matter.


Subject(s)
Aging/pathology , Diffusion Tensor Imaging/statistics & numerical data , Models, Neurological , Nerve Fibers, Myelinated/pathology , Vascular Diseases/epidemiology , Vascular Diseases/pathology , Age Distribution , Aged , Aged, 80 and over , Denmark/epidemiology , Female , Humans , Incidence , Male , Middle Aged , Reproducibility of Results , Risk Assessment , Risk Factors , Sensitivity and Specificity , Sex Distribution
11.
Acta Neurol Scand ; 125(5): 338-44, 2012 May.
Article in English | MEDLINE | ID: mdl-21793807

ABSTRACT

OBJECTIVES: Although disease load in multiple sclerosis (MS) often is based on T2 lesion volumes, the changes in T2 of normal appearing brain tissue (NABT) are rarely considered. By means of magnetic resonance, (MR) we retrospectively investigated whether T2 changes in NABT explain part of the cognitive impairment seen in MS and constitute a supplement to traditional measurement of T2 lesion volume. MATERIALS AND METHODS: Fifty patients with clinically definite MS were included (38 women, 12 men). Patients were MR scanned, neuropsychologically tested, and evaluated clinically with the Kurtzke Expanded Disability Status Scale (EDSS) and the Multiple Sclerosis Impairment Scale (MSIS). Voxel-wise T2 estimates and total T2 lesion volume were tested for correlations with eight cognitive domains, a general cognitive dysfunction factor (CDF), and the two clinical scales. RESULTS: We found distinct clusters of voxels with T2 estimates correlating with CDF, mental processing speed, complex motor speed, verbal fluency, and MSIS. A significant negative correlation was found between total lesion volume and CDF (r = -0.34, P = 0.02), verbal intelligence (r = -0.40, P = 0.005), mental processing speed (r = -0.34, P = 0.03), visual problem solving (r = -0.40, P = 0.01), and complex motor speed (r = -0.39, P = 0.01). No significant correlation was detected between total lesion load and the clinical measures EDSS and MSIS. CONCLUSION: Our results suggest that even in the NABT MR detects changes likely to be associated with an underlying pathology and possibly contributes to the cognitive impairment in MS.


Subject(s)
Brain/pathology , Cognition Disorders/pathology , Diffusion Magnetic Resonance Imaging/methods , Multiple Sclerosis/pathology , Nerve Fibers, Myelinated/pathology , Adult , Brain/physiopathology , Cognition Disorders/etiology , Cognition Disorders/physiopathology , Female , Humans , Male , Middle Aged , Multiple Sclerosis/complications , Multiple Sclerosis/physiopathology , Retrospective Studies
12.
Neurology ; 77(7): 645-51, 2011 Aug 16.
Article in English | MEDLINE | ID: mdl-21813786

ABSTRACT

OBJECTIVE: We wanted to investigate if retinal nerve fiber layer thickness (RNFLT) measured by optical coherence tomography (OCT) might be a good marker of acute and chronic changes in the afferent visual pathway following acute optic neuritis (ON). METHODS: We studied the relationship of optic nerve lesion length, optic nerve mean area, and RNFLT, quantified by OCT, with fMRI response to a visual paradigm in 40 patients with acute ON and 19 healthy controls in a prospective cohort study over a 6-month period. RESULTS: The main finding was a significant correlation of optic nerve lesion length and mean area with fMRI response in affected eyes in the acute phase and between RNFLT and fMRI response in affected eyes after recovery. CONCLUSION: RNFLT is a very good measure of damage to the afferent visual pathway in recovered patients with ON and should be included in future fMRI studies when looking for visual reorganization in recovered patients with ON.


Subject(s)
Optic Atrophy/pathology , Optic Nerve/pathology , Optic Neuritis/pathology , Retina/pathology , Adolescent , Adult , Female , Humans , Image Processing, Computer-Assisted , Magnetic Resonance Imaging , Male , Middle Aged , Optic Atrophy/physiopathology , Optic Nerve/physiopathology , Optic Neuritis/physiopathology , Prospective Studies , Retina/physiopathology , Tomography, Optical Coherence , Visual Pathways/pathology , Visual Pathways/physiopathology
13.
J Neurol Sci ; 307(1-2): 100-5, 2011 Aug 15.
Article in English | MEDLINE | ID: mdl-21621224

ABSTRACT

The aim of this 3-year follow-up study was to investigate whether corpus callosum (CC) atrophy may predict future motor and cognitive impairment in an elderly population. On baseline MRI from 563 subjects with age-related white matter changes (ARWMC) from the Leukoaraiosis And DISability (LADIS) study, the CC was segmented and subdivided into five anterior-posterior regions (CC1-CC5). Associations between the CC areas and decline in motor performance and cognitive functions over a 3-year period were analyzed. CC atrophy at baseline was significantly associated with impaired cognitive performance (p<0.01 for CC1, p<0.05 for CC5), motor function (p<0.05 for CC2 and CC5), and walking speed (p<0.01 for CC2 and CC5, p<0.05 for CC3 and total CC), and with development of dementia at 3 years (p<0.05 for CC1) after correction for appropriate confounders (ARWMC volume, atrophy, age, gender and handedness). In conclusion, CC atrophy, an indicator of reduced functional connectivity between cortical areas, seems to contribute, independently of ARWMC load, to future cognitive and motor decline in the elderly.


Subject(s)
Aging/pathology , Cognition Disorders/pathology , Corpus Callosum/pathology , Memory Disorders/pathology , Psychomotor Disorders/pathology , Aged , Aging/physiology , Atrophy , Cognition Disorders/physiopathology , Cohort Studies , Corpus Callosum/physiopathology , Female , Follow-Up Studies , Humans , Male , Memory Disorders/physiopathology , Psychomotor Disorders/physiopathology , Walking/physiology
14.
Br J Radiol ; 83(988): 307-17, 2010 Apr.
Article in English | MEDLINE | ID: mdl-19690078

ABSTRACT

Severe brain damage is often followed by serious complications. Quantitative measurements, such as regional volume and surface area under various conditions, are essential for understanding functional changes in the brain and assessing prognosis. The affected brain tissue is variable, hence traditional imaging methods are not always applicable and automatic methods may not be able to match the individual observer. Stereological techniques are alternative tools in the quantitative description of biological structures, and have been increasingly applied to the human brain. In the present study, we applied stereological techniques to representative CT and MRI brain scans from five patients to describe how stereological methods, when applied to scans of trauma patients, can provide a useful supplement to the estimation of structural brain changes in head injuries. The reliability of the estimates was tested by obtaining repeated intra- and interobserver estimates of selected subdivisions of the brain in patients with acute head injury, as well as in an MR phantom. The estimates of different subdivisions showed a coefficient of variation (CV) below 12% in the patients and below 7% for phantom estimation. The validity of phantom estimates was tested by the average deviation from the true geometric values, and was below 10%. The stereological methods were compared with more traditional region-based methods performed on medical imaging, which showed a CV below 7% and bias below 14%. It is concluded that the stereological estimates may be useful tools in head injury quantification.


Subject(s)
Brain Injuries/diagnosis , Brain/pathology , Image Interpretation, Computer-Assisted/methods , Subarachnoid Hemorrhage/diagnosis , Algorithms , Brain Injuries/etiology , Craniocerebral Trauma/complications , Humans , Magnetic Resonance Imaging/methods , Phantoms, Imaging , Reproducibility of Results , Subarachnoid Hemorrhage/etiology , Tomography, X-Ray Computed/methods
15.
J Magn Reson Imaging ; 29(4): 768-73, 2009 Apr.
Article in English | MEDLINE | ID: mdl-19306365

ABSTRACT

PURPOSE: To explore relations between spatial distribution of multiple sclerosis (MS) lesions, and disability. In MS, the presence of asymptomatic brain lesions challenges the prediction of disability based on conventional brain MRI. Hypothesizing that symptomatology may partly be determined by lesion location, this retrospective study explored relations between lesion location and disability using voxelwise analyses in standard space. MATERIALS AND METHODS: Using nonparametric permutation-based statistics, voxelwise lesion probability on T2 lesion masks was related to expanded disability status scale (EDSS) and MS functional composite (MSFC) subdomain scores and demographic characteristics of 325 MS patients. To identify statistically significant locations, a cluster-forming threshold of 3.1 was used. RESULTS: In clusters in the periventricular region, lesion probability correlated significantly (P < 0.001) with disability and disease duration, and was higher in progressive than in relapsing disease. When controlled for lesion load (LL), no significant clusters survived. Presence and number of spinal cord lesions did not correlate with lesion probability in any location, and did not influence correlations with disability when included in its analyses. CONCLUSION: Periventricular lesions were related to disability. LL influenced relations between disability and lesion probability throughout the brain, suggesting interplay between lesional burden and its location in determining disability in MS.


Subject(s)
Magnetic Resonance Imaging/methods , Multiple Sclerosis/pathology , Adult , Brain Mapping/methods , Cross-Sectional Studies , Disability Evaluation , Female , Humans , Image Processing, Computer-Assisted , Male , Middle Aged , Multiple Sclerosis/physiopathology , Retrospective Studies , Statistics, Nonparametric
16.
AJNR Am J Neuroradiol ; 29(8): 1498-504, 2008 Sep.
Article in English | MEDLINE | ID: mdl-18556357

ABSTRACT

BACKGROUND AND PURPOSE: The corpus callosum (CC) is the most important structure involved in the transmission of interhemispheric information. The aim of this study was to investigate the potential correlation between regional age-related white matter changes (ARWMC) and atrophy of CC in elderly subjects. MATERIALS AND METHODS: In 578 subjects with ARWMC from the Leukoaraiosis And DISability (LADIS) study, the cross-sectional area of the CC was automatically segmented on the normalized midsagittal MR imaging section and subdivided into 5 regions. The ARWMC volumes were measured quantitatively by using a semiautomated technique and segmented into 6 brain regions. RESULTS: Significant correlation between the area of the rostrum and splenium regions of the CC and the ARWMC load in most brain regions was identified. This correlation persisted after correction for global atrophy. CONCLUSION: Increasing loads of ARWMC volume were significantly correlated with atrophy of the CC and its subregions in nondisabled elderly subjects with leukoaraiosis. However, the pattern of correlation between CC subregions and ARWMC was not specifically related to the topographic location of ARWMC. The results suggest that ARWMC may lead to a gradual loss of CC tissue.


Subject(s)
Brain/pathology , Corpus Callosum/pathology , Leukoaraiosis/epidemiology , Leukoaraiosis/pathology , Magnetic Resonance Imaging/methods , Nerve Fibers, Myelinated/pathology , Aged , Europe/epidemiology , Female , Humans , Male , Prevalence
17.
Eur Neurol ; 59(5): 229-36, 2008.
Article in English | MEDLINE | ID: mdl-18264011

ABSTRACT

BACKGROUND AND PURPOSE: Neurological deterioration following acute stroke is common and associated with increased morbidity and mortality. The underlying pathophysiological mechanisms are not fully understood, and it is difficult to predict which patients are at risk of deterioration. Our study aimed to assess if acute MRI findings could be used for the prediction of stroke in progression (SIP). METHODS: Prospectively 41 patients, 13 with lacunar infarcts and 28 with territorial infarcts, were admitted to an acute stroke unit within 24 h of stroke onset (median 11 h, range 3- 22). Diffusion-weighted imaging (DWI), perfusion-weighted imaging and magnetic resonance angiography were performed 3 times, immediately after clinical evaluation, on day 7 and after 3 months. Clinical neurological assessments were performed every 2 h during the first 24 h and once daily from day 2 to 7. SIP was defined as a permanent decrease of >or=3 Scandinavian Stroke Scale (SSS) points for speech or >or=2 SSS points for consciousness or >or=2 SSS points for limb strength, when assessed at baseline compared to the day after admission and daily during the following week. Patients were followed up on day 90 and assessed using the modified Rankin Scale, Barthel Index and SSS score. Patients with and without SIP were compared using both clinical and MRI data obtained on admission, on day 7 and after 3 months. RESULTS: Fifteen patients (37%) developed SIP. Increased DWI lesion volume on day 7 in all strokes was associated with SIP (chi(2), p = 0.005). All lacunar infarcts with a DWI volume >1.5 cm(3) at baseline (4 patients) developed SIP (p < 0.005). Patients with territorial infarcts and SIP had lower baseline SSS scores with severer symptoms than non-SIP patients (p

Subject(s)
Brain/pathology , Magnetic Resonance Imaging , Stroke/pathology , Adult , Aged , Aged, 80 and over , Diffusion Magnetic Resonance Imaging , Disease Progression , Female , Humans , Magnetic Resonance Angiography , Male , Middle Aged , Recovery of Function
18.
Diabet Med ; 24(2): 166-71, 2007 Feb.
Article in English | MEDLINE | ID: mdl-17257279

ABSTRACT

HYPOTHESIS: Based on recent findings on the association between vascular risk factors and hippocampal atrophy, we hypothesized that hypertension and diabetes mellitus (DM) are associated with medial temporal lobe atrophy (MTA) in subjects without disability, independent of the severity of white matter hyperintensities. METHODS: In the Leukoaraiosis And DISability in the elderly (LADIS) study, we investigated the relationships between DM, hypertension, blood pressure and MTA in 582 subjects, stratified by white matter hyperintensity severity, using multinomial logistic regression. MTA was visually scored for the left and right medial temporal lobe (score 0-4), and meaned. RESULTS: Mean age was 73.5 years (sd 5.1), 54% was female. Of the subjects, 15% had DM, and 70% had a history of hypertension. The likelihood of having MTA score 3 was significantly higher in subjects with DM (OR 2.9; 95% CI: 1.1-7.8) compared with an MTA score of 0 (no atrophy). The odds ratio for MTA score 2 was not significantly increased (OR 1.8; CI: 0.9-4). Systolic and diastolic blood pressure and a history of hypertension were not associated with MTA. There was no interaction between DM and hypertension. Stratification on white matter hyperintensities (WMH) did not alter the associations. CONCLUSION: Our study strengthens the observation that MTA is associated with DM, independently of the amount of small vessel disease as reflected by WMH.


Subject(s)
Diabetic Angiopathies/pathology , Hypertension/pathology , Temporal Lobe/pathology , Aged , Aged, 80 and over , Atrophy/pathology , Female , Humans , Magnetic Resonance Imaging , Male , Risk Factors
19.
Neurobiol Aging ; 28(6): 955-63, 2007 Jun.
Article in English | MEDLINE | ID: mdl-16797787

ABSTRACT

Corpus callosum (CC) is the main tract connecting the hemispheres, but the clinical significance of CC atrophy is poorly understood. The aim of this work was to investigate clinical and functional correlates of CC atrophy in subjects with age-related white matter changes (ARWMC). In 569 elderly subjects with ARWMC from the Leukoaraiosis And DISability (LADIS) study, the CC was segmented on the normalised mid-sagittal magnetic resonance imaging (MRI) slice and subdivided into five regions. Correlations between the CC areas and subjective memory complaints, mini mental state examination (MMSE) score, history of depression, geriatric depression scale (GDS) score, subjective gait difficulty, history of falls, walking speed, and total score on the short physical performance battery (SPPB) were analyzed. Significant correlations between CC atrophy and MMSE, SPPB, and walking speed were identified, and the CC areas were smaller in subjects with subjective gait difficulty. The correlations remained significant after correction for ARWMC grade. In conclusion, CC atrophy was independently associated with impaired global cognitive and motor function in subjects with ARWMC.


Subject(s)
Aging/pathology , Corpus Callosum/pathology , Corpus Callosum/physiopathology , Age Factors , Aged , Aged, 80 and over , Atrophy , Cognition Disorders/etiology , Cognition Disorders/pathology , Cross-Sectional Studies , Depression/etiology , Disabled Persons , Female , Gait/physiology , Humans , Leukoaraiosis/pathology , Longitudinal Studies , Magnetic Resonance Imaging/methods , Male , Middle Aged , Neuropsychological Tests , Psychomotor Performance/physiology , Sex Factors , Tomography Scanners, X-Ray Computed
20.
J Neurol Neurosurg Psychiatry ; 76(11): 1497-500, 2005 Nov.
Article in English | MEDLINE | ID: mdl-16227537

ABSTRACT

OBJECTIVE: To assess the associations of medial temporal lobe atrophy (MTA) and white matter hyperintensities (WMH) with cognitive function in a large group of independently functioning elderly people. METHODS: Data were drawn from the multicentre, multinational leukoaraiosis and disability (LADIS) project which is studying prospectively the role of WMH as an independent predictor of the transition to disability in non-disabled elderly people. In all, 639 participants were enrolled in the LADIS study. For the present analysis, data on 581 subjects were available. Cognitive function was assessed by the mini-mental state examination (MMSE). Visual ratings of WMH and MTA were undertaken on magnetic resonance images (MRI). RESULTS: The presence of either severe WMH or MTA was associated with a modest but non-significant increase in frequency of mild cognitive deficits (severe WMH: odds ratio (OR) = 1.9 (95% confidence interval (CI), 1.0 to 3.7); MTA present: OR = 1.5 (95% CI, 0.8 to 2.8)). However, subjects with the combination of MTA and severe WMH had a more than fourfold increase in frequency of mild cognitive deficits (OR = 4.1 (95% CI, 2.3 to 7.4)). Analysis of variance with post hoc Bonferroni t tests showed that subjects with both MTA and severe WMH performed worse on MMSE than those with either no MRI abnormality or a single MRI abnormality (p<0.05). CONCLUSIONS: These results provide further evidence for the combined involvement of both Alzheimer type pathology and vascular pathology in the earliest stages of cognitive decline and suggest an additive effect of WMH and MTA.


Subject(s)
Cognition Disorders/diagnosis , Leukoaraiosis/pathology , Temporal Lobe/pathology , Aged , Atrophy/complications , Atrophy/pathology , Cognition Disorders/etiology , Disability Evaluation , Female , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Neurofibrillary Tangles/pathology , Neuropsychological Tests , Plaque, Amyloid/pathology , Prospective Studies , Severity of Illness Index
SELECTION OF CITATIONS
SEARCH DETAIL
...