Daniel Hořínek

Cortical and subcortical atrophy in alzheimer disease: Parallel atrophy of thalamus and hippocampus

Brain atrophy is a key imaging hallmark of Alzheimer disease (AD). In this study, we carried out an integrative evaluation of AD-related atrophy. Twelve patients with AD and 13 healthy controls were enrolled. We conducted a cross-sectional analysis of total brain tissue volumes with SIENAX. Localized gray matter atrophy was identified with optimized voxel-wise morphometry (FSL-VBM), and subcortical atrophy was evaluated by active shape model implemented in FMRIB’s Integrated Registration Segmentation Toolkit. SIENAX analysis demonstrated total brain atrophy in AD patients; voxel-based morphometry analysis showed atrophy in the bilateral mediotemporal regions and in the posterior brain regions. In addition, regarding the diminished volumes of thalami and hippocampi in AD patients, subsequent vertex analysis of the segmented structures indicated shrinkage of the bilateral anterior thalami and the left medial hippocampus. Interestingly, the volume of the thalami and hippocampi were highly correlated with the volume of the thalami and amygdalae on both sides in AD patients, but not in healthy controls. This complex structural information proved useful in the detailed interpretation of AD-related neurodegenerative process, as the multilevel approach showed both global and local atrophy on cortical and subcortical levels. Most importantly, our results raise the possibility that subcortical structure atrophy is not independent in AD patients.

Robust Detection and Segmentation for Diagnosis of Vertebral Diseases Using Routine MR Images

The diagnosis of certain spine pathologies, such as scoliosis, spondylolisthesis and vertebral fractures, is part of the daily clinical routine. Very frequently, magnetic resonance image data are used to diagnose these kinds of pathologies in order to avoid exposing patients to harmful radiation, like X‐ray. We present a method which detects and segments all acquired vertebral bodies, with minimal user intervention. This allows an automatic diagnosis to detect scoliosis, spondylolisthesis and crushed vertebrae. Our approach consists of three major steps. First, vertebral centres are detected using a Viola–Jones like method, and then the vertebrae are segmented in a parallel manner, and finally, geometric diagnostic features are deduced in order to diagnose the three diseases. Our method was evaluated on 26 lumbar datasets containing 234 reference vertebrae. Vertebra detection has 7.1% false negatives and 1.3% false positives. The average Dice coefficient to manual reference is 79.3% and mean distance error is 1.76 mm. No severe case of the three illnesses was missed, and false alarms occurred rarely—0% for scoliosis, 3.9% for spondylolisthesis and 2.6% for vertebral fractures. The main advantages of our method are high speed, robust handling of a large variety of routine clinical images, and simple and minimal user interaction.

The MRI volumetry of the posterior fossa and its substructures in trigeminal neuralgia: a validated study

PurposeOur aim was to determine whether the anatomical configuration of the posterior fossa and its substructures might represent a predisposition factor for the occurrence of clinical neurovascular conflict in trigeminal neuralgia (TN).MethodsWe used MRI volumetry in 18 patients with TN and 15 controls. The volume of the pontomesencephalic cistern, Meckel’s cave and the trigeminal nerve on the clinical and non-affected sides was compared. The reliability has been assessed in all measurements.ResultsThe posterior fossa volume was not different in the clinical and control groups; there was no difference between the affected and non-affected sides when measuring the pontomesencephalic cistern and Meckel’s cave volume either. The volume of the clinically affected trigeminal nerve was significantly reduced, but with a higher error of measurement.ConclusionsWe did not find any association between the clinical neurovascular conflict (NVC) and the size of the posterior fossa and its substructures. MRI volumetry may show the atrophy of the affected trigeminal nerve in clinical NVC.

DTI-MRI biomarkers in the search for normal pressure hydrocephalus aetiology: a review.

Normal pressure hydrocephalus (NPH) is a clinical syndrome characterized by gait disturbances, urinary incontinence and dementia. Clinical presentation overlaps with Alzheimer disease (AD). Early recognition thus early intervention (shunting) is important for successful treatment, but lack of a diagnostic test with sufficient sensitivity and specificity complicates the diagnosis. We performed literature search and composed a structured review of imaging biomarkers of NPH. Morphometric studies are not sufficient to diagnose NPH. Hydrocephalus is a common finding in elderly people due to the symmetric brain atrophy and is even more pronounced in patients with AD. The key MRI biomarker seems to be diffusion tensor imaging (DTI). According to recent studies, the DTI analysis of the splenium corporis callosi, posterior limb of internal capsule, hippocampus and fornix combined with measurement of Evans index is a promising MRI biomarker of NPH and could be used for NPH diagnostics and in the differential diagnosis from AD and other dementias.

Recognition of Facial Emotional Expression in Amnestic Mild Cognitive Impairment

We examined whether recognition of facial emotional expression would be affected in amnestic mild cognitive impairment (aMCI). A total of 50 elderly persons met the initial inclusion criteria; 10 were subsequently excluded (Geriatric Depression Score > 5). 22 subjects were classified with aMCI based on published criteria (single domain aMCI [SD-aMCI], n = 10; multiple domain aMCI [MD-aMCI], n = 12); 18 subjects were cognitively normal. All underwent standard neurological and neuropsychological evaluations as well as tests of facial emotion recognition (FER) and famous faces identification (FFI). Among normal controls, FFI was negatively correlated with Mini-Mental Status Examination scores and positively correlated with executive function. Among patients with aMCI, FER was correlated with attention/speed of processing. No other correlations were significant. In a multinomial logistic regression model adjusted for age, gender, and education, a poorer score on FER, but not on FFI, was associated with greater odds of being classified as MD-aMCI (odds ratio [OR], 3.82; 95% confidence interval [CI], 1.05-13.91; p = 0.042). This association was not explained by memory or global cognitive score. There was no association between FER or FFI and SD-aMCI (OR, 1.13; 95% CI, 0.36-3.57; p = 0.836). Therefore, FER, but not FFI, may be impaired in MD-aMCI. This implies that in MD-aMCI, the tasks of FER and FFI may involve segregated neurocognitive networks.

The Pattern of Diffusion Parameter Changes in Alzheimer's Disease, Identified by Means of Linked Independent Component Analysis

Several recent studies have indicated that white matter is affected in Alzheimers disease (AD). Diffusion tensor imaging is a tool by which the white matter microstructure can be examined in vivo, and might offer a possibility for the identification of the pattern of white matter disintegration in AD. In the current analysis, we made use of a novel model-free analysis approach of linked independent component analysis to identify a motif of diffusion parameter alterations exemplifying AD. Analysis of the diffusion data of 16 AD patients and 17 age-matched healthy subjects revealed six independent components, two of which demonstrated differences between the patients and controls. Component #0 was dominated by axial diffusivity, but significant alterations in fractional anisotropy and mean and radial diffusivity were also detected. Alterations were found in regions of crossing of major white matter pathways, such as forceps, corona radiate, and superior longitudinal fascicle, as well as medio-temporal white matter. These results lend support to the coexistence of white matter disintegration of the late myelinating associating fibers and wallerian degeneration-related disintegration, in accordance with the retrogenesis and wallerian degeneration hypothesis.

Magnetic resonance imaging and histology correlation in Cushing's disease

INTRODUCTION We continuously look for new techniques to improve the radicality of resection and to eliminate the negative effects of surgery. One of the methods that has been implemented in the perioperative management of Cushings disease was the combination of three magnetic resonance imaging (MRI) sequences: SE, SPGR and fSPGR. MATERIAL AND METHODS We enrolled 41 patients (11 males, 30 females) diagnosed with Cushings disease. A 3D tumour model with a navigation console was developed using each SPGR, fSPGR and SE sequence. The largest model was then used. In all cases, a standard four-handed, bi-nostril endoscopic endonasal technique was used. Endocrinological follow-up evaluation using morning cortisol sampling was performed for 6-34 months in our study. RESULTS In total, 36 patients (88%) were disease-free following surgery. Our results indicate we achieved 100% sensitivity of MR. Overall, the conformity of at least one donor site, as compared with the places designated on MR, was in 78% of patients. We searched the place of compliance in individual locations. There is a consensus in individual locations in 63 of the 123 cases (or 56%). The correlation gamma function at a 5% significance level was then 0.27. DISCUSSION The combination of MR sequences (SE, SPGR, fSPGR), neuronavigation system and iMRI led to increased sensitivity of up to 100%. Specificity reached 56% in our study. CONCLUSION We found a high success rate in surgical procedure in terms of the correlation between MR findings and histology, which leads to remission of Cushings disease.

APOE E4 affects spatial working memory and attention in patients with amnestic mild cognitive impairment

6 3.8, namci-s: 179.6 6 11.2, namci-m: 143.6 6 19.9). There were significant differences on the scores of SNSB-D and several cognitive domains of language, visuospatial function, memory and frontal executive function among the subtypes of MCI. According to post-hoc analysis, the subtypes of amnestic and non-amnestic multi-domian MCI showed more deficits in all cognitive domains compared with other types of MCI. Conclusions: Our study shows characteristic and different pattern of cognitive deficits in patients with MCI, and these results may be helpful to predict the conversion tendency to dementia conditions according to subtypes of MCI.

P1-213: Relation atrophy of the amygdala to emotional impairment in Alzheimer's disease

en’s criteria. Telephone testing with MCAS was conducted an average of 15 days after an office visit. Diagnoses were established by consensus conference. Results: For MCAS total scores, the AD group performed significantly worse than the MCI group, who in turn performed worse than the HC group. MCAS total scores significantly correlated with in-office Mini Mental State Examination (r 0.77). Linear discriminant analysis, based upon MCAS subtest scores, revealed that none of AD subjects was misclassified as HC or MCI (95% CI 0%-20%). Among MCI subjects, 17% (95% CI 0%-23%) were misclassified as HC, whereas 3% (95% CI 0%-10%) were misclassified as AD. Among HC subjects, 17% (95% CI 0%-28%) were misclassified as MCI, whereas none was misclassified as AD (95% CI 0%-6%). Conclusions: Our results suggest that this brief telephone cognitive screen performs well at distinguishing AD from MCI and healthy older adults. Although the test was less accurate in discriminating MCI from HC, findings are promising given the diagnostic complexity of these cases. Thus, the MCAS has potential as a screening tool for both clinical and research settings in identifying patients with a range of memory disorders.