Author
Federico Rocca
Bio: Federico Rocca is an academic researcher from National Research Council. The author has contributed to research in topics: Mutation (genetic algorithm) & Single-nucleotide polymorphism. The author has an hindex of 13, co-authored 25 publications receiving 580 citations.
Papers
More filters
TL;DR: It is concluded that, in order to avoid artifacts and exclude the several sources of bias that may influence the analysis, an optimal method should comprise a careful preprocessing of the images, be based on multimodal, complementary data, take into account spatial information about the lesions and correct for false positives.
Abstract: White matter hyperintensities (WMH) are commonly seen in the brain of healthy elderly subjects and patients with several neurological and vascular disorders. A truly reliable and fully automated method for quantitative assessment of WMH on magnetic resonance imaging (MRI) has not yet been identified. In this paper, we review and compare the large number of automated approaches proposed for segmentation of WMH in the elderly and in patients with vascular risk factors. We conclude that, in order to avoid artifacts and exclude the several sources of bias that may influence the analysis, an optimal method should comprise a careful preprocessing of the images, be based on multimodal, complementary data, take into account spatial information about the lesions and correct for false positives. All these features should not exclude computational leanness and adaptability to available data.
140 citations
TL;DR: It is likely that cerebellar neurodegeneration underlying essential tremor is reflected in abnormal communications between key regions responsible for working memory and that adaptive mechanisms occur to limit the expression of cognitive symptoms.
Abstract: Essential tremor is a common neurological disorder characterized by motor and cognitive symptoms including working memory deficits Epidemiological research has shown that patients with essential tremor are at a higher risk to develop dementia relative to age-matched individuals; this demonstrates that cognitive impairments reflect specific, although poorly understood, disease mechanisms Neurodegeneration of the cerebellum has been implicated in the pathophysiology of essential tremor itself; however, whether cerebellar dysfunctions relate to cognitive abnormalities is unclear We addressed this issue using functional neuroimaging in 15 patients with essential tremor compared to 15 sex-, education- and age-matched healthy controls while executing a verbal working memory task To remove confounding effects, patients with integrity of the nigrostriatal terminals, no dementia and abstinent from medications altering cognition were enrolled We tested whether patients displayed abnormal activations of the cerebellum (posterior lobules) and other areas typically engaged in working memory (dorsolateral prefrontal cortex, parietal lobules) Between-groups differences in the interactions of these regions were also assessed with functional connectivity methods Finally, we determined whether individual differences in neuropsychological and clinical measures modulated the magnitude of regional brain responses and functional connectivity data in patients with essential tremor Despite similar behavioural performances, patients showed greater cerebellar response (crus I/lobule VI) compared to controls during attentional-demanding working memory trials (F = 88; P5005, corrected) They also displayed altered functional connectivity between crus I/lobule VI and regions implicated in focusing attention (executive control circuit including dorsolateral prefrontal cortex, inferior parietal lobule, thalamus) and in generating distracting self-related thoughts (default mode network including precuneus, ventromedial prefrontal cortex and hippocampus) (T-values432; P5005, corrected) These findings were modulated by the variability in neuropsychological measures: patients with low cognitive scores displayed reduced connectivity between crus I/lobule VI and the dorsolateral prefrontal cortex and enhanced connectivity between crus I/lobule VI and the precuneus (T-values437; P5005, corrected) It is likely that cerebellar neurodegeneration underlying essential tremor is reflected in abnormal communications between key regions responsible for working memory and that adaptive mechanisms
100 citations
TL;DR: A new index was more powerful than MRPI in differentiating PSP patients in the early stage of the disease with slowness of vertical saccades from patients with PD, thus helping clinicians to consolidate the diagnosis based on clinical features, in vivo.
84 citations
TL;DR: Evidence is found that MD in MS may be linked with connectivity alterations at the limbic-motor interface, a group of regions that translates emotions into survival-oriented behaviors, which provides strong support for neurobiological accounts positing thatMD in MS is mediated by abnormal ‘communications’ within limbic circuits.
Abstract: Background:Major depression (MD) is a common psychiatric disorder in multiple sclerosis (MS). Despite the negative impact of MD on the quality of life of MS patients, little is known about its underlying brain mechanisms.Objective:We studied the whole-brain connectivity patterns that were associated with MD in MS. Alterations were mainly expected within limbic circuits.Methods:Diffusion tensor imaging data were collected in 20 MS patients with MD, 22 non-depressed MS patients and 16 healthy controls. We used deterministic tractography and graph analysis to study the white-matter connectivity patterns that characterized MS patients with MD.Results:We found that MD in MS was associated with increased local path length in the right hippocampus and right amygdala. Further analyses revealed that these effects were driven by an increased shortest distance between both the right hippocampus and right amygdala and a series of regions including the dorsolateral and ventrolateral prefrontal cortex, orbitofrontal co...
49 citations
TL;DR: It is shown that a conspicuous amount of 18F-choline diagnostic pitfalls are easily recognizable and attributable to inflammation and shows that a new advance in knowledge is the minimal difference in terms of physiological tracer bio-distribution between male and female patients.
47 citations
Cited by
More filters
Journal Article•
TL;DR: The International Parkinson and Movement Disorder Society (MDS) Clinical Diagnostic Criteria for Parkinson9s disease as discussed by the authors have been proposed for clinical diagnosis, which are intended for use in clinical research, but may also be used to guide clinical diagnosis.
Abstract: Objective
To present the International Parkinson and Movement Disorder Society (MDS) Clinical Diagnostic Criteria for Parkinson9s disease.
Background
Although several diagnostic criteria for Parkinson9s disease have been proposed, none have been officially adopted by an official Parkinson society. Moreover, the commonest-used criteria, the UK brain bank, were created more than 25 years ago. In recognition of the lack of standard criteria, the MDS initiated a task force to design new diagnostic criteria for clinical Parkinson9s disease.
Methods/Results
The MDS-PD Criteria are intended for use in clinical research, but may also be used to guide clinical diagnosis. The benchmark is expert clinical diagnosis; the criteria aim to systematize the diagnostic process, to make it reproducible across centers and applicable by clinicians with less expertise. Although motor abnormalities remain central, there is increasing recognition of non-motor manifestations; these are incorporated into both the current criteria and particularly into separate criteria for prodromal PD. Similar to previous criteria, the MDS-PD Criteria retain motor parkinsonism as the core disease feature, defined as bradykinesia plus rest tremor and/or rigidity. Explicit instructions for defining these cardinal features are included. After documentation of parkinsonism, determination of PD as the cause of parkinsonism relies upon three categories of diagnostic features; absolute exclusion criteria (which rule out PD), red flags (which must be counterbalanced by additional supportive criteria to allow diagnosis of PD), and supportive criteria (positive features that increase confidence of PD diagnosis). Two levels of certainty are delineated: Clinically-established PD (maximizing specificity at the expense of reduced sensitivity), and Probable PD (which balances sensitivity and specificity).
Conclusion
The MDS criteria retain elements proven valuable in previous criteria and omit aspects that are no longer justified, thereby encapsulating diagnosis according to current knowledge. As understanding of PD expands, criteria will need continuous revision to accommodate these advances. Disclosure: Dr. Postuma has received personal compensation for activities with Roche Diagnostics Corporation and Biotie Therapies. Dr. Berg has received research support from Michael J. Fox Foundation, the Bundesministerium fur Bildung und Forschung (BMBF), the German Parkinson Association and Novartis GmbH.
1,655 citations
TL;DR: An impressive set of data in different model systems strongly suggest that mitochondrial dysfunction plays a central role in clinically similar, early-onset autosomal recessive PD forms caused by parkin and PINK1, and possibly DJ-1 gene mutations.
Abstract: Parkinson's disease (PD) is a common motor disorder of mysterious etiology. It is due to the progressive degeneration of the dopaminergic neurons of the substantia nigra and is accompanied by the a...
546 citations
TL;DR: The findings suggest that BIANCA, which will be freely available as part of the FSL package, is a reliable method for automated WMH segmentation in large cross-sectional cohort studies.
303 citations
TL;DR: It is shown how invertebrate models, notably Drosophila melanogaster and Caenorhabditis elegans, can be used to explore AGE-related pathways in depth and to identify and assess drugs that will mitigate against the detrimental effects of AGEs-adduct development.
303 citations
TL;DR: The roles ofheterozygous LRRK2 mutations and heterozygous parkin and PINK1 mutations in the development of parkinsonism are discussed, and an integrated aetiological model for this complex disease is proposed.
Abstract: Summary The association of six genes with monogenic forms of parkinsonism has unambiguously established that the disease has a genetic component. Of these six genes, LRRK2 (leucine-rich repeat kinase 2, or PARK8 ), parkin ( PARK2 ), and PINK1 (PTEN-induced putative kinase 1, or PARK6 ) are the most clinically relevant because of their mutation frequency. Insights from initial familial studies suggest that LRRK2 -associated parkinsonism is dominantly inherited, whereas parkinsonism linked to parkin or PINK1 is recessive. However, screening of patient cohorts has revealed that up to 70% of people heterozygous for LRRK2 mutations are unaffected, and that more than 50% of patients with mutations in parkin or PINK1 have only a single heterozygous mutation. Deciphering the role of heterozygosity in parkinsonism is important for the development of guidelines for genetic testing, for the counselling of mutation carriers, and for the understanding of late-onset Parkinson's disease. We discuss the roles of heterozygous LRRK2 mutations and heterozygous parkin and PINK1 mutations in the development of parkinsonism, and propose an integrated aetiological model for this complex disease.
296 citations