The sense of smell is a complex chemosensory processing in human and animals that allows them to connect with the environment as one of their chief sensory systems. In the field of functional brain imaging, many studies have focused on locating brain regions that are involved during olfactory processing. Despite wealth of literature about brain network in different olfactory tasks, there is a paucity of data regarding task design. Moreover, considering importance of olfactory tasks for patients with variety of neurological diseases, special contemplations should be addressed for patients. In this article, we review current olfaction tasks for behavioral studies and functional neuroimaging assessments, as well as technical principles regarding utilization of these tasks in functional magnetic resonance imaging studies.

Faezeh Vedaei

Mohammad Fakhri

Mohammad Hossein Harirchian

Kavous Firouznia

Yones Lotfi

Mohammad Ali Oghabian

Methodological Considerations in Conducting an Olfactory fMRI Study

Background: Progressive MS is associated with a high frequency of cognitive impairment. However, it is not clear to what
extent this reflects global dysfunction, or independent deficits in specific functions.Objective: To characterise patterns of cognitive impairment in progressive MS on a multi-dimensional cognitive assessment
tool well established in neurodegenerative diseases.Methods: Patients with secondary (SPMS; n = 60) and primary progressive MS (PPMS; n = 28) were assessed using the
Addenbrooke&#x2019;s Cognitive Examination-Revised (ACE-R) multi-dimensional cognitive assessment scale. Independent dimensions of impairment and their relative contribution to the overall burden of cognitive dysfunction were then determined by factor analysis.Results: Two independent dimensions of impairment were seen: frontal-executive (attention, verbal fluency, recall) on one
hand, and language and visuospatial functions on the other. These accounted for 55&#x25; and 45&#x25; respectively of the variance not
explained by a global influence (14.2&#x25; and 11.6&#x25; respectively of total variance). Isolated language and visuospatial dysfunction
was seen in both groups, whereas isolated impairment in frontal-executive functions was underrepresented in SPMS (p = 0.001)
and not seen in PPMS patients (p = 0.040).Conclusions: In addition to a prominent global influence on cognitive performance, patients with progressive MS commonly
exhibit language and visuospatial deficits. Evaluation of these abilities should therefore be included in clinical assessment
of cognition in progressive MS.

Peter Connick

Siddharthan Chandran

Thomas H. Bak

Patterns of Cognitive Dysfunction in Progressive MS

Although the prevalence of neuropsychiatric disorders among patients with cerebrovascular illness is relatively high, there are only few case reports describing post-stroke psychotic symptoms. In general, post-stroke psychoses have been reported to emerge few days after the vascular event and to vanish soon afterwards. In this report, we describe delayed-onset post-stroke delusional disorder, persecutory type. A middle-aged female patient developed a persistent delusional disorder with homicidal behavior about one year after a cerebrovascular accident affecting the right fronto-temporo-parietal region and a long period of chronic post-stroke mixed anxiety and depressive symptoms. Our case suggests that there might be long intervals between stroke and the appearance of psychotic symptoms.

Ra&#xed;ssa B. Barboza

Gabriel R. De Freitas

Fernanda Tovar-Moll

Leonardo   F. Fontenelle

Delayed-Onset Post-Stroke Delusional Disorder: A Case Report

Optic Neuritis (ON) has been associated to both parvocellular dysfunction and to an alteration of the magnocellular pathway. After objective visual field and acuity recovery, ON patients may complain about their vision suggesting a residual subclinical deficit. To better characterize visual abnormalities, 8 patients recovering from a first ON episode as well as 16 healthy controls performed a simple detection task and a more complex categorization task of images presented in low spatial frequencies (to target the magnocellular system) or in high spatial frequencies (to target the parvocellular system) or of non-filtered images. When completing the tasks with their (previously) pathologic eye, optic neuritis patients showed lower accuracy compared to controls or to their healthy eye for low spatial frequency images only. Conjointly, the longest reaction times were observed with the previously pathologic eye regardless the type of images and to a greater extent in the categorization task than in the detection task. Such data suggest two distinct, although associated, types of residual dysfunction in ON: a magnocellular pathway alteration and a more general (magno and parvocellular) visual dysfunction that could implicate the cognitive levels of visual processing.

Anne-Claire Viret

C&#xe9;line Cav&#xe9;zian

Olivier Coubard

Vivien Vasseur

Noa Raz

Netta Levin

Catherine Vignal

Olivier Gout

Sylvie Chokron

Optic Neuritis: From Magnocellular to Cognitive Residual Dysfunction

Purpose: To evaluate patterns of activation, convergence and divergence of three functional magnetic resonance imaging (fMRI) Working Memory (WM) tasks in two different age groups. We want to understand potential impact of task and subjects&#x2019; age on WM activations as well as most important areas with regard to WM functions.Materials and Methods: Thirty-five healthy volunteers completed visual, verbal, and novel auditory WM tasks. The subjects were selected from age extremes to depict possible impact of normal aging. General Linear Model was used to report significant activations and the effect of group. One-to-one comparison of the tasks and Combined Task Analysis was also performed.Results: Most of the observed differences between the tasks were seen in areas that were responsible for feature processing. Frontal regions were mainstay activation areas, regardless of the utilized stimulus. We found an age-related reduction in activity of visual (in visually-presented tasks) and auditory (in auditory task) cortices but an age-related increase in prefrontal cortex for all tasks.Conclusion: Regardless of the type of the task stimuli, frontal regions are the most important activation areas in WM processing. These areas are also main targets of age-related changes with regard to activation patterns. Our results also indicate that prefrontal overactivity in working memory might be a compensatory effort to mask age-related decline in sensory processing.

Hajir Sikaroodi

Farid Maleki

Hossein Ghanaati

Impacts of Normal Aging on Different Working Memory Tasks: Implications from an fMRI Study

Topiramate is a sulfamate-substituted monosaccharide anticonvulsant that is associated with anorexia and weight loss and has been used to treat binge eating disorder and bulimia nervosa. This report describes a man with frontotemporal dementia, behavioural variant, associated with abnormal eating behaviour which appeared to respond to topiramate. We review the physiological basis of abnormal eating behaviour in frontotemporal dementia and explore possible mechanisms of action by which topiramate may modify eating behaviour in this condition.

Colin Singam

Mark Walterfang

Ramon Mocellin

Andrew Evans

Dennis Velakoulis

Topiramate for Abnormal Eating Behaviour in Frontotemporal Dementia

Introduction: Patients with unilateral neglect may show line bisection errors selectively in either near (within hand reaching) or far (beyond hand reaching) space which suggests that these two spatial areas are coded differently by the brain. This exploratory study investigated, whether any difference in performance between these spatial domains might be task-independent or modulated by the requirement for a motor response.Methods: A 31-year-old right brain damaged patient (MF) and a group of age matched healthy controls were assessed with two serial visual search tasks and a Landmark paradigm. Both types of task required either a directional (pointing) or non-directional (button press) motor response. Participants were assessed with both task types and response modes in near (57 cm) and far space (114 cm).Results: MF showed left neglect during visual search only in far space for the perceptual condition and in near space for the motor condition. MF showed no neglect in both versions of the Landmark task irrespective of spatial distance. A voxel-based morphometric assessment of MF's brain lesion showed marked damage in the right ventro-temporal cortex, superior temporal gyrus, insula, inferior frontal gyrus, angular gyrus and bilaterally in the posterior cingulate cortex.Conclusions: Our preliminary findings suggest that processing of far space during visual search is associated with ventral stream damage but only when space is coded through visual information. Neglect involving directional motor activity in near space seems to be associated with damage of structures sharing close connections with the dorsal stream.

Lina Aimola

Igor Schindler

Annalena Venneri

Task- and Response Related Dissociations between Neglect in Near and Far Space: A Morphometric Case Study

A patient with delusion of pregnancy as an early feature of frontotemporal dementia with motor neurone disease (FTD/MND) who was reported some years ago was posthumously found to harbor the C9ORF72 hexanucleotide repeat expansion, now known to be the most common genetic cause of FTD/MND. Some series have found psychosis to be common in FTD associated with this mutation, so this test should be considered in individuals with clinical features of FTD and MND and/or with a family history of either disorder who present with bizarre delusions.

A. J. Larner

Delusion of Pregnancy: A Case Revisited

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