Behavioural Neurology - Volume 24, issue 2

Authors: Richardson, Jessica D. | Baker, Julie M. | Morgan, Paul S. | Rorden, Chris | Bonilha, L. | Fridriksson, Julius

Article Type: Research Article

Abstract: Lesion-symptom mapping studies are based upon the assumption that behavioral impairments are directly related to structural brain damage. Given what is known about the relationship between perfusion deficits and impairment in acute stroke, attributing specific behavioral impairments to localized brain damage leaves much room for speculation, as impairments could also reflect abnormal neurovascular function in brain regions that appear structurally intact on traditional CT and MRI scans. Compared to acute stroke, the …understanding of cerebral perfusion in chronic stroke is far less clear. Utilizing arterial spin labeling (ASL) MRI, we examined perfusion in 17 patients with chronic left hemisphere stroke. The results revealed a decrease in left hemisphere perfusion, primarily in peri-infarct tissue. There was also a strong relationship between increased infarct size and decreased perfusion. These findings have implications for lesion-symptom mapping studies as well as research that relies on functional MRI to study chronic stroke. Show more

Keywords: Aphasia, arterial spin labeling (ASL), hypoperfusion, ischemic stroke, peri-infarct

DOI: 10.3233/BEN-2011-0283

Citation: Behavioural Neurology, vol. 24, no. 2, pp. 117-122, 2011

Authors: Gardini, Simona | Concari, Letizia | Pagliara, Salvatrice | Ghetti, Caterina | Venneri, Annalena | Caffarra, Paolo

Article Type: Research Article

Abstract: This study investigated the cognitive profile and the cerebral perfusion pattern in a highly educated 70 year old gentleman with posterior cortical atrophy (PCA). Visuo-perceptual abilities, spatial memory, spatial representation and navigation, visuo-spatial mental imagery, semantic and episodic-autobiographical memory were assessed. Regional cerebral blood flow (rCBF) was imaged with SPECT. Cognitive testing showed visual-perceptual impairment, apperceptive visual and landmark agnosia, topographical disorientation with way-finding deficits, impaired map learning and poor mental …image generation. Semantic memory was normal, while episodic-autobiographical memory was impaired. Reduced rCBF was found mainly in the right hemisphere, in the precentral gyrus, posterior cingulate and middle temporal gyri, cuneus and precuneus, in the left superior temporal and lingual gyri and in the parahippocampus bilaterally. Hypoperfusion in occipito-parietal regions was associated with visuo-spatial deficits, whereas deficits in visuo-spatial mental imagery might reflect dysfunction related to hypoperfusion in the parahippocampus and precuneus, structures which are responsible for spatial and imagery processing. Dissociating performance between preserved semantic memory and poor episodic-autobiographical recall is consistent with a pattern of normal perfusion in frontal and anterior temporal regions but abnormal rCBF in the parahippocampi. The present findings indicate that PCA involves visuo-spatial imagery deficits and provide further validation to current neuro-cognitive models of spatial representation and topographical disorientation. Show more

Keywords: Posterior cortical atrophy, imagery, spatial abilities, visual process, dementia, rCBF

DOI: 10.3233/BEN-2011-0279

Citation: Behavioural Neurology, vol. 24, no. 2, pp. 123-132, 2011

Authors: Butler, Paul M. | McNamara, Patrick | Durso, Raymon

Article Type: Research Article

Abstract: Behavioral neurologists have long been interested in changes in religiosity following circumscribed brain lesions. Advances in neuroimaging and cognitive experimental techniques have been added to these classical lesion-correlational approaches in attempt to understand changes in religiosity due to brain damage. In this paper we assess processing dynamics of religious cognition in patients with Parkinson's disease (PD). We administered a four-condition story-based priming procedure, and then covertly probed for changes in religious belief. …Story-based priming emphasized mortality salience, religious ritual, and beauty in nature (Aesthetic). In neurologically intact controls, religious belief-scores significantly increased following the Aesthetic prime condition. When comparing effects of right (RO) versus left onset (LO) in PD patients, a double-dissociation in religious belief-scores emerged based on prime condition. RO patients exhibited a significant increase in belief following the Aesthetic prime condition and LO patients significantly increased belief in the religious ritual prime condition. Results covaried with executive function measures. This suggests lateral cerebral specialization for ritual-based (left frontal) versus aesthetic-based (right frontal) religious cognition. Patient-centered individualized treatment plans should take religiosity into consideration as a complex disease-associated phenomenon connected to other clinical variables and health outcomes. Show more

Keywords: Religiosity, Parkinson's disease, brain laterality, aesthetics, dopamine, frontal lobes

DOI: 10.3233/BEN-2011-0282

Citation: Behavioural Neurology, vol. 24, no. 2, pp. 133-141, 2011

Authors: Kharkar, Siddharth | hernandez, Robert | Batra, Sachin | Metellus, Philippe | Hillis, Argye | Williams, Michael A. | Rigamonti, Daniele

Article Type: Research Article

Abstract: Introduction: Patients with Pseudotumor Cerebri Syndrome (PTCS) may complain of difficulty in thinking or concentrating; however there has been little formal cognitive evaluation in this population. Objective: To evaluate the characteristics and nature of cognitive impairment in patients with PTCS. Methods: We retrospectively reviewed records of 10 patients diagnosed with PTCS who were cognitively tested at presentation. In each cognitive test, "Borderline deficit" (BD) was defined as a score more than 1 …standard deviation (SD) below and "Definite Deficit" (DD) as a score more than 2 SD below the mean for age, sex and education. In each cognitive domain, impairment was defined as a single test score more than 2 SD below the mean, or scores of more than 1 SD below the mean for age, sex and education in > 50% of tests. Results: Mean age of patients was 43.4 ± 13.5 years. 8/10(80%) patients were female. 3/10(30%) had papilledema; 3/10(30%) had significant cerebral venous outflow obstruction. Impairment was most commonly seen and was most severe in the WMS logical memory I (BD-44%, DD-44%), WMS logical memory II (BD-37.5%, DD-50%), RAVLT delayed recall (BD-30%, DD-40%) and RAVLT retention(BD-40%, DD-30%) tests. Evaluation of cognitive domains revealed impairment in memory and learning (80%), executive function (10%), visuo-spatial skills (30%), and language (30%). Conclusion: Our results indicate that patients with PTCS can have significant cognitive impairment, particularly in learning and memory. The prevalence needs to be studied in a larger cohort. The relationship of cognitive impairment with chronically elevated intracranial pressures and its role in contributing to patient morbidity needs to be investigated further. Show more

Keywords: Cognition, impairment, morbidity, pseudotumor cerebri syndrome

DOI: 10.3233/BEN-2011-0325

Citation: Behavioural Neurology, vol. 24, no. 2, pp. 143-148, 2011

Authors: Franceschi, Massimo | Caffarra, Paolo | Savarè, Rita | Cerutti, Renata | Grossi, Enzo | the ToL Research Group,

Article Type: Research Article

Abstract: The early differentiation of Alzheimer's disease (AD) from frontotemporal dementia (FTD) may be difficult. The Tower of London (ToL), thought to assess executive functions such as planning and visuo-spatial working memory, could help in this purpose. Twentytwo Dementia Centers consecutively recruited patients with early FTD or AD. ToL performances of these groups were analyzed using both the conventional statistical approaches and the Artificial Neural Networks (ANNs) modelling. Ninety-four non aphasic FTD and …160 AD patients were recruited. ToL Accuracy Score (AS) significantly (p < 0.05) differentiated FTD from AD patients. However, the discriminant validity of AS checked by ROC curve analysis, yielded no significant results in terms of sensitivity and specificity (AUC 0.63). The performances of the 12 Success Subscores (SS) together with age, gender and schooling years were entered into advanced ANNs developed by Semeion Institute. The best ANNs were selected and submitted to ROC curves. The non-linear model was able to discriminate FTD from AD with an average AUC for 7 independent trials of 0.82. The use of hidden information contained in the different items of ToL and the non linear processing of the data through ANNs allows a high discrimination between FTD and AD in individual patients. Show more

Keywords: Alzheimer's disease, frontotemporal dementia, Tower of London, neuropsychology, executive functions

DOI: 10.3233/BEN-2011-0327

Citation: Behavioural Neurology, vol. 24, no. 2, pp. 149-158, 2011

Authors: Allen, Mark D. | Owens, Tyler E. | Fong, Alina K. | Richards, Douglas R.

Article Type: Research Article

Abstract: Recent progress has been made using fMRI as a clinical assessment tool, often employing analogues of traditional "paper and pencil" tests. The Trail Making Test (TMT), popular for years as a neuropsychological exam, has been largely ignored in the realm of neuroimaging, most likely because its physical format and administration does not lend itself to straightforward adaptation as an fMRI paradigm. Likewise, there is relatively more ambiguity about the neural systems associated with this test than …many other tests of comparable clinical use. In this study, we describe an fMRI version of Trail Making Test-B (TMTB) that maintains the core functionality of the TMT while optimizing its use for both research and clinical settings. Subjects (N=32) were administered the Functional Trail Making Test-B (f-TMTB). Brain region activations elicited by the f-TMTB were consistent with expectations given by prior TMT neurophysiological studies, including significant activations in the ventral and dorsal visual pathways and the medial pre-supplementary motor area. The f-TMTB was further evaluated for concurrent validity with the traditional TMTB using an additional sample of control subjects (N=100). Together, these results support the f-TMTB as a viable neuroimaging adaptation of the TMT that is optimized to evoke maximally robust fMRI activation with minimal time and equipment requirements. Show more

Keywords: fMRI, clinical fMRI, cognitive assessment, neuropsychological assessment, Trail Making

DOI: 10.3233/BEN-2011-0278

Citation: Behavioural Neurology, vol. 24, no. 2, pp. 159-171, 2011

Authors: Poletti, Michele | Bonuccelli, Ubaldo

Article Type: Research Article

Abstract: Premorbid personality characteristics could have a pathoplastic effect on behavioral symptoms and personality changes related to neurodegenerative diseases. Patients with personality disorders, in particular of the dramatic cluster, may present functional frontolimbic abnormalities. May these neurobiological vulnerabilities linked to a premorbid personality disorder predispose or represent a risk factor to subsequently develop a neurodegenerative disorder? Are subjects with personality disorders more at risk to develop a dementia than mentally healthy subjects? This …topic is discussed presenting the clinical case of a patient who suffered of a probable Narcissistic Personality Disorder and subsequently developed a clinically diagnosed Frontotemporal Dementia. Show more

Keywords: Narcissistic personality disorder, frontotemporal dementia, risk factors

DOI: 10.3233/BEN-2011-0326

Citation: Behavioural Neurology, vol. 24, no. 2, pp. 173-176, 2011