Alexia due to ischemic stroke of the visual word form area.
Abstract The visual word form area (VWFA) is a region in the posterior left occipitotemporal cortex adjacent to the fusiform gyrus hypothesized to mediate word recognition. Evidence supporting the role of this area in reading comes from neuroimaging studies of normal subjects, case-controlled lesion studies, and studies of patients with surgical resection of the VWFA for tumors or epilepsy. Based on these prior reports, a small discrete lesion to the VWFA would be expected to cause alexia in a literate person without prior brain process, but such a case has not previously been reported to our knowledge. Here, we r...
Source: Neurocase - March 25, 2013 Category: Neurology Authors: Turkeltaub PE, Goldberg EM, Postman-Caucheteux WA, Palovcak M, Quinn C, Cantor C, Coslett HB Tags: Neurocase Source Type: research
Sensory-specific anomic aphasia following left occipital lesions: Data from free oral descriptions of concrete word meanings.
ne M Abstract The present study investigated hierarchical lexical semantic structure in oral descriptions of concrete word meanings produced by a subject (ZZ) diagnosed with anomic aphasia due to left occipital lesions. The focus of the analysis was production of a) nouns at different levels of semantic specificity (e.g., "robin"-"bird"-"animal") and b) words describing sensory or motor experiences (e.g., "blue," "soft," "fly"). Results show that in contrast to healthy and aphasic controls, who produced words at all levels of specificity and mainly vision...
Source: Neurocase - February 21, 2013 Category: Neurology Authors: Mårtensson F, Roll M, Lindgren M, Apt P, Horne M Tags: Neurocase Source Type: research
Effects of mental rotation on acalculia: Differences in the direction of mental rotation account for the differing characteristics of acalculia induced by right and left hemispheric brain injury.
Abstract We observed a 59-year-old right-handed man with an infarction in his right-middle cerebral artery that included the parietal lobe, who abnormally manipulated mental images in the horizontal direction, resulting in calculation disturbances. Three years later, the patient suffered an infarction in the left parietal lobe and displayed abnormalities during the creation of mental images; i.e., he rotated them in the vertical direction, which again resulted in calculation disturbances. These mental imagery disturbances might indicate that a common acalculia mechanism exists between the right and left hemisphere...
Source: Neurocase - February 15, 2013 Category: Neurology Authors: Asada T, Takayama Y, Oita J, Fukuyama H Tags: Neurocase Source Type: research
Cerebellar hyperperfusion in semantic dementia.
We examined with resting perfusion single photon emission tomography one patient with semantic dementia and the data were compared with a normal subject database. Region of interest and Statistical Parametric Mapping 2 analysis showed in the patient hypoperfusion of the left temporal and parietal lobe and hyperperfusion in the superior vermis and cerebellar hemispheres (lobules IV, V, and VI). The cerebellum shows increased flow of possible compensatory significance in patients with language disturbance associated to cerebral degenerative changes. PMID: 23414345 [PubMed - as supplied by publisher] (Source: Neurocase)
Source: Neurocase - February 15, 2013 Category: Neurology Authors: Vella A, Nave RD, Vetrugno R, Diciotti S, Boschi S, Bonamici FB, Mascalchi M Tags: Neurocase Source Type: research
Susceptibility to interference and intrusion errors in consequence of the dominant hemisphere's hippocampal infarct: A case report.
We present a case of a man with an ischemic lesion of the left hippocampus. Detailed neuropsychological assessment revealed susceptibility to retroactive interference and a tendency to make intrusion errors in addition to mild deficits in the verbal memory processes. Although retroactive interference and intrusion errors are normally considered to be the manifestations of frontal lobe dysfunctions, the idea of susceptibility to interference has recently begun to emerge in the literature, as an explanation of medial temporal lobe amnesia. Our data support this new theory, suggesting that one role of the hippocampus is to de...
Source: Neurocase - February 13, 2013 Category: Neurology Authors: Andrejkovics M, Balla P, Bereczki D Tags: Neurocase Source Type: research
Frontotemporal dementia in eight Chinese individuals.
Abstract Frontotemporal dementia (FTD) has rarely been reported in Chinese populations. There are many potential reasons for this, including possible hesitancy on the part of patients or families to bring FTD-related symptoms to medical attention. Here, we present data on eight Chinese individuals, all of whom met criteria for the behavioral variant of FTD or the semantic variant of primary progressive aphasia. These patients presented for neurological evaluation at a relatively advanced stage. The mean MMSE score at initial presentation was 15. Behavioral symptoms were common and usually elicited during the medic...
Source: Neurocase - February 1, 2013 Category: Neurology Authors: Chao SZ, Rosen HJ, Azor V, Ong H, Tse MM, Lai NB, Hou CE, Seeley WW, Miller BL, Matthews BR Tags: Neurocase Source Type: research
Limb apraxia in acute ischemic stroke: A neglected clinical challenge?
Abstract Symptoms of limb apraxia and executive dysfunctions are currently not explicitly considered by the National Institutes of Health Stroke Scale and, thus, not routinely tested by clinicians in the acute care of patients with suspected stroke. Neuropsychological testing, clinical examination, MRI, and functional magnetic resonance imaging (fMRI) were performed in a right-handed patient with acute onset of left-sided sensorimotor hemiparesis due to a right hemisphere ischemic stroke. Deficits in the execution of meaningless and meaningful gestures were not detected properly on initial clinical examination but...
Source: Neurocase - January 4, 2013 Category: Neurology Authors: Schell C, Suchan J, Himmelbach M, Haarmeier T, Borchers S Tags: Neurocase Source Type: research
Implausible future events in a confabulating patient with an anterior communicating artery aneurysm.
Abstract Abstract Patient MW, a known confabulator, and healthy age-matched controls produced past and future events. Events were judged on emotional valence and plausibility characteristics. No differences in valence were found between MW and controls, although a positive emotional bias toward the future was observed. Strikingly, MW produced confabulations about future events that were significantly more implausible than those produced by healthy controls whereas MW and healthy controls produced past events comparable in plausibility. A neurocognitive explanation is offered based on differences between rememberi...
Source: Neurocase - January 2, 2013 Category: Neurology Authors: Cole SN, Fotopoulou A, Oddy M, Moulin CJ Tags: Neurocase Source Type: research
Brain (18)F-FDG and (11)C-PiB PET findings in two siblings with FTD/ALS associated with the C9ORF72 repeat expansion.
We describe a patient in whom early clinical evaluation, MRI and fluorodeoxyglucose (FDG) positron emission tomography (PET) findings failed to definitively differentiate between FTD and Alzheimer's disease (AD), whereas (11)C-Pittsburgh compound B (PiB) PET was negative for amyloid pathology. He later developed ALS symptoms, and post mortem neuropathological findings were diagnostic of FTD-ALS, while no findings suggested AD. His sister was diagnosed with FTD, and the C9ORF72 expansion was detected in both siblings. We conclude that (11)C-PiB PET imaging may help the early differential diagnosis between AD and FTD, includ...
Source: Neurocase - December 5, 2012 Category: Neurology Authors: Martikainen MH, Gardberg M, Jansson L, Röyttä M, Rinne JO, Kaasinen V Tags: Neurocase Source Type: research