MR imaging of cavernous sinus invasion by mucormycosis: a case study

Cavernous sinus thrombosis is a serious condition, which, if not recognized early, can lead to a fulminant course. Knowledge of risk factors along with early recognition of signs and symptoms may alter the course of this condition. We present a case of a patient with cavernous sinus thrombosis with characteristic findings on MRI. Biopsy of the sinuses revealed mucromycosis as the offending agent.

Perceptual and semantic components of memory for objects and faces: a pet study

Previous studies have suggested differences in the neural substrates of recognition memory when the contributions of perceptual and semantic information are manipulated. In a within-subjects design PET study, we investigated the neural correlates of the following factors: material type (objects or faces), semantic knowledge (familiar or unfamiliar items), and perceptual similarity at study and test (identical or different pictures). There was consistent material-specific lateralization in frontal and temporal lobe regions when the retrieval of different types of nonverbal stimuli was compared, with objects activating bilateral areas and faces preferentially activating the right hemisphere. Retrieval of memories for nameable, familiar items was associated with increased activation in the left ventrolateral prefrontal cortex, while memory for unfamiliar items involved occipital regions. Recognition memory for different pictures of the same item at study and test produced blood flow increase in left inferior temporal cortex. These results have implications for our understanding of the neural correlates of perceptual and semantic contributions to recognition memory.

Temporal lobe rating scale: application to Alzheimer's disease and frontotemporal dementia

OBJECTIVES

Temporal lobe atrophy as assessed by MRI can be measured in several ways. Volumetric measurements are quantitative but very time consuming and require extensive training to perform, so are not easily transferable to clinical practice. Visual rating scales, by contrast, are quick and widely applicable. Although medial temporal lobe atrophy is well described in Alzheimer's disease (AD), it is uncertain how early these changes can be detected and whether they discriminate AD from other neurodegenerative diseases, most notably frontotemporal dementia (FTD). The objectives were (1) to develop a widely applicable temporal lobe rating scale, and (2) to characterise and quantify the patterns of temporal lobe atrophy in AD versus temporal and frontal variants of FTD.

METHODS

The temporal lobe assessments were made using an established hippocampal rating scale extended to incorporate additional temporal regions. This was firstly validated with volumetric analysis and then applied to 30 probable AD, 30 FTD (consisting of 17 temporal variant (semantic dementia) and 13 frontal variant) and 18 control coronal MRI images.

RESULTS

Bilateral hippocampal atrophy was found in 50% of the patients with AD. Contrary to expectations, patients with semantic dementia also had hippocampal atrophy, which for the left side exceeded that seen in AD; other regions (temporal pole, parahippocampal gyrus, and lateral temporal lobe), spared in AD, were severely atrophied in this group. The patients with frontal variant FTD occupied an intermediate position and were largely indistinguishable from AD.

CONCLUSIONS

Hippocampal atrophy is, therefore, not specific for AD. Semantic dementia can be distinguished from AD, by the presence of severe bilateral atrophy of the temporal pole, parahippocampal and lateral regions. These findings have implications for the differential diagnosis of dementias.

Severe anterograde amnesia with extensive hippocampal degeneration in a case of rapidly progressive frontotemporal dementia

Frontotemporal dementia (FTD) is usually characterized as a spectrum of relatively slowly progressive disorders with largely focal frontal or temporal presentations. The development of clinical and research criteria for discriminating FTD from Alzheimer's disease has relied, in part, on the relative preservation of episodic memory in FTD. We present a patient with FTD who, in addition to the more typical behavioural and language deficits, had a profound anterograde amnesia at the time of diagnosis. Neuroimaging confirmed atrophy of frontal and temporal lobes bilaterally, most marked in the anterior left temporal region. At post-mortem, non-Alzheimer pathology resulting in devastating cell loss was revealed in the hippocampi, as well as in the frontal and temporal cortex, thus providing neuroanatomical corroboration of the episodic memory deficit. Progression of the disease was extraordinarily rapid, with just 2 years between reported onset and time of death. This case demonstrates that the pattern of FTD may include severe anterograde amnesia as a prominent and early consequence of the disease.

Semantic knowledge and episodic memory for faces in semantic dementia

Previous studies have documented poor recognition memory for faces in patients with semantic dementia. Preserved face recognition memory was found in this study, however, so long as atrophy was confined predominantly to the left temporal lobe. Patients with structural damage to the right temporal lobe were typically impaired, with the status of the hippocampus and parahippocampal gyrus (including the perirhinal cortex) on the right being critical. Two single-case studies of patients with predominantly left temporal lobe pathology confirmed good recognition memory for famous faces, even if semantic knowledge about the celebrities depicted was severely degraded. An effect of semantic knowledge on recognition memory became apparent only when perceptually different photographs of the famous people were used at study and test. These results support the view that new episodic learning typically draws on information from both perceptual and semantic systems.

Chimeric cells of maternal origin in juvenile idiopathic inflammatory myopathies. Childhood Myositis Heterogeneity Collaborative Group

We identified maternal microchimerism by fluorescence in-situ hybridisation in magnetically-separated CD4 or CD8 peripheral blood cells of eight of nine male patients with juvenile idiopathic inflammatory myopathy, compared with two of nine healthy male controls. We also found maternal microchimerism in inflammatory lesions (one skin sample and nine muscle biopsy samples) of all ten patients examined, compared with two of ten biopsy samples from patients with other muscle disorders. These results suggest that maternal cells may be involved in the pathogenesis of juvenile idiopathic inflammatory myopathy.

Ex vivo generation of effective Epstein-Barr virus (EBV)-specific CD8+ cytotoxic T lymphocytes from the peripheral blood of immunocompetent Epstein Barr virus-seronegative individuals

BACKGROUND

Although readily accomplished from immunocompetent Epstein-Barr virus- (EBV) seropositive individuals, the effective ex vivo generation of EBV-specific cytotoxic T lymphocytes (CTL) from the peripheral blood mononuclear cells (PBMC) of EBV-seronegative subjects has proven to be a challenge. The focus of our study was to ascertain optimized culture conditions required for the ex vivo generation of EBV-reactive autologous CTL from the PBMC of EBV-seronegative volunteers.

METHOD

Freshly isolated PBMC obtained from immunocompetent EBV-seronegative and -seropositive individuals were used to generate EBV-specific autologous CTL lines using both conventional and a novel, modified ex vivo culture technique.

RESULTS

In contrast to responses observed in EBV-seropositives after two to three rounds of ex vivo stimulation, gamma-irradiated autologous lymphoblastoid cell lines (LCL) were incapable of eliciting an effective anti-EBV cytotoxic response when freshly-isolated PBMC from EBV-seronegative individuals were used as responders. Under these culture conditions, CD4+ T cells with preferential expression of the Th2-type cytokine IL-4 were predominantly expanded in the PBMC obtained from EBV-seronegative individuals. However, the addition of recombinant human (rh) IL-12 during the primary phase of ex vivo stimulation resulted in augmentation of EBV-specific cytolysis of autologous LCL by CD8+ T cells. Furthermore, there was down-regulation in the secretion of IL-4 and up-regulation in that of the Th1-type cytokine IFN-gamma by responder CD4+ and CD8+ T cells.

CONCLUSIONS

Taken together these data suggest that the addition of rhIL-12 during the primary phase of ex vivo stimulation of freshly isolated PBMC from EBV-seronegative individuals results in skewing of the immune response predominantly towards a CD4+ Th1-type (IFN-gamma) with the generation of an efficacious CTL-mediated anti-EBV reactivity. This novel ex vivo approach for generating effective autologous EBV-specific CTL could be adopted to treat refractory post-transplant lymphoproliferative disorders, which may be encountered in EBV-seropositive-->EBV-seronegative organ transplant recipients. Additionally, these ex vivo generated anti-EBV T cells could also be infused perioperatively to enhance prophylactically immunity against EBV infection in high-risk EBV-seronegative organ allograft recipients.

Phonological and articulatory impairment in Alzheimer's disease: a case series

We demonstrate that phonological and articulatory impairments may occur at presentation or early in the course of Alzheimer's disease, contrary to claims that these aspects of language production are relatively preserved until the final stages of this disease. Six patients with pathologically confirmed Alzheimer's disease (AD) and four patients with clinically diagnosed dementia of the Alzheimer's type (DAT) presented with one of five different clinical profiles: nonfluent progressive aphasia, mixed progressive aphasia, progressive aphasia diagnosed as DAT from neuropsychological assessment, initial amnestic syndrome with prominent phonological errors, and biparietal syndrome. Analysis of their conversational speech, single-word production, and performance of highly familiar series speech tasks such as counting revealed false start errors, phonological paraphasias, and/or articulatory difficulty. Neuropathological changes were located in left perisylvian regions consistent with speech and language impairment but atypical for Alzheimer's disease.

Non-verbal semantic impairment in semantic dementia

The clinical presentation of patients with semantic dementia is dominated by anomia and poor verbal comprehension. Although a number of researchers have argued that these patients have impaired comprehension of non-verbal as well as verbal stimuli, the evidence for semantic deterioration is mainly derived from tasks that include some form of verbal input or output. Few studies have investigated semantic impairment using entirely non-verbal assessments and the few exceptions have been based on results from single cases ([3]: Breedin SD, Saffran EM, Coslett HB. Reversal of the concreteness effect in a patient with semantic dementia. Cognitive Neuropsychology 1994;11:617-660, [12]: Graham KS, Becker JT, Patterson K, Hodges JR. Lost for words: a case of primary progressive aphasia? In: Parkin A, editor. Case studies in the neuropsychology of memory, East Sussex: Lawrence Erlbaum, 1997. pp. 83-110, [21]: Lambon Ralph MA, Howard D. Gogi aphasia or semantic dementia? Simulating and assessing poor verbal comprehension in a case of progressive fluent aphasia. Cognitive Neuropsychology, (in-press). This study employed sound recognition and semantic association tasks to investigate the nature of the verbal and non-verbal comprehension deficit in 10 patients with semantic dementia. The patients were impaired on both verbal and non-verbal conditions of the assessments, and their accuracy on these tasks was directly related to their scores on a range of other tests requiring access to semantic memory. Further analyses revealed that performance was graded by concept and sound familiarity and, in addition, identified significant item consistency across the different conditions of the tasks. These results support the notion that the patients' deficits across all modalities were due to degradation within a single, central network of conceptual knowledge. There were also reliable differences between conditions. The sound-picture matching task proved to be more sensitive to semantic impairment than the word-picture matching equivalent, and the patients performed significantly better on the picture than word version of a semantic association test. We propose that these differences arise directly from the nature of the mapping between input modality and semantic memory. Words and sounds have an arbitrary relationship with meaning while pictures benefit from a degree of systematicity with conceptual knowledge about the object.

Histology of the urethral plate: implications for hypospadias repair

PURPOSE

We define the histology of the urethral plate in boys with hypospadias.

MATERIALS AND METHODS

Subepithelial biopsies of the urethral plate were obtained in 17 boys, including 13 with distal and 4 with penoscrotal hypospadias. Ventral penile curvature was noted in 5 cases. Specimens were evaluated by 7 light microscopy after hematoxylin and eosin staining.

RESULTS

All biopsies demonstrated well vascularized connective tissue comprised of smooth muscle and collagen. There was no evidence of fibrous bands or dysplastic tissue.

CONCLUSIONS

The urethral plate consists of epithelium overlying connective tissue. We found no histological evidence of fibrous cords historically considered responsible for chordee.

The role of conceptual knowledge in object use evidence from semantic dementia

It has been reported that patients with semantic dementia function well in everyday life and sometimes show striking preservation of the ability to use objects, even those specific objects for which the patient has degraded conceptual information. To explore this phenomenon in nine cases of semantic dementia, we designed a set of semantic tests regarding 20 everyday objects and compared performance on these with the patients' ability to demonstrate the correct use of the same items. We also administered a test of mechanical problem solving utilizing novel tools, on which the patients had completely normal ability. All but the mildest affected patient showed significant deficits of naming and on the visually based semantic matching tasks. Object use was markedly impaired and, most importantly, correlated strongly with naming and semantic knowledge. In a small number of instances, there was appropriate use of an object for which the patient's knowledge on the semantic matching tasks was no better than chance; but this typically applied to objects with a rather obvious relationship between appearance and use, or was achieved by trial and error. The results suggest that object use is heavily dependent upon object-specific conceptual knowledge, supplemented to some degree by a combination of visual affordances and mechanical problem solving.

Successful dose-intensive treatment of desmoplastic small round cell tumor in three children

Desmoplastic small round cell tumor (DSRCT) is a rare soft tissue tumor of primitive origin occurring primarily in children and young adults. Based on published reports in the literature, the response to conventional chemotherapy is poor. We report three pediatric patients successfully treated with dose-intensive, multimodal therapy. Between August 1994 and March 1998, we evaluated three consecutive patients with DSRCT at Children's Hospital and Regional Medical Center, Seattle, Washington. We established the diagnosis based on clinical presentation, radiologic staging, and pathologic review with immunohistochemical staining. All patients received a combined modality protocol including dose-intensive chemotherapy (two of them with peripheral blood stem cell [PBSC] support), second look surgery, and consolidative local irradiation. The patients remain in continuous remission at 66, 42, and 26 months after diagnosis, respectively. Two of our patients were younger than any previously reported patient, extending the age group for which DSRCT should be considered on diagnosis of small round cell tumors. The uniform survival achieved in our series indicates potential benefit for the combination of dose-intensive multiagent chemotherapy, local irradiation, and aggressive surgical approach in this disease.

Ovarian sarcoma with pathologic features of clear cell sarcoma of the kidney

We report a case of an unusual sarcoma arising in the ovary of an infant girl. Histologically, the tumor was composed of clear, undifferentiated cells set in an arborizing vascular stroma. Immunohistochemical staining was positive only for vimentin. Ultrastructural evaluation demonstrated undifferentiated cells with interdigitating broad cell processes that encompassed irregular electron lucent spaces that contained flocculent extracellular material. Light and electron microscopic features of the tumor resembled a clear cell sarcoma of the kidney. Although the cell of origin is unproven, both tumors may arise from primitive mesenchymal cells that may not be restricted to the kidney.

The rise and fall of frequency and imageability: noun and verb production in semantic dementia

This study examines the impact of progressive degeneration of conceptual knowledge on the content words used in connected speech elicited using the Cookie Theft picture description (Goodglass & Kaplan. 1983). We began with an analysis of control subjects' descriptions with regard to word types and their frequency and imageability. Because the impairment of conceptual knowledge in semantic dementia is graded by concept familiarity, we created a model of a standardized normal Cookie Theft description that was then progressively degraded by the systematic removal of lower bands of word frequency. We drew two main predictions from this model: reduced availability of the lower bands of word frequency should result in (a) an apparent deficit for noun retrieval in relation to verb retrieval and (b) an apparent reverse imageability effect. Results from a longitudinal study. in which three patients with semantic dementia each described the Cookie Theft picture on three occasions during the progression of their disease, confirmed these predictions. An additional cross-sectional analysis, adding narratives from a larger number of cases, demonstrated that the decline in ability to produce suitable words for the picture description is closely related to the extent of semantic impairment as measured in tests of word comprehension and production. Both verbs and nouns are affected by the degradation of semantic memory; the fact that the impairment to noun production is manifested earlier and more catastrophically may be attributed to the relatively lower frequency of these terms.

Escherichia coli O157:H7-induced hemolytic-uremic syndrome: histopathologic changes in the colon over time

The 1993 E. coli O157:H7 epidemic in the Western United States has provided a unique opportunity to evaluate the histopathologic temporal progression of disease in the colon in children who developed hemolytic uremic syndrome (HUS). In this report we briefly summarize the clinical courses of eight patients and then discuss the colonic pathology observed in specimens obtained at surgery or at the time of autopsy. The patients were divided into two groups: group 1 consisted of six subjects whose colonic samples were obtained during the acute phase of disease, and group 2 consisted of two subjects whose samples were obtained late in their disease. Both the gross and microscopic findings showed that the most severely affected as well as the earliest affected regions of the colon were the left and transverse portions. Only later in the disease progression was there right-sided colon involvement. These findings are in contrast to the distribution described in E. coli O157:H7 hemorrhagic colitis without HUS, thus suggesting a different mechanism of injury.

MR angiographic diagnosis of cerebral venous sinus thrombosis following allogeneic bone marrow transplantation

Allogeneic bone marrow transplantation is frequently associated with neurological complications, particularly intracerebral bleeds and infections. Cerebral venous sinus thrombosis has only rarely been reported following allogeneic transplants. We report three cases of cortical venous thrombosis following allografting for acute lymphoblastic leukaemia. Two patients received marrow from HLA-identical siblings and one from an unrelated donor. Two of the patients presented with grand mal seizures and one presented with a headache. No neurological abnormalities were found upon clinical examination and lumbar puncture was normal in all three cases. In two of the patients computed tomography (CT) of the brain was normal and in the third showed non-specific abnormalities. Magnetic resonance imaging (MRI) with MR angiography (MRA) demonstrated cerebral venous sinus thrombosis in all three patients. In conclusion, cerebral venous sinus thrombosis should be considered in the differential diagnosis when neurological symptoms occur following allogeneic bone marrow transplantation. We therefore advocate the use of MRA for unexplained neurological symptoms post-allograft since without it cerebral venous sinus thrombosis may easily be missed.

Insights from semantic dementia on the relationship between episodic and semantic memory

An influential theory of long-term memory, in which new episodic learning is dependent upon the integrity of semantic memory, predicts that a double dissociation between episodic and semantic memory is not possible in new learning. Contrary to this view, we found, in two separate experiments, that patients with impaired semantic memory showed relatively preserved performance on tests of recognition memory if the stimuli were perceptually identical between learning and test. A significant effect of semantic memory was only seen when a perceptual manipulation was introduced in the episodic task. To account for these findings, we propose a revision to current models of long-term memory, in which sensory/perceptual information and semantic memory work in concert to support new learning.

The role of speech production in auditory-verbal short-term memory: evidence from progressive fluent aphasia

We report investigations of auditory-verbal short-term memory (AVSTM) in a patient with progressive fluent anomic aphasia. Despite having apparently normal AVSTM as measured by digital span, FM was significantly impaired in immediate serial recall of short sequences of familiar words, and even in reproducing a single word after a filled delay of just a few seconds. In both tasks, unlike normal subjects, she produced numerous phonological errors, often consisting of phonological segments from the intended target word concatenated with segments from other words in the stimulus sequence. Her success in these tasks was modulated (i) consistently by word frequency (high > low), (ii) inconsistently by word imageability (high > low), and (iii) most dramatically by 'nameability': that is, FM was much more likely to reproduce a word correctly in AVSTM if it was a word that she could also produce successfully in picture-naming tasks. On the basis of these and additional experiments designed to exclude other interpretations, we conclude that AVSTM may be crucially supported by activation of the lexical phonological representations responsible for production of content words in speech.

The impact of semantic memory impairment on spelling: evidence from semantic dementia

We assessed spelling and reading abilities in 14 patients with semantic dementia (with varying degrees of semantic impairment) and 24 matched controls, using spelling-to-dictation and single-word reading tests which manipulated regularity of the correspondences between spelling and sound, and word frequency. All of the patients exhibited spelling and reading deficits, except at the very earliest stages of disease. Longitudinal study of seven of the patients revealed further deterioration in spelling, reading, and semantic memory. The performance of both subject groups on both spelling and reading was affected by regularity and word frequency, but these effects were substantially larger for the patients. Spelling of words with exceptional (or more precisely, unpredictable) sound-to-spelling correspondences was most impaired, and the majority of errors were phonologically plausible renderings of the target words. Reading of low frequency words with exceptional spelling-to-sound correspondences was also significantly impaired. The spelling and reading deficits were correlated with, and in our interpretation are attributed to, the semantic impairment.