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PubMed2006

Differential working memory impairment in bipolar disorder and schizophrenia: effects of lifetime history of psychosis.

BACKGROUND: Although bipolar disorder and schizophrenia have long been viewed as distinct illnesses, there is growing evidence that these two complex diseases share some common genes, which may manifest as overlapping neuropsychological impairments. Although working memory dysfunction has been proposed to be central to the pathophysiology of schizophrenia, it has received less attention in studies of bipolar disorder. METHOD: We applied measures of working memory to patients with schizophrenia (n = 15), patients with schizoaffective disorder (n = 15), patients with psychotic (n = 11) and non-psychotic (n = 15) bipolar disorder, and demographically matched healthy subjects (n = 32), in order to determine the extent to which these groups show common or unique impairments. RESULTS: While patients with bipolar disorder (with and without psychotic features) and those with schizophrenia/schizoaffective disorder were impaired on backward digit span, only patients with a lifetime history of psychotic features, regardless of diagnosis, were impaired on spatial delayed response task. CONCLUSIONS: Backward digit span performance is comparable in bipolar disorder and schizophrenia, and may be an appropriate endophenotypic marker that cuts across diagnostic categories. In contrast, spatial working memory performance clearly distinguishes non-psychotic bipolar disorder patients from patients with functional psychosis.

Adult↗
PubMed1996

Memory systems analyses of mnemonic disorders in aging and age-related diseases.

The effects upon memory of normal aging and two age-related neurodegenerative diseases, Alzheimer disease (AD) and Parkinson disease, are analyzed in terms of memory systems, specific neural networks that mediate specific mnemonic processes. An occipital memory system mediating implicit visual-perceptual memory appears to be unaffected by aging or AD. A frontal system that may mediate implicit conceptual memory is affected by AD but not by normal aging. Another frontal system that mediates aspects of working and strategic memory is affected by Parkinson disease and, to a lesser extent, by aging. The aging effect appears to occur during all ages of the adult life-span. Finally, a medial-temporal system that mediates declarative memory is affected by the late onset of AD. Studies of intact and impaired memory in age-related diseases suggest that normal aging has markedly different effects upon different memory systems.

Adult↗
PubMed2005

Implicit and explicit memory in children with congenital and acquired brain disorder.

Implicit and explicit memory were examined in 8- to 15-year-old children with myelomeningocele and shunted hydrocephalus, severe traumatic brain injuries, or orthopedic injuries. Each group included between 22 and 29 children. Children completed a fragmented picture identification task to assess perceptual priming and a semantic decision-making task to assess conceptual priming. Each task also assessed procedural learning as well as explicit recall and recognition. All 3 groups showed significant perceptual and semantic priming of similar magnitude. In contrast, both brain-disordered groups displayed poorer explicit memory than did the comparison group. No group showed significant procedural learning on either task. Age and IQ were stronger predictors of explicit recall than of implicit memory. The findings indicate that implicit memory is relatively intact in many children with congenital and acquired brain disorders, despite deficits in explicit memory, and support the existence of separate memory systems in children.

Adolescent↗
PubMed1995

Misattribution of eating and obsessive-compulsive disorder symptoms to repressed memories of childhood sexual or physical abuse.

We describe three women with eating or obsessive-compulsive disorders who were told on initial presentation for treatment that their symptoms were due to forgotten experiences of childhood abuse and that recalling these repressed memories was critical to their recovery. The two patients who attempted to uncover these memories in psychotherapy were unable to do so and deteriorated. All three patients responded to treatment with conventional psychopharmacologic agents, however. These cases suggest that insisting to patients that they have been abused when they do not think they have been may have deleterious consequences.

Adolescent↗
PubMed1977

Functions of the centre section (trunk) of the corpus callosum in man.

The case is reported of a patient in whom the middle sagittal third of the corpus callosum had been removed for the treatment of an underlying angioma. The special advantages of the case are that the patient is a young, relatively healthy person of normal IQ. The angioma had not interfered with interhemispheric transmission and the patient was described as neurologically normal before operation. After operation left-side neglect and extensive somatic disconnection were seen. A change in the balance between the hemispheres for handedness and ear superiority in dichotic listening was observed. The patient developed an aphasia after operation characterized by a simplification of language, the inavailability of complex ideas and emotional communication. He showed a disorder of memory--'autopragmatic amnesia'--in whice. The patient showed disorders of visuo-spatial transfer. These symptoms are thought to typify a syndrome of the centre trunk region of the corpus callosum, to follow as a direct function of the operation performed upon the callosum, and to illustrate the function of this region of the brain.

Adult↗
PubMed2005

Memory fragmentation in dissociative identity disorder.

This study examined the quality of self-reported memories of traumatic experiences in participants with dissociative identity disorder (DID) and compared them with their memories of non-traumatic, but emotionally significant life experiences. Systematic interview data were gathered from 30 DID patients in The Netherlands. All participants reported a history of severe childhood abuse; 93.3% reported some period of amnesia for the index traumatic event, and 33.3% reported periods of amnesia for significant non-traumatic childhood experiences. All participants who had been amnestic for their trauma reported that their memories were initially retrieved in the form of somatosensory flashbacks. This suggests that, like PTSD patients, DID patients at least initially recall their trauma not as a narrative, but as somatosensory re-experiencing. Surprisingly, however, DID participants also recalled emotionally charged non-traumatic life events with significant somatosensory components, a phenomenon that has not been previously reported. This finding raises important issues regarding basic memory processing abnormalities in DID patients.

Adult↗
PubMed1988

Clinical determination of mental competence. A theory and a retrospective study.

In an attempt to establish a method for determination of mental competence, a two-part investigation was undertaken. First, a model for mental competence was devised that would be applicable across a broad range of neurologic disorders; this model was based on a patient's ability to make complex decisions. Second, a retrospective analysis of competence in 92 inpatients on a neurobehavioral service was carried out. The model was a useful way to view competence, at least in this population. Competence could be classified as operational, limited to a single cognitive domain, or as general, cutting across all domains in a way for which no compensation could be devised. The results suggest that a model of competence based on analysis of individual cognitive operations will provide a sound clinical approach to a common problem that is presently not well characterized.

Adult↗
PubMed2005

Sporadic and familial dementia with ubiquitin-positive tau-negative inclusions: clinical features of one histopathological abnormality underlying frontotemporal lobar degeneration.

BACKGROUND: Frontotemporal lobar degeneration comprises a group of diseases with clinical presentations and underlying histopathologies that overlap. Familial disease occurs in up to 50% of frontotemporal lobar degeneration cases. One of several underlying histopathological abnormalities is of ubiquitin-positive tau-negative inclusions, similar to those in motor neuron disease. OBJECTIVE: To compare clinical features of familial and sporadic cases in this pathological subgroup. DESIGN AND PATIENTS: Case note review of dementia patients with ubiquitin-positive tau-negative inclusion pathological abnormalities proven by autopsy. SETTING: United Kingdom tertiary referral center. MAIN OUTCOME MEASURES: Analysis of clinical features. RESULTS: Eleven familial cases (autosomal dominant) and 18 sporadic cases were identified. Most familial case patients presented with behavioral disturbances similar to those seen in sporadic behavioral cases. Semantic dementia was only seen in sporadic cases. Atypical features occurred in a minority. Sporadic and familial behavioral cases showed no differences in age at onset or disease duration. Neuropsychological test results revealed frontal or temporal deficits in most, but unexpected early parietal deficits in 1. CONCLUSIONS: Behavioral features in familial and sporadic cases were similar, but semantic dementia only occurred in sporadic cases. Diagnostic confusion with Alzheimer disease and corticobasal degeneration occurred in some cases.

Age of Onset↗
PubMed1997

Semantic, phonological, and perceptual changes following left and right intracarotid injection (Wada) with a low amytal dosage.

Intracarotid injection of a low dosage of amobarbital (75 mg, 5% solution) was studied in 30 temporal lobectomy candidates while naming achromatic, incongruously, and congruously colored pictorial objects and reading real, nonsense, and embedded words. Semantic errors and phonological alexia followed the left injection, while the right injection induced visuoperceptual errors. When the contralateral hemisphere was anesthetized, the left brain formulated supraordinate categories for words and objects, while the right brain applied concrete labels. The basic language proficiency of patients influenced recovery and outcome; left temporal patients who were interictally anomic performed especially poorly after both injections. Codifying phonological and perceptual changes during the intracarotid amobarbital procedure can improve interpretations about language laterality and organization.

Adult↗
PubMed1993

Locative prepositional phrases in severe aphasia.

Six severely aphasic patients were trained on C-VIC, a computerized alternative communication system. Patients with both global and Broca's aphasia were able to produce and comprehend locative prepositions using C-VIC. The Broca's aphasic patients were able to produce and interpret symbol order correctly in C-VIC locative prepositional phrases, despite their difficulties in performing the same tasks using English. One patient's verbal production of locative prepositional phrases improved markedly after C-VIC training. These results suggest that the "mapping" impairment suffered by some Broca's aphasics may be ameliorated by use of alternative communication system, such as C-VIC.

Aphasia↗
PubMed1998

Discourse after closed head injury in young children.

This study examined narrative discourse in 23 children, ages 6 to 8 years, who sustained a severe closed head injury (CHI) at least 1 year prior to assessment. Narratives were analyzed at multiple levels using language and information structure measures. Results revealed significant discourse impairments in the CHI group on all measures of information structure, whereas differences in the linguistic domain failed to reach significance. In addition, effects of age at injury and lateralization of lesion on discourse were considered. Although no significant differences were found according to age at injury, a consistent pattern of generally poorer discourse scores was found for the early injured group (< 5 years). With regard to lesion focus, the group findings were unimpressive. However, preliminary examination of individual CHI cases with relatively large lateralized lesions suggested that the late injured children may show the language-brain patterns reported in brain-injured adults, whereas early injured children may not.

Age Factors↗
PubMed2000

Conceptual structure and the structure of concepts: a distributed account of category-specific deficits.

We present a new account of the fine-grained structure of semantic categories derived from neuropsychological, behavioral, and developmental data. The account places theoretical emphasis on the functions of the referents of concepts. We claim (i) that the distinctiveness of functional features correlated with perceptual features varies across semantic domains; and (ii) that category structure emerges from the complex interaction of these variables. The representational assumptions that follow from these claims make strong predictions about what types of semantic information are preserved in patients showing category-specific deficits following brain damage. These claims are illustrated with a connectionist simulation which, when damaged, shows patterns of preservation of distinctive and shared functional and perceptual information which varies across semantic domains. The data model both dissociations between knowledge for artifacts and for living things and recent neuropsychological evidence concerning the robustness of functional information in the representation of concepts.

Brain↗
PubMed1991

Early diagnosis of Alzheimer dementia?

The main problems in early diagnosis of Alzheimer dementia (AD) are: 1. The differentiation between normal aging and AD i.e. difficulties in the assessment of cognitive disturbances in the healthy elderly and in early demented subjects. 2. Interference with other dementia syndromes. 3. Lack of information in the population and among physicians about the different causes and courses of dementia syndromes. The first two aspects are discussed in this paper.

Aging↗
PubMed1996

A cognitive-behavioral model of compulsive hoarding.

Compulsive hoarding is a little studied phenomenon within the research literature. The information available on compulsive hoarding is diverse and not well integrated. In the present article we propose a tentative cognitive-behavioral model of compulsive hoarding. The purpose of such a model is to provide a framework for the development and testing of hypotheses about compulsive hoarding. In this model hoarding is conceptualized as a multifaceted problem stemming from: (1) information processing deficits; (2) problems in forming emotional attachments; (3) behavioral avoidance; and (4) erroneous beliefs about the nature of possessions. Specific hypotheses about each of these are discussed.

Cognitive Behavioral Therapy↗
PubMed1996

Impairment of the semantic network in schizophrenia.

It is well established that patients with schizophrenia display a variety of language impairments. Despite considerable research, however, the underlying mechanisms of the language deficits in schizophrenia remain unclear. Representations of semantic networks of 56 patients with schizophrenia and 28 normal comparison (NC) subjects of similar ages and educational levels were generated by multidimensional scaling and Pathfinder analyses of their responses on the Animal Fluency Test. On the basis of traditional scoring techniques (i.e., total number of correct animal names generated in 60 s), all patients performed significantly worse than the NC subjects. More detailed analyses of the underlying semantic networks revealed that performance in the patients varied according to age of onset and subtype of schizophrenia. The semantic network of patients with late-onset schizophrenia (i.e., with onset after age 45) was virtually identical to that of the NC group. In contrast, the semantic network of patients with a younger age of onset was disorganized and differed significantly from that of the NC subjects. Findings demonstrated that patients with nonparanoid subtypes displayed greater disorganization in their semantic networks than patients with a paranoid subtype. Although general fluency impairments (e.g., difficulties in initiation, retrieval, and search mechanisms) may be sensitive to schizophrenia, per se, specific deficits in the structure of semantic knowledge may be associated with certain characteristics of individual patients with schizophrenia, such as an earlier age of onset and nonparanoid subtype.

Adult↗
PubMed2004

Suicidal behaviors and drug abuse: impulsivity and its assessment.

Impulsivity appears to play an important role in suicidal behaviors and drug abuse, which are two psychiatric problems that may interact with one another. Interpretation of the literature on impulsivity in these behaviors may be complicated by the variety of measurement techniques for the assessment of impulsivity. There are three general types of impulsivity assessment: self-report, biological, and laboratory behavioral. Because laboratory behavioral measures both meet an operational definition of impulsivity and are sensitive to state-dependent changes in impulsivity, this paper presents data that focuses on laboratory behavioral performance among samples emitting suicidal behaviors or substance abuse. To better account for influence of impulsivity in these psychiatric disturbances, no single source of measurement should be used without the consideration of other types of instruments.

Decision Making↗