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Biomedical subjects

I Reinvang

Publications and source records attributed to I Reinvang.

At least 19 recordsLinked to original sources
PubMed1998

Event-related potentials to stimuli with emotional impact in posttraumatic stress patients.

BACKGROUND: Psychophysiological research has given conflicting results with respect to whether the abnormal physiologic responses observed in posttraumatic stress disorder (PTSD) reflect a general abnormality or are linked to trauma-related stimuli. We studied differences in the central nervous processing of words with emotional impact in survivors after a ship fire disaster. METHODS: Event-related potentials were studied in 11 survivors with posttraumatic stress pathology, and compared with 9 survivors without such pathology. Nonwords and words with negative or positive emotional valence were used as distractors in a P3 oddball paradigm. RESULTS: PTSD subjects had increased N1 latency to standard tones and increased positive amplitude to both words and nonwords compared with controls, occurring between 200 and 350 msec after stimulus onset. The amplitudes to emotionally meaningful words were significantly related to Clinician-Administered PTSD Scale-assessed PTSD dimensions, in particular avoidance and arousal. CONCLUSIONS: The abnormality in information processing observed in PTSD patients seems in part to be linked with increased attention, in part with emotional responses to the trauma. Intrusion was mainly related to the processing of nonwords, while arousal and avoidance were related to event-related potential amplitudes to emotionally meaningful words, suggesting that intrusion has a different neurobiological basis than arousal and avoidance.

Acoustic Stimulation↗
PubMed1998

Electrophysiological localization of brain regions involved in perceptual memory.

Event-related potentials (ERP) were recorded during perceptual discrimination and short-term memory, varying the interstimulus interval (1-10 s) in delayed spatial frequency discrimination. Accuracy of discrimination remained unimpaired across this time interval, but choice reaction times increased. A brain source localization (BESA) model showed that the activity of the parietal and right temporal sources increased with long retention intervals in a sequential activation pattern where a long-latency component of the parietal source specific to the memory condition was observed, the latency of which matched a memory-related increase in choice reaction times in the cognitive task. It is suggested that the temporal sources are involved in encoding and storage of visual information, and the parietal source is involved in memory retrieval.

Electroencephalography↗
PubMed1998

Focal retrograde amnesia associated with vascular headache.

We report the case of a 42-year-old man with repeated attacks of headache associated with retrograde amnesia. Neuropsychological tests before and after the major episode of amnesia showed mild neuropsychological deficits but with spared anterograde memory and learning functions. The amnesia was dense for a period of 15-20 years and included people and events (public and private). There was also a suggestion of amnesia for learned skills. Neurologically he had mild clinical signs and focal EEG-abnormalities in the left fronto-temporal region, but CT, MRI, and SPECT showed no abnormality. Five years after the onset of amnesia there was no recovery of the retrograde memory deficit, but a PET (glucose) scan was normal and neuropsychological testing showed no deficits. An association with migraine has been reported for some non-classical amnesias, but this is the first case of selective retrograde amnesia in a patient with headache as a primary neurological diagnosis.

Amnesia, Retrograde↗
PubMed1998

Amnestic disorders and their role in cognitive theory.

Amnesia refers to a disorder of memory, and classical amnesia with continuous problems in acquiring new information is the most studied type of amnesia. The integration into a memory systems model of clinical studies of classical amnesia, cognitive theory, and studies with neuroimaging methods is one of the prime success stories in modern cognitive neuroscience. The clinical spectrum of amnesia encompasses a wide range of disorders ranging from specific encoding deficits for language or visuospatial information to psychogenic amnesia with confusion and loss of memory for personal identity. Two cases are reviewed, one with selective verbal amnesia and the other with focal retrograde amnesia, presenting some puzzles and challenges to current modular thinking about memory that may lead to theoretical advances. An interactive model emphasizing the communication between brain codes and regions in memory may have promise.

Adult↗
PubMed1998

Association between intraoperative cerebral microembolic signals and postoperative neuropsychological deficit: comparison between patients with cardiac valve replacement and patients with coronary artery bypass grafting.

OBJECTIVES: To examine the association between intraoperative cerebral microembolic signals (MES) and postoperative neuropsychological deficit in patients with valve replacement (VR) and patients with coronary artery bypass grafting (CABG). METHODS: Neuropsychological examination (10 tests) was performed 1-2 days before and 2 months after surgery (VR (n=26) and CABG (n=14)). The intraoperative number of cerebral MES were monitored from the right middle cerebral artery using transcranial Doppler. RESULTS: A higher number of cerebral MES were detected in VR patients with neurological deficit (6/26) compared with those without deficit (20/26) (MES median number 2083 v 645, p=0.04). No such difference was found in patients with CABG (2/14 v 12/14) (MES median number 50 v 112, p=0.2). CONCLUSION: A high number of MES were detected in patients with VR with neuropsychological deficit. In patients with CABG with such a deficit, a low number of MES were detected. This difference in number may be explained by relatively more gaseous emboli in the first and more solid in the second. However, the results in the patients with CABG should be interpreted with caution due to the few patients in this subgroup.

Adult↗
PubMed1996

Serial position effects in visual short-term memory for words and abstract spatial patterns.

Two experiments tested the effects of list position, and retention-interval in recognition for two distinct stimulus categories in young adults. Stimulus categories were spatial abstract patterns and words presented on a computer screen. At short delay intervals recency effects predominates and at longer delay intervals a primacy effect predominates in both experiments, indicating similar basic memory processes producing the serial position functions for the two different categories of visual stimuli, but as length of retention-interval increases, memory for first list items improves for words and remains constant for abstract patterns. Recency functions are similar for both stimulus categories tested.

Adult↗
PubMed1995

[Language disorders].

Language is the basis for acquisition and execution of communicative skills. The neurological structures underlying language can be localized through clinical-pathological studies and neuroimaging studies. The classical language areas (Broca and Wernicke areas) are involved in lesions causing aphasia, and the main types of aphasia are motor (Broca), sensory (Wernicke), global and anomic aphasia. In stable lesions a negatively accelerated recovery curve is observed. Age and severity of aphasia are important prognostic factors. Treatment consists of broadly targeted language stimulation, but specialists services are important for assessment, education, and selection of patients for special forms of therapy.

Adolescent↗
PubMed1995

A follow-up study of neuropsychological functioning in AIDS-patients. Prognostic significance and effect of zidovudine therapy.

Thirty-three patients with AIDS were subjected to neuropsychological and immunological testing with semi-annual examinations over a two year period. No patient had signs of opportunistic infections or neoplasms in the CNS. Patients who were neuropsychologically impaired at the time of AIDS diagnosis (n = 12) survived for a significantly shorter period than did the non-impaired subjects (n = 21), and neuropsychological function at first test had a significant predictive value concerning survival time. The poor prognosis associated with impaired neuropsychological status was seen also in patients treated with zidovudine (ZDV). Of the 21 patients who started ZDV treatment shortly after the first neuropsychological examination, 12 were retested. Follow-up data showed that this group of patients had a significant improvement in neuropsychological functioning during the first 6 months. However, a decrease in performance was observed at second follow-up. In the group not treated with ZDV (n = 7), two initially normal patients developed signs of HIV-encephalopathy, while none of the initially normal ZDV-treated patients did so. This might suggest a prophylactic effect of ZDV on development of neuropsychological dysfunction. Changes in neuropsychological test results were correlated with changes in serum concentration of neopterin irrespective of ZDV treatment, suggesting that monocyte/macrophage activation may be involved in the pathogenesis of HIV-encephalopathy.

AIDS Dementia Complex↗
PubMed1995

Variability in cognitive function among persons at high genetic risk of Huntington's disease.

The present study explores cognitive variability and specificity of cognitive decline in persons at high genetic risk (AR+ persons) of Huntington's disease (HD). Risk status was determined by RFLP markers. Three subgroups were defined according to neuropsychological test performance. One subgroup showed a typical HD pattern of impairment, a second group selectively impaired verbal memory function, and a third group was more heterogeneous. Verbal memory function was frequently impaired among AR+ persons. The specificity of verbal memory dysfunction was evaluated by using a multivariate statistical clustering procedure. While 60% of the AR+ persons were allocated to clusters typical of "subcortical dementia", most AR- persons were allocated to a "normal" cluster. However, the variability was wide within both the AR+ and AR- group. The heterogeneity among AR+ persons was consistent with findings in genetic, neuroimaging, and neuropathological studies of HD. Multidisciplinary studies should be performed to better understand biological determinants of cognitive variability, and to facilitate clinical diagnosis and councelling in individual AR+ persons.

Adult↗
PubMed1994

Effects of cholinergic blockade on language in healthy young women. Implications for the cholinergic hypothesis in dementia of the Alzheimer type.

To investigate the effect of cholinergic blockade on language, 22 healthy young women performed tests of reading, spelling and oral language after a subcutaneous injection of 0.4 or 0.6 mg scopolamine. The results were compared with the performance after 0.6 mg methylscopolamine, which produce no central cholinergic effects. The reading and spelling tests were constructed to evaluate the lexical and phonological strategies for reading and spelling of single words. After scopolamine there were dose-dependent impairments in reading, spelling, verbal fluency and object naming. In 25-60% of the subjects receiving 0.6 mg scopolamine there were clinically significant impairments on tests assessing the lexical and phonological strategies. This pattern is similar to the deficits in reading and spelling observed in patients with dementia of the Alzheimer type. Cholinergic loss may be associated with the language impairments found in dementia of the Alzheimer type.

Acetylcholine↗
PubMed1994

Characteristic patterns of verbal memory function in patients with Huntington's disease.

Various aspects of verbal memory in patients with Huntington's disease (HD) were studied using the California Verbal Learning Test (CVLT). We tested if the level and interplay between 5 parameters of different memory mechanisms and processes were sufficiently specific to allow acceptable discrimination between patients with HD, patients with Parkinson's disease (PD), and patients without known CNS disease or injury. The HD-patients were characterized by a deficit in acquisition, elevated rates of recall errors and increased use of a passive learning strategy. Preserved aspects were shown in retention over time, interference effects and recognition relative to recall. Employing multivariate classification and validation techniques, the 5 CVLT-features demonstrated good separability between the HD-patients and the control patients. Qualitative similarities between subgroups were suggested, but more disease-specific data seemed necessary in further studies. A number of findings suggested a defect in the active organization of items to be encoded and recalled in HD. Similar findings in the PD-group might indicate that this trait is common in several types of 'subcortical dementia'.

Adult↗
PubMed1994

Assessment of 'subcortical dementia' in patients with Huntington's disease, Parkinson's disease, multiple sclerosis and AIDS by a neuropsychological screening battery.

Four diagnostic groups categorized as 'subcortical dementia' were studied using a neuropsychological screening battery. The specificity of the battery in disclosing characteristic patterns of impairment in subgroups within the category, and the correspondence between natural subgroups generated by an unsupervised statistical classification technique and the diagnostic labels were investigated. All cognitive affected subgroups demonstrated impairment on tests of sensomotor function, cognitive efficiency and/or memory, and were characterized in terms of severity of impairment as well as a progressive involvement of functional areas. The diagnostic groups were not evenly represented in all natural subgroups. Affected AIDS-patients seemed to resemble patients with Huntington's disease more than the other diagnostic groups. The screening battery could give a general characterization of the pattern of 'subcortical dementia' and different levels of impairment, but more specific process-oriented tasks are needed to contrast diagnostic groups within the concept of 'subcortical dementia'.

AIDS Dementia Complex↗
PubMed1994

HIV-related neuropsychological impairment and immunodeficiency. CD8+ lymphocytes and neopterin are related to HIV-encephalopathy.

The relationship between neuropsychological test performance and immunological parameters was studied in 52 HIV-positive patients within different stages of the infection. All subjects were neuropsychologically tested, the CD4+ and CD8+ lymphocyte count were measured in peripheral blood, and the concentration of neopterin and HIV-p24 antigen were measured in serum. Ten patients with AIDS were defined as neuropsychologically impaired. The CD8+ cell count was the only immunological parameter that could significantly discriminate between AIDS patients with and without neuropsychological impairment. For the total group, significant positive correlations were found between neuropsychological test results and the number of CD8+ and CD4+ lymphocytes, and significant negative correlations were observed between serum concentration of neopterin and neurocognitive function. Regression analyses showed that up to 51% of the variance in test performance could be explained by CD8+ cells and neopterin concentration. The possible role of CD8+ lymphocytes and neopterin in the pathogenesis of HIV-related CNS-dysfunction is discussed.

AIDS Dementia Complex↗
PubMed1994

Neuropsychological findings in a non-clinical sample of workers exposed to solvents.

The risk of long-term damage to the CNS after exposure to mixed solvents in work environments is controversial. Thirty-six workers were studied who had been exposed to organic solvents for more than 10 years (mean 24.5 years) in a working environment. The workers and unexposed controls were studied with a battery of neuropsychological and cognitive tests. Significant group differences were observed for the Wechsler adult intelligence scale (WAIS) digit span and symbol digit substitution, and on paired associate learning and continuous word recognition. The results suggest that long-term work-related exposure to organic solvents may have chronic toxic effects.

Adult↗
PubMed1993

A follow-up study of neuropsychological function in asymptomatic HIV-infected patients.

A group of asymptomatic HIV-infected patients (CDC II and III) was followed-up over a two year period with semi-annual neuropsychological testing. Of the total sample of 36 subjects, all were retested at test two (T2), 19 at test three (T3) and 13 at test four (T4). A subgroup of subjects was further tested on a simple and a complex task of reaction time. The CD4+ and CD8+ lymphocyte counts were measured in peripheral blood. According to our criteria, no patient could be defined as neuropsychologically impaired. A significant improvement in performance was found from T1 to T2 and from T2 to T3, with a leveling off between T3 and T4. No associations were observed between reaction time and changes in neuropsychological test results and immunological parameters. Our results indicate that neuropsychological impairment does not develop gradually in the asymptomatic stages of HIV-infection. Furthermore, measurements of reaction time do not seem to have any prognostic significance neither for neurocognitive function nor for immunological status as measured by us.

AIDS Dementia Complex↗
PubMed1992

Slowed reaction time in asymptomatic HIV-positive patients.

A total of 24 asymptomatic HIV-infected patients (CDC II/III) and 27 HIV-negative controls were tested for speed of reaction and for general neuropsychological functioning. Reaction time was assessed with two computerized tests with differing levels of cognitive complexity. The results show that the asymptomatic HIV-positive patients have a significantly longer mean reaction time to simple and complex stimuli (SRT p < 0.001, CPT p < 0.05), and a significantly greater standard deviation (SD) (SRT-SD p < 0.005). No significant differences were observed on any of the clinical neuropsychological tests, or in the number of false positive (FP) or non-responses to stimuli (NR) from the CPT. The results indicate that asymptomatic HIV-infected patients are slower and have a greater intra-subject variability in speed using a simple test for reaction time. The difference is less pronounced when doing a more demanding cognitive task and not significant in a test of visuo-motor coordination or on other clinical neuropsychological tests. Emotional state or cognitive strategies affecting speed/accuracy trade-off do not account for the findings.

AIDS Dementia Complex↗
PubMed1991

Neuropsychological findings and depressive symptoms in patients with Huntington's disease.

Twenty patients with Huntington's disease (HD) and a comparison group were studied by a depression scale (MADRS) and a neuropsychological test-battery assessing central areas of cognitive function. The main purpose was to analyze the consistency of findings across patients and focus on the role of specific factors in the impairments. The HD-patients are impaired relative to norms and the comparison-group in all areas but verbal conceptual function. We further divided the HD-patients into subgroups according to severity of neuropsychological impairment. The groups generally show a pattern of increasing deficits. Early changes are found in tests of cognitive efficiency, memory and sensomotor function, but the pattern of impairment is variable. The more severely affected subgroups show an increased decline in performance and progressive involvement of a broader range of functions. The pattern of depressive symptoms in HD-patients indicates that cognitive symptoms of concentration difficulties and lassitude are prominent in all subgroups.

Adult↗