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PubMed1991

Cognitive dysfunction in multiple sclerosis. I. Frequency, patterns, and prediction.

Previous frequency estimates of cognitive dysfunction in multiple sclerosis have ranged from 54 to 65 percent. These studies may overestimate the frequency in the general MS population, since the patients in these studies were recruited from clinic populations. In the present study, we administered a comprehensive neuropsychological test battery to 100 community-based MS patients and 100 demographically matched healthy controls. Of 31 cognitive test indices examined, 48 MS patients and five controls were impaired on four or more test indices, yielding an overall frequency rate of 43% for the MS group. The pattern of cognitive decline was not uniform: MS patients were more frequently impaired on measures of recent memory, sustained attention, verbal fluency, conceptual reasoning, and visuospatial perception, and less frequently impaired on measures of language and immediate and remote memory. We developed a brief (20-minute) screening battery empirically by selecting the four most sensitive test indices from the comprehensive battery. The brief battery yielded a sensitivity value of 71% and a specificity value of 94% in discriminating cognitively intact from impaired MS patients, as defined by the comprehensive battery. Cognitive impairment was not significantly associated with illness duration, depression, disease course, or medication usage, but was significantly (albeit weakly) correlated with physical disability.

Adult↗
PubMed1986

Behavioral deficits induced by low doses of apomorphine in rats: evidence for a motivational and cognitive dysfunction which discriminates among neuroleptic drugs.

In order to further assess the alterations (motor, motivational or cognitive) that might underlie animal behavioral deficits associated with a reduced dopamine transmission, the effects of apomorphine at doses thought to stimulate dopaminergic autoreceptors were studied on rat operant behavior. Apomorphine (30 micrograms/kg SC) decreased the number of food rewards obtained, when rats trained on a continuous reinforced schedule were shifted to schedules of fixed ratio higher than 2:FR3, FR4, and FR8. In rats shifted to a FR4 schedule, apomorphine (7.5, 15, 30, 60 micrograms/kg SC) dose-relatedly reduced the number of rewards obtained. In rats subjected to previous extinction sessions, apomorphine (30 micrograms/kg) did not affect lever pressing reinstated on presentation of primary reinforcers but inhibited responding renewed on presentation of secondary reinforcers. Under a FR(3 + 1) schedule where the last (rewarded) response was distinct from the initial (non-rewarded) responses, the detrimental effect of apomorphine on response rates was considerably weaker than under a conventional FR4 schedule. The reward deficits caused by apomorphine under the FR4 schedule were dose-dependently and completely reversed by amisulpride (0.125, 0.25, 0.5, 1 and 2 mg/kg), pimozide (0.125 mg/kg), sulpiride (8, 16, 32 and 64 mg/kg), but not by conventional neuroleptics (namely chlorpromazine, fluphenazine, haloperidol, metoclopramide and thioridazine). It is suggested that behavioral deficits associated with a reduced dopamine transmission such as that caused by low doses of apomorphine involve motivational and cognitive dysfunctions rather than motor impairments. In account of its differential sensitivity to neuroleptic drugs, apomorphine-induced deficit might have some relevance for a further delineation of the mechanisms of action of these compounds.

Animals↗
PubMed1990

Hypoglycemic thresholds for cognitive dysfunction in humans.

Nineteen healthy adult volunteers were studied to define the nature of and threshold for the cognitive dysfunction that occurs during insulin-induced hypoglycemia. The P300 cerebral event-related potential is an electrophysiological correlate of cognitive decision-making processes that can be measured in response to either an auditory or visual stimulus. P300 and reaction time (RT) were recorded from a visual stimulus under euglycemic conditions and at plasma glucose concentrations of 3.3 and 2.6 mM during insulin infusion in 10 subjects. Reducing plasma glucose levels to 3.3 mM was not associated with an increase in either the latency or amplitude of the P300 component or a change in RT. However, further lowering of plasma glucose to 2.6 mM resulted in an increase in the latency of P300 and a prolongation in RT. Similar changes were seen for the auditory P300 in experiments performed on 9 additional subjects in which both auditory and visual stimuli were presented. The prolongation of P300 did not correct immediately when plasma glucose was raised to basal levels with intravenous glucose but returned to normal 45-75 min later, after ingestion of a carbohydrate-containing meal. Analysis of another event-related potential, P140 (a measure of the sensory processes), showed no change in response to hypoglycemia. Prolongation of RT paralleled the prolongation of P300 latency, suggesting that motor processes were not altered. Therefore, hypoglycemia appears to induce abnormalities in decision-making processes.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

[Cognitive dysfunctions of alcohol dependence using event related potentials].

Event-related potentials (ERPs) have been used to investigate cognitive dysfunction in alcoholics. Previous findings are not concordant. Thirty alcoholics, and sex and age matched healthy controls (N = 30) were tested. The average age of alcoholics and the controls were 43.8 +/- 10.3 years and 44.7 +/- 11.5 years, respectively. All subjects were right handed and free from medication. Alcoholics met the criteria of DSM-III-R for alcohol dependence. ERPs were recorded during presentation of auditory stimuli. The stimuli consisted of 1kHz tone bursts referred to as 'frequent (non-target) stimuli' and 2kHz tone-bursts referred to as 'rare (target) stimuli'. The probability of frequent stimuli and rare stimuli were 0.8 and 0.2, respectively. The amplitudes of N100 and P300 were smaller in alcoholics than the controls. However, the latencies of these components were not different between the groups. The amplitudes and latencies of both N200 and P200 were not different between two subject groups. Although in the controls the maxima of P300 were seen only at parietal region, in alcoholics P300 maxima were seen at parietal region (16 out of 30, 53.3%), at frontal region (11 out of 30, 36.7%) and at occipital region (3 out of 30, 10.0%). Correlations between the distributions of P300 maxima and brain CT findings were examined in alcoholics. While CT abnormalities were been in 2 out of 19 (10.5%) subjects having P300 maxima at pareital region, in subjects having P300 maxima at frontal region the abnormalities were seen in 10 out of 11 subjects (90.9%). Correlations between values of CT measurements and the amplitudes (Pz) of P300 were examined.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Behavioral disturbance, cognitive dysfunction, and functional skill. Prevalence and relationship in Alzheimer's disease.

The nature and severity of behavioral problems, and their relationship to cognitive and functional abilities, was investigated in 56 community-residing patients with Alzheimer's disease. Measures evaluated three domains of function: behavior, cognition and activities of daily living. Problems of cognitive functioning, such as memory loss, confusion, and disorientation were most prevalent, reported to occur in 84%, 82%, and 64% of the sample, respectively. Problems with activity and emotional distress were next, affecting 20 to 43% of the sample. The mean number of problems reported was 10 per patient. Twenty-two percent of caregivers reported a minimum of 15 problems occurring at least twice a week and no caregiver reported an absence of problems. Male patients were reported to have more behavioral difficulties. Level of behavioral disturbance was largely unrelated to cognitive or functional ability. Age was unrelated to cognitive or behavioral disturbance but significantly related to activities of daily living. Results indicated that behavioral problems are prevalent and pervasive in even moderately impaired community-residing Alzheimer disease patients, and that age may be more important than level of cognitive dysfunction in predicting difficulties with activities of daily living.

Activities of Daily Living↗
PubMed1992

Effects of previous glycaemic control on the onset and magnitude of cognitive dysfunction during hypoglycaemia in type 1 (insulin-dependent) diabetic patients.

To determine whether the degree of previous glycaemic control may modify cognitive responses to hypoglycaemia, the glycaemic thresholds for, and magnitude of cognitive dysfunction as assessed by P300 event-related potentials as well as subjective and hormonal responses during hypoglycaemia were evaluated. Hypoglycaemia was induced by intravenous insulin infusion in 18 Type 1 (insulin-dependent) diabetic patients, 7 of whom were strictly controlled (HbA1c: 6.3 +/- 0.3%; mean +/- SEM; Group 1) and 11 of whom were poorly controlled (HbA1c: 9.1 +/- 0.4%; Group 2). Within 60 min, mean blood glucose declined from 5.6 and 5.7 mmol/l (baseline) to a nadir of 1.6 and 1.8 mmol/l followed by an increase to 5.6 and 4.3 mmol/l after 120 min in Group 1 and 2, respectively. There was no significant difference between the groups in regard to P300 latency at baseline, but between 50 and 70 min a significant prolongation of this component was noted in Group 2 as compared with Group 1 at blood glucose levels between 1.6 and 2.3 mmol/l (p less than 0.05). The glycaemic thresholds at which a significant increase of P300 latency over baseline was first noted were 1.6 +/- 0.2 mmol/l in Group 1 and 3.5 +/- 0.2 mmol/l in Group 2 (p less than 0.05). The glucose thresholds at which this prolongation was no longer demonstrable were 1.9 +/- 0.1 mmol/l in Group 1 and 3.8 +/- 1.4 mmol/l in Group 2, respectively (p less than 0.05). The glycaemic threshold at which the P300 amplitude was first significantly reduced was 2.2 mmol/l in Group 2, whereas no such reduction was observed in Group 1.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

Central nervous system side effects of nonsteroidal anti-inflammatory drugs. Aseptic meningitis, psychosis, and cognitive dysfunction.

A review of the literature regarding central nervous system side effects of the nonsteroidal anti-inflammatory drugs (NSAIDs) revealed three general categories: aseptic meningitis, psychosis, and cognitive dysfunction. Aseptic meningitis is found most commonly in patients with lupus treated with ibuprofen, but it should be considered in any patient with meningitis if the patient has used NSAIDs. Psychosis, although infrequently reported with NSAIDs, should be suspected in an elderly patient started on a regimen of indomethacin who acutely develops disorientation, paranoia, or hallucinations. Finally, there appears to be some potential for memory dysfunction and attention deficits in elderly patients treated with NSAIDs. Until further studies are available on the incidence and severity of these cognitive changes, physicians should use low doses of NSAIDs in the elderly and remain alert to the possibility of such adverse side effects.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1990

Cognitive dysfunction in adult survivors of allogeneic marrow transplantation: relationship to dose of total body irradiation.

Bone marrow transplant (BMT) patients are exposed to several potential sources of neurologic damage including the neurotoxicity of pre-BMT preparative regimens. The latter generally include a combination of total body irradiation (TBI) and high-dose chemotherapy. Cognitive functioning in 30 adult allogeneic BMT patients (mean of 47 months post-BMT) treated for either acute or chronic leukemia was assessed by two standardized self-report questionnaires. Consistent with hypothesis, results of both univariate and multivariate analyses indicated that increased dose of TBI was associated with increased cognitive dysfunction. Furthermore, this relationship remained even after the impact of psychological distress upon cognitive functioning was accounted for. TBI-related cognitive impairment primarily involved slowed reaction time, reduced attention and concentration, and difficulties in reasoning and problem-solving. These results complement previous findings of an inverse association between dose of TBI and self-perceptions of health and physical functioning in BMT survivors and indicate the importance of including quality of life measures in clinical trials of therapeutic innovations in the field of BMT.

Adolescent↗
PubMed1986

An unusual cluster of tardive dyskinesia in schizophrenia: association with cognitive dysfunction and negative symptoms.

Factors associated with the emergence or nonemergence of involuntary movements (tardive dyskinesia) during long-term neuroleptic treatment were investigated in an atypical, isolated population of 31 schizophrenic inpatients with an unusually high prevalence of this syndrome. Patients with involuntary movements could not be distinguished from those without such movements by general characteristics or conventional indices of neuroleptic or anticholinergic treatment. However, they were more likely to show either marked cognitive dysfunction or muteness. These findings support the proposal that, at least in schizophrenia, subtle organic changes may contribute to vulnerability to the emergence of involuntary movements.

Adult↗
PubMed1977

Schizophrenic cognitive dysfunction: a deficit in rule transfer.

This study examined conceptual rule learning (RL) deficit in male schizophrenic Ss categorized into three groups as defined by Whitaker Index of Schizophrenic Thinking (WIST). Ss were administered a conjunctive, disjunctive, conditional or biconditional rule learning task, WIST, and Shipley-Hartford Memory Scale. It was shown that: (a) the WIST reliably differentiates among three levels of thought disorder as reflected by a deficit in inter-problem transfer of rule learning; (b) certain WIST and Shipley parameters reliably predict RL performance; and (c) phenothiazine dosage levels show no influence on the WIST and no correlation with RL. The findings indicate that cognitive dysfunction in schizophrenics is evidenced by limited inductive reasoning, insufficient channel capacity for filtering out irrelevant information, and inability to gain from antecedent RL experience. Principal locus of schizophrenic thought disorder is examined within a stimulus encoding-information processing paradigm.

Adult↗
PubMed1987

Cognitive dysfunction, negative symptoms, and tardive dyskinesia in schizophrenia. Their association in relation to topography of involuntary movements and criterion of their abnormality.

Little is known of factors that, on an individual basis, confer vulnerability to the emergence of involuntary movements (tardive dyskinesia) during long-term neuroleptic treatment. In this study of 88 chronic schizophrenic inpatients, 22 variables (four demographic, 14 medication history, and four features of illness) were compared for any association(s) with the presence, by differing topographies and criteria of abnormality, and severity of involuntary movements. Irrespective of the criterion used, the presence of marked cognitive dysfunction-muteness bore a consistent and highly significant primary association with both the presence and the overall severity of orofacial dyskinesia; no such association was found in relation to the presence of limb-truncal dyskinesia. Flattening of affect was the only other variable consistently associated with the presence of orofacial movements. The reliability and prominence of the association between the presence of orofacial, but not of limb-truncal, movements and cognitive dysfunction-negative symptoms suggest that these varying topographies may not constitute a unitary syndrome. This strong association, not with indexes of neuroleptic exposure but rather with features of the illness for which that treatment was prescribed, suggests some neurologic process, more subtle than may previously have been appreciated, as a vulnerability factor of some importance. In schizophrenia it appears to be intimately related to the disease process.

Adult↗
PubMed1992

Treatment of cognitive dysfunctions and behavioral deficits in schizophrenia.

Integrated Psychological Therapy (IPT) is a structured intervention program that prescribes steps to remediate cognitive and behavioral dysfunctions that are characteristic of the psychopathology of schizophrenia. Evaluative studies of IPT indicated that the program improved schizophrenic patients' elementary cognitive processes such as attention, abstraction, and concept formation but that patients' performance was still below the normal range. The clinical utility of IPT will depend on studies that document the hierarchical generalization of improvements from the cognitive to the social and symptomatic levels of functioning.

Antisocial Personality Disorder↗
PubMed1992

The Test for Severe Impairment: an instrument for the assessment of patients with severe cognitive dysfunction.

OBJECTIVE: To develop a reliable and valid test of cognitive function suitable for patients with severe cognitive impairment. DESIGN: Administration of a test; test-retest reliability; comparison to traditional test. SETTING: Chronic long-term-care facility. PATIENTS OR OTHER PARTICIPANTS: The participants were 40 elderly residents with severe cognitive impairment. MAIN OUTCOME MEASURES: Results of the Test for Severe Impairment (TSI) and its subsections (language, memory, executive function, and motor performance); correlation of test and retest scores; correlation of TSI with Mini-Mental State Exam. RESULTS: The TSI was significantly correlated with the Mini-Mental State Exam (r = 0.83, P less than or equal to 0.0001). Test-retest reliability was high (r = 0.96, P less than 0.0001). The internal reliability of the test was also good (alpha = 0.90). Preliminary result of a factor-analysis suggests that factor scores may be derived that relate to memory, language production, and knowledge of body parts. CONCLUSIONS: The TSI is a valid and reliable test of cognitive function in patients with severe cognitive impairment. It is appropriate to use it as a unified scale.

Aged↗
PubMed1991

[Disseminated sclerosis: organic basis for mental disorders and cognitive dysfunction].

The MRI-(magnetic resonance imaging) scanner has improved the knowledge of the organic basis of cognitive defects in multiple sclerosis. Recent studies demonstrated a correlation of MRI-verified single lesions, atrophy of the corpus callosum and cognitive defects; but failed to demonstrate the convincing correlation between psychic symptoms and MRI-verified lesions.

Atrophy↗