Biomedical subjects

Ben Schmand

Publications and source records attributed to Ben Schmand.

9 recordsLinked to original sources

PubMed2006

Memory function and serotonin transporter promoter gene polymorphism in ecstasy (MDMA) users.

Although 3,4-methylenedioxymethamphetamine (MDMA or ecstasy) has been shown to damage brain serotonin (5-HT) neurons in animals and possibly humans, little is known about the long-term consequences of MDMA-induced 5-HT neurotoxic lesions on functions in which 5-HT is involved, such as cognitive function. Because 5-HT transporters play a key element in the regulation of synaptic 5-HT transmission it may be important to control for the potential covariance effect of a polymorphism in the 5-HT transporter promoter gene region (5-HTTLPR) when studying the effects of MDMA as well as cognitive functioning. The aim of the study was to investigate the effects of moderate and heavy MDMA use on cognitive function, as well as the effects of long-term abstention from MDMA, in subjects genotyped for 5-HTTLPR. A second aim of the study was to determine whether these effects differ for females and males. Fifteen moderate MDMA users (<55 lifetime tablets), 22 heavy MDMA+ users (>55 lifetime tablets), 16 ex-MDMA+ users (last tablet > 1 year ago) and 13 controls were compared on a battery of neuropsychological tests. DNA from peripheral nuclear blood cells was genotyped for 5-HTTLPR using standard polymerase chain reaction methods.A significant group effect was observed only on memory function tasks (p = 0.04) but not on reaction times (p = 0.61) or attention/executive functioning (p = 0.59). Heavy and ex-MDMA+ users performed significantly poorer on memory tasks than controls. In contrast, no evidence of memory impairment was observed in moderate MDMA users. No significant effect of 5-HTTLPR or gender was observed. While the use of MDMA in quantities that may be considered "moderate" is not associated with impaired memory functioning, heavy use of MDMA use may lead to long lasting memory impairments. No effect of 5-HTTLPR or gender on memory function or MDMA use was observed.

Adult↗

PubMed2005

Cognitive profile of patients with newly diagnosed Parkinson disease.

OBJECTIVE: To determine the frequency and pattern of cognitive dysfunction in patients with newly diagnosed Parkinson disease (PD) and to identify its demographic and clinical correlates. METHODS: A cohort of 115 consecutive patients with newly diagnosed PD and 70 healthy controls underwent a comprehensive neuropsychological assessment including tests of psychomotor speed, attention, language, memory, executive and visuospatial functions, as well as measures of affective status. Patients also received quantitative ratings of motor symptom severity and functional status. Neuropsychological performance of PD patients was compared with that of healthy controls and with available normative data. Independent demographic and clinical predictors of cognitive impairment were identified with multiple logistic regression analysis. RESULTS: Relative to controls, PD patients performed significantly worse on most cognitive measures. However, further analysis revealed that group differences in cognitive performance could mainly be explained by measures of immediate memory and executive function. Comparison with normative data showed that impairments were most frequent on measures of executive function, memory and psychomotor speed. In all, 24% of PD patients (4% of controls) displayed defective performance on at least three neuropsychological tests and were classified as cognitively impaired. Late onset of disease was an independent predictor of cognitive dysfunction in PD. CONCLUSION: Cognitive impairments are common even in newly diagnosed Parkinson disease patients, with deficits being most prominent in the domains of memory and executive functions. Older age at disease onset is likely to be an important determinant of cognitive dysfunction in Parkinson disease.

Affective Symptoms↗

PubMed2005

Effort and cognition in schizophrenia patients.

OBJECTIVE: The aim of this study was to determine whether low cognitive test scores in schizophrenia patients are due to insufficient effort and, if so, to what extent. METHOD: Mental effort was measured with the Word Memory Test (WMT), an effort test that has been extensively validated. Schizophrenic patients (n=64), non-psychotic psychiatric patients (n=63), neurological controls (n=20), and normal controls (n=44) were tested with a neuropsychological test battery measuring memory, attention and executive functioning. RESULTS: The majority of the schizophrenia patients and a quarter of the psychiatric patients scored below the cut-offs for normal effort on the WMT. Scores on the effort test explained a significant amount of variance in the neuropsychological test performance of schizophrenic patients. This lends support to the notion that cognitive functioning in schizophrenia is compromised by insufficient effort. Furthermore, poor mental effort was related to negative symptoms. CONCLUSIONS: Poor mental effort might be considered a core symptom of schizophrenia, representing an executive, monitoring or motivational problem. Mental effort should be taken into consideration in the neuropsychological assessment of schizophrenic patients and of psychiatric patients in general. Controlling for this variable may have a considerable impact on research, assessment and treatment of cognitive disorders in schizophrenic patients.

Adolescent↗

PubMed2005

Cognitive outcome in adults with moderate disability after pneumococcal meningitis.

OBJECTIVES: To assess cognitive outcome and quality of life in patients with moderate disability after bacterial meningitis as compared to patients with good recovery. METHODS: Neuropsychological evaluation was performed in 40 adults after pneumococcal meningitis; 20 patients with moderate disability at discharge on the glasgow outcome scale (GOS score 4) and 20 with good recovery (GOS score 5). RESULTS: Patients with GOS score 4 had similar test results as compared to patients with GOS score 5 for the neuropsychological domains 'intelligence', 'memory' and 'attention and executive functioning'. Patients with GOS score 4 showed less cognitive slowness than patients with GOS score 5. In a linear regression analysis cognitive speed was related to current intelligence, years of education and time since meningitis. Overall performance on the speed composite score correlated significantly with time since meningitis (-0.62; P<0.001). Therefore, difference between both groups may have been related to a longer time between meningitis and testing for GOS four patients (29 vs. 12 months; P<0.001). CONCLUSIONS: Patients with moderate disability after bacterial meningitis are not at higher risk for neuropsychological abnormalities than patients with good recovery. In addition, cognitive slowness after bacterial meningitis may be reversible in time.

Adolescent↗

PubMed2005

Unilateral pallidotomy versus bilateral subthalamic nucleus stimulation in PD--a comparison of neuropsychological effects.

OBJECTIVE: To compare the cognitive and behavioural effects of unilateral pallidotomy and bilateral subthalamic nucleus (STN) stimulation. METHODS: After baseline examination 34 patients were randomly assigned to unilateral pallidotomy (4 left-sided, 10 right-sided) or bilateral STN stimulation (n = 20). At baseline and six and twelve months after surgery we administered neuropsychological tests of language, memory, visuospatial function, mental speed and executive functions. Also a depression rating scale, and self and proxy ratings of memory and dysexecutive symptoms were administered. RESULTS: Six months after surgery, the STN group and the pallidotomy group differed significantly in change from baseline in number of errors on two tests of executive functioning. After 12 months the STN group reported less positive affect compared with baseline than the pallidotomy group. One patient in the STN group showed an overall cognitive deterioration due to complications. CONCLUSIONS: Although we need larger groups to draw firm conclusions, our results suggest that bilateral STN stimulation has slightly more negative effects on executive functioning than unilateral pallidotomy.

Deep Brain Stimulation↗

PubMed2004

Cognitive impairment in survivors of out-of-hospital cardiac arrest.

BACKGROUND: The huge importance of rapid provision of care, especially early defibrillation, for survival of out-of-hospital cardiac arrest (OHCA) is well known. This prospective cohort study investigated cognitive functioning of OHCA survivors in relation to the time-related elements of the resuscitation. METHODS: Fifty-seven consecutive survivors, from a cohort of 308 witnessed OHCA patients with ventricular fibrillation as the initial rhythm, underwent extensive neuropsychologic examination, including tests of memory, attention, and executive functioning, 6 months after the resuscitation. Time-related aspects of the resuscitation were collected on scene. Cognitive functioning was studied in relation to the administration of cardiopulmonary resuscitation (CPR) prior to ambulance arrival, and time from collapse to start of CPR, defibrillation, and return of spontaneous circulation (ROSC). RESULTS: Depending of the test, between 11% and 28% of survivors were cognitively impaired, while 58% scored unimpaired for all tests. Daily life activities were limited in 19% of the patients. Patients who received CPR prior to arrival of the ambulance showed a trend towards overall better cognitive functioning and significant better immediate memory and visuomotor tracking (P =.03 and P <.01). We found a weak correlation between the time to CPR, time to defibrillation, or time to ROSC and cognitive functioning. CONCLUSIONS: The majority of survivors of OHCA with ventricular fibrillation as the initial rhythm are cognitively unimpaired. Long delays to ROSC are compatible with good cognitive outcome. Initiation and cessation of resuscitation efforts should not be based on the duration of circulatory arrest.

Activities of Daily Living↗

PubMed2003

Suboptimal performance on neuropsychological tests in patients with suspected chronic toxic encephalopathy.

Suboptimal performance during neuropsychological testing can seriously complicate assessment in behavioral neurotoxicology. We present data on the prevalence of suboptimal performance in a group of Dutch patients with suspected chronic toxic encephalopathy (CTE) after long-term occupational exposure to solvents. One hundred and forty-five subjects referred to one of two Dutch national assessment centers for CTE were administered the Amsterdam Short-Term Memory Test (ASTM) and the Test of Memory Malingering (TOMM), two tests specifically developed for the detection of suboptimal performance. For both tests, very cautious cut-off scores were chosen with a specificity of 99%. Results indicated that suboptimal performance appears to be a substantial problem in this group of patients with suspected CTE after long-term exposure to organic solvents. Only 54% of our subjects obtained normal scores on both tests of malingering, i.e. at or above cut-off score. The two tests seemed to measure the same concept in that nearly all the subjects with low TOMM scores also had low ASTM scores. However, a higher proportion of subjects scored below the cut-off on the ASTM than on the TOMM.

Adult↗

PubMed2002

Cognitive impairment in adults with good recovery after bacterial meningitis.

Adults without neurologic sequelae after bacterial meningitis are supposed to live without restrictions. Neuropsychological outcome was assessed in 51 adults from a prospective cohort with good recovery, defined as Glasgow Outcome Scale score 5, after pneumococcal or meningococcal meningitis. Patients who recovered well after pneumococcal meningitis showed cognitive slowness (P=.001). A cognitive disorder was found in 27% of these patients. Patients who previously had meningococcal meningitis were not significantly different from control subjects. Scores on general health and quality of life questionnaires revealed lower scores for patients with meningitis, which were related to cognitive slowing (R, -0.46 to -0.38). In conclusion, adults surviving pneumococcal meningitis were at significant risk of neuropsychological abnormalities, even if they were clinically well recovered.

Adolescent↗

PubMed2002

A comparison of three tests to detect feigned amnesia: the effects of feedback and the measurement of response latency.

Three experiments provided validation data for an English language version of the Amsterdam Short Term Memory Test (ASTM test) developed to detect feigned memory impairment. Using a simulation design, the ASTM test compared favourably with the Test of Memory Malingering (TOMM) and appeared better than a newly-devised Digit Recognition Test (DRT). Feedback on the correctness of responses had no significant effect on performance but notable trends were apparent. Simulators were significantly slower than controls on computerised versions of the ASTM test and the TOMM. Convergent findings indicate that the English language version of the ASTM test may be useful in detecting malingering.

Adolescent↗