Performance validity in outpatients with multiple sclerosis and cognitive complaints.

BACKGROUND: Suboptimal performance during neuropsychological assessment renders cognitive test results invalid. However, suboptimal performance has rarely been investigated in multiple sclerosis (MS). OBJECTIVES: To investigate potential underlying mechanisms of suboptimal performance in MS. METHODS: Performance validity testing, neuropsychological assessments, neuroimaging, and questionnaires were analyzed in 99 MS outpatients with cognitive complaints. Based on performance validity testing patients were classified as valid or invalid performers, and based on neuropsychological test results as cognitively impaired or preserved. Group comparisons and correlational analyses were performed on demographics, patient-reported, and disease-related outcomes. RESULTS: Twenty percent displayed invalid performance. Invalid and valid performers did not differ regarding demographic, patient-reported, and disease-related outcomes. Disease severity of invalid and valid performers with cognitive impairment was comparable, but worse than cognitively preserved valid performers. Lower performance validity scores related to lower cognitive functioning, lower education, being male, and higher disability levels (p < 0.05). CONCLUSION: Suboptimal performance frequently occurs in patients with MS and cognitive complaints. In both clinical practice and in cognitive research, suboptimal performance should be considered in the interpretation of cognitive outcomes. Identification of factors that differentiate between suboptimal and optimal performers with cognitive impairment needs further exploration.

Magnesium and headache after aneurysmal subarachnoid haemorrhage.

BACKGROUND: In patients with aneurysmal subarachnoid haemorrhage (SAH), headache typically is severe and often requires treatment with opioids. Magnesium has analgesic effects in several conditions, but whether it reduces headache after SAH is unknown. METHODS: In a cohort of 108 SAH patients included in the randomised controlled trial Magnesium in Aneurysmal Subarachnoid Haemorrhage-II (MASH-II), severity of headache was regularly assessed on an 11-point scale until day 10 after SAH. Headache was treated according to a standardised protocol with acetaminophen, codeine, tramadol or piritramide. Serum magnesium levels were assessed every other day. Differences in mean headache scores between patients with mean high (>1.0 mmol/l) and normal (< or =1.0 mmol/l) magnesium levels were analysed with a Student t test. Crude and adjusted ORs for the use of codeine, tramadol and piritramide for patients with high versus normal magnesium levels were calculated with logistic regression. RESULTS: The 61 patients with high magnesium levels had lower mean headache scores (4.1) than the 47 patients with normal magnesium levels (4.9; mean difference, 0.8; 95% CI 0.1 to 1.6) and required less tramadol (adjusted OR, 0.3; 95% CI 0.1 to 0.7) or piritramide (adjusted OR 0.2; 95% CI 0.1 to 0.5). There were no differences in the use of acetaminophen or codeine. CONCLUSION: In SAH patients, elevated serum magnesium levels are associated with slightly less severe headache and less frequent use of opioids. These data imply that intravenous magnesium therapy, besides a supposed beneficial effect on outcome, also provides pain relief for SAH patients, for whom it might also improve functional outcome.

A case-control pilot study on cognitive functioning, symptom validity and psychological wellbeing in HIV-1-infected patients in the Netherlands.

The objective of this study was to examine and relate both cognitive functioning and psychological wellbeing in Dutch HIV-1-infected patients (n = 30) in comparison with a matched healthy control group (n = 30), taking symptom validity into account. Significant differences in performance between patients and controls were found in the domain Working memory (P = 0.036), but not in the other cognitive domains. There was a significant difference in all dimensions of the psychological wellbeing scale, measured with the SCL-90-R (P values between 0.002 and 0.023), except for agoraphobia, cognitive performance difficulty and sleep disturbances. No correlations were found between the performance on the Working memory domain and wellbeing. Future research should focus on unravelling the underlying mechanisms of neurocognitive dysfunction further using neuropsychological tests, including a symptom validity test in combination with neuroimaging techniques in larger samples.