Standardization of the psychometric hepatic encephalopathy score in a French population.

The Psychometric Hepatic Encephalopathy Score (PHES) has previously been standardized in thirteen countries on three continents, confirming its status of gold standard test to detect minimal hepatic encephalopathy (MHE). In the meantime, performance has also been shown to vary with variables such as age, education, and barely sex. The present study aimed at standardizing the PHES in a French population. One hundred and ninety-six French healthy participants completed a French version of the paper-and-pencil PHES, involving five tests and six measures. Importantly, the balance was perfect between all levels of the three controlled factors, which were sex, age (seven decade-levels from 20-29 to 80-89 years), and education (two levels below or above 12 years of education). Raw measures were transformed to fit the normal distribution. ANOVAs on transformed variables showed no effect of sex, but an effect of age on all measures, and of education on five measures. Multiple or simple regressions were completed to build up normograms. Thorough analysis of variability within each test failed to find outliers that may bias the results. Comparison between French and seminal German data showed that they highly fitted though cultural and cognitive style specificities could be observed. This is the first study to standardize the PHES in a French population and to extensively explore the effects of sex, age and education using perfectly balanced samples. Subtle differences between countries of the same continent emphasize the need to build up normative data in each country to get accurate PHES in patients.

Primary insomnia patients' performances during simulated car following and urban driving in the afternoon.

According to epidemiological studies, insomnia is associated with an increase in risk of traffic accidents. Recent investigations revealed that patients with insomnia had driving performance impairment under monotonous conditions. However, it is unclear whether other driving abilities may be impacted by insomnia, especially those needing more attentional resources than those involved in monotonous driving. Other findings revealed that impaired performances are more likely to occur with the increase of cognitive demands. However, such tests did not reflect difficulties in situations of everyday life expressed by patients with insomnia, such as driving in an urban environment with traffic and critical situations. Therefore, behaviour in situations encountered in everyday life has to be explored. The aim of the present study was to assess driving performances of patients with insomnia in daily routine tasks such as urban and car-following tests. For this purpose, 15 patients with insomnia and 16 good sleepers performed an urban test of driving with original risk scenarios and a car-following test during the middle afternoon. No significant behavioural difference between patients with insomnia and good sleepers has been found in both the urban test and the car-following test, showing that patients with insomnia have no impairment in behaviour implicated in daily contexts driving tasks of short period of time performed in the late afternoon. Although our results provide a first step towards knowledge of behavioural performance during daily routine driving tasks in patients with insomnia, future studies are needed using on-the-road driving tests and/or different population of patients with insomnia before generalisation.

Effects of three therapeutic doses of codeine/paracetamol on driving performance, a psychomotor vigilance test, and subjective feelings.

RATIONALE: Some recent pharmacoepidemiological studies revealed an elevated risk of driving accidents after opioid analgesics uses. Among analgesics, codeine is often associated with paracetamol in numerous pharmaceutical specialties. OBJECTIVES: The objective of this study was to evaluate the dose-effect relationship of three usual therapeutic doses of codeine/paracetamol on driving ability, psychomotor performance, subjective alertness, in link with blood concentrations in healthy young volunteers. METHODS: Driving performance, responses to psychomotor vigilance tests, and scales reflecting alertness were evaluated during the morning after drug intake in a double-blind, randomized, placebo-controlled study. Sixteen healthy volunteers (23.4 ± 2.7 years old, 8 men and 8 women) participated in this balanced, cross-over study. Three doses of codeine/paracetamol (20/400, 40/800, 60/1200 mg) were evaluated against placebo. Two blood samples were collected, 1 and 4 h after drug intake. In serum, codeine and morphine concentrations were determined in serum using high-performance liquid chromatography electrospray ionization-tandem mass spectrometry, and paracetamol concentrations using fluorescence polarization immunoassay. RESULTS: Driving and psychomotor performance were not affected by any of the three codeine/paracetamol doses. However, significant, though modest, correlations were observed between the driving parameters and both morphine and codeine blood concentrations. CONCLUSIONS: This study did not reveal any significant impairment in performance due to the three therapeutic doses used in healthy young volunteers. However, the relationships between drug blood concentration and behavioral measures suggest that an inter-subject variability in blood concentration may influence the power of the observed drug effect.

Zolpidem and zopiclone impair similarly monotonous driving performance after a single nighttime intake in aged subjects.

RATIONALE: Although hypnotics are primarily used by older people, the residual effects the morning after a single nighttime intake of the two most commonly prescribed hypnotics, zolpidem (Zp) and zopiclone (Zc), on older middle-aged drivers have not been evaluated and compared. METHODS: Sixteen healthy subjects, 55 to 65 years of age, participated in this double-blind, balanced, cross-over study. Zc (7.5 mg), Zp (10 mg) and flunitrazepam (Fln) (1 mg) or a placebo was administered at each subject's home at 11.00 pm. The next morning, at 9.00 am, the subjects had to drive in a simulated monotonous driving environment for 1 h. During each morning session, two blood samples were collected, and subjective feelings of alertness were completed three times. RESULTS: In comparison to placebo, Zp and Zc equivalently and significantly impaired the standard deviation of lateral position, the standard deviation of speed and the number of road exits. Detectable blood concentrations were found with Zp in 11 subjects at 8.30 am and at 1.30 pm. The subjective alertness factor was significantly impaired with Zp. CONCLUSIONS: This is the first study revealing residual effects of Zp on driving performance in ageing drivers which are similar to that of Zc. Studying the effects of medication in different age ranges appears useful to complete the studies on behavioural-pharmacological effects of medication. To reduce the incidence of driving accidents due to prescription drugs, patients should be warned at the time of treatment initiation that they should avoid driving.