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How different types of tic disorders are diagnosed and the appropriate therapeutic options for their management, with a focus on Tourette syndrome.

Learning to master a task is expected to be accompanied by a decrease in effort during task execution. We examine the possibility to monitor learning using physiological measures that have been reported to reflect effort or workload. Thirty-five participants performed different difficulty levels of the n-back task while a range of physiological and performance measurements were recorded. In order to dissociate non-specific time-related effects fromeffects of learning, we used the easiest level as a baseline condition. This condition is expected to only reflect non-specific effects of time. Performance and subjective measures confirmed more learning for the difficult level than for the easy level. The difficulty levels affected physiological variables in the way as expected, therewith showing their sensitivity. However, while most of the physiological variables were also affected by time, time-related effects were generally the same for the easy and the difficult level. Thus, in a well-controlled experiment that enabled the dissociation of general time effects from learning we did not find physiological variables to indicate decreasing effort associated with learning. Theoretical and practical implications are discussed.

Learning to master a task is expected to be accompanied by a decrease in effort during task execution. We examine the possibility to monitor learning using physiological measures that have been reported to reflect effort or workload. Thirty-five participants performed different difficulty levels of the n-back task while a range of physiological and performance measurements were recorded. In order to dissociate non-specific time-related effects fromeffects of learning, we used the easiest level as a baseline condition. This condition is expected to only reflect non-specific effects of time. Performance and subjective measures confirmed more learning for the difficult level than for the easy level. The difficulty levels affected physiological variables in the way as expected, therewith showing their sensitivity. However, while most of the physiological variables were also affected by time, time-related effects were generally the same for the easy and the difficult level. Thus, in a well-controlled experiment that enabled the dissociation of general time effects from learning we did not find physiological variables to indicate decreasing effort associated with learning. Theoretical and practical implications are discussed.

This study investigates the correlation between brain magnetic resonance imaging findings and blink reflex abnormalities in patients with relapsing remitting multiple sclerosis. Twenty-six patients and 17 healthy subjects were included in this study. Blink reflex test (BRT) results were obtained using right and left stimulations; thus, 52 BRT results were recorded for the patient group, and 34 BRT results were recorded for the control group. The magnetic resonance imaging (MRI) findings were classified based on the existence of brainstem lesions (hyperintense lesion on T2 weighted (W) and fast fluid-attenuated inversion recovery MRI or contrast-enhancing lesion on T1W MRI). Correlation analysis was performed for the BRT and MRI findings. The percentage of individuals with abnormal BRT results (including R1 latency, ipsilateral R2 latency, and contralateral R2 latency) was significantly higher in the patient group as compared to the control group (p values: 0.015, 0.001, and 0.002, respectively). Correlation analysis revealed significant correlations between contralateral R2 latency abnormalities and brainstem lesions (p value: 0.011). Our results showed significant correlation correlations between contralateral R2 latency abnormalities and brainstem lesions and these results may be explained the effects of multiple demyelinating lesions of the brain stem of patients with relapsing remitting multiple sclerosis. © 2013 Belgian Neurological Society.

The objective of this study was to establish the possible occurrence of eye irritation and subjective symptoms in human volunteers exposed to propylene glycol monomethyl ether (PGME) vapour at concentrations of 0, 100 and 150 ppm. Testing was conducted in 12 healthy male volunteers using a repeated measures design. Each subject was exposed for 2.5 h to each of the three exposure conditions that were spaced 7 days apart. The exposure sequences were counterbalanced and the exposure to the test substance and the effect measurements were conducted in a double-blind fashion. During all exposure sessions, 20 ppm diethyl ether was used as a 'masking agent' for vapour exposure. Measurements of pre- and post exposure eye redness, corneal thickness, tear film break-up time, conjunctival epithelial damage, blinking frequency, and subjective ratings on discomfort were used to evaluate the possible irritating effects of PGME. The results indicated no significant treatment effects for any of the objective parameters. Results of the subjective ratings indicated very slight effects on the eyes in the 150 ppm PGME condition only. No significant effects of treatment were found for the remaining questions concerning the perceived intensity of the smell in the room, the (un)pleasantness of the smell, the perceived effects on the skin, effects on the throat, shivering, muscle aching, and intestinal cramps. In conclusion, the results of the present study indicated minimal subjective eye effects at 150 ppm only, and no impact on the objective measures of eye irritation at either of the two exposure levels. It was concluded that the no adverse effect concentration for eye irritation due to PGME vapour was at least 150 ppm. © 2003 Elsevier Science Ireland Ltd. All rights reserved.

The objective of this study was to establish the possible occurrence of eye irritation and subjective symptoms in human volunteers exposed to propylene glycol monomethyl ether (PGME) vapour at concentrations of 0, 100 and 150 ppm. Testing was conducted in 12 healthy male volunteers using a repeated measures design. Each subject was exposed for 2.5 h to each of the three exposure conditions that were spaced 7 days apart. The exposure sequences were counterbalanced and the exposure to the test substance and the effect measurements were conducted in a double-blind fashion. During all exposure sessions, 20 ppm diethyl ether was used as a 'masking agent' for vapour exposure. Measurements of pre- and post exposure eye redness, corneal thickness, tear film break-up time, conjunctival epithelial damage, blinking frequency, and subjective ratings on discomfort were used to evaluate the possible irritating effects of PGME. The results indicated no significant treatment effects for any of the objective parameters. Results of the subjective ratings indicated very slight effects on the eyes in the 150 ppm PGME condition only. No significant effects of treatment were found for the remaining questions concerning the perceived intensity of the smell in the room, the (un)pleasantness of the smell, the perceived effects on the skin, effects on the throat, shivering, muscle aching, and intestinal cramps. In conclusion, the results of the present study indicated minimal subjective eye effects at 150 ppm only, and no impact on the objective measures of eye irritation at either of the two exposure levels. It was concluded that the no adverse effect concentration for eye irritation due to PGME vapour was at least 150 ppm. © 2003 Elsevier Science Ireland Ltd. All rights reserved.

The sensitivity of physiological measures to mental workload has been investigated in a flight simulator. Twelve pilots had to fly through a tunnel with different levels of difficulty. Additionally, they had to perform a memory task with four levels of difficulty. The easiest memory task was combined with the easiest tunnel task and the most difficult memory task with the most difficult tunnel task. Between the tunnel tasks, subjects had to fly a pursuit task in which a target jet had to be followed. Rest periods before and after the experiment were used as a baseline for the physiolog-ical measures. Mental workload was measured with heart period, continuous blood pressure, respiration and eye blinks. Heart rate variability, blood pressure variability and the gain between systolic blood pressure and heart period (modulus) was derived from the measures. All measures showed differences between rest and flight, and between the pursuit and the tunnel task. Only heart period was sensitive to the different levels in the tunnel task. Since heart rate variability was affected by respiration, it could only be interpreted together with the respiratory data. The modulus, how-ever, was hardly influenced by respiration and therefore, appears te be a better measure than heart rate variability. From the respiratory parameters, the duration of a respiratory cycle was the most sensitive to changes in workload. The time in between two successive eye blinks (blink interval) increased and the blink duration decreased as more visual information had to be processed. Increas-ing the difficulty of the memory task leaded to a decrement in blink interval, probably caused by subvocal activity during the rehearsal of the letters. Blink duration was not influenced by memory load.

The purpose of our study was to assess sevoflurane for inhalational rapid induction compared with halothane. 40 ASA I-II unpremedicated patients aged between 2168 years and planned elective operation, were randomly divided into two equal groups. Vital capacity breathing was reached to the patients and inhalational rapid induction was administrated with 8 % sevoflurane or 4 % halothane in 66 % nitrous oxide and 33 % oxygen. Time to loss of eyelash reflex, breathing frequency until loss of eyelash reflex and airway complications observed, were recorded. Blood pressure, heart rate, peripheral O2 saturation and end tidal CO2 were measured at certain interval. The patients were asked their impressions about the method in postanaesthetic period. Time to loss of eyelash reflex were found to be 44.3±13 and 64.6±16 seconds, and breathing frequency until loss of eyelash were found 4.5±2.8 and 8.2±2.8 for sevoflurane and halothane respectively. Time (p

The sensitivity of physiological measures to mental workload has been investigated in a flight simulator. Twelve pilots had to fly through a tunnel with different levels of difficulty. Additionally, they had to perform a memory task with four levels of difficulty. The easiest memory task was combined with the easiest tunnel task and the most difficult memory task with the most difficult tunnel task. Between the tunnel tasks, subjects had to fly a pursuit task in which a target jet had to be followed. Rest periods before and after the experiment were used as a baseline for the physiolog-ical measures. Mental workload was measured with heart period, continuous blood pressure, respiration and eye blinks. Heart rate variability, blood pressure variability and the gain between systolic blood pressure and heart period (modulus) was derived from the measures. All measures showed differences between rest and flight, and between the pursuit and the tunnel task. Only heart period was sensitive to the different levels in the tunnel task. Since heart rate variability was affected by respiration, it could only be interpreted together with the respiratory data. The modulus, how-ever, was hardly influenced by respiration and therefore, appears te be a better measure than heart rate variability. From the respiratory parameters, the duration of a respiratory cycle was the most sensitive to changes in workload. The time in between two successive eye blinks (blink interval) increased and the blink duration decreased as more visual information had to be processed. Increas-ing the difficulty of the memory task leaded to a decrement in blink interval, probably caused by subvocal activity during the rehearsal of the letters. Blink duration was not influenced by memory load.

Hartslag, bloeddruk en oogknippers geven goed verschillende niveaus van mentale inspanning weer. Hartslagvariabiliteit kan tijdens het uitvoeren van complexe taken verstoord worden door ademhaling.

Hartslag, bloeddruk en oogknippers geven goed verschillende niveaus van mentale inspanning weer. Hartslagvariabiliteit kan tijdens het uitvoeren van complexe taken verstoord worden door ademhaling.