**2.7 Reading test (Fig. 2)**

124 Sleep Disorders

chair or on the bed and will be asked to refrain movements (e.g., grimacing, shaking), which may prevent falling asleep to refrain (Hartse et al. 1982, Mitler et al. 1982). Three to four times a day electrophysiological recordings (C3/A2, C4/A1, EOG and EMG) are recorded in 2-hour intervals of 20 minutes. The earliest start of the first test procedure should be scheduled two hours after waking. As with the MSLT test history is filmed with a video camera. Evaluated will be the sleep latency from the moment "light off" until the onset of the

In various standardization studies, inconsistent cut-off values were found from 13.5 to 18 minutes (Banks et al. 2004, Rühle 2005). Reasons for the different standard values according to Shreter et al. (2006) are that the test exercises have a significant influence on occasion staying awake in the test situation. So they provided proof that the sleep latency on the MWT was deliberately suppressed because the OSAS patients were afraid to get the license revoked. In considering the relationship between the MWT and ESS were calculated a satisfactory correlation of r = .48 (p < .001), with the common variance of the two devices

The Pupillograph Sleepiness Test (PST) from Amtech (Weinheim) reflects the fatigue waves of the pupil described by Löwenstein. Normally, the pupil size will be constant in normal central nervous system activation in the dark for a long time. However, occur with increased daytime sleepiness after a few minutes spontaneous fluctuations (oscillations) on the pupil, which are recorded with infrared videography. Cause of fluctuations in pupil size is a mechanism of the autonomic nervous system. With reduced central nervous system activating two divisions acting simultaneously, which inhibit the Edinger-Westphal nucleus. This leads to instability of the central sympathetic activation and consequently fluctuating in an inhibition of parasympathetic activity and the Edinger-Westphal nucleus (Löwenstein et

Fig. 1. Experimental setup for the pupillography. The patient wears an infrared protective

The average Pupil Unrest Index (PUI) is the average pupil size fluctuations in millimetres per second over a period of 11 minutes. Higher PUI values indicate a clinically significant

goggle, has propped his chin on a device and looks toward the infrared camera.

first two epochs of sleep stage 1 or 2.

was only 23% (Sangal et al. 1997b).

**2.6 Pupillography (Fig. 1)** 

al. 1963, Yoss et al. 1970).

**Evaluation** 

In the first version of the *Reading test*, it was up to the patients and healthy controls, to select a passage according to their interests. Therefore, it was possible that the individual level of activation of OSAS patients may have influenced the excitement level of the books. For this reason, the story "One day, maybe one night" by Arnold Stadler (2003) was selected. This is a retrospective narrative. Due to the low excitement level of the narrative it was assumed that the degree of tonic activation would remain constant.

Fig. 2. In 2A is seen as the patient reads in a semi-recumbent position, the modified form of the story "One day, maybe one night" by Arnold Stadler (Fischer paperback 2003). In the face of the electrodes are glued EOG, EEG and the EMG and its right to recognize a polysomnography. In **2B**, the patient is asleep and the book has resigned.

The text was justified, typed in the font "Times New Roman" and the size 12. The pages were not numbered and included 36 lines with 11 cm length. A lamp (40 watts) was used for lighting, placed at a distance of one meter above the patient's head. At the beginning of the *Reading test*, the patient was informed by a verbal instruction, to read the text as possible in the normal reading speed and without interruptions. Patients were asked to keep the book at a distance of 40 cm. Lack of vision and of reading ability has been excluded by

The Effects of Sleep-Related Breathing Disorders on Waking Performance 127

Rühle and colleagues (2005) researched into an effect size analysis of the ESS the question, if daytime sleepiness could be investigated through a situation. Therefore, the authors analyzed the effect sizes of the eight items. From methodological considerations, it was reasonable to imagine, to come across items with good to very good discriminatory power,

In the study, which took place in the sleep laboratory of the Helios Clinic in Hagen-Ambrock, 209 male OSAS patients and 164 healthy subjects participated. To calculate the effect sizes for each item the difference between of the two item means (of patients and healthy subjects) was divided by the standard deviation of the normal population. Rühle et al. received low to very good effect sizes (ES) between 0.19 to 1.50 The best effect sizes were found for the situation "in reading" (ES = 1.50), "watching TV" (ES = .90), "sit and be passive" (ES = .85) and for "traffic-related stopping" (ES = .61). Similarly, there was an increased mean effect size of ES = .88 for the four selected items, compared to a mean effect size of ES = .68 for the total scale. Some situations of ESS was associated with both healthy subjects and OSAS patients with a high propensity for sleep, e.g. to "lie down to rest" (ES = .19), as a "passenger" (ES = .22) and "talk with someone sitting" (ES = .24). For the development of everyday life and job-related tests - as it had been suggested by Johns (2000), the reading activity was an important characterisation of daytime sleepiness, because it discriminates at the best between

Although MWT and MSLT are often used in practice, since years there is the assumption that its operationalization does not correspond to the tonic activation. Johns (1998) excludes that the MSLT is suitable as a predictor of daytime sleepiness in everyday situations, regardless how strict are implementation and evaluation standards. Although have the sleep latency on both tests satisfactory correlations as Sangal and colleagues (1992, 1997a) showed in subjects with various sleep disorders (r = .41, p < .001) and in Narcolepsy patients (r = .52, p < .001). However, the tests clarify maximum of 20-25% of common variance, indicating that the test methods measure different constructs of daytime sleepiness. Reasons for the average correlations according to Sangal et al. (1992) are that patients with pathological MSLT values were able to stay awake in the MWT, while others who fell asleep

In addition, Johns described measurement error as reasons for the variability of individual test results. It argues that the measurements are depended on the situation character, internal attitude and physical condition of the patient. Kotterba and colleagues (2007) reported that the sleep latency of the MSLT corresponds to the individual property to switch off quickly. In the opinion of John (2000) was the MLST least suitable and is no longer

In handling the tests are very time-consuming and labour intensive (because of multiple tests during the day) as well as it is uneconomical. This would be calling in question the use of the method (Danker-Hopfe et al. 2006, Johns 2000). Because the claim of a standardized implementation and evaluation it could also be performed only by professionally-equipped sleep laboratories (Randerath 1997). Daytime sleepiness can be measured more easily and

**2.8.1 Effect size analysis of the Epworth Sleepiness Scale** 

because the ESS has a good to very good reliability and validity.

OSAS patients and healthy individuals in comparison to the other ESS items.

**2.8 Conclusion** 

**2.8.2 MSLT and MWT criticism** 

regarded as the gold standard.

in the MWT were able to stay awake in the MSLT.

possibly more effectively with the ESS (Johns 2000).

spontaneous, aloud reading of few sentences, if the patient was able to read 3-5 sentences correctly and fluently. About the intention and the period of reading, the patients were not informed in order to allay apprehensions and expectations.
