**4.2 Number-connection test (ZVT)**

The number-connection test is composed from four number matrices. Each matrix contains 90 unsorted numbers. It must be connected according to the statement by lines from 1 to 90. For estimating the test processing time, the experimenter uses a stopwatch.

The Effects of Sleep-Related Breathing Disorders on Waking Performance 137

evaluation of brain damage.The mean of **correct reproductions** of the 15-44-year old persons was 8 (IQ score of 95-109). In contrast, the mean of the OSAS patients was **6.76** before therapy (IQ score: 70-79), after a 3-day treatment with nCPAP it was **7.84** (IQ score: 80- 94).The mean of **error numbers** of 15-39-year-old persons was three (IQ score of 95-104). The error mean of the study patients was **4.46** before therapy (IQ score: 90-94), after 3-day

As mentioned above, in several studies could be demonstrated neuropsychological and cognitive deficits in OSAS patients (Bédard et al. 1991, Naëgelé et al. 1995, Gresel et al. 1996, Engleman et al. 2000). This allowed finding inter alia differences between healthy subjects and OSAS patients in the assessment of cognitive processing speed and of performance speed (ZVT) (Cassel et al. 1989, Kotterba et al. 1997, Büttner et al. 2007). Also in the Benton test to record the performance of visual memory the OSAS patients showed – compared with healthy subjects – significantly worse results in the number of errors. None significant results were found for the number of correct reproductions. This may have resulted through the sample composition or sample size. On the other hand, it could be that the increased error number and the nearly normal number of correct responses is a criterion or a feature

It can be said that OSAS patients differ from healthy individuals with respect to cognitive skills. These differences can be verified both the memory processes (Benton) and in cognitive processing speed and performance speed (ZVT). These impairments can have

In various studies improved performance under nCPAP therapy have be determined regarding to changes in neuropsychological parameters and/or test performance. Lamphere et al. (1989) could be shown that after one therapy night there was a significant improvement of the attention, which normalized after 14 days of nCPAP. In several studies it could be detected also a reduction in both subjective and objective daytime sleepiness (Montplaisir et al. 1992, Engleman et al. 1993, 1994, Douglas et al. 2000 – according to Schwarzenberg-Kesper et al. (1987) is the improvement of daytime sleepiness an essential motif for a good therapeutic compliance of the patients). Sforza et al. (1995) found after one year of nCPAP treatment an objectively reduced daytime sleepiness, which increased again after a night of therapy interruption. In several studies could be verified also improved further neuropsychological deficits. Kotterba et al. (1998) reported a significant improvement in the simple attention as well as the divided attention, in the cognitive performance and the processing speed. The latter could be replicated also by Büttner et al. (2007). Even an improvement of vigilance or sustained attention, and various cognitive deficits due to the nCPAP therapy was described many times (Denzel et al. 1993, Engleman

Other studies have shown, however, that the cognitive and neuropsychological deficits don't increase or only improving in certain areas, which could indicate an irreversible hypoxic damage of the CNS (Montplaisir et al. 1992, Bédard et al. 1993, Kotterba et al. 1998) and thus point up the importance of early diagnosis and treatment of OSAS underscores.

treatment with nCPAP it was **2.66** (IQ score: 105-109) (Büttner et al. 2007).

for the detection of neurocognitive deficits in OSAS patients (Büttner et al. 2007).

serious consequence, if or as long as they remain untreated.

**4.4.1 CPAP therapy and its effect** 

et al. 1994, Randerath 1997, 2000, Büttner 1999).

**4.4 Conclusion** 

**Conclusion** 

The test is used to measure the basal, all intelligence performances underlying, largely milieu independent and genetically related cognitive performance speed. It corresponds with those ability bundles, which in literature will be called as "*liquid*" intelligence, "*perceptual speed*" or "*processing speed*" are. The test has a wide range of applications. It can apply from 8th years up for all age levels; from the special school to high school and universities (for all levels of education). It is very economical and can be use on an individual or group test. For the processing of the tests the subjects require 5 to 10 minutes (Oswald and Roth, 1987).

The high reliability of the test (test-retest reliability between rtt = .84 and rtt = .973; parallel test reliability between r = .95 and r = .98) is largely independent of age and educational level of the subject. The correlations with various intelligence techniques (PSB, HAWIE, IST-70, RAVEN, CFT-3) are between r = .40 and r = .83. For the individual experiments exist currently standards for 8th to 60th years (n > 2,000), standard values for the group version of the ZVT are available for the age range from 9 to 16 years. The mean of the norm sample (16-60 years) is a **T-value** of 50 ± 10.The Sleep Apnea patients achieved before therapy a Tvalue of **39.82 ± 10.73**, under a only 3-day-CPAP therapy, there was a significant improvement (T-value: **43.08 ± 10.50**) (Büttner et al. 2007).

#### **4.3 Benton Test**

The *Benton Visual Retention Test* is one of the best known and most widely used tests of immediate remembering for visual-spatial stimuli. The test consists of three parallel series, each with 10 geometric stimulus cards. The test person or the patient is shown one stimulus card for a short time (10 seconds), the figure of the card is to be draw directly after showing or after a short delay as accurately as possible. Further testing variations allow a shorter presentation time from 5 seconds, direct copying or simply selecting/choosing of a seen template from four alternatives. The *drawing form* allows evaluating, especially in children, the assessment of the draw ability, whereas the *electing/choosing form* evaluates the memory without the drawing component. The German edition follows the fifth American edition of 1992. It contains a simplified scoring system, additional evaluation examples, advanced standard values and a summary with new findings (Benton test at the onset of dementia). The German Benton also contains, in contrast to the U.S., the election form. The numerous new German-published studies for the Benton test were specifically considered. The test is used in adults until an old age and in children older than 7 years (Benton 1974).

Retest reliability for the *drawing form* is rtt = .854. The relationship between *drawing form* and *electing/choosing form* is relatively low (r = .55). There are numerous studies, especially in the

<sup>3</sup> This retest reliability has been verified by the authors of the following sources:

<sup>1.</sup> http://www.google.de/search?q=cache:5m0-sgoxY1AJ:wt.fb3.uni-wuppertal.de/fachschaft/ psychologie/studi\_hilfen/files/Hauptstudium/Diagnostik/Zahlen-Verbindungs-Test\_(ZVT). doc++reliabilit%C3%A4t+zvt+test+&hl=de&lr=lang\_de&ie=UTF-8: (rtt = .81) and

<sup>2.</sup> http://www.testraum.ch/Serie%204/ZVT.htm: (rtt between .81 and .97).

Learning effects of the ZVT may thus be concluded in clinical trials.

<sup>4</sup> This retest reliability has been verified by the authors of the following sources:

<sup>1.</sup> http://www.testzentrale.de/tests/t0300401.htm: Retest reliability for the *drawing form* was rtt = .85

<sup>2.</sup> http://www.unifr.ch/ztd/lernsystem/tb/benton.html#Testentwicklung: Retest reliability for the *drawing forms* C, D and E is given as average of rtt = 0.85.

Learning effects of the Benton test may thus be concluded in clinical trials.

evaluation of brain damage.The mean of **correct reproductions** of the 15-44-year old persons was 8 (IQ score of 95-109). In contrast, the mean of the OSAS patients was **6.76** before therapy (IQ score: 70-79), after a 3-day treatment with nCPAP it was **7.84** (IQ score: 80- 94).The mean of **error numbers** of 15-39-year-old persons was three (IQ score of 95-104). The error mean of the study patients was **4.46** before therapy (IQ score: 90-94), after 3-day treatment with nCPAP it was **2.66** (IQ score: 105-109) (Büttner et al. 2007).
