Executive Dysfunction in Patients with Obstructive Sleep Apnea Syndrome

Abstract

Aims: To clarify whether patients with obstructive sleep apnea syndrome (OSAS) have executive dysfunction, to identify the domains of executive function affected and to establish the severity of any dysfunction. Methods: A full-night polysomnography and a comprehensive neuropsychological assessment focusing on executive functions were conducted on 40 newly diagnosed OSAS patients and 20 healthy controls. The severity of dysfunction was analyzed using norm-referenced data. Results: All patients and controls were men. The groups did not differ statistically significantly in terms of age, education or intelligence quotient. Patients showed poorer performance than controls on the copy of the Rey-Osterrieth Complex Figure test, the Block Design, the Trails B of the Trail Making Test and the Intra-Extra Dimensional Set Shifting test. Based on the normative data, most OSAS patients performed at a normal level, but a few patients had either mild dysfunction (2.5–12.5%) or moderate to severe dysfunction (5–15%). Conclusions: OSAS patients have lower set-shifting and analysis/synthesis performance than healthy controls. According to the normative data, most patients in the present study had normal performance, but there were also a few patients with more serious deficits.

Executive Dysfunction and Learning Effect after Continuous Positive Airway Pressure Treatment in Patients with Obstructive Sleep Apnea Syndrome

“…Before CPAP treatment, OSAS patients showed mildly impaired mental set shifting performance and visuospatial organizational skills compared to healthy controls, which is in line with our earlier results with a larger patient sample [8]. After at least 6 months of CPAP treatment, OSAS patients’ executive performance showed no improvement and they continued to perform more poorly than healthy controls.…”

“…However, the two groups did not differ in terms of their education or IQ. In addition, the pretreatment findings regarding OSAS patients’ poorer performance in mental set-shifting and visuospatial organizational skills were mostly the same as in our previous studies with age-matched study groups [8]. Another limitation is that the study groups had differences in their sleep condition prior to the neuropsychological control assessment.…”

“…The subjects for this study were drawn from the same set of 40 patients whose pretreatment executive functioning was investigated in our recent study [8]. The inclusion criteria were CPAP use at least 4 h per night and at least 5 nights per week over a period of 6 months or longer.…”

“…Executive functions refer to a person’s ability to engage successfully in adaptive, independent, purposive and self-serving behavior [4]. Earlier studies have reported decreased mental set-shifting performance, visuospatial organizational skills [5,6,7,8], behavioral inhibition [6,7,9], and reduced working memory in OSAS patients [6,7,10,11]. …”

“…In our recent study [8], OSAS patients showed lower mental set-shifting and visuospatial organizational skills than healthy controls. Our focus here is on the impact of CPAP treatment on the observed dysfunction after at least 6 months of treatment.…”