Treatment of obstructive sleep apnea and rehabilitation outcome in stroke

Several studies have shown a relationship between obstructive sleep apnea
syndrome (OSAS) and cardiovascular diseases, such as hypertension, heart
disease and stroke. OSAS has also been associated with an increase of fatigue
and depression, and a decrease of cognitive functioning. Stroke patients with
OSAS have found to be more functionally impaired than stroke patients without
OSAS. Moreover, OSAS seems to have an additional negative effect on existing
cognitive deficits due to the stroke. Continuous positive airway pressure
(CPAP) is the most frequently used method of treatment for OSAS. Although
research on CPAP treatment in stroke patients is still scarce, treatment seems
to improve rehabilitation outcome of stroke patients.

In this study the relation of OSAS with functional status and cognition, and
the effect of treatment with CPAP on outcomes of rehabilitation in stroke
patients will be investigated. The main research questions are:
1) Is there a relationship between (the severity of) OSAS and cognitive and
functional status?
2) Does CPAP treatment improve cognitive and functional outcome of
rehabilitation?
Firstly, we expect to confirm that OSAS has an additional negative effect in
stroke patients on cognitive and functional status. Secondly, we expect that
CPAP treatment will improve outcomes of rehabilitation in stroke patients.

Case-control study to address research question 1.
Randomized controlled trial to address research question 2.

Stroke patients who screen positive for OSAS will be randomized over four weeks
of nocturnal use of CPAP and four weeks of CAP treatment dealy (N=70). These
patient groups will be compared at baseline, and after four weeks and three
months (RCT part of the project), and they will be compared to patients who
screen negative for OSAS (N=70; case-control part of the project).

All stroke patients admitted in Heliomare are screened for OSAS and undergo a
neuropsychological assessment and assessment of functional status as part of
the routine intake procedure. Present day Heliomare is the only rehabilitation
centre in the Netherlands that screens stroke patients for SAS;
neuropsychological evaluation is required by national guidelines for stroke
rehabilitation. Subjects with OSAS will be randomized to the experimental or
control condition and subjects without OSAS will be assigned to an
observational control group. All subjects will undergo two more cognitive and
functional assessments after the treatment period and at follow-up after two
months. Additionally, OSAS patients will be asked to undergo a polygraphic
sleep examination after the intervention period and at follow-up. In the
experimental condition four weeks of CPAP therapy will be given, while in the
control condition CPAP treatment is delayed for four weeks.
There is no risk associated with participation in this study.