Effect of continuous positive airway pressure treatment on short-term memory performance over 24 h of sustained wakefulness in patients with obstructive sleep apnea-hypopnea syndrome.
BACKGROUND
Few studies have examined the impact of continuous positive airway pressure (CPAP) therapy on short-term memory (STM) over sustained wakefulness in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS). We have investigated if impaired STM can be reversed by CPAP treatment in a 24-h sustained wakefulness paradigm.


METHODS
Our follow-up study was conducted with repeated-memory tasks within 12 OSAHS patients and 10 healthy controls who underwent three 32-h sessions, one before CPAP (T0) and the second (T3) and the third (T6), after 3 and 6 months of treatment, respectively, for OSAHS patients. Each session included one night of sleep followed by 24h of sustained wakefulness, during which both groups performed STM tasks including both digit span (DS) and Sternberg tasks.


RESULTS
Untreated OSAHS patients had no deficit in the forward DS task measuring immediate memory but were impaired in STM, especially working memory assessed by the complex Sternberg task and the backward DS. However, only performance in the latter was improved after 6 months of CPAP treatment.


CONCLUSIONS
Because the high level of memory scanning required high speed in information processing, persistent impairment on the complex Sternberg task may be attributable to working memory slowing, possibly enhanced by sustained wakefulness.
Laboratoire de Psychologie des Cognitions (EA 4440-UdS), Strasbourg, France; Université de Strasbourg (UdS), France. Electronic address: jeromegreneche@yahoo.fr.
Jérôme
J
Grenèche
Jean
J
Krieger
Frédéric
F
Bertrand
Christine
C
Erhardt
Myriam
M
Maumy
Patricia
P
Tassi
D000328:Adult; D001288:Attention / Q000502:physiology; D002940:Circadian Rhythm / Q000502:physiology; D003071:Cognition / Q000502:physiology; D045422:Continuous Positive Airway Pressure / Q000379:methods*; D006970:Disorders of Excessive Somnolence / Q000503:physiopathology / Q000628:therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D009483:Neuropsychological Tests; D017286:Polysomnography; D020181:Sleep Apnea, Obstructive / Q000503:physiopathology* / Q000628:therapy*; D012894:Sleep Stages / Q000502:physiology; D014851:Wakefulness / Q000502:physiology*
Daytime sleepiness; EEG; Obstructive sleep apnea hypopnea syndrome; Short-term memory; Sternberg task; Sustained wakefulness; Working memory