Information processing speed in obstructive sleep apnea syndrome: a review.

To provide a comprehensive review of studies on information processing speed in patients with obstructive sleep apnea syndrome (OSAS) as compared to healthy controls and normative data, and to determine whether continuous positive airway pressure (CPAP) treatment improves information processing speed. A systematic review was performed on studies drawn from Medline and PsycINFO (January 1990-December 2011) and identified from lists of references in these studies. After inclusion criteria, 159 articles were left for abstract review, and after exclusion criteria 44 articles were fully reviewed. The number of patients in the studies reviewed ranged from 10 to 157 and the study samples consisted mainly of men. Half of the studies reported that patients with OSAS showed reduced information processing speed when compared to healthy controls. Reduced information processing speed was seen more often (75%) when compared to norm-referenced data. Psychomotor speed seemed to be particularly liable to change. CPAP treatment improved processing speed, but the improvement was marginal when compared to placebo or conservative treatment. Patients with OSAS are affected by reduced information processing speed, which may persist despite CPAP treatment. Information processing is usually assessed as part of other cognitive functioning, not as a cognitive domain per se. However, it is important to take account of information processing speed when assessing other aspects of cognitive functioning. This will make it possible to determine whether cognitive decline in patients with OSAS is based on lower-level or higher-level cognitive processes or both.

Is persistent visual neglect associated with poor survival?

BACKGROUND: The association of visual neglect with survival after right hemisphere (RH) stroke has received only limited attention. OBJECTIVE: This study explores the relationship of visual neglect and its spontaneous recovery to survival in a homogenous patient group with first-ever RH stroke. METHODS: Fifty-one RH stroke patients who suffered an infarct between 1994 and 1997 were retrospectively followed for survival until August 31, 2009. Acute-phase neurological, neuropsychological and neuroradiological data were studied to identify predictors of survival. RESULTS: Twenty-eight patients died during the follow-up. Age, education, and poor recovery of visual neglect emerged as significant single predictors of death. The best set of predictors for poor survival in the multivariate model was poor recovery of visual neglect and low education. CONCLUSIONS: Poor recovery of visual neglect is associated with long-term mortality in RH infarct patients. The follow-up of RH patients' neuropsychological performance gives additional information about the prognosis.

Improved computational fronto-central sleep depth parameters show differences between apnea patients and control subjects.

All-night EEG recordings from 12 male apnea patients and 12 age-matched healthy control subjects were studied in the present work. The spectral mean frequency was used to provide computational sleep depth curves from two frontopolar and two central EEG channels. Our previously presented computational parameters quantifying the properties of the sleep depth curves were improved. The resulting light sleep percentage (LS%) values were higher in apnea patients than in control subjects in the right central brain position (P = 0.028), in concordance to our previous work. Moreover, apnea patients showed higher LS% values in the right frontopolar position (P = 0.008). Also, apnea patients showed a smaller anteroposterior sleep depth difference than control subjects on the right hemisphere (P = 0.002). These are interesting new findings, achieved by the present methodology. Thus, the developed computational parameters were able to quantify, at least to some degree, the disruption of sleep process caused by the recurrent apneic events.

Depression and anxiety in obstructive sleep apnea syndrome: a review.

OBJECTIVE - To provide an update on recent research on depression and anxiety in obstructive sleep apnea syndrome (OSAS). METHODS - A review was carried out on reports drawn from MEDLINE and PSYCHLIT (January 1995-June 2006) and identified from their list of references. The selection criteria were met by 55 articles. RESULTS - Sample sizes in the reviewed studies varied widely and consisted mainly of working age men. Depression and anxiety were mostly evaluated with commonly used mood scales; only a few studies provided a psychiatric diagnosis. Prevalence figures fluctuated considerably for both depression (7-63%) and anxiety (11-70%). The effect of the continuous positive airway pressure (CPAP) on mood was inconsistent. CONCLUSIONS - Variations in the prevalence of depression and anxiety are affected by patient characteristics, mood assessment methods, and overlap between mood alterations and OSAS-related symptoms. CPAP might improve mood alterations but more long-term follow-up studies are needed to verify the effectiveness.

A review of executive functions in obstructive sleep apnea syndrome.

OBJECTIVES: To provide an update on recent research concerning obstructive sleep apnea syndrome (OSAS) and executive functions. METHODS: A systematic review was carried out on reports drawn from MEDLINE and PSYCHLIT (January 1990-December 2005) and identified from lists of references in these reports. The selection criteria were met by 40 articles. RESULTS: The sample sizes in the reviewed studies varied widely and consisted mostly of selected groups. Most patient samples were heterogeneous in terms of the severity of OSAS. Executive functions were generally assessed with standardized test methods. Half of the studies assessed executive functions using only one or two tests. The most defected domains of executive functions were working memory, phonological fluency, cognitive flexibility, and planning. Continuous positive airway pressure (CPAP) treatment improved performance times, cognitive flexibility, and planning. Deficits in working memory and phonological fluency persisted. CONCLUSIONS: Executive functions are the most defected cognitive domain in OSAS. Previous studies are affected by the heterogeneity of patient samples and the definitions of the domains of executive functions. Executive functions in OSAS should be assessed with a standardized neuropsychological test battery including assessments of different domains of executive functions. More research is needed on the efficiency of CPAP treatment on executive dysfunctions.