Cognitive and motor reaction times in obstructive sleep apnea syndrome: A study based on computerized measures.

Obstructive Sleep Apnea Syndrome (OSAS) is mainly associated with executive dysfunction. Although delayed reaction times (RTs) in patients with OSAS have been reported, sensitivity of processing speed has not been adequately assessed. This study suggests sensitive and reliable measures to clarify whether different components of information processing speed, i.e. cognitive and motor responses, are equally impaired in OSAS. Thirty-three patients with OSAS were compared with thirty healthy controls. The MoCA test was administered to assess participants' global neuropsychological profile. Cognitive and motor reaction times were measured using a detector panel which allows to distinguish between stimulus encoding, decision processing, and selection of the appropriate motor response. Logistic regression models highlighted both MoCA test and motor RTs as the best predictors differentiating patients from healthy participants. Results support the hypothesis of a slight decline in the cognitive profile of patients with OSAS and identify significant slowing down in the motor component of responses. It could be hypothesized that slower motor responsiveness is the cause of the global cognitive profile of these patients. With aging, motor movements and RTs usually become impaired and hypoxia might accelerate the aging process by compromising first of all the motor component of RTs.

Obstructive sleep apnea and its controversial effects on cognition.

Obstructive sleep apnea syndrome is a sleep disorder that may affect many brain functions. We are interested in the cognitive consequences of the condition with regard to the quality of life of individuals with this disorder. A debate is still underway as to whether cognitive difficulties caused by obstructive sleep apnea actually induce a "pseudodementia" pattern. This work provides a brief overview of the main controversies currently surrounding this issue. We report findings and opinions on structural and cognitive brain changes in individuals affected by obstructive sleep apnea by highlighting the involvement of executive functions and the possible reversibility of signs following-treatment with continuous positive airway pressure. Much research has been done on this issue but, to the best of our knowledge, a review of the present state of the literature evaluating different points of view has not yet been carried out.

Assessment of the Incremental Diagnostic Value of Florbetapir F 18 Imaging in Patients With Cognitive Impairment: The Incremental Diagnostic Value of Amyloid PET With [18F]-Florbetapir (INDIA-FBP) Study.

IMPORTANCE: Cerebral amyloidosis is a key abnormality in Alzheimer disease (AD) and can be detected in vivo with positron emission tomography (PET) ligands. Although amyloid PET has clearly demonstrated analytical validity, its clinical utility is debated. OBJECTIVE: To evaluate the incremental diagnostic value of amyloid PET with florbetapir F 18 in addition to the routine clinical diagnostic assessment of patients evaluated for cognitive impairment. DESIGN, SETTING, AND PARTICIPANTS: The Incremental Diagnostic Value of Amyloid PET With [18F]-Florbetapir (INDIA-FBP) Study is a multicenter study involving 18 AD evaluation units from eastern Lombardy, Northern Italy, 228 consecutive adults with cognitive impairment were evaluated for AD and other causes of cognitive decline, with a prescan diagnostic confidence of AD between 15% and 85%. Participants underwent routine clinical and instrumental diagnostic assessment. A prescan diagnosis was made, diagnostic confidence was estimated, and drug treatment was provided. At the time of this workup, an amyloid PET/computed tomographic scan was performed, and the result was communicated to physicians after workup completion. Physicians were asked to review the diagnosis, diagnostic confidence, and treatment after the scan. The study was conducted from August 5, 2013, to December 31, 2014. MAIN OUTCOMES AND MEASURES: Primary outcomes were prescan to postscan changes of diagnosis, diagnostic confidence, and treatment. RESULTS: Of the 228 participants, 107 (46%) were male; mean (SD) age was 70.5 (7) years. Diagnostic change occurred in 46 patients (79%) having both a previous diagnosis of AD and an amyloid-negative scan (P < .001) and in 16 (53%) of those with non-AD diagnoses and an amyloid-positive scan (P < .001). Diagnostic confidence in AD diagnosis increased by 15.2% in amyloid-positive (P < .001; effect size Cohen d = 1.04) and decreased by 29.9% in amyloid-negative (P < .001; d = -1.19) scans. Acetylcholinesterase inhibitors and memantine hydrochloride were introduced in 61 (65.6%) patients with positive scan results who had not previously received those drugs, and the use of the drugs was discontinued in 6 (33.3%) patients with negative scan results who were receiving those drugs (P < .001). CONCLUSIONS AND RELEVANCE: Amyloid PET in addition to routine assessment in patients with cognitive impairment has a significant effect on diagnosis, diagnostic confidence, and drug treatment. The effect on health outcomes, such as morbidity and mortality, remains to be assessed.