Neuropsychological assessment in idiopathic REM sleep behavior disorder (RBD): does the idiopathic form of RBD really exist?

OBJECTIVE: To evaluate the cognitive performance of patients with idiopathic REM sleep behavior disorder (RBD). METHODS: The authors studied 17 consecutive patients with idiopathic RBD vs 17 age- and education-matched control subjects. Tests given to each patient and control included Mini-Mental State Examination, verbal and spatial short-term memory, visual selective attention, verbal fluency, prose memory, visuoconstructional abilities, spatial learning, and executive function tests. A self-administered depression rating scale was also used. RESULTS: RBD patients had significantly lower scores than control subjects in two tests: copy of Rey-Osterrieth Figure and Corsi Supraspan Learning. No correlation was found between the results of neuropsychological tests and RBD duration or with polysomnographic findings. CONCLUSIONS: Visuospatial constructional dysfunction and altered visuospatial learning may be present in idiopathic RBD. A neuropsychological assessment may be indicated in RBD patients.

Cognitive dysfunction in patients with obstructive sleep apnea (OSA): partial reversibility after continuous positive airway pressure (CPAP).

The aims of this study were to assess cognitive function in obstructive sleep apnea (OSA) patients and to evaluate the effect of short- and long-term treatment with continuous positive airway pressure treatment (CPAP). A battery of neuropsychological tests, the Epworth Sleepiness Scale (ESS), and the Beck Inventory Scale were administered to 23 patients with severe OSA (age: 56.5+/-6.13; AHI: 54.9+/-13.37) and to 23 age- and education-matched controls. The OSA patients were evaluated in a baseline condition and in two follow-up treatment sessions (after 15 days and 4 months of CPAP, respectively). At baseline, OSA patients had a significant impairment, compared to controls, in tests of sustained attention, visuospatial learning, executive function, motor performance, and constructional abilities. The longitudinal evaluation showed that after a 15-days CPAP treatment attentive, visuospatial learning, and motor performances returned to normal levels. A 4-months CPAP treatment did not result in any further improvement in cognitive tests. Performance on tests evaluating executive functions and constructional abilities was not affected by short- and long-term treatment with CPAP. The findings of this study confirm the hypothesis of partial reversibility of cognitive dysfunction in OSA patients after CPAP.