Background/Objectives: Cervical dystonia (CD) is a condition characterized by involuntary activity of cervical muscles, which is often accompanied by various non-motor symptoms. Recent studies indicate impaired saccadic eye movements in CD. Local administration of botulinum toxin type A (BoNT/A), which causes temporary paralysis of the injected muscle, is the first-line treatment of focal dystonia, including CD. To our knowledge, concurrent observation of the effect of BoNT/A on smooth eye movements, voluntary saccades, memory-guided saccades, and antisaccades in CD has not yet been explored. The aim of this study was to assess the effect of BoNT/A on eye movements and non-motor symptoms in patients with CD, which, when altered, could imply a central effect of BoNT/A. Methods: Thirty patients with CD performed smooth pursuit, prosaccadic expression, memory-guided saccades, and antisaccade tasks; eye movements were recorded by an eye tracker. Motor and non-motor symptoms, including depression, anxiety, pain, disability, and cognitive changes prior to and after BoNT/A administration, were also evaluated. Results: The number of correct onward counts (p < 0.001), overall correct memory-guided saccades count (p = 0.005), motor symptoms (p = 0.001), and non-motor symptoms, i.e., anxiety (p = 0.04), depression (p = 0.02), and cognition (p < 0.001) markedly improved after BoNT/A administration. Conclusions: Memory-guided saccades, depression, and anxiety improve after BoNT/A in CD.

Background/Objectives: Obstructive sleep apnea (OSA) is a common sleep-related breathing disorder associated with cognitive decline. Evidence regarding the reversibility of these deficits after continuous positive airway pressure (CPAP) therapy remains inconsistent. Methods: This prospective observational study included 60 adults with newly diagnosed moderate-to-severe OSA (median age 51 years; 80% male), who underwent baseline assessment using P300 event-related potentials and the Montreal Cognitive Assessment (MoCA). After three months of CPAP therapy with confirmed good compliance, both measures were re-evaluated. Results: After three months of CPAP therapy, a statistically significant reduction in P300 latency (p < 0.001) and an increase in amplitude were observed, accompanied by significant improvements in executive function (p < 0.001), attention (p < 0.001), and delayed recall (p < 0.001). Conclusions: CPAP therapy leads to measurable recovery of cognitive function in patients with moderate-to-severe OSA, suggesting partial reversibility of neurocognitive impairment associated with sleep-disordered breathing. These findings highlight the importance of early recognition and treatment of OSA to prevent long-term cognitive decline.