Central Sleep Apnea. Osa or central sleep apnea both can cause sleepiness, tiredness, problems with attention, concentration, memory etc.
Daytime sleepiness. If the question is what are the symptoms of central apnea (csa) vs. What are symptoms of obstructive apnea (osa)... They are essentially the same - daytime fatigue. The physiologic consequences of each lead to different problems but the symptoms may be the same. Best to get a sleep study to determine the nature of the apnea. Patient history and exams rarely accurately predict the presence of apnea.