What temporary condition can cause a loss of consciousness due to insufficient blood supply to the brain?

Syncope is the correct answer because it specifically refers to a temporary loss of consciousness resulting from insufficient blood flow to the brain. This condition can occur due to various reasons, such as a sudden drop in blood pressure or heart rate, leading to a decrease in cerebral perfusion. When the brain does not receive enough blood, which carries oxygen and nutrients, it results in a transient state of unconsciousness.

The other options represent different medical situations: dizziness may involve a sensation of spinning or lightheadedness but does not necessarily include a complete loss of consciousness; a stroke is a serious event that leads to a more permanent loss of function and consciousness due to long-term interruptions in blood supply; and arrhythmia refers to irregular heartbeats that can affect blood flow but may not directly lead to a transient loss of consciousness unless they result in severe hypotension or cardiac output issues. Thus, the definition of syncope aligns precisely with the question regarding temporary loss of consciousness due to insufficient blood supply to the brain.