What characterizes a Transient Ischemic Attack (TIA)?

A Transient Ischemic Attack (TIA) is characterized by a temporary interruption in the blood supply to a part of the brain. This disruption in blood flow can lead to neurological symptoms similar to those of a stroke, but differs from a stroke in that the effects are temporary and usually resolve within a few minutes to 24 hours. The symptoms of a TIA can include weakness, numbness, difficulty speaking, or vision problems, but these symptoms do not persist after the blood flow is restored.

The other provided options describe different medical conditions. A sudden and severe headache may indicate a variety of issues, including migraines or possibly a ruptured aneurysm, but does not specifically define a TIA. Permanent loss of vision in one eye suggests a more serious condition such as retinal detachment or a stroke affecting the visual pathways, rather than the transient nature of a TIA. Loss of balance and coordination can be a symptom of various neurological disorders or injuries, but it does not specifically characterize a TIA. Thus, the essential feature that defines a TIA is indeed the temporary interruption of blood supply to the brain, aligning with option A.