Yes. The brain cells need glucose to produce energy to run the brain networks, which keep you awake, think, enjoy yourself, manage stress and make decisions, and above all keep you alife. Hypogycemia can lead to brain death.
Confusion. Depending on the severity, you can encounter temporary faintness, confusion, disorientation, headache, dizziness, and, if glucose levels drop dangerously low, coma. Typically, this can be handled with a low carbohydrate, high protein diet, but best to uncover why this is occurring.