What manifestations can be expected when adequate levels of glucose are unavailable for energy source for the brain?

When adequate levels of glucose are unavailable for the brain, individuals may experience symptoms such as confusion, dizziness, irritability, and difficulty concentrating. Severe deficiency can lead to more serious manifestations like seizures, loss of consciousness, and even coma. The brain, being highly dependent on glucose for energy, can suffer impaired cognitive function and neurological disturbances in such conditions. Additionally, prolonged lack of glucose can result in long-term cognitive deficits.