Anti-seizure medications are generally not effective, since they do not provide nourishment to the starved brain. While ketogenic diets have been proven effective to control seizures and relieve some movement disorders in many GLUT1 deficiency patients, some patients do not respond as well as others. In addition, some critical symptoms, including cognitive deficits and certain movement difficulties, tend to persist in GLUT1 deficiency patients treated by a ketogenic diet, raising the question whether GLUT1 deficiency is caused simply by a lack of proper brain energy or if there are more complicated and widespread systems and processes affected.