Provides communication from the brain to the rest of the body and from the body back to the brain; facilities the ability to reason, interact with other individuals., Headache, Nausea, Vomiting, Weakness, Mood swings, Testing motor function, Testing sensory function, Testing urethral function, Pain, Burning around eyes, Decreased visual ability, Eye redness, Visual disorder, Ophthalmoscope, Angiography, Deafness, Pain in ear, Ringing in ear, Dizziness, Otoscope, Audiometry