To the Editor.
—Hemifield visual evoked potentials (HVEPs) can provide helpful objective evidence of a hemianopic field defect. We present a patient with a traumatic homonymous hemianopia in whom the defect was clinically obscured by a functional overlay but was clearly documented with HVEPs.
Report of a Case.
—A 25-year-old woman suffered a head injury with 5 days' loss of consciousness following a motor vehicle accident. On awakening, she complained of headaches and difficulty with left-sided vision. Confrontation visual field testing showed left field loss on one occasion and normal results on another. The results of computed tomographic scanning and magnetic resonance imaging of the head and full-field pattern-reversal VEP and electro-encephalogram were reportedly normal. Because the results of these studies were normal, the patient's visual loss was believed to be nonorganic and either malingering or hysterical.The patient's headaches and visual symptoms persisted and 3 months following the accident