Metabolic imaging in hemianopsia using positron emission tomography with ¹⁸ F-deoxyfluoroglucose

To evaluate the usefulness of metabolic mapping by positron emission tomography using ¹⁸ F-deoxyfluoroglucose as a tracer in the diagnosis of hemianopsia, we examined eight patients who had had cerebrovascular accident, and four controls. Neuro-ophthalmologic examination disclosed hemianopsia in five and incomplete hemianopsia in three patients; computed tomography showed low-density areas in four patients; and nuclear magnetic resonance imaging demonstrated a prolonged T ₂ area in five patients. The cerebral metabolic rate for glucose without visual stimulation in the visual cortex was 7.4 ± 1.0 mg/min/100 g of brain without interhemispheric asymmetry. Light stimulation increased cerebral metabolic rate for glucose in the visual cortex of the nonaffected hemisphere and decreased it in the affected hemisphere. Asymmetry in the metabolic rate in the posterior medial occipital cortex in complete hemianopsia was 22% 12% (P<.01).