Transient Homonymous Superior Quadrantanopsia in Nonketotic Hyperglycemia: A Case Report and Systematic Review

BACKGROUND AND PURPOSE: Nonketotic hyperglycemia often causes transient visual field defects, but only scattered anecdotes are available in the literature. METHODS: We report a patient with homonymous superior quadrantanopsia due to nonketotic hyperglycemia and provide a systematic literature review of the clinical features of 40 previously reported patients (41 in total, including our case) with homonymous visual field defects in association with nonketotic hyperglycemia. RESULTS: The typical visual field defect was congruous (84.6%), homonymous hemianopsia (87.8%) with macular splitting (61.5%) or sparing (38.5%). It was transient and repetitive in 54.5% of the patients, but it developed as a persistent form in the remainder. Positive visual symptoms such as hallucinations and phosphenes developed in 73.2% of patients. Brain MRI revealed corresponding abnormalities in most patients (84.8%), characterized by a low-intensity white-matter signal or a high-intensity gray-matter signal on T2-weighted or fluid-attenuated inversion recovery images with diffusion restriction or gadolinium enhancement. Most (97.0%) patients recovered completely, with 48.5% treated by glycemic control alone and the remainder also receiving antiepileptic agents. CONCLUSIONS: Nonketotic hyperglycemia should be considered a possible cause of transient visual field defects, especially when it is associated with repetitive positive visual symptoms and typical MRI findings in hyperglycemic patients.