Visual hallucination of coloured numbers secondary to hyperglycaemia

Summary

A 70-year-old Indian woman presented with confusion and visual hallucinations of brightly coloured numbers slowly roving across the right visual field. These hallucinations occurred for a few minutes every few hours. Examination revealed a right homonymous hemianopia. Blood sugar was 37 mmol/l. EEG identified left occipital seizure activity. There was clinical and electrophysiological resolution with normalisation of the hyperglycaemia. There are few cases of hyperglycaemia associated with positive visual phenomena and hemianopia in the literature and this is the first case reported presenting with numerical hallucinations. Hyperglycaemia must be kept on a differential diagnosis list of unusual visual phenomena as it is easily correctable.