Late onset continuous verbal perseveration after glial tumor surgery: A rare ictal phenomenon

Objective: Perseveration is a rarely observed symptom during the course of neurosurgical diseases. As all perseverations are not uniform, determination of the corresponding brain regions is of great importance prior to deciding whether it represents a destructive or an irritative process. Clinical Presentation: A right-handed 33-year-old patient with a subtotally excised left temporoparietal low-grade astrocytoma was readmitted 9 months later with a complaint of new-onset continuous verbal perseveration which is primarily a sign of a non-dominant hemisphere abnormality. Repeat magnetic resonance imaging showed no change in the residual tumor size or in the edema. No new tumor focus was detected. Discussion: The patient's electroencephalogram indicated a contralateral right-sided epileptic focus. The carbamezapine dosage was increased and the perseverations subsided rapidly. Conclusion: The late-onset ictal perseveration did not imply tumor progression and was triggered by the focus on the contralateral hemisphere, most probably caused by radiotherapy