Background: Paroxysmal occipital discharges (PODs) demonstrating the phenomena of fixation-off sensitivity have classically been described in childhood epilepsies with occipital paroxysms.
Aim: We attempted to delineate the demographic, clinical and imaging characteristics of patients whose interictal electroencephalograms (EEGs) showed occipital discharges with fixation-off sensitivity at our center.
Materials and methods: During the period between 2003 and 2005, patients whose interictal EEGs showed PODs were included in the study. A detailed history, clinical examination and EEG findings along with imaging characteristics were analyzed.
Results: Of the 9,104 interictal EEGs screened during the study period, 11 patients (6 females and 5 males) aged between 5 and 17 years were identified to have PODs with fixation-off sensitivity. Five had history of generalized tonic-clonic seizures. Three patients could be classified under Panayiotopoulos syndrome; the remaining 8 (72.2%) patients had symptomatic epilepsy.
Conclusion: This study suggests that the phenomenon of fixation-off sensitivity is found not only in patients of idiopathic focal epilepsies, but also in a substantial number of patients of symptomatic epilepsy. The high proportion of symptomatic epilepsy with phenomenon of fixation-off sensitivity may be related to the referral pattern.