Value of scalp delayed rhythmic ictal transformation (DRIT) in presurgical assessment of XXXX .

@entity1 @entity410 @entity1315
OBJECTIVES: To estimate the localising and lateralising value of delayed rhythmic ictal transformation (DRIT) on the scalp EEG during presurgical assessment for @entity1315 . METHODS: Two hundred and eighty eight @entity410 recorded simultaneously with scalp and foramen ovale (FO) electrodes were studied retrospectively in 110 @entity1 . DRIT was defined as sustained regular rhythmic waveforms seen on scalp recordings after scalp @entity410 onset. The incidence and laterality of scalp DRIT was evaluated by comparison to FO electrodes. RESULTS: Scalp DRIT was seen in 192 @entity410 , 65% of which showed focal mesial temporal onset (FMTO) recorded by FO electrodes. FMTO onset was seen in 73% of the 122 @entity410 showing unilateral scalp DRIT, in 32% of the 62 @entity410 showing bilateral asymmetrical scalp DRIT, and in 14% of the seven @entity410 showing bilateral symmetrical DRIT on the scalp. Among the 89 @entity410 showing unilateral scalp DRIT and FMTO, both were ipsilateral in 70 @entity410 (79%). Among the 38 @entity410 showing bilateral asymmetrical DRIT and FMTO, the largest amplitude of scalp DRIT was ipsilateral to the FO onset in 27 @entity410 (71%). CONCLUSION: Two thirds of @entity410 showed unilateral scalp DRIT, which had a lateralising value of up to 79%. SIGNIFICANCE: Scalp DRIT is a reliable marker to lateralise @entity410 focus in @entity1 without a focal @entity410 onset on the scalp EEG.
