To analyze the semiological characteristics of the language and speech disorders arising during epileptic seizures, and to describe the patterns of language and speech disorders that can predict laterality of the epileptic focus.

This study retrospectively analyzed 95 consecutive videos of seizures with language and/or speech disorders in 44 patients admitted for diagnostic video–EEG monitoring. Laterality of the epileptic focus was defined according to electro-clinical correlation studies and structural and functional neuroimaging findings. Language and speech disorders were analyzed by a neurologist and a speech therapist blinded to these data.

Language and/or speech disorders were subdivided into eight dynamic patterns: pure anterior aphasia; anterior aphasia and vocal; anterior aphasia and “arthria”; pure posterior aphasia; posterior aphasia and vocal; pure vocal; vocal and arthria; and pure arthria. The epileptic focus was in the left hemisphere in more than 4/5 of seizures presenting with pure anterior aphasia or pure posterior aphasia patterns, while discharges originated in the right hemisphere in almost 2/3 of seizures presenting with a pure vocal pattern. No laterality value was found for the other patterns.

Classification of the language and speech disorders arising during epileptic seizures into dynamic patterns may be useful for the optimal analysis of anatomo-electro-clinical correlations. In addition, our research has led to the development of standardized tests for analyses of language and speech disorders arising during seizures that can be conducted during video–EEG sessions.