Lateralized periodic discharges in insular status epilepticus: A case report of a periodic EEG pattern associated with ictal manifestation

Objective: Insular lobe seizures generally represent a misconceived ictal phenomenon characterized by specific neurological signs. Aphasia can be a rare presenting sign associated with insular lobe epilepsy which could be easily mistaken for a manifestation of other acute brain diseases. Method: We describe an insular status epilepticus (SE) characterized by sudden onset of language disturbance associated with hypersalivation and paraesthesia. A concomitant EEG recording showed the presence of Lateralized Periodic Discharges plus superimposed fast activity (LPDs + F). After an adequate acute endovenous anti-seizure treatment, a normalization of the EEG abnormalities with a complete resolution of all the neurological symptoms was achieved. Discussion: Language disturbances can be usually found in various pathological acute pictures involving the dominant frontal and temporal lobes. The presence of certain EEG pattern, could rise the suspect of aphasia as a critical manifestation. LPDs pattern is usually correlated with structural lesions. The association between LPDs and seizure is controversial but it seems to be more consistent when they are associated with "Plus modifiers" and with an high periodic frequency. Conclusion: Our case underlines the importance of considering focal SE in the differential diagnosis of patients presenting aphasia, even in the absence of previous history of epilepsy. We describe how LPDs can be associated with SE in a patient affected by a brain tumour, supporting the idea that some characteristic periodic patterns could be associated with seizure occurrence.