Seizure-associated aphasia has good lateralizing but poor localizing significance

Summary

Objective

To investigate the occurrence of ictal and postictal aphasia in different focal epilepsy syndromes.

Methods

We retrospectively analyzed the video-electroencephalographic monitoring data of 1,118 patients with focal epilepsy for seizure-associated aphasia (SAA). Statistical analysis included chi-square analysis and Fisher’s exact test.

Results

We identified 102 of 1,118 patients (9.1%) in whom ictal or postictal aphasia (SAA) was part of their recorded seizures (n = 59 of 102; 57.8%) or who reported aphasia by history (n = 43; 42.2% only reported aphasia by history). Postictal aphasia was present in 18 patients (30.5%). Six of the 59 patients had both ictal and postictal aphasia (10.2%). SAA occurred either with left hemisphere seizure onset or with seizures spreading from the right to the left hemisphere. SAA was most common in patients with parieto-occipital epilepsy (10.9%; five of 46 patients), followed by patients with temporal (6.7%; 28 of 420 patients), focal (not further localized; 4.8%; 22 of 462 patients), and frontal epilepsy (2.1%; four of 190 patients; p = 0.04). SAA was more common in parieto-occipital epilepsy than in frontal epilepsy (p = 0.02). In contrast, there was no significant difference in SAA between temporal and parieto-occipital epilepsy (p = 0.36).

Significance

SAA has a high lateralizing but limited localizing value, as it often reflects spread of epileptic activity into speech-harboring brain regions.

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