Seizure or syncope: lessons over time

Abstract

A 25-year-old woman with recurrent syncopal episodes presented with a first time generalized tonic clonic (GTC) seizure. She had experienced two prior fainting spells lasting seconds and associated with diet pills and dehydration. She had another similar spell prior to falling, sustaining a laceration to the right posterior occiput, and having a witnessed GTC seizure. Her scalp electroencephalography (EEG) showed left temporal slowing with sharp features. T1-weighted and T2-weighted MRI revealed two moderately enhancing focal lesions within the left frontal and temporal regions. These findings raised the possibility of an underlying seizure focus. Repeat imaging studies of this patient 1 month later, however, demonstrated resolution of these findings and an area of encephalomalacia, consistent with a traumatic coup contrecoup injury. A repeat EEG was normal. Therefore, the cause of the loss of consciousness was due to syncope with the consequent head injury giving rise to an isolated seizure. Understanding the underlying cause of a seizure is important in dictating treatment. In this setting the patient was not initiated on seizure medication and has done well.

Figure 1

Initial MRI and electroencephalogram (EEG) findings: (A) axial fluid-attenuated inversion recovery MRI of the brain showing: (A) a 7 mm × 5 mm lesion in the left frontal region (black arrowhead) and a 9 mm × 6 mm lesion in the anterior left temporal region (black arrowhead); (B) post-contrast axial T1-weighted MRI showing lesion enhancement of both lesions; and (C) the EEG was notable for left temporal slowing with some sharp features (outlined area).

Figure 2

Repeat imaging 1 month post-event showing: (A) head CT scan with a small region of encephalomalacia (white arrowheads) in the left frontal lobe; (B) axial fluid-attenuated inversion recovery brain MRI of the same lesions in the left frontal and temporal regions; and (C) the same lesions unenhanced on post-contrast axial T1-weighted MRI.