Researchers at the Epilepsy Unit, Hospital Clinic de Barcelona, Spain investigated brain areas involved in startle-induced seizures, using a functional neuroimaging approach in 4 adult patients whose seizures began at age 4 months to 10 years. Presurgical evaluation included ictal SPECT coregistered to MRI. Startle-induced seizures were bilateral asymmetric tonic with ictal-EEG pattern located over the mesial centroparietal region. Three patients had a significant hyperperfusion (> 2 SD above the reference) involving the supplementary motor area, the perirolandic area, and precuneus. Ictal EEG-fMRI showed an initial activation located over the precuneus, supplementary motor area, cingulate gyrus, and the precentral/perirolandic area. Startle-induced seizures triggered by unexpected stimuli are generated by the interaction of a frontoparietal network located over the mesial brain surface. [1]

COMMENT. Startle epilepsy is triggered by unexpected stimuli, generally a sudden noise, somatosensory, or visual stimuli. First described by Alajouanine and Gastaut (1955), and included in the ILAE classification 2001. A frontoparietal epileptic network is involved, and not a discrete focus.