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Keywords:

  • Polarization;
  • Photic stimulation;
  • Photoparoxysmal

Summary: Purpose: Pharmacotherapy for photosensitive epilepsy is not always effective and is associated with well-recognized toxicities. Nonpharmacologic approaches to the management of photosensitive epilepsy have included the use of sunglasses of various types. Blue lenses have been shown to suppress the photoparoxysmal response more effectively than lenses of other colors with similar overall transmittances. Recently, cross-polarized glasses have shown promise. The axes of polarization of the two lenses of such glasses are perpendicular to one another. We tested the effect of combining the use of blue and cross-polarized lenses in three patients with photosensitive epilepsy.

Methods: We recorded the EEG response to photic stimulation, television screens, and computer monitors in three patients with photosensitive epilepsy. If photoparoxysmal responses were provoked in any of these scenarios, testing was repeated with the patient wearing nonpolarized, parallel-polarized, and blue cross-polarized sunglasses.

Results: One of our patients had clinical seizures that were inadequately suppressed with moderate doses of valproate (VPA) but completely suppressed with blue cross-polarized lenses. The second patient's photoparoxysmal response was suppressed by both parallel-polarized and blue cross-polarized glasses, whereas the third patient's photoparoxysmal response was not suppressed by either.

Conclusions: These preliminary data suggest that blue cross-polarized lenses may be useful in the treatment of photosensitive epilepsies and that their efficacy can be predicted in the EEG laboratory.