Usefulness of Blue Sunglasses in Photosensitive Epilepsy

Abstract

The suppressive effect of sunglasses upon photoparoxysmal responses (PPRs) elicited by 15-Hz flicker stimuli with a low luminance of nearly 10 nits was studied in eight patients with photosensitive epilepsy. Using three commercially available sunglasses of neutral density (ND), blue, and brown, the influence upon generalized PPRs elicited by a flickering dot pattern (FDP) and red flicker (RF) stimuli was separately examined in six patients; the luminance of the visual stimuli decreased from roughly one-fifth (ND and brown sunglasses) to one-tenth (blue sunglasses). With FDP stimulation, four of the six patients wearing each of the three sunglasses had no provocation of PPRs, whereas two of the six patients had provocation of generalized PPRs with all of the sunglasses. With RF stimulation, two of the six patients wearing ND sunglasses had provocation of generalized PPRs; three of the six patients wearing brown sunglasses had similar provocation; in contrast, none of the six patients showed provocation of PPRs while wearing blue sunglasses. These results suggest that the suppressive effect of the three sunglasses on FDP stimulation is mainly due to a luminance diminution, whereas that of blue sunglasses on RF stimulation is produced by an inhibitory effect of short wavelengths and possibly by a luminance diminution. Thus, blue sunglasses are thought to be useful in the treatment of patients with photosensitive epilepsy.

Pattern Sensitivity and Photosensitivity in Epileptic Children with Visually Induced Seizures

“…In patients with photosensitivity only (group B), the most common environmental triggering factor was flickering lights (e.g., sunlight through moving foliage, artificial bright lights, disco lights), whereas environmental patterns were never effective. In both these groups, use of blue sunglasses might be beneficial in preventing seizures, as was recently stressed by Takahashi and Tsukahara (1992). In patients with pattern sensitivity only (group C), pattern stimuli were very effective and often stereotyped, with high specificity and selectivity of spatial frequency and orientation of the constituent elements of the pattern.…”

A Study of the Effect of Color Photostimulation from a Cathode‐ray Tube (CRT) Display on Photosensitive Patients: The Effect of Alternating Red–Cyan Flicker Stimulation

“…If one compiles the findings by Harding (7), Tobimatsu (15), and Takahashi (16), one may readily reach to a conclusion that when red/blue stimuli are repeated alternately, blue augments the stimulus caused by red; but when they are applied simultaneously, they antagonize each other's action.…”

“…When focal PPR is included, the rates increased to 25.2% (26 of 103 times), 22.6% (38 of 168 times), 16.7% (12 of 72 times), and 11.1% (eight of 72 times) for groups A, B, C, and D, respectively. The rates were slightly higher in groups A and B.…”

“…On December 16,1997, an incident happened simultaneously in several areas in Japan, in which about 700 individuals (mainly young children, low teens) developed acute symptoms, such as convulsions and loss of consciousness, while viewing a popular TV animation program, "Pocket Monster" (broadcast by TV Tokyo) (1). Subsequent studies suggested a possibility that most of these symptoms were photosensitive seizures that were provoked by approximately 12-Hz alternating red/ blue inversion frames that lasted about 4 s during the second half of the program (2,3).…”

Suppressive Efficacies by Adaptive Temporal Filtering System on Photoparoxysmal Response Elicited by Flickering Pattern Stimulation

“…Before and after recourse to AEDs, it is useful to consider nonpharmacologic methods of treatment that include simple avoidance of causative stimulus, the wearing of dark glasses, and the like (9). As one specific measure in the case of complex stimuli such as TV, it is known that blue sunglasses in particular are capable of suppressing PPR elicited by pattern flicker and red flicker stimuli (27), suggesting that blue sunglasses may be applicable as a simple measure to prevent TV‐induced seizures. In addition to the wearing of dark or blue sunglasses, it is hoped that the ATFS filter will play an important role as a nonpharmacologic method of photosensitive seizure treatment.…”