Clinical features of 16 cases of headache which were provoked after watching 3-D videos.

OBJECTIVE: Although a lot of people have recently reported headaches provoked after watching 3-D videos, the clinical features of the so-called "3-D headache" have not been clarified. In this study, we investigated the clinical features of headaches provoked after watching 3-D videos.

METHODS: We conducted a questionnaire survey by email to cases who described headaches caused by watching 3-D videos on a Weblog. We established the diagnostic criteria for 3-D headaches, which are as follows for a definite 3-D headache: A) Provoked after watching 3-D videos, but was never provoked by 2-D videos, B) Never experienced previously, C) Unclassifiable by the ICHD-II. A possible 3-D headache was one that met the criteria of A) and B) the same as above, C) Classified as a "probable" subform by the International Classification of Headache Disorders-2nd Edition (ICHD-II).

RESULTS: We received answers from 16 cases (5 males, 11 females, average age of 35.8 years old). Eleven of the 16 cases had experienced an entirely new type of headache after watching 3-D videos. Of these 11 cases, 5 were diagnosed as having a definite "3-D headache". The other 6 cases were diagnosed as having possible 3-D headaches. The remaining 5 of 16 cases were suspected to be attacks of primary headaches that the cases were accustomed to having experienced. The common characteristics of the 5 definite 3-D headaches were that they were bilateral and non-pulsating, and the duration was from 10 minutes to 24 hours. The intensity of the 3-D headache was as follows; severe in 2 cases, moderate in 2 cases, and mild is one case. Three of the 4 cases with moderate to severe headache had nausea.

CONCLUSION: The headaches provoked after watching 3-D videos include not only the attacks of primary headaches but also the headache attacks unclassifiable by the ICHD-II.