Abstract
The case of a 25-year-old white male, who had migrainous headaches each time he sat in front of his personal computer screen, is described. Changing the screen frequency from 60 to 75 Hz through a Windows command could abolish the headaches. In several surveys, computer screens have been reported to be a migraine trigger. We hypothesize that this environmental trigger may be related to the abnormal flicker fusion thresholds that have been described in migraineurs. It may be that modifying the frequencies of light sources, such as computer screens, could become a non-pharmacological approach to prevent migraine attacks.
Introduction
Elementary and complex light stimuli have been reported to trigger migraine attacks (1, 2). Several types of peculiarities in visual processing have been reported in migraineurs (3, 4). Furthermore, it has been recently shown that not only intense light stimulation, but also optokinetic stimuli, may increase scalp tenderness (5, 6). These observations stress the point that visual stimuli may be not only a migraine trigger but also an ‘overloading’ factor for a ‘sensitive migraine brain’. This hypothesis would be particularly important in the contemporary environment, due to widespread and varied light sources. Although many patients report television and screen triggered headaches (7–9), this was the first case seen by us in which a consistent report was obtained. We report this case and discuss the potential role played by light sources in triggering migraine attacks.
Case report
A 25-year-old computer systems analyst came to our headache clinic because of a recent history of headaches. Five months before he had been transferred from another state where he worked in the facilities of the same company. As soon as he had started work in a new place, he realized that he felt headaches every time he sat in front of his own, or any other, personal computer screen in the company, a phenomenum that had not happened when doing the same thing at his original workplace. After facing the screen for 2–3 min, he would develop a throbbing, low-intensity headache (3 points in a scale of 10) with a bilateral frontotemporal distribution and associated photophobia and nausea. The headache subsided about 5–10 min after withdrawing from the computer. A detailed anamnesis revealed his mood to be a little cyclothymic. He also reported difficulties in sustaining attention in his daily tasks and complained of frequent shifts from one uncompleted activity to another, and that he was easily distracted by irrelevant stimuli. He has myopia, nasal septum deviation and a past history of an intestinal intussusception in his infancy. More recently, he had been diagnosed as having a hiatal hernia associated with esophagitis, asymptomatic at the time of evaluation. Two months before, he had suffered a mild right facial paresis that remitted rapidly. His neurological examination was unrewarding. A CT scan of the head was normal. Attention deficit disorder was diagnosed in accordance with findings in the following exams: arithmetic and digit symbol subtests of the Weschler Adult Intelligence Scale – Revised (WAIS-R); forward and backward digit span, attention/concentration subtests of the Weschler Memory Scale (WMS); Five Point Test; Trail Making Test and CEPA attention subtest. Associated generalized anxiety was also diagnosed in accordance with the DSM-IV criteria. After an appointment with our team, he checked the screen frequency of his computers. The screens at his original workplace had been set to display at a 75-Hz frequency, but in the new workplace they were set to display at a 60-Hz frequency. Changing the frequency of his screen to 75 Hz through a Windows® command abolished his video-induced headaches completely. Two months later, methylphenidate 10 mg t.i.d., pindolol 2.5 mg b.i.d. and alprazolan 0.5 mg b.i.d. were prescribed, which resulted in improvement of both his attention deficit and anxiety symptoms. The patient was still headache free after a 3-month follow-up. Out of eight blind challenge tests modifying his computer screen frequency back to 60 Hz, six induced visual discomfort and two provoked headaches. Further questioning revealed that he used to present severe nausea while immersed in virtual reality.
Discussion
Headaches induced by visual stimuli are not a new phenomenon in neurology. From 3 to 38% of migraineurs have reported visual stimuli, usually a bright light, as a migraine trigger (9, 10). Intense light has been proven to lower the trigeminal cervical pain thresholds and occasionally to induce non-migrainous headaches (5). Headache has also been reported as an adverse event of light therapy for depression (11). Flickering light stimulation can induce nausea and irritability, and may be followed by migraine attacks (12). Migraine attacks have been reported to be naturally induced by complex visual stimuli and experimentally by using checkerboard patterns (2). Headaches and other symptoms akin to those occurring during migraine attacks have been reported by individuals immersed in virtual reality (13). However, with the exception of bright environmental light, none of the aforementioned stimuli are consistently delivered to headache-prone individuals during their lifetime. In a recently conducted survey in France, the patients interviewed by Henry et al. (9) have self-reported four different types of light stimuli among 21 migraine headache precipitants. Computer screen was reported to trigger migraine by 22.5% of the 1486 patients fully interviewed. As could be anticipated, dazzling light and sunshine were reported as triggers by even larger groups (38.8 and 36.5%, respectively) and neon light by a smaller group (22.2%) (9). The numbers in this study are higher than those in a previous report (14), but this difference might reflect the increasing use of computers.
As the patient herein described had myopia, an eye-strain headache could be suspected, but eye-strain headaches differ markedly from the headache described by him (15). Indeed, his headache shared some features with migraine such as the throbbing nature, the nausea and the photophobia. Incomplete migraine syndromes in migraineurs have been recently uncovered by the Spectrum study (16), and the modular theory of the headaches (17) might explain those migraine-like headaches. Perhaps the condition that best correlates to the case stated above is the syndrome of idiopathic photosensitive occipital lobe epilepsy, which presents features very akin to migraine attacks, such as elementary visual symptoms, followed in most cases by a slow clustering of cephalic pain, epigastric discomfort and vomiting, with either normal or only mildly impaired responsiveness (18, 19). For these patients, television and computer screens are the main triggers (19). A decade ago, and more recently, preventing migraine by filtering specific light frequencies through tinted glasses has been tried (20, 21), but at the present time a solution may rest in another measure, for example, modifying the frequencies of light sources, such as computer screens.