User login
Patients with migrane are more sensitive to all colors of light during the ictal phase than the during interictal phase, according to a recent study, but control subjects do not experience pain when exposed to different colors of light. In order to identify the origin of this photophobia in migraineurs, researchers compared the electrical waveforms that were generated in the retina and visual cortex of 46 interictal migraineurs to those generated in 42 healthy controls using color-based electroretinography and visual evoked potential paradigms. They found:
- Unexpectedly, it was the amplitude of the retinal rod-driven b-wave, which was consistently larger in the migraineurs than in the controls, rather than the retinal cone-driven a-wave or the visual evoked potentials that differ most strikingly between the 2 groups.
- Mechanistically, these findings suggest that the inherent hypersensitivity to light among migraine patients may originate in the retinal rods rather than retinal cones or the visual cortex.
Clinically, these findings may explain why migraineurs complain that the light is too bright even when it is dim.
Bernstein CA, N R-R, Noseda R, et al. The migraine eye: distinct rod-driven retinal pathways’ response to dim light challenges the visual cortex hyperexcitability theory. [Published online ahead of print October 29, 2018]. Pain. doi:10.1097/j.pain.0000000000001434.
Patients with migrane are more sensitive to all colors of light during the ictal phase than the during interictal phase, according to a recent study, but control subjects do not experience pain when exposed to different colors of light. In order to identify the origin of this photophobia in migraineurs, researchers compared the electrical waveforms that were generated in the retina and visual cortex of 46 interictal migraineurs to those generated in 42 healthy controls using color-based electroretinography and visual evoked potential paradigms. They found:
- Unexpectedly, it was the amplitude of the retinal rod-driven b-wave, which was consistently larger in the migraineurs than in the controls, rather than the retinal cone-driven a-wave or the visual evoked potentials that differ most strikingly between the 2 groups.
- Mechanistically, these findings suggest that the inherent hypersensitivity to light among migraine patients may originate in the retinal rods rather than retinal cones or the visual cortex.
Clinically, these findings may explain why migraineurs complain that the light is too bright even when it is dim.
Bernstein CA, N R-R, Noseda R, et al. The migraine eye: distinct rod-driven retinal pathways’ response to dim light challenges the visual cortex hyperexcitability theory. [Published online ahead of print October 29, 2018]. Pain. doi:10.1097/j.pain.0000000000001434.
Patients with migrane are more sensitive to all colors of light during the ictal phase than the during interictal phase, according to a recent study, but control subjects do not experience pain when exposed to different colors of light. In order to identify the origin of this photophobia in migraineurs, researchers compared the electrical waveforms that were generated in the retina and visual cortex of 46 interictal migraineurs to those generated in 42 healthy controls using color-based electroretinography and visual evoked potential paradigms. They found:
- Unexpectedly, it was the amplitude of the retinal rod-driven b-wave, which was consistently larger in the migraineurs than in the controls, rather than the retinal cone-driven a-wave or the visual evoked potentials that differ most strikingly between the 2 groups.
- Mechanistically, these findings suggest that the inherent hypersensitivity to light among migraine patients may originate in the retinal rods rather than retinal cones or the visual cortex.
Clinically, these findings may explain why migraineurs complain that the light is too bright even when it is dim.
Bernstein CA, N R-R, Noseda R, et al. The migraine eye: distinct rod-driven retinal pathways’ response to dim light challenges the visual cortex hyperexcitability theory. [Published online ahead of print October 29, 2018]. Pain. doi:10.1097/j.pain.0000000000001434.