Pinheiro CF1, Carvalho GF1, Moraes R2, Sestari L1, Maciel NM1, Dach F3, Van Emmerik R4, Bevilaqua-Grossi D1
1Ribeirão Preto Medical School, University of São Paulo, Department of Health Sciences, Ribeirão Preto, Brazil, 2School of Physical Education and Sports of Ribeirão Preto, University of São Paulo, Biomechanics and Motor Control Lab, Ribeirão Preto, Brazil, 3Ribeirão Preto Medical School, University of São Paulo, Department of Neurosciences and Behavioral Sciences, Ribeirão Preto, Brazil, 4School of Public Health and Health Sciences, University of Massachusetts, Department of Kinesiology, Amherst, United States
Background: Postural control impairments are common in people with migraine. These patients have light sensitivity due the disease, and it remains during the headache-free period. The light intensity influences the balance, but it was only observed in older adults under dim ambient light conditions. Nevertheless, it is unknown if higher lighting levels can influence the balance, especially in individuals with visual hypersensitivity, like migraineurs.
Purpose: To assess the balance of women with migraine and non-headache subjects under different light conditions.
Methods: The sample consisted of 14 women with migraine (30.6 ± 8.1 years) and 14 non-headache women (27.2 ± 2.8 years). Participants were evaluated in a force plate in bipodal posture during 30 seconds under three light conditions:
(1) ambient (AMB, 270 lx),
(2) visual discomfort threshold (VDT, 400 lx), and
(3) intense visual discomfort (IVD, 2000 lux).
The light conditions were defined based on visual sensitivity of the migraine group. Stabilometric data were collected with a sample rate of 100Hz and filtered with a fourth-order low-pass Butterworth digital filter with a cutoff frequency of 10 Hz. We analyzed the center of pressure (CoP) area, CoP speed and CoP root mean square (RMS). Except for the sway area, all variables were calculated in anteroposterior (a-p) and mediolateral (m-l) directions. Center of pressure data was transformed using log10. The CoP parameters were compared between groups across the three light conditions using ANCOVA (p .05) and the age was used as a covariate.
Results: We observed interaction between group and lighting conditions for CoP area (F2,50= 10.39, p .000), CoP speed (a-p: F2,50= 7.41, p = .004; m-l: F2,50= 4.99, p = .01), and CoP RMS (a-p: F2,50= 5.82, p = .009 and m-l: F2,50= 5.91, p = .009). The migraine group presented greater CoP area under the three conditions, and greater CoP speed and CoP RMS under both visual discomfort light conditions, compared to controls. Intra-group analysis showed greater CoP area, speed and RMS for both visual discomfort light conditions compared to the ambient condition, only in the migraine group.
Conclusion(s): The exposure to bright light that triggers a visual discomfort alters the postural control of patients with migraine, boosting some pre-existing deficits, while the same lighting levels do not affect controls.
Implications: The proprioceptive training should be implemented as part of the migraine rehabilitation process due to the balance impairments in individuals with migraine. Furthermore, the disturbing effect of light sensitivity on postural control of migraineurs also should be considerate to delineate therapeutic approaches for patients with migraine.
Keywords: photosensitivity, headache, posture
Funding acknowledgements: CAPES Foundation and FAPESP Foundation (2015/18031)
Purpose: To assess the balance of women with migraine and non-headache subjects under different light conditions.
Methods: The sample consisted of 14 women with migraine (30.6 ± 8.1 years) and 14 non-headache women (27.2 ± 2.8 years). Participants were evaluated in a force plate in bipodal posture during 30 seconds under three light conditions:
(1) ambient (AMB, 270 lx),
(2) visual discomfort threshold (VDT, 400 lx), and
(3) intense visual discomfort (IVD, 2000 lux).
The light conditions were defined based on visual sensitivity of the migraine group. Stabilometric data were collected with a sample rate of 100Hz and filtered with a fourth-order low-pass Butterworth digital filter with a cutoff frequency of 10 Hz. We analyzed the center of pressure (CoP) area, CoP speed and CoP root mean square (RMS). Except for the sway area, all variables were calculated in anteroposterior (a-p) and mediolateral (m-l) directions. Center of pressure data was transformed using log10. The CoP parameters were compared between groups across the three light conditions using ANCOVA (p .05) and the age was used as a covariate.
Results: We observed interaction between group and lighting conditions for CoP area (F2,50= 10.39, p .000), CoP speed (a-p: F2,50= 7.41, p = .004; m-l: F2,50= 4.99, p = .01), and CoP RMS (a-p: F2,50= 5.82, p = .009 and m-l: F2,50= 5.91, p = .009). The migraine group presented greater CoP area under the three conditions, and greater CoP speed and CoP RMS under both visual discomfort light conditions, compared to controls. Intra-group analysis showed greater CoP area, speed and RMS for both visual discomfort light conditions compared to the ambient condition, only in the migraine group.
Conclusion(s): The exposure to bright light that triggers a visual discomfort alters the postural control of patients with migraine, boosting some pre-existing deficits, while the same lighting levels do not affect controls.
Implications: The proprioceptive training should be implemented as part of the migraine rehabilitation process due to the balance impairments in individuals with migraine. Furthermore, the disturbing effect of light sensitivity on postural control of migraineurs also should be considerate to delineate therapeutic approaches for patients with migraine.
Keywords: photosensitivity, headache, posture
Funding acknowledgements: CAPES Foundation and FAPESP Foundation (2015/18031)
Topic: Neurology; Pain & pain management; Disability & rehabilitation
Ethics approval required: Yes
Institution: Ribeirão Preto Medical School
Ethics committee: Ethics Committee of the Clinics Hospital FMRP/USP
Ethics number: protocol number 15269/2016
All authors, affiliations and abstracts have been published as submitted.
