The Influence of Photophobia on Postural Control in Patients With Migraine

Background: People with migraine exhibit postural control impairments. These patients also have an increased light sensitivity due to the disease, and it remains during the headache-free period. It is currently unknown if increased lighting levels can alter the balance control, especially in individuals with visual hypersensitivity, such as migraineurs. This study aimed to assess the balance and photophobia of women with migraine and non-headache controls under different light conditions.

Methods: This cross-sectional study consisted of 14 women with migraine (mean ± SD 30.6 ± 8.1 years old) and 14 women without any kind of headache (mean ± SD 27.2 ± 2.8 years old) screened from a tertiary headache clinical hospital and the local community. Quiet standing balance was evaluated during bipodal and unipodal support, under 3 light conditions: ambient (AMB) - 270 lx, visual discomfort threshold (VDT) - 400 lx, and intense visual discomfort (IVD) - 2000 lx. Sway area of the center of pressure was processed and compared between groups. The association of migraine with the risk of presenting a greater imbalance in the discomfort lighting conditions was verified.

Results: Compared to the non-headache controls, the migraine group presented greater sway area in bipodal stance under the 3 light conditions (mean difference (95% CI)): AMB 0.81 cm² (0.19 to 1.43), P = .011; VDT 3.17 cm² (0.74 to 5.60), P = .001; IVD 5.56 cm² (2.75 to 8.37), P < .0001. Within-subject analysis showed increased sway area in bipodal stance among all lighting conditions for the migraine group only (mean difference (95% CI)): VDT-AMB 2.20 cm² (0.23 to 4.18), P = .024; IVD-AMB 4.50 cm² (2.38 to 6.62), P < .0001, IVD-VDT 2.29 cm² (0.57 to 4.01), P = .005. The Prevalence Ratio (PR) analysis showed that migraine was associated with the risk of presenting greater imbalance in both bipodal and unipodal standing conditions for both VDT (PR value (95% CI) - bipodal: PR = 4.00 (1.02 to 15.59), P = .045; unipodal: PR = 4.00 (1.43 to 11.15), P = .008), and the IVD (bipodal: PR = 3.33 (1.13 to 9.58), P = .025; unipodal: PR = 5.50 (1.48 to 20.42), P = .010) lighting conditions.

Conclusion: Photophobia might be a disturbing factor that worsens the balance of patients with migraine during the quiet standing posture.