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.

Sinusoidal Transcranial Direct Current Versus Galvanic Vestibular Stimulation for Treatment of Lateropulsion Poststroke.

OBJECTIVE: To compare the effects of Transcranial Direct Current Stimulation (tDCS) versus Galvanic Vestibular Stimulation (GVS) on Lateropulsion following stroke. METHODS: Patients with Stroke and Burke Lateropulsion Scale (BLS) scores greater than or equal to 2 gave informed consent to receive sinusoidal 1 Hz DC (0-2 mA) anodal stimulation over the affected parietal cortex versus similar GVS with ipsilesional mastoidal anode. Seated haptic center of pressure (COP-X) was measured using an AMTI analog-to-digital forceplate. An inclinometer (Biopac ) measured lateral thoracic tilt. COP-X Power Spectra were analyzed over 3 frequency intervals: 0-.3 Hz, .3-1 Hz, and 1-3 Hz. RESULTS: Six males/4 females age 66 ± 9.5 standard deviation with admission BLS scores of 5.4 ± 3.7 within 8.6 ± 8.1 days poststroke were enrolled. COP-X medial-lateral speed increased for both the tDCS and the GVS protocols compared to sham condition. Fourier Analysis of COP-X velocity for 0-.3 Hz responses showed a significant increase for tDCS stimulation. The .3-1 Hz responses for the tDCS condition were decreased from baseline. Lateral thoracic tilt showed significant improvement for tDCS compared to Sham stimulation at 10 minutes and for GVS versus Sham at 15 minutes. DISCUSSION: Anodal tDCS over the ipsilesional PIVC increases low frequency postural responses usually attributed to visual control with down regulation of median frequency vestibular responses, biasing postural control toward more dependence on visual as opposed to vestibular control. CONCLUSIONS: 2 mA sinusoidal 1 Hz anodal tDCS over the ipsi-lesional PIVC or similar ipsi-lesional anodal GVS improve Lateropulsion following stroke.

Knee Kinetics and Kinematics of Young Asymptomatic Participants during Single-Leg Weight-Bearing Tasks: Task and Sex Comparison of a Cross-Sectional Study.

This cross-sectional study aimed to describe and compare kinetic and kinematic variables of the knee joint during stair descent, single-leg step down, and single-leg squat tasks. It also aimed to investigate potential sex difference during the tasks. Thirty young asymptomatic individuals (15 males, 15 females) were assessed during the performance of single-leg weight-bearing tasks. The kinetic and kinematic data from the knee were evaluated at the peak knee moment and at peak knee flexion. Single-leg squat presented a higher peak knee moment (2.37 Nm/kg) and the greatest knee moment (1.91 Nm/kg) at knee peak angle in the frontal plane, but the lowest knee flexion (67°) than the other two tasks (p < 0.05). Additionally, the single-leg step down task presented a higher varus knee angle (5.70°) when compared to stair descent (3.71°) (p < 0.001). No substantial sex difference could be observed. In conclusion, in asymptomatic young individuals, single-leg squats presented the greatest demand in the frontal and sagittal planes. Single-leg step down demanded a greater angular displacement than stair descent in the frontal plane. We did not identify a significant difference among the sex and studied variables.

Neck Active Movements Assessment in Women with Episodic and Chronic Migraine.

We aimed to compare movement parameters and muscle activity during active cervical spine movements between women with episodic or chronic migraine and asymptomatic control. We also assessed the correlations between cervical movement measures with neck-related disability and kinesiophobia. Women with episodic (n = 27; EM) or chronic (n = 27; CM) migraine and headache-free controls (n = 27; CG) performed active cervical movements. Cervical range of motion, angular velocity, and percentage of muscular activation were calculated in a blinded fashion. Compared to CG, the EM and CM groups presented a reduced total range of motion (p < 0.05). Reduced mean angular velocity of cervical movement was also observed in both EM and CM compared to CG (p < 0.05). Total cervical range of motion and mean angular velocity showed weak correlations with disability (r = -0.25 and -0.30, respectively; p < 0.05) and weak-to-moderate correlations with kinesiophobia (r = -0.30 and -0.40, respectively; p < 0.05). No significant correlation was observed between headache features and total cervical range of motion or mean angular velocity (p > 0.05). No differences in the percentage of activation of both flexors and extensors cervical muscles during active neck movements were seen (p > 0.05). In conclusion, episodic and chronic migraines were associated with less mobility and less velocity of neck movements, without differences within muscle activity. Neck disability and kinesiophobia are negative and weakly associated with cervical movement.

Comparison of cervical muscle isometric force between migraine subgroups or migraine-associated neck pain: a controlled study.

This study aimed to verify if migraine frequency or migraine-associated neck pain were associated with a reduction of normalized force and altered electromyographic activity during maximal cervical muscle isometric contractions. Additionally, it aimed to assess the correlation of normalized isometric force with years with migraine, headache frequency, headache intensity, migraine-related disability, and severity of cutaneous allodynia. The sample comprises 71 women with migraine (40/31 episodic/chronic, 42/18 with/without neck pain) and 32 women without headache. Cervical muscle isometric force in flexion, extension, and lateral flexion was assessed synchronized with the acquisition of superficial electromyography from the cervical muscles. Women with episodic migraine presented lower normalized isometric force in extension, flexion, and right and left lateral flexions than controls (P < 0.05). Women with migraine and neck pain exhibited lower cervical extension and right/left lateral-flexions normalized isometric force than controls (P < 0.05). No significant differences were observed in antagonist activity. Normalized isometric force in all directions showed weak to moderate correlations with the severity of self-reported symptoms of cutaneous allodynia (- 0.25 ≥ r ≥ - 0.39). No additional linear correlation with clinical migraine features was observed. In conclusion, cervical muscle weakness may be associated with episodic migraine and neck pain concurrent with migraine attacks without altered antagonist activity. Additionally, it may also be related to the severity of cutaneous allodynia.

Muscle endurance and cervical electromyographic activity during submaximal efforts in women with and without migraine.

BACKGROUND: Despite previous reports supporting cervical muscle weakness and altered motor control in migraine, the endurance under standardized submaximal loads has not been investigated. Therefore, this study aimed to assess the endurance and muscle activity of the cervical musculature during submaximal isometric contractions in women with migraine and those without headache. METHODS: Cervical muscle endurance tests were performed for flexors and extensors at 25%, 50%, and 75% of the output force during maximal isometric contraction using the Multi-Cervical Rehabilitation Unit with customized biofeedback. Initial values and relative rates of changes in root mean square and median frequency were calculated using cervical muscle superficial electromyography. FINDINGS: Women with chronic migraine presented significantly shorter flexor endurance time in all load tests than controls (25%, P = .001, 50%, P = .005; 75%, P = .013), while episodic migraine only differed from controls at 75% (P = .018). The frequency of neck pain and/or pain referred to the head after the endurance test was up 12% in the control group, 40% in the episodic migraine group and 68% of the chronic migraine group. Few differences between groups were observed in the electromyographic variables and none of them was related to a worse performance in the endurance tests. INTERPRETATION: Cervical flexor endurance was reduced in women with chronic migraine when independent of the load, whereas it was reduced to 75% of the maximal force in those with episodic migraine. No difference in the electromyographic variables could be related to this reduced flexor endurance. Also, no differences were detected in extensors endurance.