Effect of Extended-Release Steroid Implants on the Contralateral Eye

Purpose To investigate the contralateral effect of extended release steroid implants on cystoid macular edema (CME). Methods Retrospective study of patients with bilateral CME receiving intravitreal injections of long-acting intravitreal corticosteroid implants. Changes in CME and central subfield thickness (CST) in the contralateral eye on optical coherence tomography (OCT) were compared to an untreated control group. Results Thirteen study patients and 14 controls were included in the study. In the treatment group CST remained stable in all of the patients. Of the controls, CST worsened in 21.4% and remained stable in 78.6%. The mean CST (6.3 ± 30.3 vs. 27.5 ± 66.1 µm, p = 0.2) and the mean macular volume (0.08 ± 0.34 vs. -0.05 ± 0.21 mm3, P = 0.8) were not statistically different between the treatment group and control group. Conclusion In this study there was no statistically significant effect on CME of contralateral intravitreal corticosteroid implants.

Mode of use by mobile phone and change of time of simple audio-motor reaction for users of mobile communication. Age related features of ipsilateral and contralateral effects

By analysing the time of a simple auditory-motor reaction with mono-presentation of an audio signal, the effect of the electromagnetic radiation of a mobile phone on the human auditory system is evaluated. Regularities in the frequency of occurrence of ipsi and contralateral effects in mobile users of different age groups are obtained. This study has no analogues in either Russian or foreign publications and is currently exclusive. The purpose was to study age-related features of the severity of ipsi and contralateral effects, depending on the mode of use of the mobile phone. To record the ipsi- and contralateral effects, we used the differences in the average values of a simple auditory-motor reaction between the left and right ears with mono-presentation of the sound signal of 573 respondents of different age groups. The obtained values were compared with the control group data for each age group (491 respondents). If the difference was greater than in the control group, the ipsilateral or contralateral effect was recorded. The severity of the effect was evaluated taking into account the lateral preferences of each participant in the experiments (to which ear the mobile phone is most often held) and the mode of use of the mobile phone. Statistical processing of the results was carried out using the non-parametric Mann-Whitney test and the method of descriptive statistics: prevalence indicator (Pr) (relative frequency of manifestation of a particular attribute in the sample). The comparison of the severity of ipsi and contralateral effects for different age groups allowed us to establish the following patterns. It was found that, in general, the manifestation of the contralateral effect decreases with age, and the ipsilateral effect increases. However, this change is not linear. It is shown that the features of the manifestation of the contralateral and ipsilateral effect for each age group depend both on the time of daily use of a mobile phone and on the total duration of use of a mobile phone. We believe that when studying multidimensional input data, an individual approach is necessary. The presented results confirm the negative effect of the radiation of mobile phones on the auditory system, primarily of our younger generation. Given the special vulnerability of children to physical environmental factors and the depth of penetration of EMR MT into the brain of a child, we believe that from a radiobiological point of view, there is already a need to develop a special SanPiN (sanitary rules and norms) for all available modern low-intensity sources of electromagnetic radiation, including Wi-Fi.

Contralateral effect of systemic absorption of low dose bevacizumab (Avastin) after unilateral intravitreal injection in severe retinopathy of prematurity (ROP)

An extremely premature baby boy born at 23 weeks’ gestational age was treated with unilateral low dose of 0.16 mg/0.025 mL intravitreal bevacizumab in the left eye for aggressive retinopathy of prematurity (ROP). He developed photographically documented changes in his contralateral right eye on imaging 5 days later. Second eye treatment was at 12 days. He has development assessment and ophthalmic review beyond age 2, which is normal. Systemic absorption of the drug caused an end organ effect to slow down and reverse ROP in his untreated right eye. Both eyes vascularised fully. His normal Bayley III developmental score at age 2 is uncommon for a 23-week gestation baby. Even at a low dose, bevacizumab has the potential for end organ effect on the second eye, and therefore other organs. In this case, there are no medium-term measurable neurodevelopmental side-effects. We suggest longer term follow-up is required before excluding unwanted side-effects.

Contralateral effects of unilateral strength training: evidence and possible mechanisms

If exercises are performed to increase muscle strength on one side of the body, voluntary strength can increase on the contralateral side. This effect, termed the contralateral strength training effect, is usually measured in homologous muscles. Although known for over a century, most studies have not been designed well enough to show a definitive transfer of strength that could not be explained by factors such as familiarity with the testing. However, an updated meta-analysis of 16 properly controlled studies (range 15–48 training sessions) shows that the size of the contralateral strength training effect is ∼8% of initial strength or about half the increase in strength of the trained side. This estimate is similar to results of a large, randomized controlled study of training for the elbow flexors (contralateral effect of 7% initial strength or one-quarter of the effect on the trained side). This is likely to reflect increased motoneuron output rather than muscular adaptations, although most methods are insufficiently sensitive to detect small muscle contributions. Two classes of central mechanism are identified. One involves a “spillover” to the control system for the contralateral limb, and the other involves adaptations in the control system for the trained limb that can be accessed by the untrained limb. Cortical, subcortical and spinal levels are all likely to be involved in the “transfer,” and none can be excluded with current data. Although the size of the effect is small and may not be clinically significant, study of the phenomenon provides insight into neural mechanisms associated with exercise and training.

Long-term motor effect of unilateral pallidal stimulation in 26 patients with advanced Parkinson disease

Object. The aim of this study was to evaluate the long-term effects of unilateral pallidal stimulation on motor function in selected patients with advanced Parkinson disease (PD). Methods. The authors enrolled 26 patients with idiopathic PD in whom there was an asymmetric distribution of symptoms and, despite optimal pharmocological treatment, severe response fluctuations and/or dyskinesias. After the patient had received a local anesthetic agent, a quadripolar electrode (Medtronic model 3387) was implanted at the side opposite the side affected or, if both sides were affected, the side contralateral to the more affected side. No serious complications occurred. After 3 months, the total Unified PD Rating Scale (UPDRS) Part III score decreased by 50.7% while patients were in the off-medication state (from 26.5 ± 9.2 to 13.1 ± 6.1) and by 55.4% while they were in the on-medication state (from 10.6 ± 6.3 to 4.7 ± 4.4). Only during the on state was the contralateral effect clearly more pronounced. The UPDRS Part IVa score decreased by 75% (from 3.7 ± 2.5 to 0.9 ± 1.1) and the UPDRS Part IVb score by 54.7% (from 3.3 ± 1.3 to 1.5 ± 1.3). At long-term follow-up review (32.7 ± 10.7 months), there was an 8.3% increase in the UPDRS Part III score while patients were in the off state (from 26.5 ± 9.2 to 28.7 ± 7.6) and a 40.2% increase in this score while patients were in the on state (from 10.6 ± 6.3 to 14.9 ± 5.1). The UPDRS Part IVa score decreased by 28.1% (from 3.7 ± 2.5 to 2.7 ± 2.3) and the UPDRS Part IVb score increased by 3.5% (from 3.3 ± 1.3 to 3.4 ± 1.6). Conclusions. Based on these unsatisfactory results at long-term review, the authors conclude that unilateral pallidal stimulation is not an effective treatment option for patients with advanced PD.