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Functional and structural brain modifications induced by oculomotor training in patients with age-related macular degeneration.

Rosengarth K, Keck I, Brandl-Rühle S, Frolo J, Hufendiek K, Greenlee MW, Plank T - Front Psychol (2013)

Bottom Line: Despite substantial variability in the training effects, on average, AMD patients benefited from the training measurements as indexed by significant improvements in their fixation stability, visual acuity, and reading speed.We also found a significant increase in gray and white matter in the posterior cerebellum after training in the patient group.Our results show that functional and structural brain changes can be associated, at least on the short-term, with benefits of oculomotor and/or reading training in patients with central scotomata resulting from AMD.

View Article: PubMed Central - PubMed

Affiliation: Institute for Experimental Psychology, University of Regensburg Regensburg, Germany.

ABSTRACT
Patients with age-related macular degeneration (AMD) are reliant on their peripheral visual field. Oculomotor training can help them to find the best area on intact peripheral retina and to efficiently stabilize eccentric fixation. In this study, nine patients with AMD were trained over a period of 6 months using oculomotor training protocols to improve fixation stability. They were followed over an additional period of 6 months, where they completed an auditory memory training as a sham training. In this cross-over design five patients started with the sham training and four with the oculomotor training. Seven healthy age-matched subjects, who did not take part in any training procedure, served as controls. During the 6 months of training the AMD subjects and the control group took part in three functional and structural magnetic resonance imaging (MRI) sessions to assess training-related changes in the brain function and structure. The sham-training phase was accompanied by two more fMRI measurements, resulting in five MRI sessions at intervals of 3 months for all participants. Despite substantial variability in the training effects, on average, AMD patients benefited from the training measurements as indexed by significant improvements in their fixation stability, visual acuity, and reading speed. The patients showed a significant positive correlation between brain activation changes and improvements in fixation stability in the visual cortex during training. These correlations were less pronounced on the long-term after training had ceased. We also found a significant increase in gray and white matter in the posterior cerebellum after training in the patient group. Our results show that functional and structural brain changes can be associated, at least on the short-term, with benefits of oculomotor and/or reading training in patients with central scotomata resulting from AMD.

No MeSH data available.


Related in: MedlinePlus

Mean % signal changes (vs. baseline) in AMD patients and normally sighted controls before, during, and after fixation training in the individual primary (V1), secondary (V2), and tertiary (V3) visual cortex and in the anatomically predefined higher visual areas in the inferior temporal gyrus (ITG), the lateral occipital cortex (LOC), and the fusiform gyrus (as labeled in Freesurfer). The stimuli were either checkerboards (I) or meaningful pictures (II, III). For checkerboards % signal change is only reported for the individual primary cortices because no significant activation was found in higher visual areas for that kind of stimulus. The stimulus either appeared in the fovea, the PRL or the OppPRL. In the control subjects, sessions 1, 2, and 3 refer to the corresponding sessions of the individually matched AMD patients. Thus, if the corresponding AMD patient started with the oculomotor training, sessions 1, 2, and 3 refer to the first, second and third fMRI session for the matching control subject. If the corresponding AMD patient had the oculomotor training after the sham training, sessions 1, 2, and 3 in the figure refer to the third, fourth and fifth fMRI session for that control.
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Figure 7: Mean % signal changes (vs. baseline) in AMD patients and normally sighted controls before, during, and after fixation training in the individual primary (V1), secondary (V2), and tertiary (V3) visual cortex and in the anatomically predefined higher visual areas in the inferior temporal gyrus (ITG), the lateral occipital cortex (LOC), and the fusiform gyrus (as labeled in Freesurfer). The stimuli were either checkerboards (I) or meaningful pictures (II, III). For checkerboards % signal change is only reported for the individual primary cortices because no significant activation was found in higher visual areas for that kind of stimulus. The stimulus either appeared in the fovea, the PRL or the OppPRL. In the control subjects, sessions 1, 2, and 3 refer to the corresponding sessions of the individually matched AMD patients. Thus, if the corresponding AMD patient started with the oculomotor training, sessions 1, 2, and 3 refer to the first, second and third fMRI session for the matching control subject. If the corresponding AMD patient had the oculomotor training after the sham training, sessions 1, 2, and 3 in the figure refer to the third, fourth and fifth fMRI session for that control.

Mentions: In this analysis we were interested in the BOLD responses when the PRL and a comparably peripheral area in the opposite hemifield, the OppPRL, were directly stimulated. We compared activation in the respective projection zones of the PRL and the OppPRL in the visual cortex, namely visual areas V1, V2, and V3. We also compare these activations to those evoked by stimulation in the fovea (scotomatous region in patients). Accordingly, for the group of patients with the PRL in the lower visual field and their respective controls, we considered BOLD activation in the dorsal portions only, pooled over both hemispheres, as the PRL projection zone, and ventral portions only as the OppPRL projection zone, also pooled over hemispheres. For the patients with the PRL in the left visual field and their respective controls, we considered BOLD activation in the right hemisphere only as the PRL projection zone and BOLD activation in the left hemisphere only as the OppPRL projection zone, pooled over dorsal and ventral portions. For the patient with her PRL in the right visual field and her control, we considered BOLD activation in the left hemisphere only for the PRL projection zone and in the right hemisphere only for the OppPRL projection zone, again pooled over dorsal and ventral portions. We computed % signal change of the BOLD signal for each condition (stimulation with flickering checkerboards or pictures of everyday objects at the PRL or OppPRL) and session, each as the difference to baseline. Figure 7 shows the mean % signal change values as a difference to baseline for all conditions and the sessions “before,” “during” and “after training,” for the patient and control group, respectively. The data from one patient (AMD 7) was excluded from this analysis, because she showed strongly negative BOLD responses.


Functional and structural brain modifications induced by oculomotor training in patients with age-related macular degeneration.

Rosengarth K, Keck I, Brandl-Rühle S, Frolo J, Hufendiek K, Greenlee MW, Plank T - Front Psychol (2013)

Mean % signal changes (vs. baseline) in AMD patients and normally sighted controls before, during, and after fixation training in the individual primary (V1), secondary (V2), and tertiary (V3) visual cortex and in the anatomically predefined higher visual areas in the inferior temporal gyrus (ITG), the lateral occipital cortex (LOC), and the fusiform gyrus (as labeled in Freesurfer). The stimuli were either checkerboards (I) or meaningful pictures (II, III). For checkerboards % signal change is only reported for the individual primary cortices because no significant activation was found in higher visual areas for that kind of stimulus. The stimulus either appeared in the fovea, the PRL or the OppPRL. In the control subjects, sessions 1, 2, and 3 refer to the corresponding sessions of the individually matched AMD patients. Thus, if the corresponding AMD patient started with the oculomotor training, sessions 1, 2, and 3 refer to the first, second and third fMRI session for the matching control subject. If the corresponding AMD patient had the oculomotor training after the sham training, sessions 1, 2, and 3 in the figure refer to the third, fourth and fifth fMRI session for that control.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3713239&req=5

Figure 7: Mean % signal changes (vs. baseline) in AMD patients and normally sighted controls before, during, and after fixation training in the individual primary (V1), secondary (V2), and tertiary (V3) visual cortex and in the anatomically predefined higher visual areas in the inferior temporal gyrus (ITG), the lateral occipital cortex (LOC), and the fusiform gyrus (as labeled in Freesurfer). The stimuli were either checkerboards (I) or meaningful pictures (II, III). For checkerboards % signal change is only reported for the individual primary cortices because no significant activation was found in higher visual areas for that kind of stimulus. The stimulus either appeared in the fovea, the PRL or the OppPRL. In the control subjects, sessions 1, 2, and 3 refer to the corresponding sessions of the individually matched AMD patients. Thus, if the corresponding AMD patient started with the oculomotor training, sessions 1, 2, and 3 refer to the first, second and third fMRI session for the matching control subject. If the corresponding AMD patient had the oculomotor training after the sham training, sessions 1, 2, and 3 in the figure refer to the third, fourth and fifth fMRI session for that control.
Mentions: In this analysis we were interested in the BOLD responses when the PRL and a comparably peripheral area in the opposite hemifield, the OppPRL, were directly stimulated. We compared activation in the respective projection zones of the PRL and the OppPRL in the visual cortex, namely visual areas V1, V2, and V3. We also compare these activations to those evoked by stimulation in the fovea (scotomatous region in patients). Accordingly, for the group of patients with the PRL in the lower visual field and their respective controls, we considered BOLD activation in the dorsal portions only, pooled over both hemispheres, as the PRL projection zone, and ventral portions only as the OppPRL projection zone, also pooled over hemispheres. For the patients with the PRL in the left visual field and their respective controls, we considered BOLD activation in the right hemisphere only as the PRL projection zone and BOLD activation in the left hemisphere only as the OppPRL projection zone, pooled over dorsal and ventral portions. For the patient with her PRL in the right visual field and her control, we considered BOLD activation in the left hemisphere only for the PRL projection zone and in the right hemisphere only for the OppPRL projection zone, again pooled over dorsal and ventral portions. We computed % signal change of the BOLD signal for each condition (stimulation with flickering checkerboards or pictures of everyday objects at the PRL or OppPRL) and session, each as the difference to baseline. Figure 7 shows the mean % signal change values as a difference to baseline for all conditions and the sessions “before,” “during” and “after training,” for the patient and control group, respectively. The data from one patient (AMD 7) was excluded from this analysis, because she showed strongly negative BOLD responses.

Bottom Line: Despite substantial variability in the training effects, on average, AMD patients benefited from the training measurements as indexed by significant improvements in their fixation stability, visual acuity, and reading speed.We also found a significant increase in gray and white matter in the posterior cerebellum after training in the patient group.Our results show that functional and structural brain changes can be associated, at least on the short-term, with benefits of oculomotor and/or reading training in patients with central scotomata resulting from AMD.

View Article: PubMed Central - PubMed

Affiliation: Institute for Experimental Psychology, University of Regensburg Regensburg, Germany.

ABSTRACT
Patients with age-related macular degeneration (AMD) are reliant on their peripheral visual field. Oculomotor training can help them to find the best area on intact peripheral retina and to efficiently stabilize eccentric fixation. In this study, nine patients with AMD were trained over a period of 6 months using oculomotor training protocols to improve fixation stability. They were followed over an additional period of 6 months, where they completed an auditory memory training as a sham training. In this cross-over design five patients started with the sham training and four with the oculomotor training. Seven healthy age-matched subjects, who did not take part in any training procedure, served as controls. During the 6 months of training the AMD subjects and the control group took part in three functional and structural magnetic resonance imaging (MRI) sessions to assess training-related changes in the brain function and structure. The sham-training phase was accompanied by two more fMRI measurements, resulting in five MRI sessions at intervals of 3 months for all participants. Despite substantial variability in the training effects, on average, AMD patients benefited from the training measurements as indexed by significant improvements in their fixation stability, visual acuity, and reading speed. The patients showed a significant positive correlation between brain activation changes and improvements in fixation stability in the visual cortex during training. These correlations were less pronounced on the long-term after training had ceased. We also found a significant increase in gray and white matter in the posterior cerebellum after training in the patient group. Our results show that functional and structural brain changes can be associated, at least on the short-term, with benefits of oculomotor and/or reading training in patients with central scotomata resulting from AMD.

No MeSH data available.


Related in: MedlinePlus