When we last left Ruth in Part 4 she had begun vision therapy for the reading difficulty she acquired due to damage in the left occipitotemporal region of her brain. This had resulted in alexia sine agraphia, or hemianiopic dyslexia – a frequent and disabling functional impairment following brain injury. As we noted in Part 2, disruption of the paraventricular white matter and the outflow of the corpus callosum impedes the visual information from accessing the angular gyrus in the language area.
I pulled the picture above from a gorgeous website of neuro images. It is a diffusion spectrum MRI image of the human brain showing three dimensional grid structure of white matter tracts. This cerebral architecture naturally supports functional spatio-temporal coherence, and incremental rewiring with correlated adaptation of structure and function in cerebral plasticity. In other words, the more we can restore Ruth’s functional abilities through therapy, the better her neurons that fire together will re-wire together.
Ruth has these intertwined problems: alexia due in part to an inability to identify letters; right homonymous hemianopia resulting in a reading scanpath into her blind field; and convergence insufficiency. Our therapy approach has been in accordance with Schuett, who suggests that compensatory therapies to reorganize eye-movement control are superior to therapies aimed toward visual field restitution or restoration. Our treatment protocol involved systematic and repetitive practice of specific eye movements for reading.
Here is a video of Ruth attempting the Test of Silent Word Reading Fluency (TOSWRF). No spaces appear between the words (e.g., dimhowfigblue), and Ruth is asked to draw a line between the boundaries of as many words as possible (e.g., dim/how/fig/blue). She comments that she can’t do it because she can’t say the name of the letters, even though she knows what the letters are.
As Ruth began to re-acquire letter recognition (see Part 4) we were able to move toward higher level activities that promote reading, such as Michigan Letter and Word Tracking Workbooks, and using the TOSWRF as a training tool. After spending considerable time the first month working on pencil and paper activities, we wanted to incorporate more elements of spatial vision into Ruth’s rehabilitation. The Sanet Vision Integrator (SVI) was a helpful program, particularly in developing saccades, the eye movement function that is the platform for reading.