Аннотация:The cerebellum takes part in all classes of eye movements and gaze fixation. It is known that cerebellar lesions of diff erent genesis cause range of oculomotor and
related cognitive disorders. Medulloblastoma spreads to vermis including regions which are mostly involved in the control of saccades but also contributes to smooth pursuit and
vergence (dorsal vermis, ansiform lobe, fastigal nucleus).
Nowadays eye movements are mainly recorded by eye tracking systems which are non-invasive and provide wide range of oculomotor parameters available to explore. We have
extended and adapted a number of paradigms which are applicable for investigation into oculomotor and cognitive functions.
Three patients with medulloblastoma participated in our pilot study (1 male, 2 female; median age 14.5 years, range 13–17). All of them had a lesion of
the cerebellar vermis, 2 tumors spread to the 4th ventricle, 1 – to the hemispheres of the cerebellum. Each of the patients had his own stage of medulloblastoma (1 – M0, 1 – M1,
1 – M2). All of them underwent surgery (2 patients had total resection, 1 – subtotal) and received RT and/or CHT by protocol HIT.
The study consisted of two experimental sessions which were performed twice (at their first and second visiting to rehabilitation center) to reveal the dynamic of oculomotor and
cognitive condition. Eye movements were recorded by Arringtion 30/60 Hz.
We applied six different tests which included qualitative and quantitative criteria: gaze control test, gaze-evoked saccade test, “10 dots”, “fence”, “antisaccades”, “go/no-go”.
Results. Tests “antisaccades” and “go/no-go” didn’t reveal significant differences between sessions probably because of low number of data. Gaze control test revealed the significant increase in gaze stability control in all patients in the second session compared with the first because of the decrease in the number of intrusive saccades. One patient showed
significantly increased accuracy of saccades in gaze-evoked saccades test. Test on strategy of scanning and working memory (“10 dots”) improvement of parameters such as search
time and number of fixations in two patients. Finally, one patient executed visual rhythm saccade test (“fence”) rightly only in the second session.
We applied a range of qualitative and quantitative paradigm and revealed the improvement of oculomotor and cognitive functions after a period of a rehabilitation
which could characterize the condition of visual pathways and attention. We plan to increase the number of patients in our study to verify the succeed application of diagnostic tests in clinical practice. Primary results suggest further findings to design correctional paradigms for training impaired functions based on biofeedback.