| Objective Study the abnormal activation of visual cortex of glaucoma with fMRI monocular stimulation, and the corelation with the visual field defect. Study the white fiber bundle of bilateral optic radiation with DTI. Combination fMRI and DTI to explore the neuropathologic mechanism ,and to explore the corelation between the functional area of cortex and the change of character of the structure.Materials and Methods 16 glaucoma patient with left eye stimulation , 16 glaucoma patient with right eye stimulation and 16 normal subjects received fMRI and DTI. The fMRI stimulation content was block design of full screen black checker. B falue of DTI was 1000 s/mm~2, and diffusion direction wasl3. Preprocessing, statistical analysis and result display of functional data were performed using SPM2. Statistical analyses included:①Group effects analysis of cortex activation area was performed in the glaucoma patient and normal subjects with monocular stimulation;②Paired t-tests of cortex activation area was performed in the normal controls with left eye stimulation, right eye stimulation and binocular stimulation respectively;③Two-sample t-tests were used to perform inter-group contrast between the glaucoma and normal controls. Two-sample t-tests was used to evaluate the difference of the FA value between the glaucoma and normal controls.Results①First, The most obvious activation area was primary visual cortex included upper lip and lower lip of calacarine fissure (BA 17) in the normal controls with monocular and binocular stimulation. Second the BA 18,19 area was activated include cuneus, lingual gyrus, middle gyrus of occipital lobe, fusiform gyrus and inferior temporal gyrus et al. Furthermore the bilateral lateral geniculate body was activated with binocular stimulation.②The dominant cerebral hemisphere of visual cortex activation was the right side in the normal controls with monocular and binocular stimulation.③No obvious difference of the visual cortex activation was found between left and right eye stimulation, and between binocular eye and left stimulation; The activated extent and intensity was obviously increased in the left visual cortex with binocular stimulation than right eye stimulation.④The spatial extent and intensity of the visual cortex activation was obviously decreased in glaucoma than in normal controls with left and right stimulation respectively, main in the visual cortex of the right visual cortex.⑤There was obvious decrease of the visual cortex activation in the glaucoma in intermediate and advanced stage, the main activation area located in the Contralateral visual cortex.⑥The FA value in the bilateral optic radiation was obviously decreased in the glaucoma than in the normal controls.Conclusion①There was asymmetric activation patterns in the visual cortex of normal humans who have undergone functional MRI with monocular and binocular stimulation. The right hemisphere is activated more strongly and to a greater spatial extent than the left hemisphere.②The spatial extent and intensity of the visual cortex activation was obviously decreased in glaucoma than in normal controls, and to some extent it reflect the topological relationship between the retina and primary visual cortex.③The bilateral optic radiation was damaged in glaucoma.④The glaucoma was entire visual pathway lesion which can help understand the neuropathological mechanism and evaluate the prognosis.⑤The integrity of the white matter fiber bundle can influence the function of projected cortex., and the function of the visual cortex was closely related to the integrity of the visual pathway. Objective The combination of fMRI and DTI was to explore the corelation between the abnormality of visual cortex activation and the change of character of the bilateral optic radiation in patient with pituitary tumor.Materials and Methods 12 pituitary tumor patient with left and right eye stimulation respectively, and 12 normal subjects received fMRI and DTI. The fMRI stimulation content was full screen checker. The other 6 normal humans and 4 pituitary tumor patient also received the fMRI with unilateral 40°screen checker stimulation. B falue of DTI was 1000 s/mm~2, and diffusion direction was13. Preprocessing, statistical analysis and result display of functional data were performed using SPM2. Statistical analyses included:①group effects analysis of visual cortex activation was performed in the pituitary tumor patient with monocular stimulation; Two-sample t-tests were used to perform inter-group contrast between the patient and normal controls. Two-sample t-tests was used to evaluate the difference of the FA value between the pituitary tumor patient and normal controls.Results①When given nosal 40°screen checker stimulation in normal humans, only ipsilateral visual cortex activation was seen, but no Contralateral cortex activation. When given temporal 40°screen checker in normal humans, only Contralateral visual cortex activation was seen, but no ipsilateral cortex activation.②The spatial extent and intensity of the visual cortex activation was obviously decreased in pituitary tumor patient with temporal visual field defect than in normal controls with monocular stimulation respectively, the main decreased activation area in the Contralateral visual cortex.③When given nosal 40°screen checker in patient with typical temporal hemianopsia, the ipsilateral visual cortex activation was seen, but no/little the Contralateral cortex activation; When given temporal 40°screen checker, neither ipsilateral nor Contralateral cortex activation was seen.④The FA value in the bilateral optic radiation was obviously decreased in the pituitary tumor patient than in the normal controls.Conclusion①The spatial extent and intensity of the visual cortex activation was obviously decreased in pituitary tumor patient than in normal controls, the main decreased activation area in the Contralateral visual cortex. fMRI reflect the structure of visual chiasm well and the topological relationship between the retina and primary visual cortex..②The bilateral optic radiation was damaged in pituitary tumor.③When the anterior visual pathway was damaged in the pituitary tumor patient, the posterior visual pathway included optic radiation and visual cortex may be secondary damage which can help understand the neuropathological mechanism and evaluate the prognosis.⑤Combination of fMRI and DTI in the patient with anterior visual pathway can confirm the correlation between the structure and cortex function. The normal activation in visual cortex need either the normal action of the neuron or the entire pathway of information importation. |
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