Functional imaging is a newly arisen interdisciplinary subject compared with the routine radiology displaying anatomy and morphology of lesions.It can exhibit the functionchanged information, such as blood flow and metabolism of organs and tissues as visual images or data to provide organizational functions and metabolic information, which makes early diagnosis, more accurate orientation, qualitative definition,and also the prognosis judgment.The ophthalmologists should pay more attention to the functional imaging applications in the field of neuro-ophthalmology.
Objective To observe the results of function MRI and perimetry in patients with visual pathway diseases.Methods Three patients (6 eyes) with pituitary adenoma and craniopharyngioma diagnosed via pathological examination and three healthy volunteers aged from 24 to 30 were collected. The best corrected visual acuity was nonlight perception1.0 in the 6 sick eyes and 1.0 in the healthy eyes; all the involved individuals had no other ocular diseases except myopia and without any contraindications of MRI. Common tests including the best visual acuity, fundus test by direct or indirect ophthalmoscope, center static visual field tested by Octopus 101 perimeter, program 32, tendency oriented perimetry were performed. The visual stimulation subtended a field of view of about 12 degrees，consisted of high contrast and drifting checkerboards. MRI parameters: GE signa VH/i 30T scanner. Functional data: GRE-EPI sequence，20 slices lying perpendicular to the calcarine sulcus. Anatomical data was obtained using 3DSPGR sequence to acquire high resolution. The cortical surface was unfolded and then cut and inflated. Functional data was presented to the inflated surface and subsequently analyzed by AFNI software.Results In six eyes, three had temporal defects, two had upper temporal visual field defects, and the other one did not finish the visual field test. The retinotopic representations of health adults were obtained by using the phaseencoded visual stimulation. The Eccentricity coordinate maps showed that foveal representations lay in the occipital poles and the representations appeared further anterior as eccentricity increased. The polar angle coordinate maps showed that early retinotopically organized areas had a representation of visual field. The visual cortex beneath the calcarine sulcus matched with the upper visual field of the opposite side and which upon the calcarine sulcus matched with the under visual field of the opposite side. Less or no visual cortex response was revealed in the patients′ function MRI or the response in injury side was vanished. The visual cortex response related with the visual field defects could not be induced in function MRI.Conclusion There is a good correlation between function MRI data and the results of perimetric evaluation. The function MRI can show the visual cortex response correlated with the visual field defects of the patients with visual pathway diseases.
Objective To investigate the neuropathogenesis of Adieprime;s pupil. Methods The neuroelectrophysiological and neuroimaging data of 42 patients with Adie's pupil (lightnear dissociation and segmental palsy of iris sphincter) were retrospectively analyzed. There were 37 patients with unilateral pupil dilation and 5 patients with bilateral pupil dilation. Cranial magnetic resonance imaging (MRI, 23 patients), Cranial CT scanning (1 patient), nerve conduction velocity (NCV, 14 patients), limb electromyogram (EMG, 5 patients), both lower extremities EMG (9 patients), visual evoked potential (VEP, 18 patients), somatosensory evoked potential (SEP, 11 patients) and electroencephalograms (EEG,5 patients) were performed on some of those patients. Results Central nervous system midline anatomic variations or minor lesions were found in 13/23 cases of MRI/CT imaging. Slowed sensory NCV and multiple sensorymotor peripheral nerve damages were evident in 6/14 cases of the NCV/EMG assay. 5/18 patients showed prolonged latency of VEP P100. 2/11 cases showed peripheral nerve damage in SEP recording, and 1/5 cases showed abnormal EEG. Conclusion Peripheral nerve damage may be an important pathogenesis of Adie's pupil, while the central nervous system damage is also involved in its pathogenesis.