PMC4533496_01
Preoperative Gd-enhanced MR images: coronal (A), sagittal (B), and visual fields:
left (C), right (D) postoperative Gd-enhanced MR images: coronal (E), sagittal
(F), and visual fields: left (G), right (H). The tumor was removed subtotally, but
visual field demonstrated complete bitemporal hemoanopsia postoperatively. Gd:
gadolinium, MR: magnetic resonance.
nmc-54-606-g1.jpg
PMC4533496_01_nmc-54-606-g1.jpg
F1
This 32-year-old woman with a repeated recurrence of nonfunctioning pituitary adenoma presented with a gradual deterioration of visual acuities in both eyes and bitemporal hemianopsia (Fig. 1). Although the tumor was resected sub totally, postoperative examination of visual functions revealed complete bitemporal hemianopsia (Fig. 1).
Intraoperative VEP findings at the beginning of surgery as control (A), at the
stage of tumor removal (B), and at the end of surgery (C). Negatively is shown as
an upward deflection. The VEP amplitude was defined as the voltage difference from
P100 to N75. During tumor removal, the VEP amplitude decreased and did not recover
to the control level. Bil: bilateral, Lt: left, Rt: right, VEP: visual evoked
potential.
nmc-54-606-g2.jpg
PMC4533496_01_nmc-54-606-g2.jpg
F2
At the final stage of the TSS when we pulled out the final piece of tumor, bilateral stimulating VEP amplitudes (N75 to P100) on both sides were decreased to below 50% of the control level (Fig. 2).
PMC4533496_02
Preoperative Gd-enhanced MR images: coronal (A), sagittal (B), and visual fields:
left (C), right (D) postoperative Gd-enhanced MR images: coronal (E), sagittal
(F), and visual fields: left (G), right (H). Although, residual tumor was observed
under chiasm, visual field recovered postoperativeply. Gd: gadolinium, MR:
magnetic resonance.
nmc-54-606-g3.jpg
PMC4533496_02_nmc-54-606-g3.jpg
F3
This 71-year old man with a nonfunctioning pituitary adenoma presented with loss of visual acuity on both eyes [right vision (RV) = (0.6), left vision (LV) = (0.6)] and bitemporal hemianopsia (Fig. 3).
Intraoperative VEP findings at the beginning of surgery as control and the end of
surgery (A) and the stage of tumor removal (B). Negatively is shown as an upward
deflection. The VEP amplitude was defined as the voltage difference from P100 to
N75. During tumor removal, the VEP amplitude decreased transiently (B:
arrow) and recovered to the control level during suspended
surgical manipulation for 5 min. VEP: visual evoked potential.
nmc-54-606-g4.jpg
PMC4533496_02_nmc-54-606-g4.jpg
F4
TSS when a relatively fibrous and firm tumor was curetted, bilateral stimulating VEP amplitudes on both sides were decreased to below 50% of the control level (Fig. 4). The surgical manipulation was stopped, and the VEP waveforms on both sides recovered to the control level in 5 min. Although the tumor resection was incomplete, a postoperative examination revealed improvements in the visual acuities on both eyes [RV = (1.0), LV = (1.0)] and a recovery of the visual field defects (Fig. 4).