Avoidance and Improvement in Visual Field Defect After Surgery for Metastatic Brain Tumors in the Parietal and the Occipital Lobe

• Published in: World neurosurgery Vol. 155; pp. e847 - e857
• Main Authors: Tanaka, Toshihide, Takei, Jun, Teshigawara, Akihiko, Yamamoto, Yohei, Akasaki, Yasuharu, Hasegawa, Yuzuru, Murayama, Yuichi
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-11-2021
• Subjects: Adult; Aged; Aged, 80 and over; Brain Neoplasms - complications; Brain Neoplasms - diagnostic imaging; Brain Neoplasms - surgery; Female; Hemianopsia; Hemianopsia - diagnostic imaging; Hemianopsia - etiology; Hemianopsia - surgery; Humans; Male; Metastatic brain tumor; Middle Aged; Neurosurgical Procedures - methods; Occipital Lobe - diagnostic imaging; Occipital Lobe - surgery; Optic radiation; Parietal Lobe - diagnostic imaging; Parietal Lobe - surgery; Parieto-occipital junction; Surgery; Treatment Outcome; Visual Field Tests - methods; Visual Fields - physiology; Optic radiation; OR; Metastatic brain tumor; MRI; Surgery; CI; MMSE; Hemianopsia; Parieto-occipital junction; DTI
• ISSN: 1878-8750; 1878-8769
• DOI: 10.1016/j.wneu.2021.09.029

Visual field defects occasionally occur secondary to tumors in the parietal and the occipital lobes. The aim of this study was to analyze the efficacy of improvement in hemianopsia after surgery for metastatic brain tumors involving or adjacent to the optic radiation (OR).
The study included 49 patients with brain metastasis in the parietal and occipital lobes in the present study. Preoperative and postoperative neurological assessments included visual field, Mini-Mental State Examination, and Karnofsky performance scale.
Of 49 patients, 33 (67.3%) presented with preoperative homonymous hemianopsia. Of these 33 patients, the visual field was improved postoperatively in 17 patients (51.5%). In all patients regardless of preoperative hemianopsia, postoperative visual fields did not deteriorate. Tractography demonstrated that the OR was split by the tumor (n = 6) and fanning of fibers expanded along the lateral side of the tumor (n = 11). All tumors were removed via surgical access toward the medial side of the tumor. Gross total resection was achieved in most tumors in the group with visual improvement (n = 16/17; 94.1%). Improvement in the visual field was attributed to tumor location in the subcortical white matter, removal rate of the tumor, and higher postoperative Karnofsky performance scale score.
The OR tended to deviate to the lateral side of the tumor in the parieto-occipital junction. The postoperative visual field improved even in cases of an occipital tumor. Based on the present study, total resection via an appropriate surgical route should be considered to preserve the OR, leading to improvement in the postoperative visual field.