PREDICTING VISUAL FIELD DEFECTS FOLLOWING SELECTIVE TRANSSYLVIAN AMYGDALOHIPPOCAMPECTOMY. Issue 11 (14th October 2015)

• Record Type: Journal Article
• Authors: Fuller, S; Hamandi, K; Jones, D K; Gray, W P
• Is Part Of: Journal of neurology, neurosurgery and psychiatry. Volume 86:Issue 11(2015)
• Page Start: e4
• Page End: e4
• Publication Date: 2015-10-14
• Subjects: Neurology -- Periodicals; Nervous system -- Surgery -- Periodicals; Psychiatry -- Periodicals; 616.8
• DOI: 10.1136/jnnp-2015-312379.57
• Languages: English
• ISSNs: 0022-3050

Abstract

Abstract : Introduction: Surgery for refractory temporal lobe epilepsy can cause postoperative visual field defects (VFD). This study aimed to predict personalised risk of VFDs for patients undergoing selective transsylvian amygdalohippocampectomy. Methods: Preoperative reconstruction of the optic radiations (OR) using diffusion tensor-based tractography was completed on two patients. The 'average resection model' uses a template from postoperative structural scans of five patient scans to predict an average resection in the patient. The OR tractography was compared with the resection margins to determine fibre involvement. The 'multiple individual comparison model' compared individual postoperative scans with the preoperative tractography to determine risk of VFD. Results: In Patient 1 the average resection overlapped the OR, so an average resection would be expected to produce a VFD. In 3/5 postoperative scans the resection intersected with the OR, indicating that 60% of prior resections would have caused a defect. In Patient 2 no overlap between resection and OR was found in either model. Perimetry confirmed VFD in patient 1 but not in patient 2. Discussion: This pilot study demonstrates that the risk of postoperative VFDs can be predicted. The two models provide qualitatively different form of quantitative risk which could inform the discussion between patient and clinician.