Visual Function after Cerebral Hemispherectomy
Stacy L. Pineles; Monica F. Chen; Federico G. Velez; Gary W. Mathern
Introduction: Cerebral hemispherectomy is an effective surgical treatment for children with intractable seizures. However surgery may result in coping strategies to improve vision including changes in head position and eye alignment . Previous studies are limited by the number of patients and focus mainly on post-hemispherectomy homonymous hemianopia [1,2]. The purpose of this study was to determine and characterize visual function changes in a large population of patients following hemispherectomy.
Methods: Observational study was conducted on a cohort of children with seizure disorder treated with cerebral hemispherectomy. An online survey sent to the parents included demographic and clinical questions. Visual function was assessed by the presence of peripheral field defects, ocular misalignment and anomalous head posture.
Results: A total of 196 participants responded (12.5% of surveys emailed out). Postoperative follow up was 92+/-78 months (range 1-382). An acquired peripheral vision defect was reported in 181 patients (93%). Persistent torticollis was noted in 122 patients (62%). Strabismus was noted in 93 patients (49%). Both torticollis and strabismus were most frequently seen immediately after surgery. Sixty-six patients (34%) underwent strabismus treatment including monocular patching, extraocular muscle, chemodernevation, and surgery.
Discussion: Immediate torticollis and strabismus are common responses in patients following cerebral hemispherectomy. Persistent peripheral vision defect is the most common visual function abnormality observed in those patients.
Conclusion: Compensatory mechanisms to improve visual function are common in patients with seizure disorders undergoing cerebral hemispherectomy. Preoperative discussion with parents and patients regarding those compensatory mechanisms is recommended.
References: 1. Koenraads Y, Van Der Linden DCP, Van Schooneveld MMJ, et al. Visual function and compensatory mechanisms for hemianopia after hemispherectomy in children. Epilepsia 2014;55(6):909-917
2.Handley S, Vargha-Khadem F, Bowman R, and Alki Liasis. Visual function 20 years after Childhood Hemispherectomy for Intractable Epilepsy. AJO 2017:177(2) 81-89.