Eight-And-A-Half Syndrome Treated with Stem Cell Therapy: Are We There Yet? A Case Report.

Introduction: Eight-and-a-half syndrome is a rare neuro-ophthalmologic condition that is often caused by stroke and requires comprehensive ophthalmologic and neurologic management. Stem cell therapy has emerged as a novel and promising candidate approach for the treatment of stroke. This case highlights the potential of stem cell therapy in treating eight-and-a-half syndrome associated with ischemic stroke. Case Presentation: This report presents a 65-year-old male who has experienced double vision for 1 month before admission. Physical examination revealed slight esotropia, horizontal gaze palsy to the right side, incomplete adduction of the right eye, gaze-evoked nystagmus to the left side, and right-sided facial and limb weakness due to ischemic strokes. Visual field impairment was right inferior homonymous quadrantanopia. Based on these findings, the patient was diagnosed with one-and-a-half syndrome and facial nerve weakness, together forming the classic presentation of eight-and-a-half syndrome. He had two cerebrovascular events, only a week apart, and a background history of subsequent atrial fibrillation. MRI revealed left temporoparietal and pontine infarcts. Despite thrombolysis and thrombectomy, the symptoms persisted. He later received intravenous and intrathecal stem cell therapy, showing significant improvement in gaze palsy, visual field, and motor function within a month. Conclusion: Stem cell therapy might be advantageous for patients with eight-and-a-half syndrome due to ischemic stroke in the subacute and chronic phases.