Stereotactic radiosurgery XX: ocular neuromyotonia in association with gamma knife radiosurgery

We report three patients who developed symptoms and signs of ocular neuromyotonia (ONM) 3–6 months after receiving gamma knife radiosurgery (GKS) for functioning pituitary tumours. All three patients were complex, requiring multi-modality therapy and all had received prior external irradiation to the sellar region. Although direct causality cannot be attributed, the timing of the development of the symptoms would suggest that the GKS played a contributory role in the development of this rare problem, which we suggest clinicians should be aware of as a potential complication. LEARNING POINTS: GKS can cause ONM, presenting as intermittent diplopia. ONM can occur quite rapidly after treatment with GKS. Treatment with carbamazepine is effective and improve patient's quality of life.