Gamma knife radiosurgery (GKR) is a safe and effective alternative to surgery for intracranial lesions. Most studies evaluating toxicity after GKR have concentrated on the delayed radiation effects.

We retrospectively reviewed 835 consecutive GKR cases for early (within 7 days) neurological complications or death.

We identified a total of 18 patients (2.2%) who had a neurological event or death. Five (0.6%) patients developed new focal deficits, 12 (1.4%) patients experienced a seizure and there were three (0.4%) deaths. Two deaths were related to development of seizures and neurological deterioration. One death was caused by a respiratory arrest related to the patient's primary cancer. Of the five patients with neurological deficits, none had a persistent deficit. In two cases the neurological deficits were due to an increase in edema. Whether this occurred as a result of the gamma knife treatment or was the natural progression of the tumor is unclear.

Complications after GKR are uncommon and the risk of a permanent deficit arising from an acute neurological event is exceedingly low.