In some examples, systems, devices, and techniques for determining a particular sleep stage of a patient, determining a seizure state of the patient during the particular sleep stage, and generating a seizure probability metric for the particular sleep stage based on the sleep stage and seizure state are described. In some cases, a patient may be more susceptible to seizure events during particular sleep stages. One or more seizure probability metrics indicative of a patient's susceptibility to seizure events during a particular sleep stage may be useful in creating a patient-specific treatment regimen.