A simple, unobtrusive wrist sensor could gauge the severity of epileptic seizures as accurately as electroencephalograms (EEGs) do — but without the ungainly scalp electrodes and electrical leads. The device could make it possible to collect clinically useful data from epilepsy patients as they go about their daily lives, rather than requiring them to come to the hospital for observation. If early results are borne out, it could even alert patients when their seizures are severe enough that they need to seek immediate medical attention.

Rosalind Picard, a professor of media arts and sciences at MIT, and her group originally designed the sensors to gauge the emotional states of children with autism. The sensor measures the electrical conductance of the skin, an indicator of the state of the sympathetic nervous system, which controls the human fight-or-flight response. In a study conducted at Children's Hospital Boston, the research team discovered that the higher a patient's skin conductance during a seizure, the longer it took for the patient's brain to resume the neural oscillations known as brain waves, which EEG measures.

Currently, patients might use a range of criteria to determine whether a seizure is severe enough to warrant immediate medical attention. One of them is duration. But during the study at Children’s Hospital, Picard says, “what we found was that this severity measure had nothing to do with the length of the seizure.” Ultimately, data from wrist sensors could provide crucial information to patients deciding whether to roll over and go back to sleep or get to the emergency room.

Source 

Also: Many technologies have been proposed for treating epileptic seizures. Read about some of them here.