tendency to suffer recurrent unprovoked seizures
abnormal electrical discharge leading to tonic clonic, strange sensations or altered behaviour
not one entity - but many causes but not including situations where seizure clearly has provoking cause eg alcohol withdrawal, febrile.

2 major subtypes
''idiopathic generalized'' - diffuse discharge at onset, tonic/clonic, absense, myoclonic jerks, usually hereditary, neuroimaging normal
''focal'' - start in one place but may spread to general, wide range Sx, structural lesion often associated,  if no alteration consciousness - simple, if there is - complex