Table 1 Classification of initial precipitating lesions (IPLs) described by Mathern et al. [34]

Nonseizure IPL

Clinically significant events that occurred under 5 years of age, not associated with seizures.

Prolonged seizure IPL

Clinically significant events that occurred under 5 years of age, associated with a motor seizure secondary to status epilepticus or a complex febrile seizure.

Non-prolonged seizure IPL

Multiple non-significant seizures with a brief loss of consciousness, not suggestive of status epilepticus

Late IPL

All IPL that occurred over 5 years of age

Idiopathic MTS

No history of clinically significant events during life