The classic presentation of Todd's paresis is a transient weakness of a hand, arm, or leg after focal seizure activity within that limb.

One retrospective observational study evaluated 328 selected patients from ages 16 to 57 years who had prolonged video-electroencephalogram (EEG) monitoring for medically intractable epilepsy and focal seizure onset; those with nonepileptic seizures, status epilepticus, and Lennox-Gastaut syndrome were excluded.

However, the study is likely biased by the inclusion only of patients with medically intractable seizures who had undergone video-EEG monitoring, and the results may not extrapolate to a general epilepsy population.

[6] The cause of Todd's paresis has been attributed to the affected cortex being ‘exhausted’ or silenced due to increased inhibition, but these conjectures are not supported.

Therefore, having a seizure during a stroke is generally considered a reason to be cautious about using thrombolytic therapy, especially if there's no clear evidence of a blocked blood vessel in the brain using imaging techniques.

This view is as a result of a recent study that showed the incidence of Todd's paresis to be in 0.4% of infants that have been diagnosed with a febrile convulsion.