Rare diseases · Sign or symptom
Focal clonic seizure
HP:0002266
What it means
A focal clonic seizure is a type of focal motor seizure characterized by sustained rhythmic jerking, that is regularly repetitive.
The movement involves sustained rhythmic jerking, this may involve a limb, half the face or one side of the body, and may spread according to a Jacksonian march: The jerking may spread to involve parts of the body according to their representation on the motor cortex (according to the homunculus).
Rare diseases that can present with this5
The range is how often this sign appears among people diagnosed with each disease — it is not a probability of having any of them. Many of these signs also occur in common, non-rare conditions. A sign on this page is a conversation to have with a clinician, not a conclusion.
Part of the broader category
Also called: Focal clonic seizures · Localised clonic seizure · Localized clonic seizure · Partial clonic seizure · Segmental clonic seizure
Tracking symptoms like this for someone? Eleplan keeps symptoms, diagnoses, medications and every specialist in one plan.
Start free with EleplanThis page uses the Human Phenotype Ontology (2026-06-23) — Human Phenotype Ontology Consortium, hpo.jax.org. Disease associations from Orphanet (INSERM), CC BY 4.0. Content is educational and is not medical advice.