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ORPHA:1929Disease
Also called Rasmussen subacute encephalitis
What it is
A rare inflammatory and autoimmune disease with epilepsy characterized by unilateral hemispheric atrophy, associated with drug-resistant focal epilepsy, progressive hemiplegia, and cognitive decline. The disease mainly affects children and begins with a prodromal period with mild hemiparesis or infrequent seizures lasting up to several years. The acute stage is marked by frequent seizures arising from one cerebral hemisphere, followed by a residual stage with persistent severe neurological deficits and relapsing epilepsy.
Key facts
- Age of onset
- Childhood
- Inheritance
- Not applicable
- Classified as
- Disease
Signs and symptoms
Common30–79%
14- Autoimmunity
- Cerebral cortical hemiatrophy
- Cognitive impairment
- EEG with focal sharp slow waves
- EEG with focal spikes
- Epilepsia partialis continua
- Focal aware seizure
- Focal impaired awareness seizure
- Focal motor seizure
- Hemiparesis
- Involuntary movements
- Repeated focal motor seizures
- Subcortical cerebral atrophy
- Ventriculomegaly
These ranges are how often a sign appears across everyone diagnosed, not a prediction for one person — most people have some of these and not others. Orphanet also records findings that are specifically absent in this disease; those are in the data but not listed here.
ICD-10 codes
ICD-10 has no distinct code for most rare diseases, so many are filed under the nearest available one. A shared code identifies the group, not this disease — the ORPHAcode above is what identifies it.
Related health topics
Reached through the ICD-10 categories this disease is filed under, so these describe the broader group rather than this disease specifically.
Cross-references
Orphadata Science: Free access data from Orphanet. © INSERM 1999. Data version 2026-06-23. Available under CC BY 4.0. This is a reference, not medical advice.
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