ORPHA:83600
Encephalitis lethargica
Also known as: Von Economo encephalitis
Publications
6,449
Trials
0
Interventional, condition-specific
Researchers
773
Distinct authors in sample
Gene link
—
Readiness
2/6
Stages with a signal
Clinical definition (Orphanet)
A rare brain inflammatory disease characterized by acute or subacute encephalitis with involvement of the midbrain and basal ganglia occurring in children as well as adults. Initial symptoms are pharyngitis and fever, followed by lethargy, sleep disturbances, extrapyramidal symptoms (parkinsonism, chorea, dystonia), neuropsychiatric manifestations (obsessive-compulsive behavior, mutism, catatonia), and ocular features (oculogyric crises). Autoantibodies against human basal ganglia are often positive. Survivors may develop post-encephalitic syndromes, most prominently parkinsonism.
How rare: <1 / 1 000 000 — fewer than one in a million. In a city the size of Kolkata, that might mean on the order of fifteen people.
Cross-references
Joined from Mondo / Orphanet. MeSH labels may enter searches; UMLS / OMIM / NCIT are stored for reference.
- MONDO:0019384
- UMLS:C0014040
- NCIT:C26761
- NCIT:C34576
Additional Mondo synonyms (4)
encephalitis lethargica · epidemic encephalitis · lethargic encephalitis · von Economo's disease
Research stages
Trial readiness signals
Where this condition sits on an open-data research pipeline — not how close a treatment is, and not medical advice. Empty stages often mean “not in these databases under this Mondo ID,” not “impossible.”
2/6 stages with a signal
Research-stage checklist from open sources (GenCC, literature, Monarch when enriched, ClinicalTrials.gov). Not a prognosis or care recommendation.
- Gene identifiedNot found
No GenCC disease–gene assertion in this build
- LiteraturePresent
6,449 matched papers (753 in last 10 years) Source
- Phenotype characterisedPresent
30 HPO annotations (e.g. Dyskinesia; Psychosis; Seizure) Source
- Animal modelNot found
No Alliance genotype “model of” associations via Monarch for these Mondo IDs
- Orphan designationNot found
No FDA or EMA orphan-drug designation matched this disease via UMLS or preferred name Source
- Interventional trialNot found
No matched interventional trial under our ClinicalTrials.gov rules
Biology
Genes and phenotypes
Gene–disease validity from GenCC, plus phenotypes and animal models joined from Monarch Initiative via Mondo ID — not a clinical diagnosis aid.
Do we know what causes it?
Not yet — the cause hasn't been pinned down in GenCC.
No strong gene–disease assertion joined for this Orphanet entity.
Phenotypes (Monarch / HPO)
30
Associated phenotypes · MONDO:0019384
- Dyskinesia
- Psychosis
- Seizure
- Coma
- Bradycardia
Showing 5 of 30 — open Monarch for the full list.
Animal models (Monarch / Alliance)
None returned for this Mondo ID. Empty here is not proof that no model organism work exists under another name or gene.
Monarch fetch 2026-07-29
Therapies
Designations, candidates, and chemicals
FDA OOPD and EMA orphan designations, Open Targets clinical candidates, and CTD chemical associations via MyDisease.info. These never change the interventional-trial headline.
Orphan designation (FDA · EMA)
No designation matched this disease via UMLS or preferred name on the FDA OOPD mirror or EMA orphan register. Absence here is not proof that none exists under another wording.
Open Targets candidates
No drugs or clinical candidates returned for this Mondo ID on Open Targets.
CTD chemicals (MyDisease.info)
No CTD chemical associations returned for this Mondo ID.
Literature
Is anyone studying this?
6,449
6,449 papers — among the better-studied rare conditions, though still a fraction of common-disease literature (breast cancer: over 700,000). Median papers in the last 10 years for a rare disease in this dataset (publications denominator n=3967) is 59.
6,449 papers since the earliest indexed year in this search — median last-10-year count for a rare disease in this dataset is 59 (publications denominator n=3967).
753 in the last 10 years · low confidence
Phrase hits: 6,449 · MeSH hits: 0
Who's working on it?
773
Distinct author names in 200 sampled papers — named people below.
Who's working on it?
No interventional trial matched this name; these authors publish on it in the sampled literature — a practical starting point for contact.
- 01Brigo F4 papers · 2026
Department of Neurology, Hospital of Merano (SABES-ASDAA), Merano-Meran, Italy.
Papers in Europe PMC - 02Chen Y3 papers · 2026
Department of Acupuncture and Moxibustion, The First Affiliated Hospital of Zhejiang Chinese Medical University (Zhejiang Provincial Hospital of Chinese Medicine), Hangzhou, China.
Papers in Europe PMC - 03Ding Y3 papers · 2026
Department of Pharmacy Administration and Clinical Pharmacy, School of Pharmaceutical Sciences, Peking University, Beijing, China.
Papers in Europe PMC - 04Martini M3 papers · 2026
Department of Health Sciences, University of Genoa, Genoa, Italy.
Papers in Europe PMC - 05Michael BD3 papers · 2025
Department of Neurology, The Walton Centre NHS Foundation Trust, Liverpool, United Kingdom.
Papers in Europe PMC - 06Tappe D3 papers · 2024
Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany. Electronic address: tappe@bnitm.de.
Papers in Europe PMC - 07
- 08Ballouz T2 papers · 2025
Epidemiology, Biostatistics and Prevention Institute, University of Zurich, Zurich, Switzerland.
Papers in Europe PMC - 09Beckers M2 papers · 2023
Center of Expertise for Parkinson & Movement Disorders, Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands.
Papers in Europe PMC - 10Berendtsen NT2 papers · 2023
Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
Papers in Europe PMC
Clinical research
Is a treatment being tested?
0
interventional trials for this specific condition
No interventional trial testing a treatment matched this specific condition name on ClinicalTrials.gov (observational studies and pan-disease registries are listed separately when present).
Data as of 11 September 2026 · last trial check 11 September 2026
No matched interventional trials. This is true for 77.2% of diseases in the trials denominator (5501 of 7126). Here are the researchers publishing on it.
low confidence · 38.6th percentile (trials denominator)
Recruiting interventional trials
From the matched ClinicalTrials.gov set
No interventional trial testing a treatment was found for this specific condition name on ClinicalTrials.gov.
See who's working on it — people publishing on this disease are often the practical next contact when no trial is listed.
Other registries (secondary)
Broader net from EU CTIS, ISRCTN, and ICTRP when available — deduped against ClinicalTrials.gov IDs already counted above. Dual-model LLM relevance gates what we keep. These rows are not added to the interventional headline.
raw 1 · after dedupe 1 · already on CT.gov 0 · kept 0 · parent 0 · uncertain 1 · dropped 0 · fetched 2026-07-30
Source notes: ictrp: Error: ICTRP public search unavailable (WHO portal is SPA-only; SOAP needs partnership). Tried: https://apps.who.int/tri
No secondary-registry studies passed dual-model relevance for this condition name (after dedupe).
Uncertain / not reviewed (1)
- isrctn·ISRCTN11138955·No longer recruiting·Reducing the risk of human Nipah virus exposure in Bangladesh through school-based education
skipped — LLM skipped (--skip-llm)
Where to find support
Condition-specific patient organisations, when Orphanet lists them, are on the disease’s Orphanet page. We also link umbrella groups that support undiagnosed and ultra-rare families.
Orphanet entry for Encephalitis lethargica — check Associations / patient organisations on that page.
India — NPRD
Last verified 2026-07-26This ORPHAcode is not on our curated NPRD list (direct or Mondo-parent match). That does not decide clinical eligibility; families in India should ask a notified Centre of Excellence about current coverage.
Hand-curated for this project. ORPHAcode mappings are best-effort and may be incomplete or imprecise for umbrella categories. Parent (Mondo) matches mean the policy lists a broader category — confirm eligibility with a Centre of Excellence. Financial entitlements summarised from public policy statements and may change. This is not official government guidance.
How we counted this
Europe PMC query (preferred label + any corrected label + Orphanet and Mondo exact synonyms, stoplisted; unioned with resolved MeSH labels when available). UMLS / OMIM / NCIT cross-references are stored on the overview but are not added to the query string.
"Encephalitis lethargica" OR "Von Economo encephalitis" OR "epidemic encephalitis" OR "lethargic encephalitis" OR "von Economo's disease"
ClinicalTrials.gov query (quoted phrases + MeSH via query.cond, plus recall-expansion terms when used):
"Encephalitis lethargica" OR "Von Economo encephalitis" OR "epidemic encephalitis" OR "lethargic encephalitis" OR "von Economo's disease"
Study-type breakdown: 0 interventional · 0 observational · 0 expanded access. Only interventional studies enter the trial headline.
Query health: ok — strategies attempted: phrase; with hits: phrase
Run this search on ClinicalTrials.gov
Confidence reasoning
- Preferred label is multi-word and distinctive
- No synonyms dropped by stoplist
- No label/synonym collisions with other diseases in this corpus
- Publication count (6449) is implausibly high for prevalence class "<1 / 1 000 000" — treat as possible over-matching, not a measure of research intensity
Ingested 2026-07-27T02:40:23.183Z