Antibody-mediated LGI1 Encephalitis: Symptoms, Biomarkers, and Mechanisms of the Chronic Phase of the Disease

Overview

The encephalitis mediated by antibodies against Leucine-rich, glioma inactivated 1 protein (anti-LGI1 encephalitis) predominantly affects men (M:F, 6:4) and mostly older than 60 years. The disease has two distinct clinical phases: The acute phase in which the majority of patients develop severe short-term memory deficits (unable to remember events or experiences that occurred a few minutes earlier). This memory impairment can be preceded or accompanied by one or more of the following: hyponatremia (60% of patients), a highly distinctive type of seizures called facio-brachial dystonic seizures (\~40% of patients), along with confusion, irritability and other types of focal seizures or less frequently, generalized seizures. In addition, many patients at this stage have symptoms of REM sleep behavior disorder. In this stage, the CSF may show pleocytosis or mild increase of proteins, the EEG is usually abnormal, and in \~60% of the patients the MRI shows typical increased FLAIR signal in medial temporal lobes (11). There is a clinical sub-phenotype (\~13% of patients) in which the disease presents as a rapidly progressive cognitive decline without the indicated FLAIR MRI changes. About 70% of patients improve rapidly with corticosteroids and immunotherapy (eg, intravenous immunoglobulins and/or plasma exchange), but the improvement is often partial. After the acute phase, there is a chronic or residual phase which represents the interval from improvement of initial symptoms until the disease is considered no longer active and the remaining symptoms are thought to be irreversible. This chronic phase may take several months (it has been less well studied), and is characterized by the absence of CSF pleocytosis and inflammatory MRI changes (albeit this may show residual hippocampal atrophy), and very low or undetectable titers of serum antibodies. Most patients are unable to return to their job or previous activities due to residual (irreversible) memory or cognitive deficits accompanied by signs of moderate brain atrophy. In addition, we and others have shown that about 27-35% of patients have relapsing symptoms after improving from the acute phase (. Although acute symptomatic seizures (facio-brachial dystonic and others) occur in \~90% of patients during the acute phase of the disease, less than 10% of patients develop chronic epilepsy often associated with hippocampal sclerosis. Therefore, the prevailing concept on this disease suggests a syndrome and clinical course in which the acute phase shows rapid, albeit partial, response to immunotherapy, and the symptoms of the chronic phase represent a burnout or irreversible process, in which the disease is no longer active, and the potential improvement of remaining symptoms is uncertain. Here investigators postulate that a better knowledge of this stage will improve treatment decisions and outcome. In Aim 1, the post-acute stage will be clinically characterized. In Aim 2, the impact of cognitive rehabilitation will be assessed. In Aim 3, a mouse model of anti-LGI1 encephalitis will be used to determine the underlying mechanisms and treatment of the postacute stage.

Interventions

• Behavioral Remote cognitive rehabilitation program
  Behavioral: Remote cognitive rehabilitation program Remote cognitive rehabilitation program will be performed through an online validated platform (Guttmann NeuroPersonalTrainer: https://gnpt.es/) run by the psychologists team. This is a Sanitary Product with CE certification (Sanitary Product RPS/430/2014; International Patent \[PCT/ES2008/00677\]) and here will be used within its approved indications. The rehabilitation program will increase in difficulty and decrease in frequency during the f

Primary outcome measures

• Age [Time frame: 12 months]
• Gender [Time frame: 12 months]
• Handedness [Time frame: 12 months]
• General medical history [Time frame: 12 months]
• Allergies [Time frame: 12 months]
• Symptoms related to anti-LGI1 encephalitis [Time frame: 12 months]
• Treatments [Time frame: 12 months]
• Functional status [Time frame: 12 months]
• Intelligence Quotient [Time frame: 12 months]
• Verbal working memory [Time frame: 12 months]

Secondary outcome measures (4)

• LGI-1 antibodies [Time frame: 12 months]
• HLA genotyping [Time frame: 12 months]
• Immune/inflammatory signaling-target gene expression pathways [Time frame: 12 months]
• NfL levels [Time frame: 12 months]

Eligibility criteria

Inclusion criteria

• Patients with Antibody-mediated LGI-1 encephalitis in the post-acute stage of the disease;
• Patients has been discharged from hospital (acute phase).

Exclusion criteria

• Inability to obtain informed consent;
• Inability to travel to the center.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

N/A

Model

Single group

Masking

Open label

Primary purpose

Supportive care

Study locations

Spain · 1 center

• Hospital Clínic de Barcelona — Barcelona

Publications

• Dalmau J, Graus F. Antibody-Mediated Encephalitis. N Engl J Med. 2018 Mar 1;378(9):840-851. doi: 10.1056/NEJMra1708712. No abstract available. PMID 29490181
• Dalmau J, Geis C, Graus F. Autoantibodies to Synaptic Receptors and Neuronal Cell Surface Proteins in Autoimmune Diseases of the Central Nervous System. Physiol Rev. 2017 Apr;97(2):839-887. doi: 10.1152/physrev.00010.2016. PMID 28298428
• Hughes EG, Peng X, Gleichman AJ, Lai M, Zhou L, Tsou R, Parsons TD, Lynch DR, Dalmau J, Balice-Gordon RJ. Cellular and synaptic mechanisms of anti-NMDA receptor encephalitis. J Neurosci. 2010 Apr 28;30(17):5866-75. doi: 10.1523/JNEUROSCI.0167-10.2010. PMID 20427647
• Planaguma J, Leypoldt F, Mannara F, Gutierrez-Cuesta J, Martin-Garcia E, Aguilar E, Titulaer MJ, Petit-Pedrol M, Jain A, Balice-Gordon R, Lakadamyali M, Graus F, Maldonado R, Dalmau J. Human N-methyl D-aspartate receptor antibodies alter memory and behaviour in mice. Brain. 2015 Jan;138(Pt 1):94-109. doi: 10.1093/brain/awu310. Epub 2014 Nov 11. PMID 25392198
• Petit-Pedrol M, Sell J, Planaguma J, Mannara F, Radosevic M, Haselmann H, Ceanga M, Sabater L, Spatola M, Soto D, Gasull X, Dalmau J, Geis C. LGI1 antibodies alter Kv1.1 and AMPA receptors changing synaptic excitability, plasticity and memory. Brain. 2018 Nov 1;141(11):3144-3159. doi: 10.1093/brain/awy253. PMID 30346486
• Titulaer MJ, McCracken L, Gabilondo I, Armangue T, Glaser C, Iizuka T, Honig LS, Benseler SM, Kawachi I, Martinez-Hernandez E, Aguilar E, Gresa-Arribas N, Ryan-Florance N, Torrents A, Saiz A, Rosenfeld MR, Balice-Gordon R, Graus F, Dalmau J. Treatment and prognostic factors for long-term outcome in patients with anti-NMDA receptor encephalitis: an observational cohort study. Lancet Neurol. 2013 Fe PMID 23290630
• Granerod J, Ambrose HE, Davies NW, Clewley JP, Walsh AL, Morgan D, Cunningham R, Zuckerman M, Mutton KJ, Solomon T, Ward KN, Lunn MP, Irani SR, Vincent A, Brown DW, Crowcroft NS; UK Health Protection Agency (HPA) Aetiology of Encephalitis Study Group. Causes of encephalitis and differences in their clinical presentations in England: a multicentre, population-based prospective study. Lancet Infect PMID 20952256
• van Sonderen A, Petit-Pedrol M, Dalmau J, Titulaer MJ. The value of LGI1, Caspr2 and voltage-gated potassium channel antibodies in encephalitis. Nat Rev Neurol. 2017 May;13(5):290-301. doi: 10.1038/nrneurol.2017.43. Epub 2017 Apr 18. PMID 28418022

Identifiers

NCT: NCT06515106 · PI23/00858

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗