The information on this website is not intended for diagnosis or treatment. Please consult your physician for health concerns.

+90 850 321 50 00

LGI1 Limbic Encephalitis

Faciobrachial Dystonic Seizures and Antibody-Mediated Memory Loss

Written by: Saygı Hospital Health Guide Editorial Board
Last updated:

This content has been compiled by the Saygı Hospital Health Guide Editorial Board and is periodically reviewed by a specialist physician.

References (5)

This content is for informational purposes only and does not constitute medical advice. You can book an appointment at our Nöroloji department. Book Appointment →

What is LGI1 Limbic Encephalitis?

LGI1 limbic encephalitis is an autoimmune disorder caused by antibodies against leucine-rich glioma-inactivated 1 protein, a secreted neuronal protein that interacts with VGKC complex; previously misclassified as VGKC-complex antibody encephalitis.

Faciobrachial dystonic seizures (FBDS) — brief, frequent (50–100/day), unilateral arm and ipsilateral face dystonic posturing — are pathognomonic and often precede cognitive decline.

MRI typically shows medial temporal lobe T2/FLAIR hyperintensity bilaterally; cerebral 18F-FDG PET may show basal ganglia hypermetabolism corresponding to FBDS.

Strongly associated with HLA-DRB1*07:01; rarely associated with thymoma or other tumors compared with other autoimmune encephalitides.

Symptoms

Faciobrachial dystonic seizures: brief, stereotyped unilateral arm jerks with ipsilateral facial grimacing, occurring up to 100 times per day
Subacute progressive memory loss (especially short-term/anterograde amnesia)
Confusion, disorientation, behavioral changes, irritability, depression
Sleep disturbance: insomnia, fragmented sleep, REM sleep behavior disorder
Hyponatremia from SIADH (low serum sodium often <125 mmol/L)
Generalized or temporal lobe seizures (less stereotyped than FBDS)
Autonomic features: hyperhidrosis, weight loss, tremor

Risk Factors

Middle-aged to elderly patients (peak age 60–70 years)
Male predominance (male-to-female ratio approximately 2:1)
HLA-DRB1*07:01 haplotype
Underlying tumor (thymoma <10%) — paraneoplastic association much weaker than other autoimmune encephalitides
History of other autoimmune disease
No specific trigger identified in most cases (often idiopathic)

When to See a Doctor?

If you experience any of the following symptoms, seek medical attention promptly:

  • New-onset stereotyped brief seizure-like episodes (especially faciobrachial dystonic posturing)
  • Subacute progressive amnesia or cognitive decline in middle-aged or elderly patient
  • Behavior change, confusion, or psychiatric symptoms with hyponatremia
  • Refractory seizures with characteristic features and abnormal MRI temporal lobe signal
  • Known LGI1 encephalitis with new symptoms or relapse

Treatment Methods

01
First-line immunotherapy: high-dose IV methylprednisolone 1 g/day for 5 days followed by oral prednisone taper, often combined with IV immunoglobulin (IVIG) 2 g/kg over 2–5 days or plasmapheresis 5–7 sessions
02
Second-line immunotherapy for refractory or severe cases: rituximab 1 g IV ×2 doses (or 375 mg/m² weekly ×4) and/or cyclophosphamide IV monthly pulses
03
Maintenance therapy in relapsing or chronic disease: mycophenolate mofetil, azathioprine, or rituximab cycles
04
Antiseizure medication for FBDS and other seizures: levetiracetam, lacosamide, or sodium channel blockers; immunotherapy is more effective than antiepileptics for FBDS
05
Hyponatremia management: fluid restriction, salt tablets, or tolvaptan for SIADH
06
Tumor screening: CT chest with thymus protocol, abdominopelvic imaging, and tumor markers; thymectomy if thymoma identified
07
Cognitive rehabilitation, occupational therapy, and psychiatric support for residual cognitive deficits
08
Long-term follow-up: serial cognitive assessments, MRI surveillance, monitoring for relapse (15–30%), and gradual tapering of immunotherapy under specialist guidance

Which Department to Visit?

You can visit our Nöroloji department for these complaints. Our specialist physicians will create the most suitable treatment plan for you.

Learn About Nöroloji Department

Let us help you

You can make an appointment with our specialists or contact us for your concerns.

Book AppointmentContact Us

Related Health Topics

Other articles from the same department you may want to explore.

Headache and Migraine

Nöroloji

What you need to know about headache types, migraine attacks, and triggering factors.

Low Back Pain

Nöroloji

Learn about the most common causes of low back pain, risk factors, and appropriate treatment approaches.

Neck Pain and Cervical Disc Herniation

Nöroloji

Learn about the symptoms and treatment options for cervical disc herniation and problems in the neck region.

Epilepsy

Nöroloji

Accurate information about epilepsy, types of seizures, and recommendations for patients and families.

Parkinson Disease

Nöroloji

Parkinson disease is caused by progressive degeneration of dopaminergic neurons and alpha-synuclein accumulation; well-timed therapy substantially improves function and quality of life.

Alzheimer's Disease and Dementia

Nöroloji

Information about early signs, diagnosis, and the care process for Alzheimer's and other types of dementia.

Multiple Sclerosis (MS)

Nöroloji

What is multiple sclerosis, who is at risk, and which treatments are applied?

Stroke

Nöroloji

What is stroke, what are the FAST signs, and why is emergency intervention critical?

Health Disclaimer: The information on this page is prepared for general informational purposes only. It does not replace medical diagnosis and treatment. Please consult your physician for your complaints. Saygı Hospital does not accept responsibility for actions taken based on the information on this page.