Autoimmune Encephalitis – Symptoms and Causes
Overview
Autoimmune encephalitis (AE) is a condition where the brain becomes inflamed due to the body’s immune system attacking its own brain cells. This differs from infectious encephalitis, which is caused by viral or bacterial infections.
Recent research shows that autoimmune and infectious encephalitis occur at similar rates.
The symptoms of AE can include:
- Memory problems
- Cognitive changes
- Behavioral shifts
- Seizures
The exact cause of autoimmune encephalitis remains unknown, but several factors may trigger it:
| Potential Triggers | Risk Factors |
|---|---|
| Certain cancers | Existing autoimmune disease |
| Specific infections | Family history of autoimmune conditions |
| Some medications |
Healthcare providers use multiple diagnostic tests to confirm autoimmune encephalitis. Without proper treatment, AE can lead to severe complications and potentially death. However, with appropriate medical intervention, the outlook is often positive.
Many patients achieve complete recovery from autoimmune encephalitis, though some individuals may experience lingering symptoms. Early diagnosis and treatment significantly improve outcomes for people with this condition.
Signs and Symptoms
People with autoimmune encephalitis may experience different symptoms. The symptoms often follow a pattern based on the type of encephalitis.
Many individuals first develop a headache, fever, and infection-like symptoms before showing:
- Mental health changes including anxiety, panic, behavior changes, agitation, seeing or believing things that aren’t real, and confused thinking
- Memory problems
- Language difficulties such as reduced speech or repeating words
- Involuntary movements
- Seizures
- Changes in awareness
- Sleep disturbances – less sleep early in the illness, followed by excessive sleep during recovery
In serious cases, autoimmune encephalitis can cause status epilepticus. This is when dangerous seizures last more than five minutes or occur back-to-back without regaining consciousness between them.
The disease may worsen steadily over time (progressive course) or alternate between improvement and worsening (relapsing-remitting pattern), similar to multiple sclerosis.
When Medical Help Is Needed
Seek emergency care immediately for:
- Seizures lasting longer than five minutes
- Multiple seizures without regaining consciousness
- High fever
- Breathing difficulties
Contact your healthcare provider right away if you notice any symptoms of autoimmune encephalitis. This condition can become serious quickly without proper treatment.
What Causes Autoimmune Encephalitis
Autoimmune encephalitis (AE) occurs when the body’s immune system incorrectly attacks healthy brain cells. This attack leads to brain inflammation and various symptoms. While researchers don’t fully understand why this happens, several factors may trigger this condition.
The immune system normally produces antibodies to fight harmful invaders like viruses and bacteria. In AE, these antibodies mistakenly target specific receptors in the brain, causing damage.
Potential triggers include:
- Certain cancers (called paraneoplastic AE)
- Viral infections, particularly herpes simplex
- Some medications, including monoclonal antibodies and transplant-related immune suppressants
People with personal or family histories of autoimmune diseases face higher risks of developing AE.
Types of Autoimmune Encephalitis
Each type of AE involves antibodies attacking different brain receptors, causing varied symptoms:
Anti-NMDA-Receptor Encephalitis
- Most common form
- Affects mainly young women and children
- Symptoms: seizures, facial movements, psychosis
Anti-GABA-B Receptor Encephalitis
- Often linked to small-cell lung cancer
- Average diagnosis age: 60
- Symptoms: seizures, confusion, memory problems
Anti-GABA-A Receptor Encephalitis
- Affects both adults (average age 40) and children
- Symptoms: seizures, movement disorders, cognitive changes
Anti-AMPA Receptor Encephalitis
- Primarily affects women around age 62
- Symptoms: confusion and memory loss
Anti-LGI1 Limbic Encephalitis
- More common in men around age 60
- Symptoms: memory loss, confusion, seizures
Anti-CASPR2 Associated Encephalitis
- More common in men around age 60
- Symptoms: confusion, memory problems, sleep issues, nerve pain
- Can cause rare Morvan syndrome with hallucinations and painful cramps
Anti-IgLON5 Disease
- Average diagnosis age: 64
- Primary symptom: unusual movements and behaviors during sleep
The specific antibody involved determines both symptom patterns and treatment approaches.
Risk Factors
Several factors may increase your chance of developing autoimmune encephalitis:
- Previous autoimmune encephalitis episode, especially without proper treatment
- History of herpes simplex virus encephalitis
- Use of immune-suppressing medications after transplant surgery
- Presence of tumors, particularly small-cell lung cancer
Scientists are currently investigating possible genetic links to autoimmune encephalitis.
Complications
Autoimmune encephalitis (AE) can lead to several serious health problems. One major issue is severe seizures called status epilepticus.
These seizures last longer than five minutes or happen repeatedly without the person regaining consciousness between episodes. The immune system’s attack on brain tissues often causes these seizures.
Breathing problems may develop in some patients. Respiratory failure can occur, requiring mechanical ventilation to help patients breathe properly. This support is crucial during severe stages of the illness.
AE can also disrupt the body’s automatic functions. Patients might experience irregular heart rates, unstable blood pressure, and problems with digestion and urination. These autonomic function disturbances require careful monitoring.
High fevers commonly affect people with autoimmune encephalitis. These temperature spikes need medical management.
Some patients face relapse after initial recovery. The condition returns, requiring additional treatment. People with specific types of encephalitis – anti-LGI1 limbic encephalitis and anti-CASPR2 associated encephalitis – have higher relapse risks than others.
Common AE Complications:
- Status epilepticus (severe seizures)
- Respiratory failure
- Autonomic dysfunction
- High fevers
- Disease relapse
Prevention
Preventing autoimmune encephalitis (AE) isn’t always possible. However, regular cancer screenings can play an important role in prevention.
It’s valuable to discuss your personal cancer risk factors with your healthcare provider. They can recommend appropriate screening tests based on your medical history and risk profile.
