About Rasmussen’s Encephalitis

Rasmussen’s encephalitis, also known as Rasmussen’s syndrome, is a very rare disease that causes inflammation of the brain. The inflammation intensifies over time, leading to severe seizures, paralysis or weakness on one side of the body, speech difficulties, and compromised brain functions including memory, attention, and cognitive abilities.

Rasmussen’s encephalitis is extremely rare. About 2.4 in every 10 million people have Rasmussen’s encephalitis.

Seizures resulting from Rasmussen’s encephalitis are typically resistant to anti-seizure medication, meaning no known medication can halt these seizures.

In many cases, the condition affects one side of the brain. However, cases of Rasmussen’s encephalitis affecting both brain hemispheres have been documented. Occasionally, it can begin in one hemisphere and later show up in the other.

Diagnosis of Rasmussen’s Encephalitis

A diagnosis of Rasmussen encephalitis is made when a patient exhibits:

• Frequent, severe, escalating seizures unresponsive to epilepsy medications;
• “Epilepsia partialis continua” – a recurring seizure type where the child remains conscious during recurrent seizures;
• Epileptic encephalopathy (when seizures impact brain function);
• Progressive deterioration of motor, cognitive, language, or sensory abilities leading to hemiparesis;
• MRI-visible damage to one brain hemisphere.

Symptom severity and progression vary between patients. In some, cortical dysplasia in the brain may accompany Rasmussen’s encephalitis. Primarily diagnosed in children under 10, about 10% of cases emerge during teenage years or adulthood.

Phases of Rasmussen’s Encephalitis

The condition unfolds in three distinct phases:

• Prodromal period

Characterized by mild hemiparesis and infrequent seizures.

• Acute stage

This phase, lasting an average of 8 months, witnesses the most extensive brain damage.

• Residual stage

Here, the neurological damage reaches its peak, though not all patients experience a cessation in their deficits.

Cause of Rasmussen Encephalitis

We don’t fully understand what causes Rasmussen’s encephalitis. Some researchers believe it is an immune condition.

Treatment Options for Rasmussen Encephalitis

Various anti-seizure medications may alleviate Rasmussen syndrome symptoms, but complete seizure freedom is rare, especially with epilepsia partialis continua. Some patients may benefit from immunomodulation therapy which can slow down the progression of the disease. Small studies have shown some success with vagal nerve stimulation (VNS) and transcranial magnetic stimulation (TMS).

However, the only potential cure for Rasmussen encephalitis is hemispherectomy or hemispherotomy surgery.

Considerations Post-Surgery

While surgery offers a high chance of alleviating the most debilitating seizures, some patients may still experience seizures post-operation.

In a study involving 41 children who underwent hemispheric surgery for Rasmussen’s encephalitis at one hospital from 1982 – 2018::

• 68% were seizure-free after one year;
• 48% remained without seizures after five years;
• 22% continued to be seizure-free ten years after surgery.

Compared to functional hemispherectomy, anatomical hemispherectomy was linked to a more extended period before seizures recurred. There wasn’t a significant difference in seizure recurrence between patients who had a complete hemispherectomy and those who underwent a less extensive surgery.

At the most recent check-in, 21 patients could walk completely on their own. Out of these, 7 patients also took part in sports.

When it comes to speech, 58% had normal speech, 26% had speech challenges like speaking slowly or finding the right words, and 16% couldn’t speak at all or had very limited speech. Interestingly, 58% of those who spoke had surgery on the right side of their brain.

Additionally, over half of the patients were in grade school, most in special education.

Two patients were in community college and seven patients had jobs.

Quality of Life After Surgery

After surgery, cognitive stability is often achieved, and there’s potential for enhancements in behavior, social communication, and various cognitive functions.

For best outcomes, early seizure control is crucial. Hemispheric disconnection remains the most effective treatment for achieving seizure freedom.

Critical Questions for Your Medical Team:

When faced with a medical situation, especially a rare one like Rasmussen’s encephalitis, it’s vital to be informed and feel confident about your child’s care. Here are five questions you might consider asking the medical team:

1. Experience and Track Record: “How many cases of Rasmussen’s encephalitis have you treated, and what have been the outcomes?”
2. Treatment Options: “What are the available treatment options for Rasmussen’s encephalitis, and what do you recommend for my child? Can you explain the pros and cons of each?”
3. Procedure Details: “If my child requires surgery, what will the procedure entail? What are the potential risks and benefits?”
4. Post-Treatment Care: “After treatment, what type of follow-up care will my child need? Are there any signs or symptoms I should watch out for?”
5. Support and Resources: “Do you have resources or support groups you can recommend for families dealing with Rasmussen’s encephalitis? How can I best support my child during this time?”

It’s also a good idea to ask about anything you don’t understand, any potential side effects of treatments, and to get a second opinion if you’re uncertain about the suggested course of action.

Key Resources

• Pathogenesis, diagnosis and treatment of Rasmussen encephalitis: a European consensus statement (Bien 2005)
• The natural history of Rasmussen’s encephalitis (Bien 2002)
• Epilepsy surgery for Rasmussen encephalitis: the UCLA experience. (Bellamkonda 2022)
• Timing of surgery in Rasmussen syndrome: is patience a virtue? (Hartman & Cross 2014)
• The Hemispherectomy Foundation maintains an active, private Facebook page for families of children with Rasmussen’s encephalitis to connect both before and after surgery. There is also a Facebook page for spanish-speaking and French families impacted by hemispherectomy.
• Rasmussen encephalitis (National Organization for Rare Disorders/NORD)