What is the treatment for subacute sclerosing panencephalitis (SSPE)?

Treatment for Subacute Sclerosing Panencephalitis (SSPE)

There is no curative treatment for SSPE, but a combination of intrathecal interferon-alpha and oral isoprinosine (inosiplex) offers the best chance for disease stabilization or improvement in patients with this fatal complication of measles infection.

Disease Overview

SSPE is a rare but devastating late complication of measles virus infection that occurs months to years after the initial infection. It represents a persistent defective measles virus infection of the central nervous system characterized by:

• Progressive neurological deterioration
• Cognitive decline
• Myoclonic jerks
• Motor dysfunction
• Ultimately leading to a vegetative state and death

Diagnostic Criteria

The diagnosis of SSPE is based on:

• Clinical presentation with characteristic stages of neurological deterioration
• Elevated measles antibody titers in cerebrospinal fluid (CSF)
• Characteristic EEG pattern showing periodic complexes
• Brain MRI findings
• CSF PCR for measles virus RNA

Treatment Algorithm

First-Line Therapy

1. Combination therapy 1, 2:
   • Oral isoprinosine (inosiplex)
   • Intrathecal interferon-alpha

This combination has shown the highest rate of disease stabilization or improvement in SSPE cases, though complete remission is rare.

Supportive Treatments

1. Seizure management:

   • Antiepileptic drugs for myoclonic jerks and seizures

2. Symptomatic management:

   • Treatment of spasticity
   • Nutritional support
   • Prevention of complications of immobility

Experimental/Adjunctive Options

1. Ribavirin 3
2. Lamivudine 4
3. Vitamin A supplementation 5
4. Ketogenic diet (limited evidence) 6

Treatment Efficacy and Expectations

Despite treatment efforts, SSPE remains a progressive and almost universally fatal disease. However, treatment may:

• Slow disease progression
• Improve quality of life temporarily
• Extend survival time beyond the typical 1-3 years after diagnosis

Important Considerations

• Patients who respond to treatment typically need to continue therapy lifelong 2
• The disease course is variable, with some patients experiencing plateau periods or temporary improvements
• Early diagnosis and treatment initiation may improve outcomes

Prevention

The only effective prevention for SSPE is measles vaccination. The MMR vaccine has dramatically reduced the incidence of SSPE in countries with high vaccination coverage 7, 5.

Pitfalls and Caveats

• SSPE can occur even in vaccinated individuals, though this is extremely rare 4
• Treatment response is unpredictable and varies between patients
• Many treatments are based on case reports and small studies rather than large clinical trials
• Long-term administration of interferon-alpha can have significant side effects
• The disease may initially be misdiagnosed as epilepsy, behavioral disorders, or other neurological conditions, delaying appropriate treatment

Monitoring

Patients on treatment should be monitored for:

• Disease progression
• Treatment side effects
• Complications of immobility
• Seizure control
• Nutritional status

While SSPE remains a devastating diagnosis with poor outcomes, early recognition and aggressive treatment with interferon-alpha and isoprinosine offers the best chance for slowing disease progression and improving quality of life for affected patients.