Summary about Disease
Subacute sclerosing panencephalitis (SSPE) is a rare, progressive, and fatal inflammatory disease of the central nervous system. It primarily affects children and young adults who had measles, typically before the age of two, even if they received the measles vaccine. SSPE is characterized by cognitive decline, behavioral changes, myoclonic seizures, and motor dysfunction. It's a slowly progressing encephalitis caused by a persistent infection with a mutated measles virus.
Symptoms
Symptoms of SSPE typically develop years after the initial measles infection (typically 6-10 years later). Initial symptoms can be subtle and may include:
Gradual decline in school performance
Personality changes (irritability, mood swings)
Behavioral problems
Forgetfulness
Muscle twitching or jerking (myoclonus)
Clumsiness As the disease progresses, more severe neurological symptoms appear:
Involuntary movements and seizures
Muscle rigidity and spasms
Vision problems, including blindness
Difficulty with speech and swallowing
Progressive cognitive decline, leading to dementia
Coma
Causes
SSPE is caused by a persistent infection of the brain with a mutated measles virus. The exact reason why the measles virus persists and causes SSPE in some individuals is not fully understood, but potential factors include:
Early age of measles infection (before 2 years of age)
Defective or incomplete immune response to measles
Mutations of the measles virus that allow it to persist in the brain
Geographical location - higher incidence in certain regions.
Medicine Used
There is no cure for SSPE, and treatment focuses on managing symptoms and slowing the progression of the disease. Medications used include:
Anticonvulsants: To control seizures (e.g., clonazepam, valproic acid)
Immunomodulators: Interferon alpha has been used to try to slow disease progression, although effectiveness varies.
Isoprinosine (Inosine Pranobex): This antiviral medication has been used in some cases with varying degrees of success.
Is Communicable
SSPE itself is not communicable (contagious). It arises from a persistent measles virus infection within the individual's brain. However, the measles virus is highly contagious. If someone with SSPE were still shedding active measles virus (which is rare but possible, especially early in the disease course), they could potentially transmit measles to unvaccinated individuals.
Precautions
The primary precaution to prevent SSPE is measles vaccination. The MMR (measles, mumps, rubella) vaccine is highly effective in preventing measles infection. Other precautions include:
Ensuring all children receive the recommended MMR vaccinations on schedule.
Maintaining high levels of herd immunity through vaccination.
Avoiding exposure to individuals with active measles infection.
Prompt diagnosis and treatment of measles infection if it occurs, to reduce the chance of the virus persisting.
How long does an outbreak last?
SSPE is not an outbreak-related disease in the traditional sense. It is a chronic, progressive condition that develops years after a measles infection. Measles outbreaks, however, can increase the risk of SSPE developing in susceptible individuals in the future. Therefore, controlling measles outbreaks is crucial to reducing the incidence of SSPE.
How is it diagnosed?
Diagnosis of SSPE typically involves a combination of clinical evaluation and diagnostic tests, including:
Clinical presentation: Characteristic symptoms such as cognitive decline, myoclonus, and seizures.
Electroencephalogram (EEG): Shows characteristic periodic complexes.
Cerebrospinal fluid (CSF) analysis: Elevated measles antibody titers in the CSF.
Magnetic resonance imaging (MRI) of the brain: May show characteristic white matter abnormalities.
Brain biopsy: Rarely performed but may be necessary in atypical cases.
Measles antibody testing: High levels of measles antibodies in the blood and cerebrospinal fluid.
Timeline of Symptoms
The timeline of SSPE symptoms is highly variable, but generally follows a progressive course:
Initial Stage (Subtle Changes): Months to years before diagnosis. Gradual decline in school performance, personality changes, behavioral problems, forgetfulness, and subtle muscle twitching.
Intermediate Stage (Neurological Progression): Increasing frequency and severity of myoclonus, seizures, muscle rigidity, vision problems, and speech difficulties. Cognitive decline becomes more pronounced.
Late Stage (Severe Disability): Profound cognitive impairment, complete loss of motor function, blindness, coma, and eventual death. The rate of progression can vary significantly between individuals.
Important Considerations
SSPE is a devastating disease with a poor prognosis.
Early diagnosis and treatment are crucial, although treatment options are limited.
Measles vaccination is the most effective way to prevent SSPE.
Genetic factors may play a role in susceptibility to SSPE, but this is not fully understood.
Continued research is needed to develop more effective treatments for SSPE.
Support for affected families is essential, as the disease places a significant emotional and financial burden on them.