Question

A child presents with myoclonus jerks and decreased performance in school. There is a history of fever at the age of 1 year with rash. It is suggestive of which condition?

• A. Subacute sclerosing panencephalitis
• B. Mesial temporal sclerosis
• C. Polio
• D. Measles

Hint:

Think about which late neurological complication follows measles infection in early childhood after a latent period of years.

Answer 1

The Correct Option is A

Step 1: Identify the key features of the clinical scenario.

• Child with myoclonic jerks (involuntary muscle contractions)
• Decreased performance in school (cognitive decline / mental deterioration)
• History of fever with rash at age 1 year (strongly suggests measles infection in infancy)

Step 2: Apply to SSPE pathophysiology. Subacute Sclerosing Panencephalitis (SSPE) is a progressive, fatal neurological disorder caused by a defective, persistent measles virus in the CNS. Key features:

• History of measles infection in early childhood (usually before age 2), which is the primary risk factor.
• Latent period of 6-8 years before neurological symptoms appear.
• Progressive neurological stages: Stage I -- behavioral changes, declining school performance; Stage II -- myoclonic jerks, seizures, EEG showing periodic complexes; Stage III -- dementia, rigidity; Stage IV -- vegetative state, death.

Step 3: Exclude other options.

• Mesial temporal sclerosis: Causes temporal lobe epilepsy, not myoclonus with cognitive decline post-febrile rash.
• Polio: Causes flaccid paralysis (anterior horn cell disease), not myoclonus or cognitive decline.
• Measles (acute): Is the causative infection, not the resulting neurological syndrome. SSPE is the correct diagnosis for the late neurological complication.

Conclusion: Myoclonus + cognitive decline + history of measles-like illness in infancy = SSPE.