Subacute sclerosing panencephalitis (SSPE) is a well-known childhood disease; however, the adult onset of SSPE cases are also widely recognized where the oldest case reported is 52 years old. We report a 61-year-old woman patient presenting with atypical clinical and EEG features, diagnosed with SSPE. Measles and SSPE have decreased dramatically owing to worldwide immunization programs; however, there are still reasons to consider SSPE in differential diagnosis even in patients presenting with atypical clinical findings and older ages. First, there is a generation who missed the immunization era, constituting a latent disease pool. Second, antivaccination movements have led to a decline in MMR (measles, mumps, rubella) vaccination worldwide, leading to measles outbreaks and potential future SSPE cases. Third, most of the vaccination programs start measles immunization at the age of 12 months, leading to a shift in the incidence below the age of 1 year, when the risk of developing SSPE in adult life is higher. Finally, disruption in vaccination programs, in which fast disease transmission due to close contact living, unhygienic conditions of refugee camps, and limited access to health care in displaced populations have also led to measles outbreaks. In conclusion, we believe that neurologists for adults should consider SSPE in differential diagnosis, even in older patients with atypical presentations.
Keywords: adult SSPE; asymmetric periodic slow waves; atypical; senile onset; vaccination.