Challenges in diagnosing SSPE.

Purpose: The typical clinical presentation of subacute sclerosing panencephalitis (SSPE) includes behavioral and intellectual changes followed by myoclonia. However, there are a considerable number of SSPE cases which present with distinct clinical features that can lead to a diagnostic difficulty. In this report, we summarize the clinical features of patients with SSPE who have uncommon presentations or features of the disease or coexisting medical conditions which may lead to diagnostic difficulties.
Methods: We studied 173 patients, all under the age of 17. Patients were included in the study group according to following criteria: onset of the disease before age 2 years, seizures occurring before the onset of myoclonia and/or behavioral symptoms, extrapyramidal or cerebellar signs and ocular manifestations as initial presenting symptoms, fulminant course including coma or death within 6 months. Additionally, patients with onset of SSPE at the setting of a known neurological disorder are defined as another group in the study.
Results: Out of 173 patients with SSPE who were followed in two neurology centers, 31 (17.9%) met our criteria.
Conclusions: We found a relative high frequency of these clinical features. Our findings suggest that clinicians should be aware of this clinical characteristics and rule out the disease in cases were other common causes have been excluded, especially in countries with insufficient measles immunization.