ADULT-ONSET SUBACUTE SCLEROSING PANENCEPHALITIS - CASE-REPORTS AND REVIEW OF THE LITERATURE

Subacute sclerosing panencephalitis (SSPE) is mainly thought of as a d isorder of childhood and adolescence and may not be readily recognized when presenting later in life. Prior reports have suggested that adul t-onset SSPE may have atypical features. We have added two cases to th e existing literature on adult-onset SSPE, compared them with a more c lassic juvenile presentation, and extensively reviewed those reports t hat were published after the etiological link with the measles virus h ad been established. Adult-onset SSPE patients present at a mean age o f 25.4 years (range 20-35 pears). They have a higher proportion of eit her negative history of measles exposure or undocumented history by th e reporting authors. Those with available history of measles exposure tend to have it either earlier (younger than 3 years old) or later (af ter 9 years) than the usual childhood measles infection. Where the pri mary infection is known, unusually long measles-to-SSPE intervals have been documented, ranging from 14 to 22 years. None of the cases follo wed measles vaccination. Visual symptomatology was very frequent, with 8 of the 13 cases reviewed having a purely ophthalmological presentat ion: only 2 patients presented with behavioral changes. Although the c ourse of the disease was progressive and fatal in the majority, there appeared to be a higher rate of spontaneous remission as compared with childhood-onset SSPE. Myoclonus, spastic hemiparesis, bradykinesia, a nd rigidity were the predominant motor manifestations. Neuropathology revealed cortical and subcortical gray matter involvement preferential ly of the occipital lobes, thalamus, and putamen. The importance of re cognizing the spectrum of potential presentations of SSPE and providin g an early diagnosis will increase as more effective treatments become available.