Three cases of Creutzfeldt-Jakob disease with prion protein gene codon180 mutation presenting with pathological laughing and crying.

Although there are no reports of pathological laughing and crying being observed in patients with Creutzfeldt-Jakob disease (CJD), the author experienced three patients with CJD with prion protein gene codon180 mutation (V180I CJD) who showed this characteristic clinical finding. This finding was observed from the early disease stage in all 3 patients and continued for several months. Startle reaction was also remarkable in all patients, although myoclonus was generally mild. The dissociation between the startle reaction and myoclonus was suspected to be another feature of V180I CJD. The pathological laughing and crying co-occured with the startle reaction and stopped right before the onset of akinetic mutism, and the degree of both symptoms was almost parallel during this period. On the basis of MRI and autopsy findings, pathological laughing and crying was suspected of being induced by the widespread cerebral cortical involvement that is characteristic of V180I CJD. From the present observations, the author speculated that pathological laughing and crying may be a comparatively frequent observation in V180I CJD patients.