Young-onset sporadic Creutzfeldt–Jakob disease with atypical phenotypic features: a case report

Sporadic Creutzfeldt–Jakob disease, with a mean survival of 6 months, is duly considered among the most fatal neurological disorders. Rapidly progressive dementia with multi-axial involvement of the nervous system is the known presentation. Although, the peak age at onset is between sixth and eighth decades, cases of young-onset sporadic Creutzfeldt–Jakob disease have also been reported in the literature. Interestingly, these young-onset cases were reported to have some features distinct from their older age group counterparts, such as slower progression as well as longer duration of illness, dominance of psychiatric manifestations at the onset, and relatively less prevalence of radiological and electroencephalographic abnormalities.

We describe here the case of a 42-year-old Asian woman from India who presented with cerebellar ataxia, pyramidal and extrapyramidal involvement, followed by rapidly progressive dementia along with myoclonus, all within a span of 1 month. Probable infective, metabolic, autoimmune, and paraneoplastic etiologies were ruled out. Magnetic resonance imaging of her brain revealed bilateral caudate nucleus hyperintensity in T₂/fluid-attenuated inversion recovery sequence. Diffusion-weighted imaging revealed bilateral caudate and putaminal diffusion restriction plus ribbon pattern in bilateral parieto-occipital and insular cortex. Serial electroencephalography revealed diffuse slowing of background activity along with triphasic waves in short periodic interval. Cerebrospinal fluid was tested positive for 14-3-3 protein. Based on these findings, a diagnosis of sporadic Creutzfeldt–Jakob disease was made.

Our patient represents an atypical clinical situation as she is much younger than the usual presentation of Creutzfeldt–Jakob disease and it progressed far too rapidly. Cognitive decline came late in the temporal sequence of clinical events; rather, the onset was dominated by features consistent with cerebellar ataxia and basal ganglia involvement. The presence of magnetic resonance imaging abnormality and electroencephalography changes are other rare findings in young-onset sporadic Creutzfeldt–Jakob disease.