LAUSR

Creutzfeldt–Jakob disease (CJD) is a rare but rapidly progressive fatal neurological disease. The criteria of the World Health Organization are currently used for the clinical diagnosis of sporadic CJD. Although magnetic resonance imaging (MRI) findings have not been included in the criteria, many studies have recently described bilateral hyperintense lesions in the caudate nuclei and putamen as well as in the cortices on diffusion-weighted MRI (DWI). Here, we report on a patient with probable sporadic CJD who demonstrated unilateral hemispheric involvement on MRI. An 87-year-old man developed progressive cognitive decline with unstable gait. His condition was diagnosed as Alzheimer’s disease at a local clinic. His Mini-Mental State Examination score was 22. One month later, he presented with tonic convulsions in the right upper and lower limbs with consciousness disturbance and was admitted to our hospital. After treatment with anticonvulsant, he became fully conscious, and his convulsions resolved. After the convulsions resolved, neurologic examination revealed akinetic mutism, right hemiparesis, right dominant upper and lower limb myoclonus, bilateral upper limb muscular rigidity, and right foot plantar dystonia. None of these symptoms ameliorated during the follow-up period. DWI on admission showed hyperintensities in the frontal, temporal, and parietal cortices only in the left hemisphere (Fig. 1a), although fluidattenuated inversion recovery (FLAIR) did not detect significant hyperintensities in those areas (Fig. 1b). An electroencephalogram showed bilateral slow waves with periodic synchronous discharges. Brain perfusion single-photon emission computed tomography showed severe hypoperfusion in the frontal, temporal, and parietal lobes and in the thalamus of the left hemisphere (Fig. 1i). Cerebrospinal fluid analysis revealed a normal number of cells, normal glucose, and slightly high protein levels. The tests for virus antibodies, polymerase chain reaction for herpes simplex virus, and paraneoplastic-associated antibodies were all negative. However, cerebrospinal fluid analysis showed a marked increase in neuron-specific enolase, total tau, and 14-3-3 protein. A prion protein gene analysis showed Codon129 Met/Met and Codon219 Glu/Glu and no mutations. Per the World Health Organization criteria, we diagnosed his condition as probable sporadic CJD. DWI at 2 weeks after admission revealed progressed hyperintensities in the frontal, temporal, and parietal cortices and in the thalamus only in the left hemisphere (Fig. 1c). Hyperintensities were observed in some of those areas, and a left subdural hematoma (SDH) was seen on FLAIR (Fig. 1d). DWI at 4 weeks after admission showed weakened hyperintensities in the frontal, temporal, and parietal cortices areas and new hyperintensities in the left caudate nucleus (Fig. 1e). Hyperintensities were observed in the left thalamus, and a worsened left SDH was observed on FLAIR (Fig. 1f). DWI at 6 weeks after admission showed almost the same hyperintensities as at 4 weeks after admission (Fig. 1g). Hyperintensities were newly observed in the left temporal and parietal cortices; a worsened left SDH and significant progression of bilateral cerebral atrophy were seen on FLAIR (Fig. 1h). During hospitalization, the general conditions of the patient gradually worsened, and he died of respiratory insufficiency at 4 months after admission. The patient’s progressive neurologic deficits were predominantly on the right side and may have