Diffusion tensor imaging in patients with Creutzfeldt-Jakob disease

Creutzfeldt–Jakob disease (CJD) is a rapidly progressive, fatal and transmissible neurodegenerative disorder. The clinical features of typical CJD are progressive dementia, generalised myoclonus and, in the later stages, akinetic mutism. Characteristic findings in laboratory examinations include periodic sharp wave complexes (PSWCs) on electroencephalogram and elevated 14-3-3 protein in CSF. However, these tests cannot be applied to assessment of the progression of the lesion. Brain biopsy confirms the diagnosis of CJD but it does not reveal how the lesion develops in the brain. MR examinations are routinely performed in Japan for patients with suspected CJD. Diffusion weighted imaging (DWI) is now accepted as the most useful imaging modality for diagnosing patients with CJD, even in the early stages or without PSWCs.1 DWI demonstrates hyperintensity for lesions in the striatum and the cerebral cortex, with high sensitivity.2 However, the underlying pathomechanism of the abnormal signals remains unclear. Diffusion tensor imaging (DTI) is a new MR technique that can indirectly assess the integrity of tissue. The diffusivity and anisotropy of water molecular displacement are quantified by apparent diffusion coefficient (ADC) and fractional anisotropy (FA), respectively. To our knowledge, however, the utility of DTI in CJD has not been reported. Here …