Towards an early clinical diagnosis of sporadic CJD VV2 (ataxic type)

Introduction Sporadic Creutzfeldt-Jakob disease (sCJD) includes a broad spectrum of clinical-pathological subtypes, which complicates the clinical differential diagnosis with other rapidly progressive neurological syndromes. Aim To provide a better characterisation of clinical features and results of diagnostic investigations, especially at an early disease stage, in patients with sCJDVV2, the second most common sCJD subtype. Methods We evaluated neurological symptoms/signs, and results of brain diffusion-weighted resonance imaging (DW-MRI), electroencephalographic recordings (EEG) and cerebrospinal fluid (CSF) biomarker studies in 120 patients with a definite (n=93) or probable (n=27) diagnosis of sCJDVV2. Results All patients presented with prominent cerebellar signs, which were often associated with memory loss and/or oculomotor, visual or peripheral/spinal cord signs. In contrast, dementia was invariably a late finding. All CSF samples were positive for the 14-3-3 protein assay and had total-tau protein levels above 1250 pg/mL. Brain DW-MRI showed hyperintensity of basal ganglia, thalamus and cerebral cortex, respectively in 91.5%, 57.4% and 19.1% of cases. EEG revealed periodic sharp-wave complexes in only 17.8% of cases. Conclusions sCJDVV2 should be considered in any patient presenting with a rapidly progressive ataxia, especially when associated with oculomotor, visual or peripheral/spinal cord signs, even in the absence of dementia or myoclonus. CSF assays and brain DW-MRI represent sensitive diagnostic tests, even at an early stage. These data strongly suggest that sCJDVV2 can be clinically diagnosed early and accurately based on clinical data, DW-MRI, CSF assays and codon 129 genotyping and provide the basis for improved and subtype-specific diagnostic criteria of sCJD.