A review of Creutzfeldt-Jakob disease and other prion diseases

Introduction. Creutzfeldt-Jakob disease (CJD) is a rapidly progressive dementia syndrome which is probably caused by prions. The annual incidence of this disease is 1/1,000,000. Most cases are sporadic in type, although 10-15% are familial. The total incidence of CJD has not changed following the epidemic due to a new variant (nv-CJD); however, this has led to greater awareness of the subject. Objective. To review current scientific knowledge of CJD. Development. A search was made for relevant literature using MEDLINE. The criteria proposed for diagnosis of CJD include the presence of progressive dementia and at least two of the following characteristics: 1. Myoclonias, 2. Cortical blindness, 3. Pyramidal, extrapyramidal or cerebellar signs, 4. Akinetic mutism, or 5 Abnormal EEG. Laboratory and neuroimaging investigations may also help in diagnosis of CJD, although neuropathological confirmation is necessary for definite diagnosis. Two promising methods of pre mortem diagnosis of CJD are determination of 14-3-3 protein in the cerebrospinal fluid, in the case of sporadic CJD, and biopsy of the palatine tonsil in the case of nv-CJD. The physiopathology of CJD seems to be centred on the proteins forming prions, which are glycoproteins found in the plasmatic membrane and are very often expressed in the neurons, particularly at neuromuscular junctions and synapses The pathological form resists proteolytic degradation, so that they accumulate in the CNS. The precise neurotoxic mechanism of these proteins is still not clear. Conclusions. There is still no treatment for CJD. Further studies of the physiopathological mechanisms of prion diseases may help in the development of treatment to delay the progress of this disease.