What characterizes Creutzfeldt-Jakob disease?
Creutzfeldt-Jakob disease (CJD) is a rare and fatal degenerative disease with rapidly progressive dementia and neurologic signs, characterized by the pathologic triad of spongiform degeneration of the brain, neuronal death, and astrocytic gliosis.
What are the varieties of CJD?
There are four varieties of CJD, which are known as sporadic, familial, iatrogenic, and variant.
Which of the varieties of CJD is the most common?
The most common type of CJD, and also prion disease in humans, is sporadic CJD (sCJD), accounting for 85%-90% of cases.
What are the eponyms of the clinical phenotypes of sCJD?
The eponyms of the clinical phenotypes of sCJD are: - the Heidenhain phenotypic variant, which signal abnormality is usually restricted to the bilateral parieto-occipital cortex, including the primary visual area; - the Brownell-Oppenheimer phenotypic variant, which usually manifests with cerebellar ataxia, and the MR involvement is selective in the cerebellar cortex; - the Stern phenotypic variant, which shows signal hyperintensity of the thalamus, and correlates with degeneration of the thalamus at histopathological analysis; - Garcin phenotypic variant that characterizes by limited involvement of the striata.
What are the clinical features of CJD
The clinical criteria of CJD are rapidly progressive dementia and at least two of the following clinical characteristics: myoclonic jerks, visual disturbance, cerebellar dysfunction, pyramidal or extrapyramidal features, and akinetic mutism, with a usually less than two-year evolution.
What are the tests that can contribute to the diagnosis of CJD?
The probable diagnosis of CJD relies on the clinical features combined with results of at least one paraclinical test – EEG, CSF analysis, and MR imaging abnormalities: - EEG may show sharp waves complexes (PSWCs); - CSF analysis usually demonstrates increased levels of the 14-3-3 protein in CSF, which is an important biomarker for the diagnosis of sCJD; - MR imaging reveals hyperintensity abnormalities in the cortical and basal ganglia.
How does one make a definitive diagnosis of CJD?
The definitive diagnosis of CJD is by the detection of an accumulation of an abnormal form of the human prion protein PrPSc in the brain. Currently, pathologic analysis of the brain specimens, by biopsy or autopsy, is required for a definitive diagnosis, which is rarely achieved. The histopathological characteristics are spongiform degeneration, neuronal loss, and gliosis.
What are the MRI findings of CJD?
The MRI findings are symmetrical or asymmetrical high signal intensity abnormalities on T2-weighted and FLAIR, associated with restricted diffusion seen to involve the caudate nuclei, the putamina, and the cerebral cortex. DWI is highly sensitive to CJD. There is a decrease in the apparent diffusion (ADC) in the affected areas. The MR changes correlate with the neuropathologic findings of spongiosis, neuronal loss, and astrogliosis.
On imaging, what are the differential diagnoses of CJD?
The differential diagnosis of CJD on imaging is hypoxic-ischemic disease, hypoglycemic encephalopathy, autoimmune encephalitis, Leigh disease, hepatic encephalopathy, osmotic demyelination syndrome and venous sinus thrombosis.
Brain MRI shows bilateral and symmetrical abnormal signal intensity in the basal ganglion, particularly evident within the head of the caudate nucleus and in the putamen.
The basal ganglia are hyperintense on T2, and more significantly on FLAIR. There is diffusion restriction involving these regions, characterized by hyperintensity on DWI, with corresponding decreased intensity on ADC maps.
There are bilateral and symmetrical focal hyperintensities on FLAIR/T2-weighted images, with no restricted diffusion, and elevated diffusivity on ADC, in the occipital cerebral cortex.
Conclusion:
The pattern of abnormality and diffusion restriction involving the basal ganglia is suspicious for Creutzfeldt-Jakob disease.