The dementia in Creutzfeldt-Jakob disease is also due to degeneration of the cerebral cortex, but the clinical manifestations are much more distinctive than in Alzheimer’s and Pick’s diseases, and a possible etiological agent is presently under investigation.
In this disorder the clinical disturbance is often ushered in by motor or sensory symptoms. Any patient may notice a varied combination of difficulty in vision, hearing, motor strength, or coordinated movements. These symptoms may progress in the course of weeks to blindness, deafness, and hemiplegia, and will often be associated with abnormal myoclonic jerks and tremors. Simultaneously the patient loses intellectual capacity. All the signs and symptoms of dementia are seen, but they develop rapidly over the course of a-few weeks. Within four to eight months of the onset of symptoms, the patient has lost all cognitive function and is bedridden and decerebrate, with severe total body and limb myoclonic jerking.
Creutzfeldt-Jakob Disease Life Expectancy
The EEG is helpful in the diagnosis of this condition because it is diffusely and severely abnormal quite early in the disease. The normal rhythms of the EEG are lost and replaced with slow activity, often interrupted with high amplitude sharp wave complexes that may be synchronous with the myoclonic jerks.
The cerebral pathology of Creutzfeldt-Jakob disease is distinctive. It consists of a severe de generation of the cerebral cortex. In the most affected parts of the cortex there is a total obliteration of the cytoarchitecture. The normal appearance of cortical layers and columnar organization of neurons is lost and is replaced by a disorganized glial overgrowth. This most severely affected region may take on a peculiar sponge-like appearance because of vacuoles that occur in both neuronal and astrocytic processes (status spongiosus).
The basal ganglia and cerebellum can also degenerate in this disease. The variety of clinical manifestations seen in patients with this disorder can be explained by variation in the sites of maximal pathologic disorder. If this is the occipital cortex, visual disturbances leading to blindness will be prominent; if the temporal cortex is affected early, then aphasia and deafness can be expected; if the cerebellum, then ataxia will characterize the early course.
With the advance of the pathologic condition the decerebrate condition is an inevitable outcome.Creutzfeldt-Jakob disease is an uncommon disorder. Most examples have occurred in middle- aged persons, but it has been described as early as age 20. There is no special sex incidence. Etiology has been as obscure as for the other dementias. However, an importantdiscovery has been made that may have far-ranging implications for the other cerebral degenerations.
It has proved possible to transmit a condition identical in clinical manifestations and in cerebral pathologic symptoms to the chimpanzee by injecting into that animal tissue from the brain of patients with Creutzfeldt-Jakob disease. It takes several months for the disorder to manifest itself in the animal. But once seen, the symptoms advance rapidly, as in the human. This evidence suggests some transmissible agent as a cause of Creutzfeldt-Jakob disease. In this respect it resembles the neurologic condition kuru discovered among New Guinea aboriginals and scrapie, a disease of sheep. Whatever the nature of these transmissible agents (they have been called slow viruses), they represent a new territory in the biology of neurologic disease, and may come to explain many other clinical and pathologic entities.