Variant Creutzfeldt-Jakob disease
Overview
The bovine spongiform encephalopathy affects cattle but the variant form can infect humans. Human infection can occur by consuming infected cattle products, especially the brain and other central nervous system tissues.
Symptoms
* Depression * Apathy * Withdrawal * Delusions * Chorea * Anxiety * Pain * Ataxia * Myoclonus * Dystonia * Dementia * Psychiatric symptoms * Depression * Withdrawal * Anxiety * Progressive ataxia * Dementia * Choreiform movements * Dystonic involuntary movements * Myoclonus * Prion protein deposits in brain * Spongiform changes in brain * Neuronal loss in brain * Gliosis * Ataxia * Myoclonus
Diagnosis
The diagnosis of CJD is suspected when there are typical clinical symptoms and signs such as rapidly progressing dementia with myoclonus. Further investigation can then be performed to support the diagnosis including * Electroencephalography — often has characteristic triphasic spikes * Cerebrospinal fluid analysis for 14-3-3 protein * MRI of the brain — often shows high signal intensity in the caudate nucleus and putamen bilaterally on T2-weighted images. Diffusion Weighted Imaging (DWI) images are the most sensitive. In about 24% of cases DWI shows only cortical hyperintensity; in 68%, cortical and subcortical abnormalities; and in 5%, only subcortical anomalies.[11] The involvement of the thalamus can be found in sCJD, even is stronger and constant in vCJD.[12] Clinical testing for CJD has always been an issue. Diagnosis has mostly been based on clinical and physical examination of symptoms. In recent years, studies have shown that the tumour marker Neuron–specific enolase (NSE) is often elevated in CJD cases[citation needed]. In one third of patients with sporadic CJD, deposits of "prion protein (scrapie)," PrPSc, can be found in the skeletal muscle and/or the spleen[citation needed]. Diagnosis of vCJD can be supported by biopsy of the tonsils, which harbour significant amounts of PrpSc; however, biopsy of brain tissue is the definitive diagnostic test.
Treatment
There is currently no cure for CJD; the disease is invariably fatal, though the search for viable treatments continues. An experimental treatment was given to a Northern Irish teenager, Jonathan Simms, beginning in January 2003.[14] The medication, called pentosan polysulphate (PPS) and used to treat interstitial cystitis, is infused into the patient's lateral ventricle within the brain. PPS does not seem to stop the disease from progressing, and both brain function and tissue continue to be lost. However, the treatment is alleged to slow the progression of the otherwise untreatable disease, and may have contributed to the longer than expected survival of the seven patients that were studied.[15] The CJD Therapy Advisory Group to the UK Health Departments advises that data are not sufficient to support claims that pentosan polysulphate is an effective treatment and suggests that further research in animal models is appropriate.[16] A 2007 review of the treatment of 26 patients with PPS finds no proof of efficacy because of the lack of accepted objective criteria.[17] Scientists have investigated using RNA interference to slow the progression of scrapie in mice. The RNA blocks production of the protein that the CJD process transforms into prions. This research is unlikely to lead to a human therapy for many years.[18] Both amphotericin B and doxorubicin have been investigated as potentially effective against CJD, but as yet there is no strong evidence that either drug is effective. Further study has been taken with other medical drugs, but none are effective.