Creutzfeldt-jakob Disease 1

8/3/2019 Creutzfeldt-jakob Disease 1

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By,

Anu EdwinJosefreeda

Group

III


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What is Creutzfeldt-Jakob disease? CreutzfeldtJakob disease or CJD is a degenerative

neurological disorder that is incurable and invariablyfatal.

It is the most common amongthe types of transmissiblespongiform encephalopathy

found in humans.


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Types of CJDThe three main categories of CJD are

sporadic CJD, which occurs for no known reason

hereditary CJD, which runs in families acquired CJD, which occurs from contact with

infected tissue, usually during a medical procedure


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TRANSMISSION The defective protein can be transmitted by contaminated

harvested human growth hormone (hGH) products,Immunoglobulins (IVIG), corneal grafts, dural graftsor electrode implants (acquired or iatrogenic form: Icjd)

The disease has also been shown to result from usage ofHGHdrawn from the pituitary glands of cadavers who died fromCreutzfeldtJakob Disease,.

Consuming beef or beef products containing prion particlescan also cause the development of classic CJD

Cannibalism has also been implicated as a transmissionmechanism for abnormal prions, causing the disease known askuru, found primarily among women and children of the Foretribe in Papua New Guinea. While the men of the tribe ate thebody of the deceased and rarely contracted the disease, the

women and children, who ate the less desirable body parts, were

8 times more likely to contract the disease from infected tissue.


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CAUSE OF CJD Transmissible spongiform encephalopathy diseases are

caused by prions. The diseases are thus sometimes calledprion diseases.

The prion that is believed to cause Creutzfeldt

Jakobexhibits at least two stable conformations. One, the nativestate, is water-soluble and present in healthy cells. As of2007, its biological function is presumably intransmembrane transport or signaling. The otherconformational state is very poorly water-soluble and

readily forms protein aggregates. People can also acquire CJD genetically through a mutation

of the gene that codes for the prion protein (PRNP). Thisonly occurs in 510% of all CJD cases.


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CAUSE The CJD prion is dangerous because it promotes refolding of

native proteins into the diseased state. The number ofmisfolded protein molecules will increase exponentially,andthe process leads to a large quantity of insoluble prions in

affected cells. This mass of misfolded proteins disrupts cellfunction and causes cell death. Mutations in the gene for theprion protein can cause a misfolding of the dominantly alphahelical regions into beta pleated sheets. This change in

conformation disables the ability of the protein to undergodigestion. Once the prion is transmitted, the defectiveproteins invade the brain and are produced in a self-sustaining feedback loop, causing exponential spread of theprion, leading to death within a few months, although a few

patients have lived as long as two years.


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RISK FACTORSMost cases of Creutzfeldt-Jakob diseaseoccur for

unknown reasons, and no risk factors can beidentified. However, a few factors seem to beassociated with different kinds of CJD.

Age.

Genetics

Exposure to contaminated tissue.


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SYMPTOMS Rapidly developing delirium or dementia (over

the course of a few weeks or months)

Blurred vision (sometimes) Changes in gait (walking)

Muscle twitching

Hallucinations

Lack of coordination (for example, stumbling andfalling)

Muscle stiffness


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SYMPTOMS Myoclonic jerks or seizures

Nervous, jumpy feelings

Personality changes Profound confusion, disorientation

Sleepiness

Speech impairment


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COMPLICATIONS Infection

Heart failure

Respiratory failure Loss of ability to function or care for oneself

Loss of ability to interact with others

Death


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TESTS AND DIAGNOSISThe exam is likely to reveal such characteristic symptoms as

muscle twitching and spasms, abnormal reflexes, andcoordination problems. People with CJD also may have areas

of blindness and changes in visual-spatial perception.In addition, doctors commonly use these tests to help detect

CJD

Electroencephalogram (EEG).

Magnetic resonance imaging (MRI).

Spinal fluid tests. lumbar puncture popularly known as aspinal tap

Tonsil biopsy.


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TREATMENT There is no treatment that can cure or control CJD. Researchers

have tested many drugs, including amantadine,steroids, interferon,acyclovir, antiviral agents, and antibiotics.Studies of a variety of other drugs are now in progress. However,so far none of these treatments has shown any consistent benefit

in humans. Current treatment for CJD is aimed at alleviating symptoms and

making the patient as comfortable as possible. Opiate drugs canhelp relieve pain if it occurs, and the drugs clonazepam andsodium valproate may help relieve myoclonus. During later

stages of the disease, changing the person's position frequentlycan keep him or her comfortable and helps prevent bedsores. Acatheter can be used to drain urine if the patient cannot controlbladder function, and intravenous fluids and artificial feedingalso may be used.


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PROGNOSIS The outcome is usually very poor. Within 6 months or

less of the onset of symptoms, the person will becomeincapable of self-care.

The disorder is fatal in a short time, usually within 8months, but a few people survive as long as 1 or 2 yearsafter diagnosis. The cause of death is usually infection,heart failure, or respiratory failure.


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PREVENTION People should never donate blood, tissues, or organs if they have

suspected or confirmed CJD, or if they are at increased risk because of afamily history of the disease, a dura mater graft, or other factor.

Wash hands and exposed skin before eating, drinking, or smoking. Cover cuts and abrasions with waterproof dressings. Wear surgical gloves when handling a patient's tissues and fluids or

dressing the patient's wounds. Avoid cutting or sticking themselves with instruments contaminated

by the patient's blood or other tissues. Use face protection if there is a risk of splashing contaminated material

such as blood or cerebrospinal fluid. Soak instruments that have come in contact with the patient in

undiluted chlorine bleach for an hour or more, then usean autoclave (pressure cooker) to sterilize them in distilled water for atleast one hour at 132 - 134 degrees Centigrade.


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Documents

Creutzfeldt-jakob Disease 1