Prion Diseases

                                     Prion Diseases

                                               P.K. Ghatak, MD

Draft CJD:

Creutzfel

1. Creutzfeldt-Jakob Disease.

In 1922, a German neurologist Hans Gerhard Creutzfeldt described a patient with a neurodegenerative disease. Alfon Maria Jakob described 4 more cases of rapidly progressive neurodegenerative disease, just as Creutzfeldt described. Dr. Jacob credited this new disease to Dr. Creutzfeldt. This rare but an important infectious disease is known as Creutzfeldt-Jakob disease (CJD).

What causes CJD.

It is a Prion (PrP)

These are several ways people can be infected.

1. Spontaneously evolved – spPrP.

2. Consuming beef of animal suffering from Mad-Cow-Disease.

3. PNRP (gene controlling Prion generation) mutated gene inherited in Autosomal dominant manner.

4. Receiving contaminated Corneal transplants, and injections of Pituitary Growth Hormone extracted from cadavers.

The CJD is a very rare disease, the incident is about 1 in 1 million in the general population worldwide and inherited CJD is only 7.5% cases of CJD, the remaining 85 % cases arise sporadically from unknown cause.

Symptoms:

In the majority of cases the initial symptoms are progressive dementia, ataxia and behavioral abnormalities, beginning age of 55 to 75. Soon patients have dysarthria, myoclonus and mutism There is rapid deterioration of condition and the majority of the patients are dead within 6 months, rarely a few survives for 2 years.

Diagnosis:

EEG shows triphasic sharp waves.

CSF :

Recently a new laboratory method is used, called QUIC or RC QUIC to multiply PrP sc protein in the CSF or other tissues in sufficient amount for a positive identification of CJD disease.

MRI of the brain typically shows punctate holes in the caudate nuclei.

Histopathology:

A combination of neuronal gliosis of Astrocytes and spongiform lesions.

Diagnostic test is Western blot detecting PrP sc protein. QUIC is a prefer test nowadays.

2. Variant CJD.

In 1996 the first human case of mad-cow disease was described. It is called Variant CJD (vCJD) to distinguish from non-animal source of Prion disease. Clinically and pathologically, both forms of CJD are the same. Prion particles are concentrated in the brain and nervous tissue of cow, once the practice of adding nerve tissue of dead animal to animal feeds was discontinued the Mad cow disease and vCJD disappeared.

3. Gerstmann-Straussler-Scheinker syndrome (GSS) is a very rare disease.

Symptoms develop with dysarthria followed by cerebellar truncal ataxia and progressive dementia. GSS is also a highly progressive and fatal disease.

The defective gene in GSS is not the same as CJD. The P102L gene mutation on chromosome 20 is present in GSS.

4. Fatal Familiar Insomnia.

Initially, symptoms are hallucination and panic attacks. A few months later, patients are unable to fall asleep and rapidly lose weight and develop dementia and death. Mutation of PRNP gene is responsible for this disease.

5. Kuru.

Headhunters of Papua New Guinea used to be cannibals. They ate the brain of their victims and cooked the brain of their deceased relatives and consumed it during funeral ceremonies, They suffered a terrible neurodegenerative disease involving muscles of the trunk and extremities.

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